Molecular mapping of a gene for stripe rust resistance in spring wheat cultivar IDO377s

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most important diseases of wheat worldwide. The best strategy to control stripe rust is to grow resistant cultivars. One such cultivar resistant to most races in North America is 'IDO377s'. To study the genetics of its resistance this spring wheat cultivar was crossed with 'Avocet Susceptible' (AvS). Seedlings of the parents, F(2) plants, and F(3) lines were tested under controlled greenhouse conditions with races PST-43 and PST-45 of P. striiformis f. sp. tritici. IDO377s carries a single dominant gene for resistance. Resistance gene analog polymorphism (RGAP) and simple sequence repeat (SSR) techniques were used to identify molecular markers linked to the resistance gene. A total of ten markers were identified, two of which flanked the locus at 4.4 and 5.5 cM. These flanking RGAP markers were located on chromosome 2B with nulli-tetrasomic lines of 'Chinese Spring'. Their presence in the ditelosomic 2BL line localized them to the long arm. The chromosomal location of the resistance gene was further confirmed with two 2BL-specific SSR markers and a sequence tagged site (STS) marker previously mapped to 2BL. Based on the chromosomal location, reactions to various races of the pathogen and tests of allelism, the IDO377s gene is different from all previously designated genes for stripe rust resistance, and is therefore designated Yr43. A total of 108 wheat breeding lines and cultivars with IDO377s or related cultivars in their parentage were assayed to assess the status of the closest flanking markers and to select lines carrying Yr43. The results showed that the flanking markers were reliable for assisting selection of breeding lines carrying the resistance gene. A linked stripe rust resistance gene, previously identified as YrZak, in cultivar Zak was designated Yr44.

Contrasting spin dynamics between underdoped and overdoped Ba(Fe1-xCox)2As2

We report the first NMR investigation of spin dynamics in the overdoped nonsuperconducting regime of Ba(Fe1-xCox)2As2 up to x=0.26. We demonstrate that the absence of interband transitions with large momentum transfer Q{AF} approximately (pi/a,0) between the hole and electron Fermi surfaces results in complete suppression of antiferromagnetic spin fluctuations for x greater than or approximately 0.15. Our experimental results provide direct evidence for a correlation between T{c} and the strength of Q{AF} antiferromagnetic spin fluctuations.

Influence of substrates in ZnO devices on the surface plasmon enhanced light emission

The substrates in emitting structure were found to have an influence on the surface plasmon mediated light emission of ZnO films. Ag film mediated photoluminescence was quenched for ZnO on silicon substrate but enhanced for ZnO on quartz or sapphire substrate. Through a theoretical simulation, the quenching for ZnO on silicon substrate is ascribed to the power lost to the substrate mode nonradiatively at the expense of the power coupled to the SP mode. The substrate with a high refractive index may capture and dissipate the emitting power which limits the efficiency of SP mediated light extraction. Therefore, a proper arrangement of the refractive index of the substrate and emitting layers in the device structure is decisive for the SP coupled light emission enhancement. Base on the theoretical analysis, a four-layered structure was advanced to recover SP mediated emission enhancement from ZnO film on silicon substrate.

Space flight alters bacterial gene expression and virulence and reveals a role for global regulator Hfq

A comprehensive analysis of both the molecular genetic and phenotypic responses of any organism to the space flight environment has never been accomplished because of significant technological and logistical hurdles. Moreover, the effects of space flight on microbial pathogenicity and associated infectious disease risks have not been studied. The bacterial pathogen Salmonella typhimurium was grown aboard Space Shuttle mission STS-115 and compared with identical ground control cultures. Global microarray and proteomic analyses revealed that 167 transcripts and 73 proteins changed expression with the conserved RNA-binding protein Hfq identified as a likely global regulator involved in the response to this environment. Hfq involvement was confirmed with a ground-based microgravity culture model. Space flight samples exhibited enhanced virulence in a murine infection model and extracellular matrix accumulation consistent with a biofilm. Strategies to target Hfq and related regulators could potentially decrease infectious disease risks during space flight missions and provide novel therapeutic options on Earth.

