bluuebunny/crossref_metadata_2025 huggingface dataset:
Stability of Alfvén wings in uniform plasmas
Authors: SALLAGO P. A. , PLATZECK A. M.
Published: May 2007

A conducting source moving uniformly through a magnetized plasma generates, among a variety of perturbations, Alfvén waves. An interesting characteristic of Alfvén waves is that they can build up structures in the plasma called Alfvén wings. These wings have been detected and measured in many solar system bodies, and their existence has also been theoretically proven. However, their stability remains to be studied. The aim of this paper is to analyze the stability of an Alfvén wing developed in a uniform background field, in the presence of an incompressible perturbation that has the same symmetry as the Alfvén wing, in the magnetohydrodynamic approximation. The study of the stability of a magnetohydrodynamic system is often performed by linearizing the equations and using either the normal modes method or the energy method. In spite of being applicable for many problems, both methods become algebraically complicated if the structure under analysis is a highly non-uniform one. Palumbo has developed an analytical method for the study of the stability of static structures with a symmetry in magnetized plasmas, in the presence of incompressible perturbations with the same symmetry as the structure (Palumbo 1998 Thesis, Universidad de Firenze, Italia). In the present paper we extend this method for Alfvén wings that are stationary structures, and conclude that in the presence of this kind of perturbation they are stable.
Abkehr von der Rückkehr: Aufbau und Theologie der Apostelgeschichte im Kontext des lukanischen Diasporaverständnisses
Authors: SCHMIDT KARL MATTHIAS
Published: May 2007

Dem Programm in Apg 1.8 entsprechend gliedert Lukas die Apostelgeschichte unter geographischer Hinsicht in drei Abschnitte, in denen er die Verbreitung des Evangeliums bis zu den Enden der Erde als neue Form der Zerstreuung beschreibt. Diese Zerstreuung wird nicht mehr wie in der alttestamentlichen Prophetie als Realisierung des Gerichts, sondern als Weg des Heils verstanden. An die Stelle einer endzeitlichen Sammlung auf dem Zion rückt der Evangelist die Sammlung Israels und der Völker in der positiv verstandenen Diaspora. Vor diesem Hintergrund endet die Apostelgeschichte sinnvoll im neuen Babylon mit Paulus' Verkündigung in Gefangenschaft.
Die Sternenfrau und ihre Kinder (Offb 12): Zur Wiederentdeckung eines Mythos
Authors: SCHREIBER STEFAN
Published: May 2007

Various interpretations have been offered to identify the woman of Rev 12, attributed with the sun, the moon, and twelve stars: Mary, Israel, or the church, or a combination of the items church and eschatological Israel. My article tries first to detect tradition historically the semantics of the sign of the woman in labour and her newborn son and arrives at the conclusion that it represents a new eschatological beginning in Israel. Then a reader-oriented approach shows the possibility of a recipient familiar with the hellenistic constructions of society to view Rev 12 as a Christian myth, narrated with elements of well-known hellenistic myths, for example, that of Telephos or of Isis/Osiris. The comparison leads to the conclusion that Rev 12 functions to induce its readers to be aware of their own eschatological identity in contrast to the identity of their social environment and to engage consciously in a cultural conflict.
Clinical and prognostic implications of seasonal pattern in bipolar disorder: a 10-year follow-up of 302 patients
Authors: GOIKOLEA J. M. , COLOM F. , MARTÍNEZ-ARÁN A. , SÁNCHEZ-MORENO J. , GIORDANO A. , BULBENA A. , VIETA E.
Published: May 2007

Background

More than 20% of bipolar patients may present with seasonal pattern (SP). Seasonality can alter the course of bipolar disorder. However, to date, long-term follow-up studies of bipolar patients presenting with SP are scarce. We present a 10-year follow-up study comparing clinical and demographic features of bipolar patients with and without SP.

Method

Three hundred and twenty-five bipolar I and II patients were followed up for at least 10 years. SP was defined according to DSM-IV criteria. Clinical variables were obtained from structured interviews with the patients and their relatives. Patients with and without SP were compared regarding clinical and sociodemographic variables and a stepwise logistic regression was performed.

Results

Seventy-seven patients (25·5%) were classified as presenting with SP, while 225 (74·5%) were considered as presenting with no significant seasonal variation. Twenty-three patients (7%) were excluded from the study because it was unclear whether they had seasonality or not. There were no differences between groups regarding demographic variables. Patients with SP predominantly presented with bipolar II disorder, depressive onset, and depressive predominant polarity. The greater burden of depression did not correlate with indirect indicators of severity, such as suicidality, hospitalizations or psychotic symptoms.

Conclusions

Our study links the presence of SP with both bipolar II disorder and predominant depressive component. However, we could not find any difference regarding functionality or hospitalization rates. Modifications in the criteria to define SP are suggested for a better understanding of bipolar disorder.
The dynamic nature of group A streptococcal epidemiology in tropical communities with high rates of rheumatic heart disease
Authors: McDONALD M. I. , TOWERS R. J. , ANDREWS R. , BENGER N. , FAGAN P. , CURRIE B. J. , CARAPETIS J. R.
Published: May 2007

