bluuebunny/crossref_metadata_2025 huggingface dataset:
Combinations of Fungicides with Phylloplane Yeasts for Improved Control of Botrytis cinerea on Geranium Seedlings
Authors: Buck J. W.
Published: May 2007

Control of Botrytis cinerea on geranium seedlings was evaluated in treatments with phylloplane yeasts in combination with 10 fungicides used to manage Botrytis blight of ornamental plants. Rhodotorula glutinis PM4 significantly reduced the development of lesions caused by B. cinerea on geranium cotyledons; however, yeast biocontrol efficacy was highly variable between trials. Treatment with the yeast in combination with azoxystrobin or trifloxystrobin at one tenth the labeled rate (7.5 μg a.i. ml-1) or the full labeled rate (7.5 μg a.i. ml-1) reduced lesion development, compared to treatment with the yeast or the fungicide alone. Vinclozolin at half the labeled rate or the full labeled rate (250 or 500 μg a.i. ml-1), in combination with R. glutinis PM4, significantly reduced the development of lesions caused by an isolate of B. cinerea resistant to vinclozolin. Copper hydroxide and iprodione at one-tenth the labeled rates, with or without yeast, were highly effective in limiting lesion development. Mancozeb did not increase the biocontrol efficacy of the yeast, and thiophanate-methyl negatively affected the yeast efficacy. Improved disease control was observed in treatments with vinclozolin at the labeled rate and R. glutinis PM4 at cell densities of 5 × 105 and 1 × 106 cells ml-1, but not 1 × 105 cells ml-1, on seedlings co-inoculated with B. cinerea in a suspension containing 1 × 105 conidia ml-1. Disease control improved in treatments with combinations of vinclozolin and eight other isolates of R. glutinis, two isolates of R. graminis, and two isolates of R. mucilaginosa. Biocontrol was not observed in treatments with two isolates of R. minuta. The combination of yeast and vinclozolin significantly reduced the germination of conidia of B. cinerea and the growth of R. glutinis PM4 in vitro. All combinations of R. glutinis PM4 with azoxystrobin, trifloxystrobin, or vinclozolin provided highly effective and consistent disease control not observed in treatments with the fungicides alone or the yeast alone.
A Model for the Invasion and Spread of Rhizomania in the United Kingdom: Implications for Disease Control Strategies
Authors: Stacey Adrian J. , Truscott James E. , Asher Michael J. C. , Gilligan Christopher A.
Published: May 2007

Rhizomania disease of sugar beet represents a major economic threat to the sugar industry in the United Kingdom. Here we use the UK rhizomania epidemic as an exemplar of a range of highly infectious spatially heterogeneous diseases. Using a spatially explicit stochastic model, we investigated the efficacy of a spectrum of possible control strategies, both locally reactive and national in character. These include the use of novel cultivars of beet with different responses to infection, changes in cultivation practice, and reactive containment policies at the farm scale. We show that strictly local responses, including a containment policy similar to that initially implemented in the United Kingdom in response to the disease, are largely ineffective in slowing the spread because they fail to match the natural scale of the epidemic. Larger spatial-scale processes are considerably more successful. We conclude that epidemics have intrinsic temporal and spatial scales that must be matched by any control strategy if it is to be both effective and efficient. We have generated probability distributions for the proportion of farms symptomatic. Over the course of the epidemic, such distributions develop a bimodality that we hypothesize to correspond to the matching of spatial heterogeneity in the susceptible population to the intrinsic scales of the epidemic.
Evidence for Natural Selection in the Mitochondrial Genome of Mycosphaerella graminicola
Authors: Zhan J. , Kema G. H. J. , McDonald B. A.
Published: May 2007

Pathogenicity assays were combined with restriction fragment length polymorphism (RFLP) markers in the mitochondrial and nuclear genomes to compare Mycosphaerella graminicola populations adapted to bread wheat (Triticum aestivum) and durum wheat (T. turgidum) in the Mediterranean Basin. The majority of isolates had unique nuclear DNA fingerprints and multilocus haplotypes. Only six mitochondrial DNA (mtDNA) haplotypes were identified among 108 isolates assayed. There were minor differences in frequencies of alleles at nuclear RFLP loci between the two host-adapted populations, but differences in the frequencies of mtDNA haplotypes were highly significant (P < 0.0001). mtDNA haplotype 1 dominated on the isolates adapted to bread wheat, and its frequency was twice as high as for the isolates adapted to durum wheat. mtDNA haplotype 4, which contained a unique ≈3-kb insertion, was detected only in isolates showing specificity toward durum wheat and was the dominant haplotype on this species. We propose that the low mitochondrial diversity in this pathogenic fungus is due to a selective sweep and that differences in the frequencies of mtDNA haplotypes between the two host-adapted populations were due to natural selection according to host species.
Rice Pi-ta gene Confers Resistance to the Major Pathotypes of the Rice Blast Fungus in the United States
Authors: Jia Yulin , Wang Zhonghua , Fjellstrom Robert G. , Moldenhauer Karen A. K. , Azam Md A. , Correll James , Lee Fleet N. , Xia Yingwu , Rutger J. Neil
Published: May 2007

