bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural characterization of Ni2Si pseudoepitaxial transrotational structures on [001] Si
Authors: Alberti Alessandra , Bongiorno Corrado , Alippi Paola , La Magna Antonino , Spinella Corrado , Rimini Emanuele
Published: September 2006

The formation of pseudoepitaxial transrotational structures has been observed during the early stage of the reaction of thin Ni layers on [001] Si substrates. During the reaction, large Ni2Si domains, characterized by single bending contours, establish a close relationship with the silicon lattice. The silicide domain consists of a core region, along the bending contour, where the silicide layer has grown epitaxially with silicon. Outside the core, the planes, at first parallel to the bending contour, continuously bend over the range 15–20°, whilst those at 90° remain aligned with silicon across the interface. Owing to the cylindrical symmetry of those transrotational structures, transmission electron microscopy analyses provided direct evidence of the bending phenomenon and allowed a complete description of the fully relaxed domain structure. A non-conventional mechanism of strain relaxation has been proposed, which is competitive with respect to the usual formation of misfit dislocations. The competitive phenomenon consists of Ni2Si lattice bending and rearrangement of the interface to minimize the Gibbs free energy of the domain.
Molecular functions and biological roles of hepatitis B virus x protein
Authors: Tang Hong , Oishi Naoki , Kaneko Shuichi , Murakami Seishi
Published: September 2006

Chronic infection of hepatitis B virus (HBV) is one of the major causes of hepatocellular carcinoma (HCC) in the world. Hepatitis B virus X protein (HBx) has been long suspected to be involved in hepatocarcinogenesis, although its oncogenic role remains controversial. HBx is a multifunctional regulator that modulates transcription, signal transduction, cell cycle progress, protein degradation pathways, apoptosis, and genetic stability by directly or indirectly interacting with host factors. This review focuses on the biological roles of HBx in HBV replication and cellular transformation in terms of the molecular functions of HBx. Using the transient HBV replication assay, ectopically expressed HBx could stimulate HBV transcription and replication with the X‐defective replicon to the level of those with the wild one. The transcription coactivation is mainly contributing to the stimulatory role of HBx on HBV replication although the other functions may affect HBV replication. Effect of HBx on cellular transformation remains controversial and was never addressed with human primary or immortal cells. Using the human immortalized primary cells, HBx was found to retain the ability to overcome active oncogene RAS‐induced senescence that requires full‐length HBx. At least two functions of HBx, the coactivation function and the ability to overcome oncogene‐induced senescence, may be cooperatively involved in HBV‐related hepatocarcinogenesis. (Cancer Sci 2006; 97: 977–983)
Relative importance of inefficient feeding and consumer excretion to organic carbon flux from Daphnia
Authors: HE XUEJIA , WANG WEN‐XIONG
Published: September 2006

1. Sloppy and inefficient feeding by zooplankton is generally thought to make a major contribution to the regeneration of the dissolved organic carbon (DOC) pool in aquatic environments. In this study, we tested experimentally the regeneration of DOC by a freshwater zooplankter feeding on two species of phytoplankton at different food concentrations and C : P ratios. We separated the DOC production because of inefficient feeding (pre‐ingestive regeneration) and zooplankton excretion and faeces release (postdigestive regeneration).

2. Within a brief incubation period (10 min), DOC production in the presence of Daphnia was not significantly different from that in the control treatment without grazers. During a longer incubation period (4 h), the amounts of radiocarbon retained in the algal cells per se were constant or were not different from those in the control treatments. These experimental results strongly suggest that inefficient feeding did not contribute significantly to DOC production in the grazer–prey system.

3. During the 4‐h incubation, calculations of the DOC per ingestion rate (i.e. DOC produced by Daphnia alone) showed that food concentration and algal species did not affect the relative DOC production, but there was considerable difference at different algal C : P ratios and grazer densities. We found that direct excretion of DOC by Daphnia occurred rapidly following food digestion and accounted for >65% of the total DOC production. Maximum DOC leakage from Daphnia faeces contributed less to DOC production than the grazer excretion, except under P‐limited conditions.

4. This study highlights the dominant role of postingestive process, especially the direct excretion by zooplankton, in DOC production in a grazer–prey system.
Effects of different pre‐freezing blanching procedures on the physicochemical properties of Brassica rapa leaves (Turnip Greens, Grelos)
Authors: Mondragón‐Portocarrero Alicia del Carmen , Pena‐Martínez Belén , Fernández‐Fernández Encarnación , Romero‐Rodríguez Angeles , Vázquez‐Odériz Lourdes
Published: September 2006

For optimal freeze storage, green vegetables should first be blanched. The present study compared four different procedures for the blanching of grelos (leaves of Brassica rapa L.): steaming for 2 min, immersion in boiling water for 2 min, immersion in boiling water containing 1% citric acid for 1 min, and immersion in boiling water containing 5% citric acid for 1 min. After blanching, the grelos were stored for up to 120 days at −18 °C, with sampling at two‐weekly intervals for analysis of physicochemical properties (ash weight, vitamin C content, pH, acid value, moisture content and CIEL*a*b* colour variables). In almost all respects steam blanching gave the best results: notably, vitamin C losses were markedly lower, while moisture content and colour remained closer to those of the fresh product.
Detecting local adaptation in widespread grassland species – the importance of scale and local plant community
Authors: BISCHOFF ARMIN , CRÉMIEUX LISÈLE , SMILAUEROVA MARIE , LAWSON CLARE S. , MORTIMER SIMON R. , DOLEZAL JIRI , LANTA VOJTECH , EDWARDS ANDREW R. , BROOK ALEX J. , MACEL MIRKA , LEPS JAN , STEINGER THOMAS , MÜLLER‐SCHÄRER HEINZ
Published: September 2006

