bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative analysis of parasite DNA in the blood of immunized and naïve mice after infection with Neospora caninum
Authors: PINITKIATISAKUL S. , MATTSSON J. G. , LUNDÉN* A.
Published: October 2007

Real-time PCR was used to study the duration and level of parasitaemia in mice immunized with immune-stimulating complexes (iscoms) containing recombinant NcSRS2, one of the immunodominant surface antigens of Neospora caninum. After challenge infection, blood was collected daily for 9 days. During this period the amounts of parasite DNA detected in immunized mice were significantly lower (P<0·001), and the duration of parasitaemia appeared to be shorter, than in non-immunized controls. Furthermore, the degree of parasitaemia seemed to correlate well with the amount of N. caninum DNA in the brain 3 weeks post-inoculation and with disease severity measured as changes in body weight. These results indicate that the protective immunity induced by the NcSRS2-iscoms was sufficient to reduce the level of parasitaemia, which probably reduced the number of parasites reaching the brain, and could be the reason for the reduction in brain parasite load and clinical symptoms. Furthermore, real-time PCR was found to be a sensitive means for rapid assessment of N. caninum in blood.
Measuring depression: comparison and integration of three scales in the GENDEP study
Authors: Uher R. , Farmer A. , Maier W. , Rietschel M. , Hauser J. , Marusic A. , Mors O. , Elkin A. , Williamson R. J. , Schmael C. , Henigsberg N. , Perez J. , Mendlewicz J. , Janzing J. G. E. , Zobel A. , Skibinska M. , Kozel D. , Stamp A. S. , Bajs M. , Placentino A. , Barreto M. , McGuffin P. , Aitchison K. J.
Published: October 2007

Background

A number of scales are used to estimate the severity of depression. However, differences between self-report and clinician rating, multi-dimensionality and different weighting of individual symptoms in summed scores may affect the validity of measurement. In this study we examined and integrated the psychometric properties of three commonly used rating scales.

Method

The 17-item Hamilton Depression Rating Scale (HAMD-17), the Montgomery–Asberg Depression Rating Scale (MADRS) and the Beck Depression Inventory (BDI) were administered to 660 adult patients with unipolar depression in a multi-centre pharmacogenetic study. Item response theory (IRT) and factor analysis were used to evaluate their psychometric properties and estimate true depression severity, as well as to group items and derive factor scores.

Results

The MADRS and the BDI provide internally consistent but mutually distinct estimates of depression severity. The HAMD-17 is not internally consistent and contains several items less suitable for out-patients. Factor analyses indicated a dominant depression factor. A model comprising three dimensions, namely ‘observed mood and anxiety’, ‘cognitive’ and ‘neurovegetative’, provided a more detailed description of depression severity.

Conclusions

The MADRS and the BDI can be recommended as complementary measures of depression severity. The three factor scores are proposed for external validation.
HIV subtypes in Scotland, 2000–2006
Authors: YIRRELL D. L. , SHAW L. , CAMPBELL E. , BURNS S. M. , CAMERON S. O. , GOLDBERG D.
Published: October 2007

The purpose of this study was to document the dynamics of HIV-1 subtypes in Scotland over a 6-year period. Viral RNA from all-new diagnoses was amplified by nested PCR and sequenced in the gag and/or env regions. Subtype was assigned by phylogenetic analysis, and aligned with demographic data including likely route and geographical origin of infection. We present data on 80% of all new diagnoses in Scotland between April 2000 and April 2006. Within the background of an expanding epidemic, subtype B predominates in men who have sex with men and intravenous drug users but there is a small but consistent number of UK-acquired infections in these risk groups caused by non-B subtypes. In heterosexuals, non-B subtypes acquired abroad, especially Africa, are still the largest group but again UK-acquired numbers are rising. The social and clinical significance of the spread of non-B subtypes in different ethnic and risk groups remains to be established.
Successes and failures: an overview of lessons learnt in the creation of targeted therapy strategies for breast cancer
Authors: Johnston S. R. D.
Published: October 2007

Therapies that target cancers according to their characteristics (estrogen receptor +ve or –ve, for example) have been a major development in treating cancers successfully and have led to an increase in survival rates. These successes have led to increased research into even more tightly focused therapies. But targeted therapies do not work for everyone, raising issues of (1) identifying patients and (2) developing therapies that reflect our increasing understanding of the complex and differentiated traits of tumors. New targeted therapies such as small molecule signal transduction inhibitors and monoclonal antibodies are being developed to address tumors at all stages of the cell proliferation cycle and it is hoped that they may eventually transform cancer into a fully treatable condition.
Review of:Estrogen receptor β expression is associated with tamoxifen response in ERα-negative breast carcinoma
Authors: Murphy L.
Published: October 2007

Citation of original article:

S. K. Gruvberger-Saal, P.-O. Bendahl, L. H. Saal, M. Laakso, C. Hegardt, P. Edeén, C. Peterson, P. Malmström, J. Isola, A. Borg, M. Fernoö.Clinical Cancer Research2007;13: 1987–1994.