The Pi-ta gene in rice prevents the infection by Magnaporthe grisea strains containing the AVR-Pita avirulence gene. The presence of Pi-ta in rice cultivars was correlated completely with resistance to two major pathotypes, IB-49 and IC-17, common in the U.S. blast pathogen population. The inheritance of resistance to IC-17 was investigated further using a marker for the resistant Pi-ta allele in an F2 population of 1,345 progeny from a cross of cv. Katy with experimental line RU9101001 possessing and lacking, respectively, the Pi-ta resistance gene. Resistance to IC-17 was conferred by a single dominant gene and Pi-ta was not detected in susceptible individuals. A second F2 population of 377 individuals from a reciprocal cross between Katy and RU9101001 was used to verify the conclusion that resistance to IC-17 was conferred by a single dominant gene. In this cross, individuals resistant to IC-17 also were resistant to IB-49. The presence of Pi-ta and resistance to IB-49 also was correlated with additional crosses between ‘Kaybonnet’ and ‘M-204’, which also possess and lack Pi-ta, respectively. A pair of primers that specifically amplified a susceptible pi-ta allele was developed to verify the absence of Pi-ta. We suggest that Pi-ta is responsible for resistance to IB-49 and IC-17 and that both races contain AVR-Pita genes.
Spatiotemporal Changes in the Population Structure of Botryosphaeria dothidea from California Pistachio Orchards
Authors: Ma Zhonghua , Luo Yong , Michailides Themis J.
Published: May 2007

Spatiotemporal changes in the population structure of Botryosphaeria dothidea, causal agent of panicle and shoot blight of pistachio, were analyzed by using microsatellite-primed polymerase chain reaction (MPPCR), partial sequences of the RNA polymerase II (RPB2) gene, and vegetative compatibility groups (VCGs). We examined 390 isolates, 378 recovered from pistachio in seven counties of California from 1990 to 2001 and 12 recovered from peach, apple, and sycamore in Georgia, North Carolina, South Carolina, Illinois, and Pennsylvania. Six microsatellite primers generated 116 polymorphic bands. Based on MP-PCR data, we observed very high (>98%) levels of genetic identity among populations of B. dothidea collected from the commercial pistachio orchards in California. The near identity of these populations was supported by VCGs and partial sequences of the RBP2 gene. These findings suggest that populations of B. dothidea from commercial pistachio orchards are spatially and temporally stable, at least in the past 5 years.
Comparative Infection Progress Analysis of Lettuce big-vein virus and Mirafiori lettuce virus in Lettuce Crops by Developed Molecular Diagnosis Techniques
Authors: Navarro Jose A. , Botella Francisco , Maruhenda Antonio , Sastre Pedro , Sánchez-Pina M. Amelia , Pallas Vicente
Published: May 2007

Nonisotopic molecular dot blot hybridization technique and multiplex reverse transcription-polymerase chain reaction assay for the specific detection of Lettuce big-vein virus (LBVV) and Mirafiori lettuce virus (MiLV) in lettuce tissue were developed. Both procedures were suitable for the specific detection of both viruses in a range of naturally infected lettuce plants from various Spanish production areas and seven different cultivars. The study of the distribution of both viruses in the plant revealed that the highest concentration of LBVV and MiLV occurred in roots and old leaves, respectively. LBVV infection progress in a lettuce production area was faster than that observed for MiLV. In spite of different rates of virus infection progress, most lettuce plants became infected with both viruses about 100 days posttransplant. The appearance of both viruses in lettuce crops was preceded by a peak in the concentration of resting spores and zoosporangia of the fungus vector Olpidium brassicae in lettuce roots.
Knot Formation Caused by Pseudomonas syringae subsp. savastanoi on Olive Plants Is hrp-Dependent
Authors: Sisto A. , Cipriani M. G. , Morea M.
Published: May 2007

The virulence of Pseudomonas syringae subsp. savastanoi, which causes hyperplastic symptoms (knots) on olive plants, is associated with secreted phytohormones. We identified a Tn5-induced mutant of P. syringae subsp. savastanoi that did not cause disease symptoms on olive plants although it was still able to produce phytohormones. In addition, the mutant failed to elicit a hypersensitive response in a nonhost plant. Molecular characterization of the mutant revealed that a single Tn5 insertion occurred within an open reading frame encoding a protein 92% identical to the HrcC protein of P. syringae pv. syringae. Moreover, sequence analysis revealed that the gene encoding the HrcC protein in P. syringae subsp. savastanoi was part of an operon that included five genes arranged as in other phytopathogenic bacteria. These results imply that hrp/hrc genes are functional in P. syringae subsp. savastanoi and that they play a key role in the pathogenicity of this plant pathogen.
Use of Tomato yellow leaf curl virus (TYLCV) Rep Gene Sequences to Engineer TYLCV Resistance in Tomato
Authors: Yang Y. , Sherwood T. A. , Patte C. P. , Hiebert E. , Polston J. E.
Published: May 2007