Adaptation of plant populations to local environments has been shown in many species but local adaptation is not always apparent and spatial scales of differentiation are not well known. In a reciprocal transplant experiment we tested whether: (i) three widespread grassland species are locally adapted at a European scale; (ii) detection of local adaptation depends on competition with the local plant community; and (iii) local differentiation between neighbouring populations from contrasting habitats can be stronger than differentiation at a European scale.

Seeds of Holcus lanatus, Lotus corniculatus and Plantago lanceolata from a Swiss, Czech and UK population were sown in a reciprocal transplant experiment at fields that exhibit environmental conditions similar to the source sites. Seedling emergence, survival, growth and reproduction were recorded for two consecutive years.

The effect of competition was tested by comparing individuals in weeded monocultures with plants sown together with species from the local grassland community. To compare large‐scale vs. small‐scale differentiation, a neighbouring population from a contrasting habitat (wet‐dry contrast) was compared with the ‘home’ and ‘foreign’ populations.

In P. lanceolata and H. lanatus, a significant home‐site advantage was detected in fitness‐related traits, thus indicating local adaptation. In L. corniculatus, an overall superiority of one provenance was found.

The detection of local adaptation depended on competition with the local plant community. In the absence of competition the home‐site advantage was underestimated in P. lanceolata and overestimated in H. lanatus.

A significant population differentiation between contrasting local habitats was found. In some traits, this small‐scale was greater than large‐scale differentiation between countries.

Our results indicate that local adaptation in real plant communities cannot necessarily be predicted from plants grown in weeded monocultures and that tests on the relationship between fitness and geographical distance have to account for habitat‐dependent small‐scale differentiation. Considering the strong small‐scale differentiation, a local provenance from a different habitat may not be the best choice in ecological restoration if distant populations from a more similar habitat are available.
Ecophysiological determinants of plant performance under flooding: a comparative study of seven plant families
Authors: MOMMER LIESJE , LENSSEN JOHN P. M. , HUBER HEIDRUN , VISSER ERIC J. W. , DE KROON HANS
Published: September 2006

Plant performance of species in river floodplains is negatively affected by submergence, due to severely hampered gas exchange under water. Several individual traits have been shown to determine flooding tolerance, but the interrelationships among these traits and their effects on plant performance still remain largely unknown.

Here, we aim for a more coherent understanding of submergence tolerance, by investigating whether different traits are alternative strategies to enhance survival under water or whether these traits act in concert.

Because responses to submergence may be taxon‐specific, we chose a multiple‐species approach that allowed phylogenetic comparisons. The phenotypic traits investigated in the current study were constitutively different in species originating from frequently flooded habitats than in species from dry habitats: wet species were taller and had a higher specific leaf area (SLA), chlorophyll content, aerenchyma content, and longer longevity of terrestrial and ‘aquatic’ leaves compared with species from dry habitats. Moreover, the frequently flooded species appeared to be more plastic for these traits in response to submergence. Neither the phylogenetic component nor the light climate under water were important for the expression of the submergence‐related traits.

Principal component analysis (PCA) showed that these traits were divided in two independent clusters structured either around the petiole (i.e. aerenchyma content and shoot length) or the leaf lamina (i.e. SLA, chlorophyll content and leaf longevity). Shoot length and aerenchyma content of the petiole were also positively correlated, albeit not significantly. A positive correlation between SLA and leaf longevity was observed under water, indicating that thinner leaves may have an increased potential for gas exchange, resulting in increased leaf longevity and plant survival.

Path analyses indicated significant positive effects of the two trait clusters on plant performance during full submergence.

Our study shows that multiple ecophysiological traits act in concert to fine tune responses to dynamic and unpredictable environments such as river floodplains.
Quantitative estimation of phenotypic plasticity: bridging the gap between the evolutionary concept and its ecological applications
Authors: VALLADARES FERNANDO , SANCHEZ‐GOMEZ DAVID , ZAVALA MIGUEL A.
Published: September 2006

Global change and emerging concepts in ecology and evolution are leading to a growing interest in phenotypic plasticity (PP), the environmentally contingent trait expression observed in a given genotype. The need to quantify PP in a simple manner in comparative ecological studies has resulted in the prevalence of various indices instead of the classic approaches, i.e. a comparison of slopes in the norms of reactions (trait vs. environment plots).

The objectives of this study were: (i) to review the most common methods for quantitative estimation of PP; (ii) to apply them to a specific case study of growth and shoot–root allocation responses to irradiance in seedlings of four woody species grown at 1%, 6%, 20% and 100% full sunlight; and (iii) to propose new methods of estimating PP.

The 17 different plasticity indices analysed rendered disparate results, with cross‐overs in species PP rankings. Statistical comparisons of PP among species were not possible with most of the indices due to the lack of confidence intervals. The non‐linear responses of the traits made the use of the slope of the reaction norm to quantify PP unrealistic, and raised awareness on values derived from studies that consider just two environments.