Abstract of the original article:

Purpose

Endocrine therapies, such as tamoxifen, are commonly given to most patients with estrogen receptor (ERα)-positive breast carcinoma but are not indicated for persons with ERα-negative cancer. The factors responsible for response to tamoxifen in 5% to 10% of patients with ERα-negative tumors are not clear. The aim of the present study was to elucidate the biology and prognostic role of the second ER, ERβ, in patients treated with adjuvant tamoxifen.

Experimental design

We investigated ERβ by immunohistochemistry in 353 stage II primary breast tumors from patients treated with 2 years adjuvant tamoxifen, and generated gene expression profiles for a representative subset of 88 tumors.

Results

ERβ was associated with increased survival (distant disease-free survival,P= 0.01; overall survival,P= 0.22), and in particular within ERα-negative patients (P= 0.003;P= 0.04), but not in the ERα-positive subgroup (P= 0.49;P= 0.88). Lack of ERβ conferred early relapse (hazards ratio, 14; 95% confidence interval, 1.8–106;P= 0.01) within the ERα-negative subgroup even after adjustment for other markers. ERα was an independent marker only within the ERβ-negative tumors (hazards ratio, 0.44; 95% confidence interval, 0.21–0.89;P= 0.02). An ERβ gene expression profile was identified and was markedly different from the ERα signature.

Conclusion

Expression of ERβ is an independent marker for favorable prognosis after adjuvant tamoxifen treatment in ERα-negative breast cancer patients and involves a gene expression program distinct from ERα. These results may be highly clinically significant, because in the United States alone, approximately 10 000 women are diagnosed annually with ERα-negative/ERβ-positive breast carcinoma and may benefit from adjuvant tamoxifen.
Cell‐Free Protein Synthesis in Microfluidic Array Devices
Authors: Mei Qian , Fredrickson Carl K. , Simon Andrew , Khnouf Ruba , Fan Z. Hugh
Published: October 2007

We report the development of a microfluidic array device for continuous‐exchange, cell‐free protein synthesis. The advantages of protein expression in the microfluidic array include (1) the potential to achieve high‐throughput protein expression, matching the throughput of gene discovery; (2) more than 2 orders of magnitude reduction in reagent consumption, decreasing the cost of protein synthesis; and (3) the possibility to integrate with detection for rapid protein analysis, eliminating the need to harvest proteins. The device consists of an array of units, and each unit can be used for production of an individual protein. The unit comprises a tray chamber for in vitro protein expression and a well chamber as a nutrient reservoir. The tray is nested in the well, and they are separated by a dialysis membrane and connected through a microfluidic connection that provides a means to supply nutrients and remove the reaction byproducts. The device is demonstrated by synthesis of green fluorescent protein, chloramphenicol acetyl‐transferase, and luciferase. Protein expression in the device lasts 5–10 times longer and the production yield is 13–22 times higher than in a microcentrifuge tube. In addition, we studied the effects of the operation temperature and hydrostatic flow on the protein production yield.
Dark Hydrogen Fermentation from Hydrolyzed Starch Treated with Recombinant Amylase Originating from Caldimonastaiwanensis On1
Authors: Chen Shing‐Der , Sheu Der‐Shyan , Chen Wen‐Ming , Lo Yung‐Chung , Huang Tian‐I , Lin Chiu‐Yue , Chang Jo‐Shu
Published: October 2007