Tomato yellow leaf curl virus (TYLCV), a member of the genus Begomovirus (family Geminiviridae), causes severe losses in tomato production in the tropics and subtropics. In order to generate engineered resistance, eight different constructs of the TYLCV replication-associated protein (Rep) and C4 gene sequences were tested in transformed tomato inbred lines. Transgenic plants were screened for resistance to TYLCV using viruliferous whiteflies. No symptoms were observed and no TYLCV genomic DNA was detected by both hybridization and polymerase chain reaction in progenies of plants transformed with three constructs. This resistance was observed in plants that contained one of the following transgenes: 2/5Rep (81 nucleotides [nt] of the intergenic region [IR] plus 426 nt of the 5′ end of the TYLCV Rep gene), Δ2/5Rep (85 nt of the IR plus 595 nt of the 5′ end of the TYLCV Rep gene in the antisense orientation), and RepΔ2/5Rep (81 nt of the IR, the entire Rep gene, and 41 nt 3′ to the end of the Rep gene fused to Δ2/5Rep). Our study differs from other transgenic Geminivirus resistance reports involving the Rep gene in that viruliferous whiteflies were used for challenge inoculation instead of agroinoculation or biolistic inoculation, and TYLCV resistance was evaluated under field conditions.
The Effects of Postplanting Environment on the Incidence of Soilborne Viral Diseases in Winter Cereals
Authors: Cadle-Davidson L. , Bergstrom G. C.
Published: May 2007

Soilborne wheat mosaic virus (SBWMV) and Wheat spindle streak mosaic virus (WSSMV) are putatively transmitted to small grains by the obligate parasite Polymyxa graminis, but little is known about environmental requirements for transmission and the resulting disease incidence. We planted susceptible wheat and triticale cultivars in field nurseries on different autumn dates in 3 years and observed the incidence of symptomatic plants in each following spring. Autumn postplanting environment explained most of the variation in disease caused by both viruses. Little apparent transmission, based on eventual symptom development, of either virus occurred after the average soil temperature dropped below 7°C for the remainder of the winter. To forecast disease, we tested an SBWMV transmission model in the field, based on laboratory results, that predicts opportunities for transmission based on soil temperature and soil moisture being simultaneously conducive. This model was predictive of soilborne wheat mosaic in 2 of 3 years. Zoospores of P. graminis have optimal activity at temperatures similar to those in the SBWMV transmission model. Furthermore, the matric potential threshold (as it relates to waterfilled pore sizes) in the SBWMV transmission model fits well with P. graminis as vector given the size restrictions of P. graminis zoospores. Conditions optimal for SBWMV transmission in the laboratory were not conducive for WSSMV transmission in the laboratory or for wheat spindle streak mosaic development in the field. This differential response to environment after emergence, as indicated by disease symptoms, may be due to virus-specific environmental conditions required to establish systemic infection via the same vector. Alternatively, the differential response may have been due to the involvement of a different vector in our WSSMV nursery than in our SBWMV nursery. Our results suggest that, as a control tactic for SBWMV or WSSMV, earliness or lateness of planting is less important in determining virus transmission and disease than the specific postplanting environment. Improved models based on the postplanting environment might predict virus-induced losses of yield potential, and in some cases, growers might avoid purchase of spring inputs such as pesticides and fertilizer for fields with greatly reduced yield potential.
Light-Dependent Oxidative Stress Determines Physiological Leaf Spot Formation in Barley
Authors: Wu Yue-Xuan , von Tiedemann Andreas
Published: May 2007

We reported previously that physiological leaf spot (PLS) formation in winter and spring barley is dependent on genotype-related oxidative stress under field conditions. In the present study, we searched for factors inducing PLS symptoms in the greenhouse similar to those observed in the field and investigated its relationship to reactive oxygen species (ROS) metabolism. We found that in the greenhouse, oxidative stress induced spring barley cv. Extract, which is sensitive to PLS, to express symptoms similar to those observed in the field. Leaves severely affected by PLS showed significantly lower activities of key enzymes in the Halliwell-Asada cycle such as ascorbate peroxidase, glutathione reductase, dehy-droascorbate reductase, and monodehydroascorbate reductase. The sensitive cultivar also showed lower levels of total superoxide dismutase (SOD) and Cu/Zn-SOD activity but a higher level of chloroplast-specific Fe-SOD activity than that of the insensitive cultivar. Thus, an unbalanced ROS metabolism in chloroplasts may trigger PLS incidence in sensitive cultivars, which is in agreement with the fact that light is essential for the induction of PLS expression under both field and greenhouse conditions. Accordingly, under greenhouse conditions, continuous light stress (7 days), but not light shock treatments, induced PLS similar to that of field conditions in sensitive cv. Extract, but not in resistant cv. Scarlett. Light with a high proportion of energy in the blue wavelength spectrum (350 to 560 nm) was significantly more PLS inductive than light with a pronounced red (photosynthetically active radiation) spectrum (580 to 650 nm). Exposure to ozone did not produce PLS-like symptoms. Furthermore, similar to earlier observations in the field, PLS symptom expression was closely correlated with the accumulation of superoxide (O2 •-) detected by both biochemical and histochemical assays. Taken together, these data suggest that PLS in barley is genotype-dependent but its expression appears to be induced by certain environmental stress factors, among which photosyn-thetically active radiation plays a major role.
Wheat Leaf Rust Uredospore Production on Adult Plants: Influence of Leaf Nitrogen Content and Septoria tritici Blotch
Authors: Robert Corinne , Bancal Marie-Odile , Lannou Christian
Published: May 2007