We propose an alternative approach to quantify PP based on phenotypic distances among individuals of a given species exposed to different environments, which is summarized in a relative distance plasticity index (RDPI) that allows for statistical comparisons of PP between species (or populations within species). RDPI was significantly correlated with 12 out of the 17 PP indices analysed. An index including the environmental range leading to the different phenotypes (environmentally standardized plasticity index, ESPI), and thus expressing plasticity per unit of environmental change, is also proposed.

The new indexes can statistically segregate and unambiguously rank species according to their PP, which can foster a better understanding of plant ecology and evolution, particularly when common protocols are used by different investigators.
Modifications of plasma platelet‐activating factor (PAF)‐acetylhydrolase/PAF system activity in patients with chronic hepatitis C virus infection
Authors: Caini P. , Guerra C. Tosti , Giannini C. , Giannelli F. , Gragnani L. , Petrarca A. , Solazzo V. , Monti M. , Laffi G. , Zignego A. L.
Published: September 2006

Summary.  Hepatitis C virus (HCV) chronically infects about 200 million individuals worldwide and leads to severe liver and lymphatic diseases. HCV circulates in the serum, associated with apoB‐containing lipoproteins. Platelet‐activating factor (PAF), a pro‐inflammatory mediator, is mainly modulated by plasma PAF‐acetylhydrolase (pPAF‐AH), associated with ApoB100‐containing low‐density lipoproteins (LDL). The aim of the study was to evaluate the potential effects of chronic HCV infection on the PAF/pPAF‐AH system. HCV‐RNA was detected in plasma, peripheral blood mononuclear cells (PBMC) and liver samples. Plasma PAF levels, pPAF‐AH activity, ApoB100 serum titres and pPAF‐AH mRNA levels in cultured macrophages were determined. Plasma PAF levels were significantly higher and pPAF‐AH activity was significantly lower in HCV patients than in controls. No significant modifications of pPAF‐AH mRNA in macrophages or in ApoB100 values were observed in HCV patients compared with controls. Patients who cleared HCV after antiviral treatment showed a complete restoration of pPAF‐AH activity and significant decrease of PAF levels during the follow‐up. No data exist about the PAF/pPAF‐AH system behaviour during HCV infection. This study shows that in HCV patients modifications of pPAF‐AH activity/PAF levels take place and that HCV clearance restored pPAF‐AH activity. This suggests that circulating viral particles play a role in PAF/pPAF‐AH system modifications and such an alteration could be involved in HCV‐related damage.
The zoophilic fruitfly Phortica variegata: morphology, ecology and biological niche
Authors: OTRANTO D. , BRIANTI E. , CANTACESSI C. , LIA R. P. , MÁCA J.
Published: September 2006

Abstract Flies belonging to the subfamily Steganinae (Drosophilidae) display unusual zoophilic feeding habits at the adult and/or larval stage. Phortica variegata (Fallén) feeds on tears or eye liquid around the eyes of humans and carnivores. When feeding it is a potential vector of Thelazia callipaeda (Railliet and Henry) eyeworms. Adult and larval stages of this fly may be easily confused with other species belonging to the same genus, and little is known on the biology and ecology of P. variegata. In April–November 2005, a total of 969 P. variegata were collected in an area with a high prevalence of canine thelaziosis. The number of flies collected weekly was then related to climatic and environmental parameters (e.g. temperature, relative humidity and total rainfall) recorded daily at the collection site. The highest number of Phortica were collected during July–August. The sex ratio (number of males : females) rose from ∼ 0.5 during May–July, to ∼ 3.0 in August and 181 during September–October. Distributional data, representing 242 sites at which P. variegata has been collected in Europe, were analysed using a desktop implementation of the genetic algorithm for rule‐set prediction (GARP) to model ecological requirements across Europe, as well as in Italy. P. variegata is shown to be mainly active at 20–25 °C and 50–75% RH. The ecological niche model suggests with a high degree of confidence that large areas of Europe are likely to represent suitable habitat for this species, mostly concentrated in central Europe. The results reported here contribute basic knowledge on the ecology and geographical distribution of P. variegata flies, which will be fundamental to gaining a better understanding of their role as vectors of human and animal pathogens.
Role of Gal11, a component of the RNA polymerase II mediator in stress‐induced hyperphosphorylation of Msn2 in Saccharomyces cerevisiae
Authors: Lallet Sylvie , Garreau Hervé , Garmendia‐Torres Cecilia , Szestakowska Dagmara , Boy‐Marcotte Emmanuelle , Quevillon‐Chéruel Sophie , Jacquet Michel
Published: September 2006