Prospective surveillance was conducted in three remote Aboriginal communities with high rates of rheumatic heart disease in order to investigate the epidemiology of group A β-haemolytic streptococci (GAS). At each household visit, participants were asked about sore throat. Swabs were taken from all throats and any skin sores. GAS isolates wereemmsequence and pattern-typed using standard laboratory methods. There were 531 household visits; 43 differentemmtypes and subtypes (emmST) were recovered. Four epidemiological patterns were observed. MultipleemmST were present in the population at any one time and household acquisition rates were high. Household acquisition was most commonly via 5- to 9-year-olds. Following acquisition, there was a 1 in 5 chance of secondary detection in the household. Throat detection ofemmST was brief, usually <2 months. The epidemiology of GAS in these remote Aboriginal communities is a highly dynamic process characterized byemmST diversity and turnover.
Decadal changes in 1870–2004 Northern Hemisphere winter sea level pressure variability and its relationship with surface temperature
Authors: Haylock M. R. , Jones P. D. , Allan R. J. , Ansell T. J.
Published: May 2007

Decadal changes in correlations between boreal winter averages of indices of the North Atlantic Oscillation (NAO) and average temperature north of 20°N (NH20N) have been reported in the literature. We show that such fluctuations are caused by changing midfrequency and high‐frequency correlations (periods less than 30 years) and are not the result of changes in the station network or a few erratic years. By examining the NAO‐temperature squared correlation on a spatial basis, we show that there have been strong decadal changes in the Pacific but a more constant relationship in the Atlantic. We explain the varying NAO‐temperature relationship by showing that sea level pressure (SLP) variance has changed markedly through time, especially in the North Pacific. We performed a principal component analysis (PCA) of the running variance of SLP using a recently released historical global gridded data set. The first PC corresponded to a reduction in variance of the NAO during the mid‐20th century, which occurred concurrently with a similar change in the variance of the El Niño–Southern Oscillation (ENSO). The loading patterns for this PC suggest that the decadal changes in the variability of ENSO could be responsible for the changes in NAO variance. The second North Pacific–dominated PC was indicative of increased variability of the strength of the Aleutian Low during the mid‐20th century, during which time the variability in the Pacific and Atlantic were in phase. These two changes in variance of SLP, together with the phase relationship between the two ocean basins, explain the changing NAO‐temperature correlation.
Processing of atmospheric nitrogen by clouds above a forest environment
Authors: Hill Kimberly A. , Shepson Paul B. , Galbavy Edward S. , Anastasio Cort , Kourtev Peter S. , Konopka Allan , Stirm Brian H.
Published: May 2007

Dissolved inorganic ions (NH4+, Ca2+, Mg2+, K+, H+, NO3−, and SO42−) and organic nitrogen (DON) were measured in cloud water samples collected over the northern lower peninsula of Michigan. Within a given cloud field, several altitudes were sampled to examine changes in concentration and speciation with altitude. Several samples were analyzed for bacterial content and activity. Convective cumulus (cumulus congestus) were more concentrated than fair weather cumulus (cumulus humilis) for all major ions and DON, with the cloudy air DON concentrations in convective cumulus being twice as large as for fair weather cumulus, and for all other ions, the droplets were 4–6 times more concentrated. The molar average distribution of nitrogen in the cloud water was 43 (±10, 1σ)% ammonium, 39 (±7)% nitrate and 18 (±11)% DON. High concentrations of bacteria were observed in the clouds with an average concentration of 2.9 × 105 (±1.0 × 105, 1σ) bacteria m−3 of cloudy air but which contributed less than 1% of the nitrogen in the cloud water. In addition, nitrifying bacteria were identified, indicating bacterial processing of nitrogen in the cloud water may occur. Air mass origin and altitude influence observed cloud water concentrations, with the exception of DON. The correlation of ammonium and sulfate, and calcium and nitrate suggest that ammonium sulfate and calcium nitrate aerosol may be important sources of these ions.
Characterization of filamentous bacteria, belonging to candidate phylum KSB3, that are associated with bulking in methanogenic granular sludges
Authors: Yamada Takeshi , Yamauchi Toshihiro , Shiraishi Koji , Hugenholtz Philip , Ohashi Akiyoshi , Harada Hideki , Kamagata Yoichi , Nakamura Kazunori , Sekiguchi Yuji
Published: May 2007

A fatal bulking phenomenon was found to occur occasionally in the methanogenic granular sludge of a mesophilic (35–40°C), full-scale upflow anaerobic sludge blanket (UASB) reactor treating organic wastewater discharged from a sugar manufacturing factory. A vast number of filamentous cells were observed in the bulking sludge that were morphologically distinct from the previously recognized anaerobic bulking agent Anaerolinea thermophila. 16S rRNA gene-based analyses of the microbial populations in the bulking sludge revealed that the dominant filamentous organisms were members of proposed candidate bacterial phylum, KSB3. Fluorescence in situ hybridization (FISH) analysis of the healthy sludge granules showed that the KSB3 filaments were the dominant granule surface population suggesting that they are fundamental constituents of the sludge granules and that they occasionally overgrow in the reactor, possibly triggering the filamentous bulking. We surveyed 10 additional mesophilic and thermophilic anaerobic sludges for the presence and diversity of KSB3 populations. Bacteria closely related to the characterized KSB3 filaments were present in two types of mesophilically grown UASB sludge granules treating actual wastewater discharged from sugar-processing industries.
Functional metaproteome analysis of protein extracts from contaminated soil and groundwater
Authors: Benndorf Dirk , Balcke Gerd U , Harms Hauke , von Bergen Martin
Published: May 2007