Leaf rust uredospore production and lesion size were measured on flag leaves of adult wheat plants in a glasshouse for different lesion densities. We estimated the spore weight produced per square centimeter of infected leaf, per lesion, and per unit of sporulating area. Three levels of fertilization were applied to the plants to obtain different nitrogen content for the inoculated leaves. In a fourth treatment, we evaluated the effect of Septoria tritici blotch on leaf rust uredospore production. The nitrogen and carbon content of the spores was unaffected or marginally affected by lesion density, host leaf nitrogen content, or the presence of Mycosphaerella graminicola on the same leaf. In leaves with a low-nitrogen content, spore production per lesion was reduced, but lesion size was unaffected. A threshold effect of leaf nitrogen content in spore production was however, evident, since production was similar in the medium- and high-fertilizer treatments. In leaves inoculated with M. graminicola and Puccinia triticina, the rust lesions were smaller and produced fewer spores. The relationships among rust lesion density, lesion size, and uredospore production were fitted to a model. We determined that the density effect on spore production resulted mainly from a reduction in lesion size, the spore production per unit of sporulating surface being largely independent of lesion density. These results are consistent with those obtained previously on wheat seedlings. The main difference was that the sporulation period lasted longer in adult leaves.
High Genetic Diversity, Phenotypic Uniformity, and Evidence of Outcrossing in Sclerotinia Sclerotiorum in the Columbia Basin of Washington State
Authors: Atallah Z. K. , Larget B. , Chen X. , Johnson D. A.
Published: May 2007

Sclerotinia sclerotiorum, the causal agent of potato stem rot, is prevalent and poorly managed on potatoes in the Columbia Basin of Washington. Because of the ubiquitous nature of the fungus and high crop diversity within the Columbia Basin, understanding the population structure and the potential for outcrossing of the pathogen would be helpful in developing disease management strategies. The population structure of S. sclerotiorum in the Columbia Basin from potato was examined using microsatellite markers and mycelial compatibility. Analysis of molecular variance revealed that 92% of the variability among 167 isolates was found within subpopulations, with limited, yet statistically significant impact of the collection date, but not the year or location of collection. Linkage disequilibrium and index of association analyses noted a potential for outcrossing in two locations, which was substantiated by the discovery of recombinant ascospores in three field-generated apothecia from the 12 apothecia examined. Microsatellite haplotypes were not correlated with mycelial compatibility groups. This high haplotypic diversity did not seem to impact pathologically important phenotypes. Greenhouse inoculations of potato plants exhibited no significant differences in aggressiveness on potato stems. Moreover, in vitro studies of response to fungicides and temperature stimuli yielded no significant differences among studied isolates. These findings illustrate the potential for outcrossing in warm temperate regions of North America, where a diversity of crops are planted simultaneously and in neighboring fields. This study also indicates that the unsatisfactory management of potato stem rot is likely not directly attributable to genetic factors, but to gaps in agricultural practices.
Interaction Between Tomato spotted wilt virus N Protein Monomers Involves Nonelectrostatic Forces Governed by Multiple Distinct Regions in the Primary Structure
Authors: Kainz Mark , Hilson Pierre , Sweeney Laura , DeRose Erin , German Thomas L.
Published: May 2007

The ambisense RNA genome of Tomato spotted wilt virus (TSWV) isby interaction with numerous copies of the virus encoded nucleocapsid (N) protein to form a subvirion structure called a ribonucleo-protein (RNP). RNPs are central to the viral replication cycle because they, and not free viral RNA, serve as templates for viral gene expression and genome replication. N protein monomers bind to viral RNA molecules in a cooperative manner. We have examined regions of the N protein that are involved in the N-N interactions that likely contribute to the cooperative binding of N to viral RNA. We created random and alanine scanning mutants of N and then screened the mutants for defects in N-N interaction using reverse and forward yeast two-hybrid assays. Our experiments identified residues in three distinct regions of the primary structure of the protein, residues 42 to 56, 132 to 152, and in the C-terminal 26 amino acids, that contribute to N-N dimerization or multimerization.interactions between N monomers mediated by the residues we identified are of a nonelectrostatic nature.
Host Genetic Effect on Deoxynivalenol Accumulation in Fusarium Head Blight of Barley
Authors: Smith K. P. , Evans C. K. , Dill-Macky R. , Gustus C. , Xie W. , Dong Y.
Published: May 2007

One of the major concerns with Fusarium head blight (FHB) of barley is the potential health risks to livestock and humans through the accumulation of the mycotoxin deoxynivalenol (DON) in infected grain. To define the role of the host in DON accumulation during the early stages of disease development, we conducted a series of greenhouse experiments. We inoculated single spikelets of greenhouse-grown plants with Fusarium graminearum, moved the plants to a dew chamber, and harvested the inoculated spikelets after 72 h for DON analysis. We conducted a quantitative trait locus (QTL) analysis using a genetic mapping population, constructed with the parents Stander and Frederickson, that segregated for DON accumulation after single-spikelet inoculation in two experiments. A single QTL on chromosome 3 explained 18 and 35% of the phenotypic variation in the two experiments. To validate this QTL for DON accumulation, we used a DNA marker to select near-isogenic lines from a family from the mapping population that was segregating at this QTL. Disease symptom development was similar between the nearisogenic lines; however, the mean DON concentration of the lines homozygous for the allele from the high DON parent was 2.5-fold more than the lines homozygous for the alternate allele. A time course experiment showed that this effect on toxin accumulation was observed at 10 days post inoculation. The near-isogenic lines developed in this study should prove useful for further exploration of the role of DON in FHB.
Prediction and Mapping of the Impact of Winter Temperature on the Development of Phytophthora cinnamomi-Induced Cankers on Red and Pedunculate Oak in France
Authors: Marçais Benoit , Bergot Magali , Pérarnaud Victorine , Levy André , Desprez-Loustau Marie-Laure
Published: May 2007