In the yeast Saccharomyces cerevisiae, the Msn2 transcription factor is a key element in mediating the environmental stress response (ESR), leading to the induction of 100–200 genes through the cis‐acting Stress Response Element (STRE) in response to various physico‐chemical stresses and nutritional variations. This activation is accompanied by a stress‐induced hyperphosphorylation of Msn2. By a systematic screening we identified two proteins essential in this process: (i) the cyclin‐dependent Ssn3/Srb10 protein kinase, part of a module of the RNA polymerase II mediator, which has already been shown to be involved in hyperphosphorylation and degradation of Msn2 upon stress, and (ii) Gal11, a component of the mediator. In a gal11 mutant, stress‐induced hyperphosphorylation of Msn2 is abolished, stress‐induced transcription of Msn2‐dependent genes is decreased and Msn2 degradation is impaired. Rgr1, another component of the mediator, is also critical for this hyperphosphorylation, indicating that the integrity of the mediator is required for this process. Moreover the transactivating region of Msn2 interacts in vitro with the N‐terminal domain of Gal11. These results point out the role of the mediator, especially its Gal11 subunit, in the hyperphosphorylation and degradation of Msn2 during stress response.
Induction of expression of hfq by DksA is essential for Shigella flexneri virulence
Authors: Sharma Ashima K. , Payne Shelley M.
Published: September 2006

Hfq plays an important role in cellular physiology by regulating the expression of several genes. Hfq synthesis in Escherichia coli is subject to auto‐repression at translational level. Studies with Shigella flexneri show that hfq transcription is regulated by a pleiotropic regulator, DksA. Comparison of gene expression profiles of wild type and dksA mutant S. flexneri determined that hfq expression was reduced in the dksA mutant. As DksA is required for stress resistance and plaque formation in cultured cell monolayers, a measure of virulence, we assessed the role of Hfq in the dksA virulence phenotype. Expression of hfq in the dksA mutant restored plaque formation, and an hfq mutant failed to form plaques. Thus, DksA plays a role in regulating hfq gene expression and this regulation is important for S. flexneri virulence. In an in vitro transcription assay, addition of DksA increased transcription of hfq and this effect was greatest with one of the known hfq promoters. Addition of ppGpp, a stringent response molecule, along with DksA in the in vitro transcription assay resulted in a further increase in transcription of hfq, indicating that DksA is required for maximal transcription of hfq during both exponential and stringent response growth conditions.
Investigating the role of calcium/calmodulin‐dependent protein kinases in Stagonospora nodorum
Authors: Solomon Peter S. , Rybak Kasia , Trengove Robert D. , Oliver Richard P.
Published: September 2006

Three genes encoding different Ca2+/calmodulin‐dependent protein kinases have been characterized in the wheat phytopathogenic fungus Stagonospora nodorum. The kinases were identified from the S. nodorum genome sequence on the basis of sequence homology to known Ca2+/calmodulin‐dependent protein kinases. Expression analysis determined that each of the kinases was expressed during growth in vitro and also during infection. The onset of sporulation triggered increased transcript levels of each of the kinases, particularly CpkA where an 11‐fold increase in expression was observed during sporulation in planta. The role of the kinases was further determined via a reverse genetics approach. The disruption of CpkA affected vegetative growth in vitro and also sporulation. The cpkA strains produced 20‐fold less spores on complex media and were unable to sporulate on defined minimal media. Infection assays showed that CpkA was not required for lesion development but was essential for sporulation at the completion of the infection cycle. Microscopic analysis revealed that the disruption of CpkA resulted in Stagonospora nodorum being unable to differentiate the mycelial knot into immature pycnidia during sporulation. A metabolite analysis of infected leaves during sporulation excluded the possible involvement of mannitol, a compound previously shown to be involved in the sporulation of Stagonospora nodorum. The disruption of CpkB did not effect growth in vitro or pathogenicity. Stagonospora nodorum strains lacking CpkC appeared unaffected during growth in planta but showed delayed lesion development and sporulation during infection.
Opposing signals differentially regulate transcript stability inAspergillus nidulans
Authors: Caddick Mark X. , Jones Meriel G. , van Tonder J. Martin , Le Cordier Hélène , Narendja Frank , Strauss Joseph , Morozov Igor Y.
Published: September 2006

A good model for gene regulation, requiring the organism to monitor a complex and changing environment and respond in a precise and rapid way, is nitrogen metabolism inAspergillus nidulans. This involves co‐ordinated expression of hundreds of genes, many dependent on the transcription factor AreA, which monitors the nitrogen state of the cell. AreA activity is in part modulated by differential degradation of its transcript in response to intracellular glutamine. Here we report that glutamine triggers synchronized degradation of a large subset of transcripts involved in nitrogen metabolism. Among these are all four genes involved in the assimilation of nitrate. Significantly, we show that two of these transcripts,niaDandniiA, are stabilized by intracellular nitrate, directly reinforcing transcriptional regulation. Glutamine‐signalled degradation and the nitrate‐dependent stabilization of theniaDtranscript are effected at the level of deadenylation and are dependent on its 3′ UTR. When glutamine and nitrate are both present, nitrate stabilization is predominant, ensuring that nitrate and the toxic intermediate nitrite are removed from the cell. Regulated transcript stability is therefore an integral part of the adaptive response. This represents the first example of distinct physiological signals competing to differentially regulate transcripts at the level of deadenylation.
Formation of active inclusion bodies in the periplasm of Escherichia coli
Authors: Arié Jean‐Philippe , Miot Marika , Sassoon Nathalie , Betton Jean‐Michel
Published: September 2006