Starch is one of the most abundant resources on earth and is suited to serve as a cost‐effective feedstock for biological hydrogen production. However, producing hydrogen from direct fermentation of starch is usually inefficient, as the starch hydrolysis is often the rate‐limiting step. Therefore, in the present work, enzymatic starch hydrolysis was conducted to enhance the feasibility of using starch feedstock for H2 production. The amylase (with a molecular weight of ca. 112 kDa) used for starch hydrolysis was produced from a recombinant E. coli harboring an amylase gene originating from Caldimonas taiwanensis On1. Using statistical experimental design, the optimal pH and temperature for starch hydrolysis with the recombinant amylase was pH 6.86 and 52.4 °C, respectively, at an initial starch concentration of 7 g/L. The hydrolyzed products contained mainly glucose, maltotriose, and maltotetrose, while a tiny amount of maltose was also detected. The enzymatically hydrolyzed products of soluble starch and cassava starch were used as the substrate for dark hydrogen fermentation using Clostridium butyricum CGS2 and Clostridium pasteurianum CH4. The highest H2 production rate (vH2) and yield (YH2) of C. butyricum CGS2 was 124.0 mL/h/L and 6.32 mmol H2/g COD, respectively, both obtained with the hydrolysate of cassava starch. The best H2 production rate (63.0 mL/h/L) of C. pasteurianum CH4 occurred when using hydrolyzed cassava starch as the substrate, whereas the highest yield (9.95 mmol H2/g COD) was obtained with the hydrolyzed soluble starch.
Amaurosis fugax mit erhöhten Akutphasenproteinen
Authors: Tappeiner  , Wolf  , Trittibach
Published: October 2007

Fallbericht einer 66-jährigen Patientin mit Amaurosis-fugax-Episoden und Halbseitenkopfschmerz, aber ansonsten regelrechten ophthalmologischen und neurologischen Befunden und unauffälliger Bildgebung. Im Gegensatz zur normalen Blutsenkungsgeschwindigkeit waren die Akutphasenproteine (C-reaktives Protein und Fibrinogen) erhöht. Die vermutete Riesenzellarteritis konnte durch eine Temporalarterien-Biopsie histologisch gesichert werden. Die Riesenzellarteritis sollte als wichtige Differentialdiagnose bei unklarer Amaurosis fugax auch bei normaler Blutsenkung in Betracht gezogen werden; Akutphasenproteine (C-reaktives Protein, Fibrinogen) können diagnostisch hilfreich sein.
On the electromagnetic field singularities near the vertex of a dielectric wedge
Authors: Budaev Bair V. , Bogy David B.
Published: October 2007

The problem of electromagnetic scattering by a dielectric wedge has attracted attention recently because of reported disagreement between the theory and numerical experiments concerning a certain behavior of the fields near the wedge vertex. The goal of this paper is to show that what is reported has been not a disagreement but a misinterpretation of the existing theory, which predicts all of the numerically observed effects.
Creep on the Rodgers Creek fault, northern San Francisco Bay area from a 10 year PS‐InSAR dataset
Authors: Funning Gareth J. , Bürgmann Roland , Ferretti Alessandro , Novali Fabrizio , Fumagalli Alfio
Published: October 2007

Deformation in the northern San Francisco Bay area is dominated by a series of sub‐parallel strike‐slip faults. Existing GPS observations provide some constraint on the slip rates of these faults, however these have only limited resolution for resolving shallow fault behavior, such as brittle creep. We use a 30 image Permanent Scatterer InSAR (PS‐InSAR) dataset spanning the time interval 1992–2001 to dramatically increase the density of surface deformation observations. We find a discontinuity in observed surface velocities across the Rodgers Creek fault, around Santa Rosa and further north, consistent with shallow creep at rates of up to 6 mm/yr. The creeping segments are located in areas of local transtension, suggesting that lowered normal stresses may play a role in the distribution of creep. The existence of creep could significantly reduce expected moment release in future earthquakes on the Rodgers Creek fault, and thus has implications for seismic hazard assessment.
Quantitative estimates of magnetic field reconnection properties from electric and magnetic field measurements
Authors: Mozer F. S. , Retinò A.
Published: October 2007

Reconnection occurs in a reconnection magnetic field geometry when there are positive electric field components tangential to the magnetopause and a magnetic field component normal to it. Because these three components are the smallest of the six electric and magnetic fields, their magnitudes are difficult to determine because of errors in, or oscillations of, the assumed constant direction normal to the current sheet. A method is described for minimizing these errors by appropriate selection of the normal direction and by analyzing the correlations between the large normal electric field and the large tangential magnetic field. The correlation coefficients are equal to ratios of the small fields, which are combined with the less accurate measurements of the averages of the small fields to produce best estimates of the small fields. For more than 120 magnetopause crossings, about 40% had such correlations that signify static conditions during those crossings. This method is applied to 22 polar subsolar magnetopause crossings to show that most were located in the ion diffusion region, as defined by the change of the total magnetic field, and that 14 had a large and steady reconnection rate with a zero parallel electric field. In these events the reconnection rate decreased with increasing guide magnetic field.
Rheological study of transient networks with junctions of limited multiplicity. II. Sol/gel transition and rheology
Authors: Indei Tsutomu
Published: October 2007