Using proteins from soil or groundwater as functional biomarkers requires efficient extraction. We developed an extraction method in which the separation of proteins from the inorganic and organic constituents of the soil matrix was achieved by a combination of 0.1 m NaOH treatment and phenol extraction. Incubation with NaOH released humic acids and proteins from soil minerals, and simultaneously, disrupted microorganisms. The subsequent phenol extraction separated the proteins from the humic organic matter. Protein extracts were applied to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and 2D-electrophoresis (2-DE). Spots and bands were excised and individual proteins identified by liquid chromatography online linked to mass spectrometry (MS) via electrospray ionization source (LC-ESI-MS). To assess the suitability of the method for the functional analysis of environmental metaproteomes, it was applied to soil that had been enriched in chlorophenoxy acid-degrading bacteria by incubation with 2,4-dichlorophenoxy acetic acid (2,4-D) for 22 days. The method was also used to analyze groundwater from the aquifer of a chlorobenzene-contaminated site. The identification of enzymes such as chlorocatechol dioxygenases was consistent with bacterial metabolic pathways expected to be expressed in these samples. The protocol enabled thus the analysis of the metaproteome of soil and groundwater samples. It thereby provides a means to study the diversity of environmental microbial communities while addressing functional aspects more directly than metagenome or even metatranscriptome analysis.
In situobservation of electric-field-induced domain switching near a crack tip in poled 0.62PbMg1∕3Nb2∕3O3–0.38PbTiO3 single crystal
Authors: Jiang Yejian , Fang Daining , Li Faxin
Published: May 2007

An in situ polarized light microscopy observation of electric-field-induced domain switching near a crack tip in poled 0.62PbMg1∕3Nb2∕3O3–0.38PbTiO3 single crystal is reported. In-plane 90° domain switching is found to concentrate near the crack tip and the size of switching zone increases with the electric field. The polarization directions of switched domains, the positions, and width of 90° switching zones accord well with theoretical results based on the domain switching model by Hwang et al. [Acta Metall. Mater. 43, 2073 (1995)]. However, contradicting with this model, no explicit 180° domain switching ahead of the crack tip is observed.
Impact-induced glass transition in elastomeric coatings
Authors: Bogoslovov R. B. , Roland C. M. , Gamache R. M.
Published: May 2007

Polybutadiene (PB) has a low glass temperature Tg and exhibits rubbery behavior during mechanical perturbation. The corresponding PB-based polyurea (PU) has a higher Tg and fails in a brittle mode for high strain rates. However, unlike in glasses, this brittle failure is accompanied by large energy dissipation. Dielectric relaxation measurements demonstrate that whereas the PB segmental dynamics are faster than the strain rate during impact loading, for PU these motions are on the order of the strain rate, ∼105s−1. Consequently, impact induces a transition to the glassy state, with the accompanying response markedly different from that of a rubber.
Solvatochromism in single-walled carbon nanotubes
Authors: Choi Jong Hyun , Strano Michael S.
Published: May 2007

The optical transition energies (Eii) of single-walled carbon nanotubes (SWCNT) are influenced by the local environment created by solvents and adsorbed molecules. Analysis of SWCNT photoluminescence (PL) energies in various dielectric media is used to elucidate a semiempirical scaling relation for Eii shifts and nanotube structural properties from a classical solvatochromic formalism. The SWCNT Kataura plot is corrected for a dielectric constant of unity and used in conjunction with the scaling to accurately describe PL energy shifts in a broad range of dielectric media.
Inducible XIST-dependent X-chromosome inactivation in human somatic cells is reversible
Authors: Chow Jennifer C. , Hall Lisa L. , Baldry Sarah E. L. , Thorogood Nancy P. , Lawrence Jeanne B. , Brown Carolyn J.
Published: May 2007

During embryogenesis, the XIST RNA is expressed from and localizes to one X chromosome in females and induces chromosome-wide silencing. Although many changes to inactive X heterochromatin are known, the functional relationships between different modifications are not well understood, and studies of the initiation of X-inactivation have been largely confined to mouse. We now present a model system for human XIST RNA function in which induction of an XIST cDNA in somatic cells results in localized XIST RNA and transcriptional silencing. Chromatin immunoprecipitation and immunohistochemistry shows that this silencing need only be accompanied by a subset of heterochromatic marks and that these can differ between integration sites. Surprisingly, silencing is XIST-dependent, remaining reversible over extended periods. Deletion analysis demonstrates that the first exon of human XIST is sufficient for both transcript localization and the induction of silencing and that, unlike the situation in mice, the conserved repeat region is essential for both functions. In addition to providing mechanistic insights into chromosome regulation and formation of facultative heterochromatin, this work provides a tractable model system for the study of chromosome silencing and suggests key differences from mouse embryonic X-inactivation.
Nuclear relocation of the nephrin and CD2AP-binding protein dendrin promotes apoptosis of podocytes
Authors: Asanuma Katsuhiko , Campbell Kirk Nicholas , Kim Kwanghee , Faul Christian , Mundel Peter
Published: May 2007