To examine the relationship between folding and aggregation in the periplasm of Escherichia coli, we have analysed the cellular fates of exported proteins fused to either the wild‐type maltose‐binding protein (MalE) or the aggregation‐prone variant MalE31. The propensity of fusion proteins to aggregate in the periplasm was determined by the intrinsic folding characteristics of the upstream protein. When β‐lactamase or alkaline phosphatase was linked to the C‐terminus of MalE31, the resultant fusion proteins accumulated in an insoluble form, but retained their catalytic activity. In addition, these protein aggregates induced an extracytoplasmic stress response, similar to unfused MalE31. However, using a fluorescent substrate, we found that alkaline phosphatase activity was present inside periplasmic aggregates. These results suggest that periplasmic inclusion body formation may result in intermolecular interactions between participating proteins without loss of function of the fused enzymes.
Application of Chimerism‐based Drug‐induced Tolerance to Rat into Mouse Xenotransplantation
Authors: Tomita Y. , Shimizu I. , Iwai T. , Zhang Q.‐W. , Okano S. , Kajiwara T. , Onzuka T. , Tominaga R.
Published: September 2006

The current critical shortage of human donor organs has stimulated the feasibility of the xenogenic transplantation, such as swine to primate. We have previously reported the induction of donor‐specific tolerance in MHC‐disparated recipient mice by using our cyclophosphamide (CP)‐induced tolerance conditioning. In this study, we examined the efficacy of our CP‐induced tolerance conditioning in xenogenic transplantation model. F344 rats and B10 mice were used as donors and recipients. Recipient mice were treated with donor spleen cells, CP, Busulfan and bone marrow cells, with or without prior NK‐cell depletion. Donor mixed chimerism, and the presence of donor reactive T‐cell population were analysed by flow cytometry. The survival of the donor skin grafts were observed after the conditioning. Donor mixed chimerism was temporary induced but terminated at 10 weeks after treatments. Donor‐specific prolongation of the skin graft survival was observed after the treatments, however, grafts were rejected in the long term. NK‐cell depletion, prior to the treatments, did not affect the levels of the mixed chimerism or graft prolongation. The donor‐reactive recipient T‐cell population was remained the same level as the untreated mice, suggesting the failure of the induction of the central T‐cell tolerance. Thus, partial efficacy of our CP‐induced tolerance treatments in the rat to mice xenotransplantation was observed. Our results suggested that the additional treatments were required to establish the stable xenogenic tolerance.
Retrospective Analysis of Patients with Lupus Nephritis: Data From a Large Clinical Immunological Center in Hungary
Authors: Brugos B. , Kiss E. , Szodoray P. , Szegedi G. , Zeher M.
Published: September 2006

The aim of this study was to review the development, histological type and outcome of 117 patients with lupus nephritis managed and followed by the Division of Clinical Immunology, 3rd Department of Internal Medicine, University of Debrecen, Debrecen, Hungary. The method used was a retrospective study in 117 patients with lupus nephritis followed between 1974 and 2004. The average occurrence of lupus nephritis was 3 (women) and 4.4 (men) years later after the diagnosis of systemic lupus erythematosus, 43 (46.2%) patients had class IV lupus nephritis. The initial therapy was intravenous cyclophosphamide treatment for 6 months in 37 (31.6%) patients. End‐stage renal disease had developed in nine (7.6%) patients. The 5‐year survival rate was 99.1%. Despite the well‐known and proved risk factors like hypertension, high serum creatinine, renal failure at onset or membranous glomerulonephritis, the outcome of the disease in our patient population was more favourable than one would expect according to the data available in the literature. The authors would like to draw attention to the importance of systematic care of patients with systemic lupus erythematosus, which may lead to a better clinical outcome.
Science communication in transition: genomics hype, public engagement, education and commercialization pressures
Authors: Bubela T
Published: September 2006

This essay reports on the final session of a 2‐day workshop entitled ‘Genetic Diversity and Science Communication’, hosted by the CIHR Institute of Genetics in Toronto, April 2006. The first speaker, Timothy Caulfield, introduced the intersecting communities that promulgate a ‘cycle of hype’ of the timelines and expected outcomes of the Human Genome Project (HGP): scientists, the media and the public. Other actors also contribute to the overall hype, the social science and humanities communities, industry and politicians. There currently appears to be an abatement of the overblown rhetoric of the HGP. As pointed out by the second speaker, Sharon Kardia, there is broad recognition that most phenotypic traits, including disease susceptibility are multi‐factorial. That said, George Davey‐Smith reminded us that some direct genotype–phenotype associations may be useful for public health issues. The Mendelian randomization approach hopes to revitalize the discipline of epidemiology by strengthening causal influences about environmentally modifiable risk factors. A more realistic informational environment paves the way for greater public engagement in science policy. Two such initiatives were presented by Kardia and Jason Robert, and Peter Finegold emphasized that science education and professional development for science teachers are important components of later public engagement in science issues. However, pressures on public research institutions to commercialize and seek industry funding may have negative impacts in both encouraging scientists to inappropriately hype research and on diminishing public trust in the scientific enterprise. The latter may have a significant effect on public engagement processes, such as those proposed by Robert and Kardia.
Effects of sulfur limitation on photosystem II functioning in Chlamydomonas reinhardtii as probed by chlorophyll a fluorescence
Authors: Antal Taras K. , Volgusheva Alena A. , Kukarskih Galina P. , Bulychev Alexander A. , Krendeleva Tatyana E. , Rubin Andrey B.
Published: September 2006