Viscoelastic and thermodynamic properties of transient gels formed by telechelic associating polymers are studied on the basis of the transient network theory that considers the correlation among polymer chains via network junctions. The global information of the gel is incorporated into the theory by introducing elastically effective chains defined according to the criterion of Scanlan [J. Polym. Sci. 43, 501 (1960)] and Case [J. Polym. Sci. 45, 397 (1960)]. We also consider the effects of superbridges whose backbone is formed by several chains connected in series and containing several breakable junctions. The dynamic shear moduli of this system are well described in terms of the Maxwell model characterized by a single relaxation time and high-frequency plateau modulus. Near the critical concentration at the sol/gel transition, superbridges become infinitely long along the backbone, thereby leading to a short relaxation time τ for the network. It is shown that τ is proportional to the concentration deviation Δ near the gelation point. The plateau modulus G∞ increases as the cube of Δ near the gelation point as a result of the mean-field treatment, and hence the zero-shear viscosity increases as η0∼G∞τ∼Δ4. The present model can explain the concentration dependence of the dynamic moduli observed for aqueous solutions of telechelic poly(ethylene oxide).
Theory of ultrafast nonresonant multiphoton transitions in polyatomic molecules: Basics and application to optimal control theory
Authors: May Volkhard , Ambrosek David , Oppel Markus , González Leticia
Published: October 2007

A systematic approach is presented to describe nonresonant multiphoton transitions, i.e., transitions between two electronic states without the presence of additional intermediate states resonant with the single-photon energy. The method is well suited to describe femtosecond spectroscopic experiments and, in particular, attempts to achieve laser pulse control of molecular dynamics. The obtained effective time-dependent Schrödinger equation includes effective couplings to the radiation field which combine powers of the field strength and effective transition dipole operators between the initial and final states. To arrive at time-local equations our derivation combines the well-known rotating wave approximation with the approximation of slowly varying amplitudes. Under these terms, the optimal control formalism can be readily extended to also account for nonresonant multiphoton events. Exemplary, nonresonant two- and three-photon processes, similar to those occurring in the recent femtosecond pulse-shaping experiments on CpMn(CO)3, are treated using related ab initio potential energy surfaces.
Rim instability by solvent-induced dewetting
Authors: Xu Lin , Shi Tongfei , Dutta P. K. , An Lijia
Published: October 2007

We study the condition of the occurrence of the rim instability in the solvent-induced dewetting process. Our experimental results show that the film thickness not only greatly influences the occurrence of the rim instability, but also influences the wavelength λ as characterized by the undulation of the deformed contact line. The molecular weight of polymer does not almost influence the occurrence of the rim instability and the wavelength λ. The wavelength λ is proportional to the width of the rim in the rim instability region. The receding contact angle θ of polymer solutions on substrates in the dewetting process is an important factor to influence the rim instability in the solvent-induced dewetting.
Cluster kinetics model for mixtures of glassformers
Authors: Brenskelle Lisa A. , McCoy Benjamin J.
Published: October 2007

For glassformers we propose a binary mixture relation for parameters in a cluster kinetics model previously shown to represent pure compound data for viscosity and dielectric relaxation as functions of either temperature or pressure. The model parameters are based on activation energies and activation volumes for cluster association-dissociation processes. With the mixture parameters, we calculated dielectric relaxation times and compared the results to experimental values for binary mixtures. Mixtures of sorbitol and glycerol (seven compositions), sorbitol and xylitol (three compositions), and polychloroepihydrin and polyvinylmethylether (three compositions) were studied.
Simulating critical dynamics in liquid mixtures: Short-range and long-range contributions
Authors: Das Subir K. , Sengers Jan V. , Fisher Michael E.
Published: October 2007

Recently, Das et al. [J. Chem. Phys. 125, 024506 (2006)] established that computer simulations of critical dynamics in a binary Lennard-Jones mixture are consistent with the predicted Stokes-Einstein behavior of the asymptotic decay rate of the order-parameter fluctuations near criticality. Here, we show that the noncritical or “background” contributions to the computed diffusion coefficient are also in agreement with both theory and experiment, thus further validating the feasibility of molecular dynamics simulations for studying dynamic critical behavior.
Molecular simulation of the crystallization of aluminum from the supercooled liquid
Authors: Desgranges Caroline , Delhommelle Jerome
Published: October 2007