Kidney podocytes and their slit diaphragms (SDs) form the final barrier to urinary protein loss. There is mounting evidence that SD proteins also participate in intracellular signaling pathways. The SD protein nephrin serves as a component of a signaling complex that directly links podocyte junctional integrity to actin cytoskeletal dynamics. Another SD protein, CD2-associated protein (CD2AP), is an adaptor molecule involved in podocyte homeostasis that can repress proapoptotic TGF-β signaling in podocytes. Here we show that dendrin, a protein originally identified in telencephalic dendrites, is a constituent of the SD complex, where it directly binds to nephrin and CD2AP. In experimental glomerulonephritis, dendrin relocates from the SD to the nucleus of injured podocytes. High-dose, proapoptotic TGF-β1 directly promotes the nuclear import of dendrin, and nuclear dendrin enhances both staurosporine- and TGF-β1-mediated apoptosis. In summary, our results identify dendrin as an SD protein with proapoptotic signaling properties that accumulates in the podocyte nucleus in response to glomerular injury and provides a molecular target to tackle proteinuric kidney diseases. Nuclear relocation of dendrin may provide a mechanism whereby changes in SD integrity could translate into alterations of podocyte survival under pathological conditions.
Proline-rich tyrosine kinase 2 regulates osteoprogenitor cells and bone formation, and offers an anabolic treatment approach for osteoporosis
Authors: Buckbinder Leonard , Crawford David T. , Qi Hong , Ke Hua Zhu , Olson Lisa M. , Long Kelly R. , Bonnette Peter C. , Baumann Amy P. , Hambor John E. , Grasser William A. , Pan Lydia C. , Owen Thomas A. , Luzzio Michael J. , Hulford Catherine A. , Gebhard David F. , Paralkar Vishwas M. , Simmons Hollis A. , Kath John C. , Roberts W. Gregory , Smock Steven L. , Guzman-Perez Angel , Brown Thomas A. , Li Mei
Published: May 2007

Bone is accrued and maintained primarily through the coupled actions of bone-forming osteoblasts and bone-resorbing osteoclasts. Cumulative
in vitro
studies indicated that proline-rich tyrosine kinase 2 (PYK2) is a positive mediator of osteoclast function and activity. However, our investigation of PYK2−/− mice did not reveal evidence supporting an essential function for PYK2 in osteoclasts either
in vivo
or in culture. We find that PYK2−/− mice have high bone mass resulting from an unexpected increase in bone formation. Consistent with the
in vivo
findings, mouse bone marrow cultures show that PYK2 deficiency enhances differentiation and activity of osteoprogenitor cells, as does expressing a PYK2-specific short hairpin RNA or dominantly interfering proteins in human mesenchymal stem cells. Furthermore, the daily administration of a small-molecule PYK2 inhibitor increases bone formation and protects against bone loss in ovariectomized rats, an established preclinical model of postmenopausal osteoporosis. In summary, we find that PYK2 regulates the differentiation of early osteoprogenitor cells across species and that inhibitors of the PYK2 have potential as a bone anabolic approach for the treatment of osteoporosis.
Mesenchyme Forkhead 1 (
FOXC2
) plays a key role in metastasis and is associated with aggressive basal-like breast cancers
Authors: Mani Sendurai A. , Yang Jing , Brooks Mary , Schwaninger Gunda , Zhou Alicia , Miura Naoyuki , Kutok Jeffery L. , Hartwell Kimberly , Richardson Andrea L. , Weinberg Robert A.
Published: May 2007

The metastatic spread of epithelial cancer cells from the primary tumor to distant organs mimics the cell migrations that occur during embryogenesis. Using gene expression profiling, we have found that the FOXC2 transcription factor, which is involved in specifying mesenchymal cell fate during embryogenesis, is associated with the metastatic capabilities of cancer cells.
FOXC2
expression is required for the ability of murine mammary carcinoma cells to metastasize to the lung, and overexpression of FOXC2 enhances the metastatic ability of mouse mammary carcinoma cells. We show that FOXC2 expression is induced in cells undergoing epithelial-mesenchymal transitions (EMTs) triggered by a number of signals, including TGF-β1 and several EMT-inducing transcription factors, such as Snail, Twist, and Goosecoid. FOXC2 specifically promotes mesenchymal differentiation during an EMT and may serve as a key mediator to orchestrate the mesenchymal component of the EMT program. Expression of
FOXC2
is significantly correlated with the highly aggressive basal-like subtype of human breast cancers. These observations indicate that
FOXC2
plays a central role in promoting invasion and metastasis and that it may prove to be a highly specific molecular marker for human basal-like breast cancers.
Nucleoporins Prevent DNA Damage Accumulation by Modulating Ulp1-dependent Sumoylation Processes
Authors: Palancade Benoit , Liu Xianpeng , Garcia-Rubio Maria , Aguilera Andrès , Zhao Xiaolan , Doye Valérie
Published: May 2007

Increasing evidences suggest that nuclear pore complexes (NPCs) control different aspects of nuclear metabolism, including transcription, nuclear organization, and DNA repair. We previously established that the Nup84 complex, a major NPC building block, is part of a genetic network involved in DNA repair. Here, we show that double-strand break (DSB) appearance is linked to a shared function of the Nup84 and the Nup60/Mlp1–2 complexes. Mutants within these complexes exhibit similar genetic interactions and alteration in DNA repair processes as mutants of the SUMO-protease Ulp1. Consistently, these nucleoporins are required for maintenance of proper Ulp1 levels at NPCs and for the establishment of the appropriate sumoylation of several cellular proteins, including the DNA repair factor Yku70. Moreover, restoration of nuclear envelope-associated Ulp1 in nucleoporin mutants reestablishes proper sumoylation patterns and suppresses DSB accumulation and genetic interactions with DNA repair genes. Our results thus provide a molecular mechanism that underlies the connection between NPC and genome stability.
MRX-dependent DNA Damage Response to Short Telomeres
Authors: Viscardi Valeria , Bonetti Diego , Cartagena-Lirola Hugo , Lucchini Giovanna , Longhese Maria Pia
Published: May 2007