Phytophthora cinnamomi is the causal agent of a perennial canker that develops on the lower bole on northern red oak and pedunculate oak. The disease has a limited range in Europe, being reported only in southwest France. This limited distribution is probably linked to the susceptibility of P. cinnamomi to frost. A model was developed in previous work to estimate the impact of temperatures of <0°C on the winter survival of P. cinnamomi in trunk cortical tissues and on the subsequent development of cankers. In this article, we report the use of this model to simulate canker development in 503 locations across France during a 30-year period. The predicted canker extension decreased sharply when the median P. cinnamomi winter survival index decreased from 0.95 to 0.65, with cankers that poorly developed when the median survival index was lower than 0.5 to 0.6. The actual incidence of the disease in 192 stands located across southwest France was compared with that of the model outputs. Both presence of disease in stands and frequency of cankered trees in infected stands, but not canker size on infected trees, were strongly related to the median P. cinnamomi survival index. No disease was present in stands with median survival index lower than 0.65, and the frequency of cankered trees in infected stands remained very low in stands with a median survival index between 0.65 and 0.70. Aspect was an additional factor explaining disease incidence, while the effect of elevation was likely due to its effect on winter temperatures. Maps of winter suitability to P. cinnamomi-induced cankers on oaks in France are presented.
Plum Pox in North America: Identification of Aphid Vectors and a Potential Role for Fruit in Virus Spread
Authors: Gildow Frederick , Damsteegt Vern , Stone Andrew , Schneider William , Luster Douglas , Levy Laurene
Published: May 2007

Thirteen aphid species were tested for their ability to transmit Pennsylvania isolates of Plum pox virus (PPV) collected in Columbia (PENN-3), Franklin (PENN-4), and York (PENN-7) Counties, PA. Four species, Aphis fabae, A. spiraecola, Brachycaudus persicae, and Myzus persicae, consistently transmitted PPV in preliminary transmission tests. Two species, Metopolophium dirhodum and Rhopalosiphum padi, were occasional inefficient vectors. Toxoptera citricida, from Florida, also was an effective vector but it does not occur in major stone-fruit-growing states. Species not transmitting PPV in parallel tests included Acyrthosiphon pisum, Aphis glycines, Aulacorthum solani, Macrosiphum euphorbiae, Rhopalosiphum maidis, and Sitobion avenae. When given a 3-day probing access period simultaneously on PPV-infected peach seedlings and healthy peach seedlings, Myzus persicae, Aphis spiraecola, A. fabae, and B. persicae transmitted PPV to 63, 31, 38, and 32% of the healthy peach seedlings, respectively. When given a similar probing period on PPV-infected peach fruit and healthy peach seedlings, the same aphid species transmitted PPV to 50, 35, 0, and 0% of seedlings, respectively. Results support the hypothesis of secondary PPV spread by indigenous aphids in Pennsylvania, and suggest that PPV-infected fruit has the potential to function as a virus source for long-distance dispersal.
Squeezing the Turnip with Artificial Neural Nets
Authors: Francl Leonard J.
Published: May 2007

Modeling in epidemiology has followed many different strategies and philosophies. Artificial neural networks (ANNs) comprise a family of highly flexible and adaptive models that have shown promise for application to modeling disease phenomena in general and plant disease forecasting in particular. ANN modeling requires the availability of representative, robust input data and exhaustive testing of model aptness and optimization; meanwhile, ANNs sacrifice much of the biological insight often derived through other model forms. On the other hand, ANNs may extract previously undetected and possibly complex relationships, which can increase prediction accuracy over mainstream statistical methods, usually in an incremental manner.
Integrated Management of Fusarium Wilt of Chickpea with Sowing Date, Host Resistance, and Biological Control
Authors: Landa Blanca B. , Navas-Cortés Juan A. , Jiménez-Díaz Rafael M.
Published: May 2007