Chlorophyll fluorescence methods were applied to probe in vivo photosystem II (PSII) function in Chlamydomonas reinhardtii grown in sulfur‐depleted media under aerobic conditions. The rates of oxygen evolution and dark reduction decreased during a 24‐h incubation in sulfur‐deficient medium, while the respiration rate increased. The analysis of chlorophyll fluorescence induction curves suggests that electron transport was perturbed on both the acceptor and donor sides of PSII. Light‐induced violaxanthin de‐epoxidation and non‐photochemical fluorescence quenching were suppressed, owing to dark accumulation of zeaxanthin. Also sulfur‐deprived cells showed elevated concentrations of violaxanthin and lutein. Sulfur deprivation stimulated a pronounced (three‐ to four‐fold) increase in chlorophyll a fluorescence intensity (parameters Fo and Fm), probably due to greater light absorption by carotenoids and changes in the excitation energy transfer and deactivation in PSII of C. reinhardtii.
Interrelationship between polyamine and ethylene in 1‐methylcyclopropene treated apple fruits after harvest
Authors: Pang Xiao‐Ming , Nada Kazuyoshi , Liu Ji‐Hong , Kitashiba Hiroyasu , Honda Chikako , Yamashita Hiroyuki , Tatsuki Miho , Moriguchi Takaya
Published: September 2006

To investigate the interrelationship between polyamine and ethylene, apple fruits (Malus domestica Borkh.) were treated with 1‐methylcyclopropene (1‐MCP). Without 1‐MCP treatment, ethylene production of apple fruits rapidly increased to maximum level at 4 days after treatment (DAT) and kept its level until 21 DAT, then gradually decreased. Accordingly, fruit firmness was progressively reduced until 26 DAT. On the other hand, ethylene production in 1‐MCP‐treated fruits was almost completely repressed until 21 DAT, retaining fruit firmness. This ethylene inhibition by 1‐MCP was accompanied by the reduction of transcript accumulations for 1‐aminocyclopropane‐1‐carboxylic acid (ACC) synthase (ACS) and ACC oxidase (ACO). The expression of MdSAMDC1 showed no differences between 1‐MCP‐treated and control fruits, whereas that of MdSAMDC2 was rather repressed in 1‐MCP‐treated fruits compared with the control. There were no statistically significant differences of free spermidine (Spd) and spermine (Spm) titers between fruits with and without 1‐MCP treatment; however, Spd titer in 1‐MCP‐treated fruits temporally increased in the early DAT, then was adjusted to similar level as that in control, whereas Spm level was always higher in 1‐MCP‐treated fruits than in the control, indicating that Spd may be under a tight homeostatic regulation, whereas Spm may not. Therefore, the results demonstrated that the antagonistic relationships between polyamine and ethylene might exist transiently in the early days after 1‐MCP treatment, but disappear later possibly because of the polyamine homeostasis mechanism and the extension of apple shelf life by 1‐MCP might be owed little to the role of polyamines and be mainly ascribed to the inhibitory effects of ethylene on modulation of all wall.
Host‐plant effects the expression of resistance to Bacillus thuringiensis kurstaki in Trichoplusia ni (Hubner): an important factor in resistance evolution
Authors: JANMAAT A. F. , MYERS J. H.
Published: September 2006

Pathogens are thought to exert strong selection on their hosts leading to increased host resistance. Bacillus thuringiensis kurstaki (Bkt) is a ubiquitous entomopathogen that has become the mainstay of nonchemical control of Lepidopteran pests and thus, the potential exists for the evolution of resistance in targeted host insects. We have studied the expression of Btk resistance in the cabbage looper, Trichoplusia ni (Hubner). For this generalist insect herbivore, three common host plants, tomato, pepper and cucumber, vary in suitability for larval growth and development. Here we show that the host plant also affects the overall toxicity of Btk, the relative expression of resistance between a resistant and a susceptible line and their F1 reciprocal crosses, and importantly, the dominance of the resistance trait. This study demonstrates that tri‐trophic interactions involving an insect, host plants and a pathogen have the potential to strongly influence the evolutionary response of an insect host to a pathogen.
Occurrence of Fungal Pathogens Associated with Grapevine Nurseries and the Decline of Young Vines in Spain
Authors: Giménez‐Jaime A. , Aroca A. , Raposo R. , García‐Jiménez J. , Armengol J.
Published: September 2006

The occurrence of fungal grapevine trunk pathogens associated with grapevine nurseries and the decline of young vines in Spain was determined in extensive surveys conducted in nurseries and vineyards with young plants. The presence of Phaeomoniella chlamydospora, Phaeoacremonium aleophilum, Cylindrocarpon spp., Botryosphaeria obtusa and Botryosphaeria spp. was detected in all the surveys that were carried out. This study provides evidence for the presence of these pathogens in Spanish grapevine nurseries. Cylindrocarpon spp., B. obtusa and Botryosphaeria spp., were isolated very early in the planting material production process, nevertheless, P. aleophilum and P. chlamydospora were not detected until the rootstock–scion combinations were planted in the field to develop shoots and roots during summer. The occurrence of trunk disease pathogens in symptomatic young vineyards was also high, suggesting that infected plant material might have been used. Phaeomoniella chlamydospora and P. aleophilum were the main species associated with the decline of young vines, followed by Botryosphaeria spp., Cylindrocarpon spp. and B. obtusa. This research confirmed the importance of fungal grapevine trunk pathogens associated with the decline of young vineyards in Spain and suggested the connection between the presence of these fungi in the nurseries and the disease in the fields.
Complete Nucleotide Sequence and Construction of an Infectious Clone of a Tunisian Isolate of Tomato yellow leaf curl Sardinia virus
Authors: Chouchane S. Gharsallah , Gorsane F. , Nakhla M. K. , Maxwell D. P. , Marrakchi M. , Fakhfakh H.
Published: September 2006