Telomere structure allows cells to distinguish the natural chromosome ends from double-strand breaks (DSBs). However, DNA damage response proteins are intimately involved in telomere metabolism, suggesting that functional telomeres may be recognized as DNA damage during a time window. Here we show by two different systems that short telomeres are recognized as DSBs during the time of their replication, because they induce a transient MRX-dependent DNA damage checkpoint response during their prolonged elongation. The MRX complex, which is recruited at telomeres under these conditions, dissociates from telomeres concomitantly with checkpoint switch off when telomeres reach a new equilibrium length. We also show that MRX recruitment to telomeres is sufficient to activate the checkpoint independently of telomere elongation. We propose that MRX can signal checkpoint activation by binding to short telomeres only when they become competent for elongation. Because full-length telomeres are refractory to MRX binding and the shortest telomeres are elongated of only a few base pairs per generation, this limitation may prevent unscheduled checkpoint activation during an unperturbed S phase.
Computational methods for diffusion-influenced biochemical reactions
Authors: Dobrzyński Maciej , Rodríguez Jordi Vidal , Kaandorp Jaap A. , Blom Joke G.
Published: May 2007

Motivation: We compare stochastic computational methods accounting for space and discrete nature of reactants in biochemical systems. Implementations based on Brownian dynamics (BD) and the reaction-diffusion master equation are applied to a simplified gene expression model and to a signal transduction pathway in Escherichia coli.

Results: In the regime where the number of molecules is small and reactions are diffusion-limited predicted fluctuations in the product number vary between the methods, while the average is the same. Computational approaches at the level of the reaction-diffusion master equation compute the same fluctuations as the reference result obtained from the particle-based method if the size of the sub-volumes is comparable to the diameter of reactants. Using numerical simulations of reversible binding of a pair of molecules we argue that the disagreement in predicted fluctuations is due to different modeling of inter-arrival times between reaction events. Simulations for a more complex biological study show that the different approaches lead to different results due to modeling issues. Finally, we present the physical assumptions behind the mesoscopic models for the reaction-diffusion systems.

Availability: Input files for the simulations and the source code of GMP can be found under the following address: http://www.cwi.nl/projects/sic/bioinformatics2007/

Contact:  m.dobrzynski@cwi.nl

Supplementary information: Supplementary data are available at Bioinformatics online.
REPRESENTING THE ALGERIAN WAR IN ALGERIAN CINEMA:
LE VENT DES AURÈS
Authors: Austin Guy
Published: May 2007

The Algerian War has been evoked by numerous French films without ever becoming part of the French national consciousness, partly because of state censorship, self-censorship and controversies around issues such as torture. French films about the war have, however, met with a certain amount of critical attention. The same cannot be said of Algerian films about the war, which have often been dismissed out of hand as state propaganda. This article considers the development of Algerian cinema in the years immediately after the liberation from French colonial rule, and delineates the features of the dominant post-war mode known as
cinéma moudjahid
(freedom fighter cinema). There follows a close analysis of the representation of indigenous suffering in Mohamed Lakhdar Hamina's 1966 film
Le Vent des Aurès
. Paying particular attention to the representation of the female protagonist in her native landscape, the article will explore how Algeria, so often fantasized as empty of Algerians in French cinema and in colonialist thought, here becomes inhabited and dramatized according to indigenous spatial, religious and cultural concerns. Conclusions will be reached regarding the place of
Le Vent des Aurès
in Algerian national cinema and the ways in which the film transcends the spatial logic of colonial rule.
Isolation and Identification of the Causal Agent of Brown Stalk Rot, A New Disease of Maize in South Africa
Authors: Goszczynska T. , Botha W. J. , Venter S. N. , Coutinho T. A.
Published: May 2007

During 2004 to 2005, an unreported disease of maize (Zea mays) was observed on commercial fields in the Northwest and Mpumalanga Provinces of South Africa. Infected plants were stunted, with a vertical crack at the first internode. Inside the stem, a dark-brown, narrow lesion was present along the crack. Internal browning inside the stem extended upward, reaching the top internode in some plants. Seed cobs were underdeveloped. Diseased plants were scattered in the fields and 10 to 70% of the crop was affected. Gram-negative, facultatively anaerobic bacteria were consistently isolated from diseased tissues. Pathogenicity tests established that representative strains induced disease symptoms similar to those observed on maize plants in the field. Physiological and biochemical characterization using the API 20E and API 50CHE systems and 16S rRNA gene sequence analyses showed that the strains belonged to the genus Pantoea. The results of these tests also separated the strains into two groups. The first group, giving a positive reaction in the indole test, was similar to Pantoea ananatis. The second group of strains was indole negative and resembled P. agglomerans. The fluorescent amplified fragment length polymorphism (F-AFLP) genomic fingerprints generated by the indole-positive strains and P. ananatis reference strains were similar and clustered together in the dendrogram, confirming that the indole-positive bacteria causing brown stalk rot on maize were P. ananatis. The F-AFLP fingerprints produced by the indole-negative strains were distinctly different from those generated by P. ananatis, P. agglomerans, P. dispersa, P. citrea, P. stewartii subsp. stewartii, and P. stewartii subsp. indologenes. The results indicated that indole-negative bacteria causing brown stalk rot on maize might belong to a previously undescribed species of the genus Pantoea. This is the first report of a new disease on maize, brown stalk rot, caused by two bacterial species, P. ananatis and an undescribed Pantoea sp.
Identification and Characterization of a Carlavirus Causing Veinal Necrosis of Coleus
Authors: Mollov Dimitre S. , Hayslett Maya C. , Eichstaedt Kari A. , Beckman Noelle G. , Daughtrey Margery L. , Lockhart Ben E.
Published: May 2007