Recombinant arginase as a novel anti-melanoma agent

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Background: BCT-100 is a recombinant arginase comprised of 329 amino acid residues. Arginase converts arginine to urea and ornithine. Previous studies suggested that melanoma cells were auxotrophic for arginine due to absence of argininosuccinate synthetase (ASS) expression. Thus, we hypothesized that recombinant arginase, BCT-100, is cytotoxic to human melanoma cells and its cytotoxicity correlates with absence of ASS expression. Methods: BCT-100 pegylated recombinant human arginase was manufactured by large scale fermentation of a recombinant B. subtilis strain LLC101 encoded with a human arginase gene. Following fermentation, the recombinant protein was extracted, purified, pegylated, and ultra-dialyzed. Ten established human melanoma cell lines were used. Cells were grown to 90% confluence, harvested, and plated at 104 cells per well in a 96-well plate and co-cultured with increasing concentrations of pegylated BCT-100 for 72 hours. CellTiter 96 Aqueous Non-radioactive Cell Proliferation Assay (Promega, Madison, WI) was used to measure percent viability, with absorbances measured at 490 nm. Total cellular RNA was isolated from established melanoma cell lines converted to cDNA at a concentration of 5 ng/ul. Quantitative real time polymerase chain reaction was performed on a 7300 Real Time PCR System, using Gene Expression Assays for ASS and GAPDH (Applied Biosystems). 10,000 fold standard curves were generated for all samples using GAPDH expression. Results: All ten cell lines demonstrated decreased viability as concentrations of BCT-100 increased. Average IC50 value was 0.11 IU/ml. Eight of the 10 cells lines have IC50 values < 0.1 IU/ml. Of the 8 cell lines with IC50< 0.1 IU/ml, all of them have low or undetectable ASS expression using quantitative RT-PCR. Of the 2cell lines with IC50 > 0.1 IU/ml, ASS expression was detected in 1 of 2. Conclusions: Arginine depletion with recombinant arginase, BCT-100, was cytotoxic to melanoma cells in vitro. The cytotoxic effect of BCT-100 on melanoma cells correlated with expression of argininosuccinate synthetase. BCT-100 is a promising novel agent for treatment of melanoma. Further in vivo experiment with BCT-100 is ongoing.

[Table: see text]

Differences in gene content between Salmonella enterica serovar Enteritidis isolates and comparison to closely related serovars Gallinarum and Dublin

Salmonella enterica serovar Enteritidis is often transmitted into the human food supply through eggs of hens that appear healthy. This pathogen became far more prevalent in poultry following eradication of the fowl pathogen S. enterica serovar Gallinarum in the mid-20th century. To investigate whether changes in serovar Enteritidis gene content contributed to this increased prevalence, and to evaluate genetic heterogeneity within the serovar, comparative genomic hybridization was performed on eight 60-year-old and nineteen 10- to 20-year-old serovar Enteritidis strains from various hosts, using a Salmonella-specific microarray. Overall, almost all the serovar Enteritidis genomes were very similar to each other. Excluding two rare strains classified as serovar Enteritidis in the Salmonella reference collection B, only eleven regions of the serovar Enteritidis phage type 4 (PT4) chromosome (sequenced at the Sanger Center) were absent or divergent in any of the other serovar Enteritidis strains tested. The more recent isolates did not have consistent differences from 60-year-old field isolates, suggesting that no large genomic additions on a whole-gene scale were needed for serovar Enteritidis to become more prevalent in domestic fowl. Cross-hybridization of phage genes on the array with related genes in the examined genomes grouped the serovar Enteritidis isolates into two major lineages. Microarray comparisons of the sequenced serovar Enteritidis PT4 to isolates of the closely related serovars Dublin and Gallinarum (biovars Gallinarum and Pullorum) revealed several genomic areas that distinguished them from serovar Enteritidis and from each other. These differences in gene content could be useful in DNA-based typing and in understanding the different phenotypes of these related serovars.

Endothelial microparticles induce formation of platelet aggregates via a von Willebrand factor/ristocetin dependent pathway, rendering them resistant to dissociation

Endothelial microparticles (EMP) released from activated or apoptotic endothelial cells (EC) are emerging as useful markers for detection of EC dysfunction. Our recent observation that EMP carry von Willebrand factor (vWf) led us to investigate their interaction with platelets. EMP were incubated with normal washed platelets in the presence or absence of ristocetin, then platelet aggregates were measured by flow cytometry. In the absence of ristocetin, negligible EMP conjugated with platelets (< 5%) but in the presence of ristocetin (1 mg mL(-1)), EMP induced up to 95% of platelets to aggregate. EMP-platelet interaction was 80% blocked by anti-CD42b, or by 0.1 microm filtration to remove EMP. Platelet aggregates induced by normal plasma or high molecular weight vWf (Humate-P) dissociated 50% within 15-25 min following 1:20 dilution. In contrast, aggregates formed with EMP persisted two- to threefold longer with the same treatment, indicating greater stability. A similar degree of prolongation of dissociation was observed using plasma from thrombotic thrombocytopenic purpura (TTP) patients compared with normal plasma. Addition of EMP to plasma from severe von Willebrand disease restored his ristocetin-induced platelet aggregation. Multimer analysis of vWf on EMP showed unusually large vWf (ULvWf). In summary, EMP carries ULvWf multimers, promote platelet aggregates, and increase the stability of the aggregates thus formed.

Characterization of Salmonella enterica subspecies I genovars by use of microarrays

Subspecies 1 of Salmonella enterica is responsible for almost all Salmonella infections of warm-blooded animals. Within subspecies 1 there are over 2,300 known serovars that differ in their prevalence and the diseases that they cause in different hosts. Only a few of these serovars are responsible for most Salmonella infections in humans and domestic animals. The gene contents of 79 strains from the most prevalent serovars were profiled by microarray analysis. Strains within the same serovar often differed by the presence and absence of hundreds of genes. Gene contents sometimes differed more within a serovar than between serovars. Groups of strains that share a distinct profile of gene content can be referred to as "genovars" to distinguish them from serovars. Several misassignments within the Salmonella reference B collection were detected by genovar typing and were subsequently confirmed serologically. Just as serology has proved useful for understanding the host range and pathogenic manifestations of Salmonella, genovars are likely to further define previously unrecognized specific features of Salmonella infections.