We report hybrid Monte Carlo molecular simulation results on the crystallization of aluminum from the supercooled liquid. We simulate the entire crystallization process at P=1atm and at temperatures 20% and 15% below the melting temperature. We demonstrate that crystallization takes place according to the same mechanism for the two degrees of supercooling considered in this work. We show that both nucleation and growth proceed into a random mixing of the hexagonal close packed structure and of the face centered cubic (fcc) phase, with a predominance of the stable fcc form. The concentration of icosahedral (Ih)-like atoms in the supercooled liquid is found to remain constant throughout nucleation and growth, showing that Ih-like atoms do not play an active role in the crystallization process. We also find that the crystallization mechanism of aluminum differs from that observed for simple fluids. While nucleation of simple fluids first proceeds into the metastable body centered cubic (bcc) phase, the fraction of bcc-like atoms in aluminum crystallites always remains very low.
Morphology and luminescence properties of zinc oxide nanopowders doped with aluminum ions obtained by hydrothermal and vapor condensation methods
Authors: Strachowski T. , Grzanka E. , Lojkowski W. , Presz A. , Godlewski M. , Yatsunenko S. , Matysiak H. , Piticescu R. R. , Monty C. J.
Published: October 2007

In this paper, we analyze the influence of Al doping on microstructure and light emission efficiency of ZnO nanoparticles obtained by the hydrothermal method and after vapor condensation method, where vaporization of the precursor powders was caused by high solar energy and subsequent deposition. We report an increase of lattice parameters with increasing level of doping as well as large emission enhancement, which we relate to surface passivation of recombination mechanisms and/or plasmon mechanism of photoluminescence stimulation.
Comparative study of trap densities of states in CdTe∕CdS solar cells
Authors: Proskuryakov Y. Y. , Major J. D. , Durose K. , Barrioz V. , Irvine S. J. C. , Jones E. W. , Lamb D.
Published: October 2007

Density of deep and shallow states has been investigated in three different kinds of CdTe∕CdS samples, two of which were grown by metal-organic chemical vapor deposition (MOCVD) and one by close-space sublimation (CSS) methods. The MOCVD samples were p doped by As and grown either with or without a ZnO buffer layer between the transparent conductor and CdS layers. Capacitance-voltage, admittance spectroscopy, and quantum efficiency measurements show pronounced effects of As doping and ZnO incorporation. It is found that A centers and vacancies of Cd, usually observed in CSS devices, are absent in the defect spectra of MOCVD samples.
Dissipation equals production in the log layer of wall-induced turbulence
Authors: Brouwers J. J. H.
Published: October 2007

Asymptotic analysis is presented of the energy balance equations derived from statistically averaged Navier-Stokes equations pertinent to wall-induced turbulence. Attention is focused on the inertial sublayer, the region outside the viscous sublayer, and the buffer layer where the log-law for mean flow holds. Production and dissipation of turbulence are shown to be equal with a relative error of O(x2∕L), where x2 is the distance from the wall and L is the external length (pipe radius, channel half-height, boundary layer thickness). Diffusion of pressure and kinetic energy together are only of relative magnitude O(x2∕L). Pressure gradient terms are shown to redistribute longitudinal turbulence production in equal portions dissipated in the three orthogonal directions.
Determination of structural transitions of atomic clusters from local and global bond orientational order parameters
Authors: Zhan Lixin , Chen Jeff Z. Y. , Liu Wing-Ki
Published: October 2007

Designing an effective order parameter for the identification of geometries in atomic clusters is an important step toward understanding the structural transitions occurring in these systems. We propose a method that simultaneously utilizes the local and global bond orientational order parameters for structural transitions. When applied to Lennard–Jones clusters at finite temperature over the size range 30≤N≤146, this method identified all the major geometries: icosahedra with Mackay overlayers, icosahedra with anti-Mackay overlayers, decahedra, octahedra, and tetrahedra. From the distributions of these geometries as a function of temperatures on clusters containing 38, 75, and 98 atoms, we are able to interpret all transition types without ambiguity.
Epitaxial growth mechanisms of AlN on SiC substrates at room temperature
Authors: Kim Myunghee , Ohta Jitsuo , Kobayashi Atsushi , Fujioka Hiroshi , Oshima Masaharu
Published: October 2007