A filamentous virus identified in coleus (Coleus × hybrida) in Minnesota and New York was found to cause veinal necrosis in coleus, although this symptom was observed only under certain conditions. The virus was transmitted readily by mechanical inoculation to coleus and Nicotiana spp. and was not transmitted by Myzus persicae. The particles of the coleus virus had a modal length of 640 nm and a single capsid protein with an estimated molecular mass of 34 kDa. The amino acid sequence of the coat protein region of the coleus virus genome had significant similarities only to the corresponding domain of carlaviruses. Based on virion morphology, capsid protein size, genome size and organization, amino acid sequence, and phylogenetic analyses, the coleus virus, which was named provisionally Coleus vein necrosis virus (CVNV), was concluded to be a new definitive member of the genus Carlavirus. A 2-kb fragment of the 3′ terminus of the CVNV genome sequence is accessible under accession number DQ915963 in GenBank.
First Report of Myrothecium roridum Causing Myrothecium Leaf Spot on Salvia spp. in the United States
Authors: Mangandi J. A. , Seijo T. E. , Peres N. A.
Published: May 2007

The genus Salvia includes at least 900 species distributed worldwide. Wild species are found in South America, southern Europe, northern Africa, and North America. Salvia, commonly referred to as sage, is grown commercially as a landscape plant. In August 2006, pale-to-dark brown, circular leaf spots 5 to 20 mm in diameter with concentric rings were observed on Salvia farinacea ‘Victoria Blue’. Approximately 5% of the plants in a central Florida nursery were affected. Lesions were visible on both leaf surfaces, and black sporodochia with white, marginal hyphal tuffs were present mostly on the lower surface in older lesions. Symptoms were consistent with those of Myrothecium leaf spot described on other ornamentals such as gardenia, begonia, and New Guinea impatiens (4). Isolations from lesions on potato dextrose agar produced white, floccose colonies with sporodochia in dark green-to-black concentric rings. Conidia were hyaline and cylindrical with rounded ends and averaged 7.4 × 2.0 μm. All characteristics were consistent with the description of Myrothecium roridum Tode ex Fr. (2,3). The internal transcribed spacer regions ITS1, ITS2, and the 5.8s rRNA genomic region of one isolate were sequenced (Accession No. EF151002) and compared with sequences in the National Center for Biotechnology Information (NCBI) database. Deposited sequences from M. roridum were 96.3 to 98.8% homologous to the isolate from salvia. To confirm pathogenicity, three salvia plants were inoculated by spraying with a conidial suspension of M. roridum (1 × 105 conidia per ml). Plants were covered with plastic bags and incubated in a growth chamber at 28°C for 7 days. Three plants were sprayed with sterile, distilled water as a control and incubated similarly. The symptoms described above were observed in all inoculated plants after 7 days, while control plants remained symptomless. M. roridum was reisolated consistently from symptomatic tissue. There are more than 150 hosts of M. roridum, including one report on Salvia spp. in Brunei (1). To our knowledge, this is the first report of Myrothecium leaf spot caused by M. roridum on Salvia spp. in the United States. Even the moderate level disease present caused damage to the foliage and reduced the marketability of salvia plants. Therefore, control measures may need to be implemented for production of this species in ornamental nurseries.

References: (1) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory. Online publication. ARS, USDA, 2006, (2) M. B. Ellis. Page 449 in: Microfungi on Land Plants: An Identification Handbook. Macmillan Publishing, NY, 1985. (3) M. Fitton and P. Holliday. No. 253 in: CMI Descriptions of Pathogenic Fungi and Bacteria. The Eastern Press Ltd. Great Britain, 1970. (4) M. G. Daughtrey et al. Page 19 in: Compendium of Flowering Potted Plant Diseases. The American Phytopathological Society. St. Paul, MN, 1995.
A Combination of Phenotypic and Genotypic Characterization Strengthens Pyrenophora tritici-repentis Race Identification
Authors: Andrie Rachael M. , Pandelova Iovanna , Ciuffetti Lynda M.
Published: May 2007

Pyrenophora tritici-repentis, causal agent of tan spot of wheat, produces multiple host-selective toxins (HSTs), including Ptr ToxA, Ptr ToxB, and Ptr ToxC. The specific complement of HSTs produced by a particular isolate determines its host cultivar specificity. Each unique specificity profile, represented by the differential induction of necrosis or chlorosis on a standard set of wheat differentials, defines a unique race. Eight races of P. tritici-repentis have been formally published, although additional races are under investigation. Although visual assessment of disease phenotype is often used in race designation of P. tritici-repentis, our results suggest that it has the potential to be misleading. Inoculation of the P. tritici-repentis isolates SO3 and PT82 on the current wheat differential set indicated classification as race 2 and race 8, respectively; however, genetic characterization revealed that these isolates do not possess the associated HSTs expected for these race assignments. Despite sharing disease phenotypes similar to known races, SO3 and PT82 were genotypically distinct from these previously characterized races of P. tritici-repentis. To ensure detection of the breadth of physiological variation among the isolates of P. tritici-repentis, our results indicate that race classification, where possible, should include both phenotypic and genotypic analyses and eventual expansion of the differential set.
Retention of Rice dwarf virus by Descendants of Pairs of Viruliferous Vector Insects After Rearing for 6 Years
Authors: Honda Kazuto , Wei Taiyun , Hagiwara Kyoji , Higashi Takahiko , Kimura Ikuo , Akutsu Katsumi , Omura Toshihiro
Published: May 2007