The full‐length genome of a Tunisian isolate of Tomato yellow leaf curl Sardinia virus (TYLCSV) was engineered and submitted to sequence analysis. The Tunisian isolate has 99% sequence identity with TYLCSV‐Sicilian (Sic), results thus providing further evidence for the inclusion of this isolate in the TYLCSV‐Sic group. A 1.7‐mer construct of the virus was obtained and efficiently agroinfiltrated into tomato and tobacco plants to induce symptoms indistinguishable from those of natural infection.
Isolation of enhanced eicosapentaenoic acid producing mutants of Nannochloropsis oculata ST‐6 using ethyl methane sulfonate induced mutagenesis techniques and their characterization at mRNA transcript level
Authors: Chaturvedi Ratnesh , Fujita Yuji
Published: September 2006

Ethyl methane sulfonate‐induced mutagenesis techniques were used to obtain cerulenin and erythromycin resistant mutant strains, which show a marked increase of 29 and 12%, respectively, in eicosapentaenoic acid content compared to the wild type (WT) strain. The increase in eicosapentaenoic acid content in both strains correlated well with a concomitant increase in 14:0, 16:0, 16:1, 18:0 and 20:4 n − 6 content of fatty acids. However, the linoleic acid content increased only in the cerulenin resistant strain, whereas the erythromycin resistant strain was completely devoid of this fatty acid, providing a contrasting feature for further study. Partial characterization of the mutant strains based on whole cell ultrastructure, growth patterns with or without selection pressure as well as at different temperatures revealed that the mutants were more thermotolerant, and maintained their morphological and genomic fidelity, although minor changes in band patterns were noted with random amplified polymorphic DNA techniques compared to the WT strain. Therefore, the developed new strains could have wider applications as planktonic feed for the mariculture industry. Further characterization of the mutants at the molecular level revealed that steady‐state mRNA transcript levels of chloroplast‐localized Δ12 desaturase and stearoyl‐ACP desaturase genes showed a contrasting transcript profile. However, the level of endoplasmic reticulum‐localized Δ12 desaturase mRNA transcript in either of the mutant strains was almost equal to that of the WT strain. Based on this observation, we postulate that the complete loss of 18:2 fatty acid content in the erythromycin resistant strain might be a result of mutation in the chloroplast‐localized Δ12 desaturase gene and that the increased content of very long chain‐polyunsaturated fatty acids might result from extrachloroplastic lipid desaturase activity, a phenomenon similar to that in the majority of angiosperms.
Taxonomic notes on three species ofHerposiphonia(Ceramiales, Rhodophyta) found in Japan
Authors: Masuda Michio , Tani Masaya , Kurihara Akira
Published: September 2006

Three species of the red algal genusHerposiphonia(Ceramiales, Rhodomelaceae) found in Japan are described, and taxonomic features of the genus are discussed.Herposiphonia crassaHollenberg is reported from Japan for the first time and is characterized by thick axes (200–350 µm in diameter) and determinate branches (100–200 µm in diameter), relatively short determinate laterals (400–1200 µm in length) with a large number of periaxial cells (15–19 per segment) and three (occasionally two or four) vigorously developed (1.8–2.5 mm in length by 50–75 µm in diameter basally) trichoblasts on each determinate lateral.Herposiphonia elongataMasuda et Kogame is also reported from Japan for the first time and is characterized by the conspicuous thickening growth of cystocarp‐bearing branches and spermatangial branches with an elongated sterile tip. Some newly found features ofHerposiphonia fissidentoides(Holmes) Okamura are presented: the rhizoid production from the central portion of parental periaxial cells in addition to the distal end, virtual absence of vegetative trichoblasts, production of procarpial trichoblasts and spermatangial branches on fertile determinate branches on short indeterminate laterals, cystocarps sometimes with a short spur, and extremely large tetrasporangia.
Outcome of posterior capsulotomy in late capsular block syndrome with posterior capsular opacification
Authors: Landa Gennady , Hoffman Peter , Pollack Ayala , Bukelman Amir , Leiba Hana , Marcovich Arie
Published: September 2006

Abstract

Background:  To examine the results of neodymium:yttrium‐aluminium‐garnet (Nd:YAG) laser posterior capsulotomy in eyes with late or previously unrecognized capsular block syndrome (CBS) presenting with deterioration of vision owing to posterior capsular opacification (PCO).

Methods:  Patients, who underwent uneventful phacoemulsification with intraocular implantation and were referred for Nd:YAG laser capsulotomy owing to PCO, were prospectively examined for the presence of CBS. When indicated, Nd:YAG laser posterior capsulotomy was carried out. Prospective follow‐up examinations were performed for the next 6 months. The outcome measures were post‐laser change in best corrected visual acuity, refraction, change in intraocular pressure, inflammation and complication rate.