Epitaxial AlN films have been grown on atomically flat 6H-SiC (0001) and 4H-SiC (0001) substrates at room temperature (RT), and their growth mechanisms have been investigated. It has been revealed that the growth of AlN at RT proceeds in a layer-by-layer mode from the initial stage. During the growth, AlN nucei have an equilateral triangular shape probably due to the anisotropy in growth rates. The triangular AlN nuclei at the adjacent terraces formed on the 6H-SiC substrates are rotated by 60°, whereas the triangular AlN nuclei on the 4H-SiC were formed in the same direction on all of the terraces. This phenomenon can be explained by the difference in the arrangement of the atoms for the topmost layers.
Recent Advances in Microwave-Assisted Polymer Synthesis
Authors: Sinnwell Sebastian , Ritter Helmut
Published: October 2007

In the past few years the use of microwave irradiation in polymer science has become a well-established technique to drive and promote chemical reactions. The main advantages of microwave heating are a strong reduction in reaction time and a high potential to contribute to green and sustainable chemistry. This article provides a short review of recent examples in the field of microwave-assisted polymer synthesis with special emphasis on radical polymerizations, step-growth polymerizations, ring-opening polymerizations, and polymer modifications.
Chain-Length-Dependent Termination in Acrylate Radical Polymerization Studied via Pulsed-Laser-Initiated RAFT Polymerization
Authors: Buback Michael , Hesse Pascal , Junkers Thomas , Theis Thomas , Vana Philipp
Published: October 2007

The chain-length dependence of the termination rate coefficient, kt, in methyl acrylate (MA) and dodecyl acrylate (DA) radical polymerization has been determined via the single pulse pulsed-laser polymerization near-infrared reversible addition–fragmentation chain transfer (SP-PLP-NIR-RAFT) technique. Polymerization is induced by a laser SP and the resulting decay in monomer concentration, cM, is monitored via NIR spectroscopy with a time resolution of microseconds. A RAFT agent ensures the correlation of radical chain length and monomer-to-polymer conversion. The obtained rate coefficients for termination of two radicals of approximately the same chain length, i, are represented by power-law expressions, kt(i,i) ∝ i–α. For both monomers, composite model behaviour of kt(i,i) showing two distinct chain length regimes is observed. The exponent αs referring to short chain lengths is close to unity, whereas the exponent αl, which characterizes the chain-length dependency of large radicals, is slightly above the theoretical value for coiled chain-end radicals. The crossover chain length, ic, which separates the two regions, decreases from MA (ic = 30) to DA (ic = 20). The results for MA and DA are consistent with earlier data reported for butyl acrylate. There appears to be a correlation of αs and ic with chain flexibility.
Toxins in transgenic crop byproducts may affect headwater stream ecosystems
Authors: Rosi-Marshall E. J. , Tank J. L. , Royer T. V. , Whiles M. R. , Evans-White M. , Chambers C. , Griffiths N. A. , Pokelsek J. , Stephen M. L.
Published: October 2007

Corn (
Zea mays
L.) that has been genetically engineered to produce the Cry1Ab protein (Bt corn) is resistant to lepidopteran pests. Bt corn is widely planted in the midwestern United States, often adjacent to headwater streams. We show that corn byproducts, such as pollen and detritus, enter headwater streams and are subject to storage, consumption, and transport to downstream water bodies. Laboratory feeding trials showed that consumption of Bt corn byproducts reduced growth and increased mortality of nontarget stream insects. Stream insects are important prey for aquatic and riparian predators, and widespread planting of Bt crops has unexpected ecosystem-scale consequences.
Conditioned eyeblink learning is formed and stored without cerebellar granule cell transmission
Authors: Wada Norio , Kishimoto Yasushi , Watanabe Dai , Kano Masanobu , Hirano Tomoo , Funabiki Kazuo , Nakanishi Shigetada
Published: October 2007