Rice dwarf virus (RDV) is characterized by its unusual ability to multiply in both plants and leafhopper vector insects and by its transovarial mode of transmission. Colonies of Nephotettix cincticeps, derived originally from pairs of leafhoppers infected with an ordinary strain of RDV, were maintained for 6 years in the laboratory and were found, at the end of this time, still to harbor RDV. Moreover, the isolate of RDV, designated RDV-I, obtained from these colonies retained the ability to infect rice plants. When we raised leafhoppers separately from eggs that had been placed individually on pieces of water-soaked filter paper and reared them in the presence of healthy rice seedlings, we found that all of these leafhoppers harbored RDV. This observation suggested that RDV-I had been maintained in the leafhoppers by transovarial transmission. Two further observations, namely, the low rate of acquisition of RDV by virus-free insect nymphs on symptomless plants on which viruliferous insects had been reared, and the fact that only 2 to 5% of plants had symptoms when rice seedlings were inoculated via RDV-I-viruliferous insects, confirmed that the maintenance of RDV-I by any other mode of transmission through plants and insects was unlikely. This efficient and long-term maintenance of RDV in a population of viruliferous insects might explain the prolonged duration of rice dwarf disease in the field, once there has been a serious outbreak.
The CC-NBS-LRR Subfamily in Pinus monticola: Targeted Identification, Gene Expression, and Genetic Linkage with Resistance to Cronartium ribicola
Authors: Liu Jun-Jun , Ekramoddoullah Abul K. M.
Published: May 2007

To investigate disease resistance gene analogs (RGAs) encoding coiled-coil-nucelotide-binding site-leucine-rich repeats (CC-NBS-LRR) proteins in western white pine, degenerate primers targeting the conserved motifs in the NBS domain were designed to amplify RGAs from genomic DNA and cDNA. Sixty-one distinct RGAs were identified with identities to well-known R proteins of the CC-NBS-LRR subfamily. These RGAs exhibited variation of putative amino acid sequences from 13% to 98%, representing a complex CC-NBS-LRR subfamily. A phylogenetic tree constructed from the amino acid sequence alignment revealed that these 61 RGAs were grouped with other CC-NBS-LRR members from angiosperms, and could be further divided into six classes with an identity threshold of 68%. To map RGAs, RGA polymorphisms and a modified amplified fragment length polymorphism (AFLP) method with incorporated sequences from the NBS domain were used to reveal NBS or NBS-AFLP markers. RGA polymorphism study revealed that three off the identified RGAs were not linked to the Cr2 gene imparting resistance to white pine blister rust. However, the AFLP strategy, using bulk segregant analysis (BSA) and haploid segregation analysis, identified 11 NBS-AFLP markers localized in the Cr2 linkage, the closest two to the gene being 0.41 cM and 1.22 cM away at either side. Eight of these markers showed significant amino acid sequence homologies with RGAs.
How complete can cervical screening be? The outcome of a call screening programme for women aged 20–60 years in Perth and Kinross
Authors: ROBERTSON A. J. , REID G. S. , STOKER C. A. , BISSETT C. , WAUGH N. , FENTON I , ROWAN J. , HALKERSTON R.
Published: May 2007

In this paper a computer system for cervical screening call and recall based on the Community Health Index (CHI) population data‐base is described. It allows the unscreened population to be identified and located on an individual general practice basis. The results of the call programme on 9517 women aged 20–60 years listed on the CHI and with no record of a cervical smear is described. There was a 24% smear uptake in the call programme which meant that after the call programme the total population cover had risen from 71% to 78%. In addition, if women with a valid reason are excluded, and the data‐base corrected for women no longer in the area, the true cover rises to 88%. An analysis of the percentage cover in each GP practice is described with the implications for implementation of screening targets for primary care.
Amphicrine carcinoma of the lung. Diagnosis by fine needle aspiration cytology
Authors: REDDY V. , GATTUSO P. , REYES C. V. , CHINOY M.
Published: May 2007

A case of pulmonary carcinoma with dual (glandular and endocrine) differentiation diagnosed by fine needle aspiration cytology is reported. By light microscopy, the neoplastic cells showed mucicarmine, periodic‐acid Schiff, and Grimelius silver positivity. On immunostaining, neuron specific enolase, chromogranin, calcitonin and serotonin were demonstrated. Electron microscopy revealed two different types of distinctive cytoplasmic inclusions in the same cell, namely: carcinoid type of neurosecretory granules and mucin droplets. Diagnostic criteria and possible histogenesis of this rare tumour entity are discussed.
Cervical screening performance in general practice. An evaluation in a single health district
Authors: HAVELOCK C. M.
Published: May 2007

This paper describes a study of cervical screening in 50 general practices in the East Berkshire Health District over a period of 2½ years. Six practices organized their own practice based screening scheme. Thirty‐nine participated in a district organized scheme and five did not actively participate in any scheme.