A 3-year experiment was conducted in field microplots infested with Fusarium oxysporum f. sp. ciceris race 5 at Córdoba, Spain, in order to assess efficacy of an integrated management strategy for Fusarium wilt of chickpea that combined the choice of sowing date, use of partially resistant chickpea genotypes, and seed and soil treatments with biocontrol agents Bacillus megaterium RGAF 51, B. subtilis GB03, nonpathogenic F. oxysporum Fo 90105, and Pseudomonas fluorescens RG 26. Advancing the sowing date from early spring to winter significantly delayed disease onset, reduced the final disease intensity (amount of disease in a microplot that combines disease incidence and severity, expressed as a percentage of the maximum possible amount of disease in that microplot), and increased chickpea seed yield. A significant linear relationship was found between disease development over time and weather variables at the experimental site, with epidemics developing earlier and faster as mean temperature increased and accumulated rainfall decreased. Under conditions highly conducive for Fusarium wilt development, the degree of disease control depended primarily on choice of sowing date, and to a lesser extent on level of resistance of chickpea genotypes to F. oxysporum f. sp. ciceris race 5, and the biocontrol treatments. The main effects of sowing date, partially resistant genotypes, and biocontrol agents were a reduction in the rate of epidemic development over time, a reduction of disease intensity, and an increase in chickpea seedling emergence, respectively. Chickpea seed yield was influenced by all three factors in the study. The increase in chickpea seed yield was the most consistent effect of the biocontrol agents. However, that effect was primarily influenced by sowing date, which also determined disease development. Effectiveness of biocontrol treatments in disease management was lowest in January sowings, which were least favorable for Fusarium wilt. Sowing in February, which was moderately favorable for wilt development, resulted in the greatest increase in seed yield by the biocontrol agents. In March sowings, which were most conducive for the disease, the biocontrol agents delayed disease onset and increased seedling emergence. B. subtilis GB03 and P. fluorescens RG 26, applied either alone or each in combination with nonpathogenic F. oxysporum Fo 90105, were the most effective treatments at suppressing Fusarium wilt, or delaying disease onset and increasing seed yield, respectively. The importance of integrating existing control practices, partially effective by themselves, with other control measures to achieve appropriate management of Fusarium wilt and increase of seed yield in chickpea in Mediterranean-type environments is demonstrated by the results of this study.
An analysis of the gene complement of a marsupial,Monodelphis domestica: Evolution of lineage-specific genes and giant chromosomes
Authors: Goodstadt Leo , Heger Andreas , Webber Caleb , Ponting Chris P.
Published: May 2007

The newly sequenced genome ofMonodelphis domesticanot only provides the out-group necessary to better understand our own eutherian lineage, but it enables insights into the innovative biology of metatherians. Here, we compareMonodelphiswithHomosequences from alignments of single nucleotides, genes, and whole chromosomes. Using PhyOP, we have established orthologs inHomofor 82% (15,250) ofMonodelphisgene predictions. Those with single orthologs in each species exhibited a high median synonymous substitution rate (dS= 1.02), thereby explaining the relative paucity of aligned regions outside of coding sequences. Orthology assignments were used to construct a synteny map that illustrates the considerable fragmentation ofMonodelphisandHomokaryotypes since their therian last common ancestor. Fifteen percent ofMonodelphisgenes are predicted, from their low divergence at synonymous sites, to have been duplicated in the metatherian lineage. The majority ofMonodelphis-specific genes possess predicted roles in chemosensation, reproduction, adaptation to specific diets, and immunity. Using alignments ofMonodelphisgenes to sequences from eitherHomoorTrichosurus vulpecula(an Australian marsupial), we show that metatherian X chromosomes have elevated silent substitution rates and high G+C contents in comparison with both metatherian autosomes and eutherian chromosomes. Each of these elevations is also a feature of subtelomeric chromosomal regions. We attribute these observations to high rates of female-specific recombination near the chromosomal ends and within the X chromosome, which act to sustain or increase G+C levels by biased gene conversion. In particular, we propose that the higher G+C content of theMonodelphisX chromosome is a direct consequence of its small size relative to the giant autosomes.
Site fidelity and movement patterns of wild subadult red drum, Sciaenops ocellatus (Linnaeus), within a salt marsh‐dominated estuarine landscape
Authors: DRESSER B. K. , KNEIB R. T.
Published: May 2007

Abstract  During summer and autumn 2002, 12 subadult red drum, Sciaenops ocellatus (Linnaeus) (261–385 mm total length) were surgically implanted with ultrasonic transmitters and released within the upper reach of the Duplin River Estuary, Sapelo Island, GA, USA. A fixed array of submerged receivers automatically recorded the time that individual tagged fish were detected at 10 sites within the study area. Ten red drum implanted with transmitters were located within the receiver array for 6–96 days post‐release. All fish exhibited a high degree of site fidelity at low tide, and movements appeared to be influenced by both tidal and diel cycles. Dispersal on flood tides was observed, but destinations (upriver or downriver) and paths taken (main channel, intertidal channels or flooded marsh surface) varied among individuals. Flood‐tide movements were generally restricted to daylight hours. If the start of flood tide occurred after sunset, fish remained stationary. Variation in details of movement patterns among individuals notwithstanding, predictable behaviour and strong site fidelity make subadult red drum vulnerable to recreational fishing in the restricted tidal channels of the tidal marsh–estuary complex. However, the same predictability provides fisheries managers a means of targeting specific areas for protection of over‐fished populations of this species.
Evidence That Down Regulation of Hypothalamic KiSS‐1 Expression is Involved in the Negative Feedback Action of Testosterone to Regulate Luteinising Hormone Secretion in the Adult Male Rhesus Monkey (Macaca mulatta)
Authors: Shibata M. , Friedman R. L. , Ramaswamy S. , Plant T. M.
Published: May 2007