Classical conditioning of the eyeblink reflex is elicited by paired presentation of a conditioned stimulus and an unconditioned stimulus and represents a basic form of cerebellum-dependent motor learning. Purkinje cells and the deep nuclei receive convergent information of conditioned stimulus and unconditioned stimulus through the mossy fiber and climbing fiber projections, respectively. To explore the relative importance of these neural circuits and the underlying mechanism in associative eyeblink learning, we adopted a novel gene-manipulating technique, termed reversible neurotransmission blocking (RNB). In this technology, cerebellar granule cells specifically expressed neurotransmission-blocking tetanus toxin in a doxycycline (DOX)-dependent manner. Extracellular recording of Purkinje cells in awake RNB mice revealed that DOX treatment and withdrawal reversibly turned off and on simple spikes elicited by granule cell inputs, respectively, without interference with complex spikes evoked by climbing fiber inputs. Blockade of granule cell inputs to Purkinje cells abolished eyeblink conditioned responses (CRs) in a DOX-dependent manner. Importantly, when granule cell inputs recovered by removal of DOX, normal CRs were immediately produced in the DOX-treated, CR-negative RNB mice from the beginning of reconditioning. This learning process in RNB mice during DOX treatment was completely abolished by bilateral lesion of the interpositus nucleus before eyeblink conditioning. These results indicate that the convergent information at the interpositus nucleus is critical for acquisition and storage of learning in intimate association with the Purkinje cell circuit for expression of CRs in eyeblink conditioning.
Molecular mechanism of mast cell–mediated innate defense against endothelin and snake venom sarafotoxin
Authors: Schneider Lars A. , Schlenner Susan M. , Feyerabend Thorsten B. , Wunderlin Markus , Rodewald Hans-Reimer
Published: October 2007

Mast cells are protective against snake venom sarafotoxins that belong to the endothelin (ET) peptide family. The molecular mechanism underlying this recently recognized innate defense pathway is unknown, but secretory granule proteases have been invoked. To specifically disrupt a single protease function without affecting expression of other proteases, we have generated a mouse mutant selectively lacking mast cell carboxypeptidase A (Mc-cpa) activity. Using this mutant, we have now identified Mc-cpa as the essential protective mast cell enzyme. Mass spectrometry of peptide substrates after cleavage by normal or mutant mast cells showed that removal of a single amino acid, the C-terminal tryptophan, from ET and sarafotoxin by Mc-cpa is the principle molecular mechanism underlying this very rapid mast cell response. Mast cell proteases can also cleave ET and sarafotoxin internally, but such “nicking” is not protective because intramolecular disulfide bridges maintain peptide function. We conclude that mast cells attack ET and sarafotoxin exactly at the structure required for toxicity, and hence sarafotoxins could not “evade” Mc-cpa's substrate specificity without loss of toxicity.
Geographical Distribution, Pathotype Characterization, and Molecular Diversity of Colletotrichum lindemuthianum in Greece and Resistance of Greek Bean Cultivars
Authors: Bardas G. A. , Koutita O. , Tzavella-Klonari K.
Published: October 2007

Thirty-five Colletotrichum lindemuthianum isolates were obtained from bean (Phaseolus vulgaris) fields in 23 prefectures of Greece during a survey conducted in 2003 and 2004. Race characterization based on the standardized set of 12 differential cultivars demonstrated the presence of races 2, 6, and 22, which are reported for first time in Greece, while race 22 is reported for the first time in the world. In addition, pathotype diversity showed significant correlation with the geographical origin of these isolates. All three races caused disease symptoms only on cultivars of Andean origin, suggesting that Greek isolates originated from South American countries. Virulence spectrum of the same isolates was also examined on a set of 30 Greek bean cultivars showing seven types of virulence. Based on their reactions to the pathogen isolates, Greek cultivars were divided into nine groups. Among these cultivars, two (Ithomi FS60 and Larisa) were resistant to all tested isolates, including the reference isolates. Molecular diversity was detected using random amplified polymorphic DNA (RAPD) primers and the restriction fragment length polymorphism (RFLP) analysis of the ribosomal DNA internal transcribed spacers, which revealed two main clusters of isolates. Thirty-two out of 35 isolates belonged to the same main cluster in both methods, indicating that Greek isolates have genotypic similarities. This study provides the information on population diversity of C. lindemuthianum, which can be useful in agricultural practices and in plant breeding programs.
Effect of Citrus Sudden Death on Yield and Quality of Sweet Orange Cultivars in Brazil
Authors: Bassanezi R. B. , Montesino L. H. , Sanches A. L. , Spósito M. B. , Stuchi E. S. , Barbosa J. C.
Published: October 2007