The proportion of women screened was highest among the practices which organized their own scheme. These practices were large, in non‐urban locations and employed a practice nurse. In contrast, practices which had a poor record of screening were small, single handed, in an urban location and were unwilling to participate in a district call scheme or organize their own scheme.

It is recommended that the practices which are prepared to organize their own screening programmes should be encouraged to do so. The resources which are saved could then be more usefully spent on providing assistance to the practices which do not offer a cervical screening service to women on their practice lists.
Cytology of colorectal adenomas
Authors: TIDBURY P. J. , TATE J. J. T. , HERBERT A.
Published: May 2007

A study of the cytological appearances of benign and malignant colorectal adenomatous polyps is reported. The aim of the study was to characterize the cytological features of adenomatous polyps and predict the likelihood of malignancy using cytology. A five grade classification of colorectal cytology has been developed and the characteristic appearances of cells from adenomatous polyps are described. The reproducibility of cytological diagnosis based on this classification has been tested in 120 smears from normal mucosa and adenomatous polyps (including polyp cancers). Correlation with histology was achieved in 88% and correlation of the cytological diagnosis between two observers was achieved in 84%. We conclude that cytology can be used reliably as an adjunct to histology in the assessment of malignancy of adenomatous polyps.
Evaluation of fine needle aspiration of the male breast for the diagnosis of gynaecomastia
Authors: MARTIN‐BATES E. , KRAUSZ T. , PHILLIPS I.
Published: May 2007

Fine needle aspiration of the male breast can present problems of diagnosis because the cytological presentation of gynaecomastia can be confused with that of adenocarcinoma. We reviewed breast aspirates from 24 male patients in order to determine the accuracy of cytology as a method of diagnosing gynaecomastia.

Discrepancies were observed between the original cytology reports on one hand and the review cytology and biopsies on the other. Of the 24 aspirates from the male breast, the cytology was reported as negative in 16 cases, suspicious in three cases and malignant in five. In four cases of the negative group, a specific diagnosis of gynaecomastia was made. In two of the negative cases the subsequent biopsies revealed adenocarcinoma. Of the five cases reported on the original cytology as adenocarcinoma, two on review showed the features of florid gynaecomastia and this was confirmed on biopsy and three confirmed the initial diagnosis of adenocarcinoma.

The cytological features of gynaecomastia which distinguish it from adenocarcinoma are discussed.
Extraction of DNA from exfoliative cytology specimens and its suitability for analysis by the polymerase chain reaction
Authors: JACKSON D. P. , PAYNE J. , BELL S. , LEWIS F. A. , TAYLOR G. R. , PEEL K. R. , SUTTON J. , QUIRKE P.
Published: May 2007

The extraction of DNA from archival exfoliative cytology samples would allow the molecular biological analysis of this readily available material using the polymerase chain reaction (PCR). We have quantitatively and qualitatively studied the extraction of DNA from a variety of cytological preparations.

For both fresh and archival cervical smears, overnight incubation with proteinase K produces high yields of high molecular weight DNA, but simply boiling the samples produces DNA suitable for PCR amplification of a single copy gene.

Increasing the proteinase K incubation to several days allows the extraction of DNA from fixed and stained archival cytology slides from a variety of sites. The extracted DNA was again suitable for PCR analysis.

Fresh and archival cytological material can be utilized for molecular biological study of disease processes using PCR. Archival cytological material is probably the best source of DNA and RNA after stored frozen tissue.
Detection of human papillomavirus (HPV) in genital warts and carcinomas by DNA in situ hybridization in Chinese patients
Authors: CHANG F. , SYRJÄNEN S. , SHEN Q. , JI H. , SYRJÄNEN K.
Published: May 2007

A series of 51 genital biopsies from normal epithelium, condylomata acuminata, leucoplakia and squamous cell carcinoma from Chinese male and female patients were analysed for the presence of human papillomavirus (HPV) types 6, 11, 16 and 18 by DNA in situ hybridization. All of the nine genital condyloma acuminata were positive for HPV DNA, in which HPV 6 was found in six cases, HPV 11 in two cases and HPV 18 in one case. Twelve out of the 21 cases (57.1% of the total) of cervical squamous cell carcinoma were shown to contain HPV DNA; HPV 16 was found in nine cases, HPV 18 in two cases and HPV 16/18 in one case. Present results support the earlier concept that HPV 6/11 are closely associated with benign genital lesions, and HPV 16/18 are mostly confined to higher grade of intra‐epithelial neoplasias and carcinoma.
The number of nucleoli in benign and malignant thyroid lesions: a useful diagnostic sign in cytological preparations*
Authors: MONTIRONI R. , BRACCISCHI A. , SCARPELLI M. , SISTI S. , MATERA G. , MARIUZZI G. M. , ALBERTI R. , COLLAN Y.
Published: May 2007

The slides of fine needle aspiration cytology specimens from 99 cases of cold thyroid nodules with known histology were reviewed and the number of nucleoli per nucleus counted and correlated with the different histopathological groups. Significant differences were observed between benign and malignant thyroid lesions in the number of nucleoli in the cytological material. Lower values were present in nodular goitres and follicular adenomas compared to carcinomas. In benign lesions the majority of nuclei contained one nucleolus and nuclei with two, three or more nucleoli were less frequent than in follicular, papillary, medullary and anaplastic carcinomas. Only one case of follicular adenoma had cells containing three or more nucleoli compared to more than half the cases of follicular carcinoma.