In the male monkey, luteinising hormone (LH) secretion is regulated by a negative feedback action of testicular testosterone that is exerted indirectly at the hypothalamic level to decelerate pulsatile gonadotrophin‐releasing hormone release (GnRH). The purpose of the present experiment was to investigate whether the kisspeptin–G protein‐coupled receptor 54 (GPR54) signalling pathway is involved in mediating the action of testosterone to suppress GnRH release in the monkey, as has been indicated by studies of nonprimates. To this end, 12 castrated adult male rhesus monkeys were implanted with either testosterone containing or empty Silastic capsules. Testosterone treatment produced a square wave increment in circulating testosterone levels within the physiologic range. After suppression of LH and follicle‐stimulating hormone secretion was established at 5–6 weeks of testosterone exposure, the animals were killed and expression of the genes encoding for kisspeptin, GPR54 and GnRH determined in the mediobasal hypothalamus and preoptic area of both treated and control animals using RNase protection assays. The suppression in pituitary gonadotrophin secretion was associated with a reduction in kisspeptin mRNA levels in the mediobasal hypothalamus, but not the preoptic area. GPR54 mRNA levels, on the other hand, were not influenced by testosterone treatment. These results are consistent with those previously reported for the rodent, and suggest that the neurobiology of the negative feedback action of testicular testosterone on LH secretion in the monkey, a representative higher primate, may be mediated by kisspeptinergic neurones upstream to the GnRH network.
Region‐ and Sex‐Specific Modulation of Anxiety Behaviours in the Rat
Authors: Toufexis D.
Published: May 2007

Recent studies in both animals and humans indicate that gonadal hormones have profound control over emotional states, and certainly contribute to the increased occurrence of psychiatric illness in women. Reports, as reviewed here, suggest that two important regions of the limbic system, the central nucleus of the amygdala (CeA) and the bed nucleus of the stria terminalis (BNST), control different aspects of emotional behaviour. Short‐term cue‐specific emotional responses, like Pavlovian fear conditioning, require activation of the CeA, while long‐duration and contextual emotional responses, are dependant on the BNST. There is accumulating experimental evidence that gender and sex hormones specifically modulate BNST‐mediated anxiety behaviours. Moreover, the functional separation between the CeA and the BNST may be exaggerated during lactation in the rat, a time of profound hormonal and behavioural change. In this study, the effects of sex hormones on fear and anxiety are reviewed with an emphasis on the differential effects of these hormones on functions subserved by the BNST as opposed to the CeA. Studies, as highlighted here, looking at sex hormone and gender effects on the ability of corticotrophin‐releasing factor and bright ambient light to enhance startle, emphasise the importance of understanding both the effect of, and brain region where, gonadal hormones exert their control over emotional behaviour.
Terminal Nerve Gonadotrophin‐Releasing Hormone (GnRH) Neurones Express Multiple GnRH Receptors in a Teleost, the Dwarf Gourami (Colisa lalia)
Authors: Hajdú P. , Ikemoto T. , Akazome Y. , Park M. K. , Oka Y.
Published: May 2007

Gonadotophin‐releasing hormone (GnRH) peptide released from the terminal nerve (TN)‐GnRH neurones of the dwarf gourami primarily modifies the electrical properties of various neurones, including the TN‐GnRH neurones themselves. However, our knowledge on the expression of GnRH receptors (GnRHRs) in the TN‐GnRH neurones is still limited. Here, we used the single‐cell reverse transcriptase‐polymerase chain reaction after whole‐cell patch‐clamp recording to study the distribution of various GnRHR types expressed in the individual TN‐GnRH neurones. We found that TN‐GnRH neurones express two of the three types of GnRHRs cloned in the dwarf gourami: GnRHR1‐2 and ‐R2, but not ‐R1‐1. Furthermore, in agreement with our previous findings, all TN‐GnRH neurones contained mRNAs of salmon GnRH but not chicken GnRH‐II.
Prevalence and clinicopathologic findings of antiphospholipid syndrome nephropathy in Thai systemic lupus erythematosus patients who underwent renal biopsies
Authors: CHEUNSUCHON BOONYARIT , RUNGKAEW PIMPATTANA , CHAWANASUNTORAPOJ RATANA , PATTARAGARN ANIRUT , PARICHATIKANOND PAISAL
Published: May 2007

Aim:  To determine the prevalence of antiphospholipid syndrome nephropathy (APSN) in Thai systemic lupus erythematosus (SLE) patients who underwent renal biopsy and to compare the relationship of renal histopathology and other significant clinical parameters between SLE patients with and without APSN.

Methods:  A retrospective analysis was undertaken in systemic lupus erythematosus patients (n = 150, 44 <15 years old, 106 0e;15 years old) who underwent renal biopsy. The specimens were evaluated for histological features of APSN and other significant clinical parameters. The result of antiphospholipid antibodies, clinical course, and renal function from chart review were analysed.

Results:  The prevalence of APSN in systemic lupus erythematosus patients who underwent renal biopsies was 34% (16% in <15‐year‐old group, 41.5% in 0e;15‐year‐old group). APSN was associated with more severe hypertension (P = 0.002 for systolic and P = 0.004 for diastolic blood pressure), acute renal failure (P = 0.003), persistent heavy proteinuria (P < 0.001 for 4+ proteinuria), severe lupus nephritis (class III and IV, P = 0.014, high activity and chronicity indices, P < 0.001) and a tendency to progress to end‐stage renal disease.

Conclusion:  Systemic lupus erythematosus patients who underwent renal biopsies in our institute showed a prevalence of APSN comparable to those in western countries. The presence of APSN was significantly higher in the adult than in the paediatric population. Its association with poor prognostic indicators suggests poor renal outcome. Clinicians should be aware of this condition in order to give proper care to systemic lupus erythematosus patients.
Colonoscopy in elderly Asians: A prospective evaluation in routine clinical practice
Authors: MA Wee‐Tah , MAHADEVA Sanjiv , KUNANAYAGAM Soraya , POI Philip Jun‐Hua , GOH Khean‐Lee
Published: May 2007

OBJECTIVE:  Colonoscopy is believed to be more complicated in elderly patients in Western countries. It is uncertain if the situation holds true among Asians. This study is to determine differences in colonoscopy performance and sedation complications between patients aged <65 years and those ≥65 years of age in an Asian population.