GenSo-EWS: a novel neural-fuzzy based early warning system for predicting bank failures

Bank failure prediction is an important issue for the regulators of the banking industries. The collapse and failure of a bank could trigger an adverse financial repercussion and generate negative impacts such as a massive bail out cost for the failing bank and loss of confidence from the investors and depositors. Very often, bank failures are due to financial distress. Hence, it is desirable to have an early warning system (EWS) that identifies potential bank failure or high-risk banks through the traits of financial distress. Various traditional statistical models have been employed to study bank failures [J Finance 1 (1975) 21; J Banking Finance 1 (1977) 249; J Banking Finance 10 (1986) 511; J Banking Finance 19 (1995) 1073]. However, these models do not have the capability to identify the characteristics of financial distress and thus function as black boxes. This paper proposes the use of a new neural fuzzy system [Foundations of neuro-fuzzy systems, 1997], namely the Generic Self-organising Fuzzy Neural Network (GenSoFNN) [IEEE Trans Neural Networks 13 (2002c) 1075] based on the compositional rule of inference (CRI) [Commun ACM 37 (1975) 77], as an alternative to predict banking failure. The CRI based GenSoFNN neural fuzzy network, henceforth denoted as GenSoFNN-CRI(S), functions as an EWS and is able to identify the inherent traits of financial distress based on financial covariates (features) derived from publicly available financial statements. The interaction between the selected features is captured in the form of highly intuitive IF-THEN fuzzy rules. Such easily comprehensible rules provide insights into the possible characteristics of financial distress and form the knowledge base for a highly desired EWS that aids bank regulation. The performance of the GenSoFNN-CRI(S) network is subsequently benchmarked against that of the Cox's proportional hazards model [J Banking Finance 10 (1986) 511; J Banking Finance 19 (1995) 1073], the multi-layered perceptron (MLP) and the modified cerebellar model articulation controller (MCMAC) [IEEE Trans Syst Man Cybern: Part B 30 (2000) 491] in predicting bank failures based on a population of 3635 US banks observed over a 21 years period. Three sets of experiments are performed-bank failure classification based on the last available financial record and prediction using financial records one and two years prior to the last available financial statements. The performance of the GenSoFNN-CRI(S) network as a bank failure classification and EWS is encouraging.

Photoreception in Neurospora: a tale of two White Collar proteins

Neurospora crassa is the best-understood fungal organism in terms of the mechanism of light responses. All known Neurospora photoresponses are mediated by blue light. Two Per-Arnt-Simdomain containing transcription factors, WHITE COLLAR-1 (WC-1) and WC-2, are essential components for almost all light responses. Recently, WC-1was shown to be a blue-light photoreceptor. How light affects the DNA binding of the WC proteins to the promoter of the circadian clock gene frequency was also demonstrated. These studies established a mechanism that explains the light responses mediated by activation of transcription. The purpose of this review is to summarize the findings of recent studies on the molecular mechanism of photoreception in Neurospora.

[Sequential BiPAP following invasive mechanical ventilation in COPD patients with hypercapnic respiratory failure]

OBJECTIVE

To estimate the feasibility and the efficacy of extubation and sequential bilevel positive airway pressure (BiPAP) in chronic obstructive pulmonary disease (COPD) patients with exacerbated hypercapnic respiratory failure.

METHODS

All patients were randomly divided into a control group and an experimental group. In addition to conventional therapy, the experimental group was treated with bilevel positive airway pressure via facial mask immediately, the control group was treated with conventional therapy alone.

RESULTS

There were no difference in clinical characteristics and gas exchange at entry. pH value, PaCO2 and PaCO2 were significantly improved in experimental group following the first 45 minutes ventilation (P < 0.05), but no additional improvement was observed when ventilation was extended to 12 hours (P > 0.05). Reintubation rate was higher in the control group compared with the experimental group (P < 0.05).

CONCLUSION

BiPAP can be well tolerated, and can improve ventilation function markedly. It can also facifiated the extubation, and reduced the reintubation rate in regular mechanical ventilation.

Embracing C(60) with multiarmed geodesic partners

1,3,5,7,9-Pentakis(4-methoxyphenylthio)corannulene (3), 1,3,5,7,9-pentakis(2-naphthylthio)corannulene (4), and 1,3,6,8-tetrakis(4-methoxyphenylthio)corannulene (5b) have been synthesized by chlorination of corannulene with ICl in CH(2)Cl(2) at 25 degrees C and subsequent nucleophilic aromatic substitution with the appropriate sodium thiophenolate in DMEU at 25 degrees C. (1)H NMR titration studies demonstrate that these novel bowl-shaped hosts form 1:1 complexes with C(60) in toluene-d(8) solution with association constants of 454, 368, and 280 M(-1), respectively.