Results:  Of 655 patients referred for capsulotomy, eight had an associated CBS in that eye. These eight eyes comprised the study cases. The presence of CBS had not been recognized before the development of PCO. Best corrected visual acuity improved in all cases. In seven out of eight (87.5%) eyes refraction was unchanged throughout the follow up. Ocular hypertension, inflammation or other complications did not develop.

Conclusion:  Nd:YAG laser capsulotomy in eyes with PCO and late or previously unrecognized CBS is a safe procedure, resulting in improved visual acuity without refractive change.
Refractory glaucoma – tube or diode?
Authors: Malik Rizwan , Ellingham Roger B , Suleman Hanif , Morgan William H
Published: September 2006

Abstract

Background:  The aim of the present study was to assess the relative effectiveness of tube surgery and cyclodiode laser in terms of achieving intraocular pressure control.

Methods:  A retrospective study was undertaken to compare patients undergoing double plate Molteno tube implantation with patients undergoing diode cyclophotocoagulation. Intraocular pressure (IOP) was documented at 7 days prior to surgery and postoperatively at various time points. Surgical success was defined as a final IOP between 6 (inclusive) and 21 mmHg (inclusive), without the use of topical medication, while ‘qualified’ success was defined as IOP within the same range with the use of topical medication.

Results:  Twenty‐eight diode patients and 26 tube patients were included for the study. An average follow up of 150 weeks (range = 21–322 weeks) was available. Mean preoperative IOP was 37 ± 12 mmHg for the tube group and 39 ± 16 mmHg for the diode group (t = 0.51, P = 0.61). The final IOP was 17 ± 12 mmHg for the tube group and 21 ± 13 mmHg for the diode group (t = 0.35, P = 0.73). Surgical success was achieved in 46% of tube eyes and 11% of diode eyes, while qualified success was achieved in 81% of tube eyes compared with 64% of eyes in the diode group. Two eyes which underwent diode became phthisical.

Conclusions:  IOP control may be achieved in a greater number of patients with tube surgery. The possible benefits of IOP control in diode patients need to be weighed against the risks of long‐term visual loss and the need for multiple re‐treatments in this group.
The impact of cataract surgery on visual functioning, vision‐related disability and psychological distress: a randomized controlled trial
Authors: Walker Janine G , Anstey Kaarin J , Hennessy Michael P , Lord Stephen R , Von Sanden Chwee
Published: September 2006

Abstract

Purpose:  Determine whether there are changes in visual functioning, vision‐related disability, health status and mood after cataract surgery.

Methods:  45 adults (mean age = 73.7 years) with bilateral cataract needing surgery for the first eye were recruited from public ophthalmology clinics. The Visual Functioning‐14 survey assessed visual disability. Minimal angle of resolution tested visual acuity, and the Melbourne Edge Test examined contrast sensitivity. Demographic, psychological, health and medication use variables were examined. Participants were randomized to either an intervention or control arm. Controls were assessed on two occasions at a 3‐month interval before having surgery. The intervention group was assessed 1–2 weeks before surgery and then reassessed 3 months after surgery.

Results:  Visual functioning improved for those who had cataract surgery with better visual acuity in the better (P = 0.010) and worse (P = 0.028) eye compared with controls. The intervention group reported fewer difficulties with overall vision‐related disability (P = 0.0001), reading (P = 0.004) and instrumental activities of daily living (P = 0.010) post‐surgery compared with controls. People with improved depression scores (P = 0.048) after surgery had less difficulty with reading compared with those with unchanged or worsened depression scores. Cataract surgery did not improve health status.

Conclusions:  First eye cataract surgery is effective in improving outcomes in visual functioning and disability. Improved mood after surgery was related to less vision‐related disability compared with unchanged or worse depression.
Comparison between central corneal thickness measurements by ultrasound pachymetry and optical coherence tomography
Authors: Leung Dexter YL , Lam Douglas KT , Yeung Barry YM , Lam Dennis SC
Published: September 2006

Abstract

Purpose:  Measurement of central corneal thickness (CCT) plays an important role in both diagnostic and therapeutic assessment of ocular diseases. Although ultrasound pachymetry (U‐PACH) is regarded as the golden standard for measurement of CCT, optical coherence tomography (OCT) may offer advantages as it can locate the central cornea with precision with no corneal touch. Nevertheless, the agreement of OCT with U‐PACH has not yet been gauged by Bland–Altman analysis. This study compares CCT measurement by OCT with that by U‐PACH.

Methods:  Healthy subjects without ocular abnormality (except refractive errors less than or equal to −6.0 D), contact lens wear or ocular surgery were recruited. CCT was measured in one eye of normal subjects using OCT and U‐PACH. Results were compared using correlation and Bland–Altman plots.

Results:  Fifty subjects were recruited. Mean ± SD CCT measured by OCT was 565 ± 33 µm. This was highly correlated (Pearson’s coefficient = 0.934) with the mean thickness measured by U‐PACH (543 ± 33 µm). The coefficients of variation were good and comparable at 7.9% for U‐PACH and 3.5% for OCT. Compared with U‐PACH, OCT consistently overestimated the CCT by a mean of 23 µm as shown on Bland–Altman plot.

Conclusion:  CCT measured by OCT and U‐PACH is highly correlated. With appropriate adjustment factor, OCT agrees well with U‐PACH and is a reliable alternative for CCT measurement.