METHODS:  A prospective, cross‐sectional study of adults attending outpatient colonoscopy at a tertiary institution. Clinical and endoscopic data were obtained from all consenting adults.

RESULTS:  Two hundred and one patients (70 elderly and 131 aged <65 years) were enrolled. Compared to the patients aged <65 years, the elderly patients had similar levels of good (42.9%vs 45.8%), satisfactory (42.9%vs 33.6%) and poor (14.3%vs 20.6%) bowel preparations (P = NS). Cecal intubation was achieved in 60 (85.7%) of the elderly patients and 116 (88.5%) of the younger adults (P = NS). The differences in mean total colonoscopy duration was not significant (30 ± 13 vs 27 ± 11 min). Although the elderly patients received lower mean sedation doses of midazolam (4.7 vs 5.1 mg) and pethidine (37.8 vs 46.4 mg) compared to the younger adults, the hypotension rates were significantly higher in the elderly patients (7.1%vs 0.8%, P = 0.01). The elderly patients had in additional one or more co‐morbid illnesses (P = 0.001), with significantly higher rates of diabetes (P = 0.004), ischemic heart disease (P = 0.03), hypertension (P = 0.001) and stroke disease (P = 0.004).

CONCLUSION:  Colonoscopy performance in elderly Asians is similar to that in younger adults. However, the conscious sedation of these patients results in a higher rate of cardio‐vascular complications.
BEFORE THE ORIGINAL POSITION: The Neo‐Orthodox Theology of the Young John Rawls
Authors: Gregory Eric
Published: May 2007

This paper examines a remarkable document that has escaped critical attention within the vast literature on John Rawls, religion, and liberalism:Rawls'sundergraduate thesis, “A Brief Inquiry into the Meaning of Sin and Faith: An Interpretation Based on the Concept of Community” (1942). The thesis shows the extent to which a once regnant version of Protestant theology has retreated into seminaries and divinity schools where it now also meets resistance. Ironically, the young Rawls rejected social contract liberalism for reasons that anticipate many of the claims later made against him by secular and religious critics. The thesis and Rawls's late unpublished remarks on religion and World War II offer a new dimension to his intellectual biography. They show the significance of his humanist response to the moral impossibility of political theology. Moreover, they also reveal a kind of Rawlsian piety marginalized by contemporary debates over religion and liberalism.
Content and Its Vehicles in Connectionist Systems
Authors: SHEA NICHOLAS
Published: May 2007

Abstract:  This paper advocates explicitness about the type of entity to be considered as content‐bearing in connectionist systems; it makes a positive proposal about how vehicles of content should be individuated; and it deploys that proposal to argue in favour of representation in connectionist systems. The proposal is that the vehicles of content in some connectionist systems are clusters in the state space of a hidden layer. Attributing content to such vehicles is required to vindicate the standard explanation for some classificatory networks’ ability to generalise to novel samples their correct classification of the samples on which they were trained.
In Defense of Wordless Thoughts About Thoughts
Authors: LURZ ROBERT W.
Published: May 2007

Abstract: Bermúdez (2003)argues that (T1) nonlinguistic creatures can think thoughts about protocausal conditional states of affairs and engage in rudimentary forms of reasoning, but (T2) they cannot ‘in principle’ think thoughts about thoughts (propositions)—in particular, they cannot have higher‐order propositional attitudes (PAs). I reconstruct Bermúdez’s argument for T2 and show that it rests upon an implausible empirical assumption and is, therefore, not a threat to current empirical research into nonlinguistic higher‐order PAs. I argue that even on an interpretation of the argument that would pose a threat to this research, a parallel argument would seem to disprove T1. Finally, I argue that on an interpretation of Bermúdez’s argument that would not pose a threat to the above empirical research but would still present a significant philosophical thesis about thought and language, the argument either appears to confuse thoughts with their representational vehicles or the representational vehicles of thoughts with those representations used to hold thoughts in mind.
How Do Young Children Process Beliefs About Beliefs?: Evidence from Response Latency
Authors: KIKUNO HARUO , MITCHELL PETER , ZIEGLER FENJA
Published: May 2007

Abstract:  Are incorrect judgments on false belief tasks better explained within the framework of a conceptual change theory or a bias theory? Conceptual change theory posits a change in the form of reasoning from 3 to 4 years old while bias theory posits that processing factors are responsible for errors among younger children. The results from three experiments showed that children who failed a test of false belief took as long to respond as those who passed, and both groups of children took longer to respond to belief questions than to questions about prior states of reality. These results seem to support the bias theory.
ON THE DETERMINATION ARGUMENT AGAINST DEFLATIONISM
Authors: PATTERSON DOUGLAS
Published: May 2007

Abstract:  It is argued that the “Determination Argument” against deflationary theories of truth put forward by Bar‐On, Horisk and Lycan depends on a confusion between the terms used in a definition or analysis and the terms used in claiming that the definition or analysis is correct. With this distinction understood, one can see that the argument poses no threat to deflationary theories of truth.