Citrus sudden death (CSD) has greatly affected sweet orange cultivars grafted on Rangpur lime in São Paulo and Minas Gerais States, Brazil. To characterize and quantify CSD damage, fruit yield and quality were assessed in each combination of sweet orange cultivar (Hamlin, Pera, Natal, and Valencia), age class (3 to 5, 6 to 10, and 11 to 15 years old), and CSD severity class (0 = no symptom, 1 = initial symptoms, and 2 = severe symptoms). For each combination, 10 trees were harvested and 20 fruit were taken for quality analysis. Damage was characterized by reduction of: (i) total weight of fruit/tree (36 and 67% for severity class 1 and 2, respectively), (ii) number of fruit/tree (27 and 55%), (iii) fruit size (13 and 25% in diameter and height [stem to styler distance]), (iv) fruit weight (32 and 56%), (v) total soluble solids (TSS)/fruit (18 and 42%), and increase of (vi) Brix (14 and 34%), (vii) acidity (16 and 41%), and (viii) TSS/90-lb. box (21 and 33%). There was no alteration on Brix/acidity ratio and percentage of juice on fruit of affected trees. Sweet orange cultivars did not differ in percentage of reduction or increase of all yield and quality variables, with the exception of Pera, which expressed increases of Brix and acidity. For more severe affected trees, the youngest plants showed a higher reduction in fruit number/tree, whereas plants 6 to 10 years old showed a higher increase in fruit acidity and TSS/box. However, no differences in percentage of reduction or increase for other variables were observed among different age classes. The damage to the above probably was associated with reduced water absorption capacity of CSD-affected trees.
Characterizing Meteorological Scenarios Favorable for Septoria tritici Infections in Wheat and Estimation of Latent Periods
Authors: Henze Matthias , Beyer Marco , Klink Holger , Verreet Joseph-Alexander
Published: October 2007

Septoria tritici epidemics were monitored on winter wheat cv. Ritmo between 1995 and 2003 at 8 to 11 locations per year in Northern Germany (area between 53.70 and 54.38°N latitude and 8.83 and 10.88°E longitude) by counting the number of pycnidia on the leaves of plants obtained from plots under natural infection. Furthermore, meteorological data (leaf wetness, temperature, and precipitation) were recorded within the same period at the same locations. Groups of similar meteorological events were identified by hierarchical cluster analysis. The temporal distance of those clusters from the point of time when an increase of more than 70 S. tritici pycnidia was observed per leaf within 1 week was calculated for all epidemiological case studies and meteorological clusters. A cluster with average temperature = 13.62 ± 2.30°C, leaf wetness = 92.39 ± 4.15%, and precipitation = 0.04 ± 0.10 mm per day was consistently observed at 20.35 ± 4.15 days before epidemic outbreaks. This estimate of a latent period was significantly affected by geographic latitude, average temperature during infection, average temperature during the latent period, year, and precipitation, but not by leaf layer and longitude. On average, an increase in temperature during the infection period by 1°C decreased latent periods by 0.95 day. Latent periods were decreased by 0.2 day upon an increase of the average temperature by 1°C during the latent period. Average latent periods decreased by 1.7 days per degree of north latitude. Latent period estimates had lower coefficients of variation than temperature sums accumulated over latent periods. The usefulness of the approach described above for general epidemiology and for increasing fungicide efficacy by improving the timing of applications is discussed.
Relationship of Beet Curly Top Foliar Ratings to Sugar Beet Yield
Authors: Strausbaugh Carl A. , Gillen Anne M. , Camp Stacey , Shock Clinton C. , Eldredge Eric P. , Gallian John J.
Published: October 2007

Sugar beet (Beta vulgaris) varieties were evaluated for disease resistance to curly top to establish if disease ratings made in inoculated nurseries correlated with disease ratings and yield in sugar beet crops exposed to natural disease outbreaks. Cultivars were planted both in inoculated curly top nurseries in Kimberly, ID, and in commercial cultivar trials in irrigated fields near Ontario, OR and Nampa, ID. Plants were evaluated for curly top using a rating scale of 0 (no symptoms) to 9 (dead). Moderate disease pressure in the Ontario (mean rating = 3.8) and Nampa (mean rating = 4.1) fields resulted in significant differences for disease rating, root yield, sugar content, and estimated recoverable sugar among cultivars. Disease ratings from both commercial fields were positively correlated (r = 0.91 and 0.82, P < 0.0001) with ratings from the inoculated nurseries. In commercial fields, root yield was negatively related to disease rating (r2 = 0.47 and 0.39, P ≤ 0.0004). For each unit increase in disease rating (increasing susceptibility), root yield decreased 5.76 to 6.93 t/ha. Thus, curly top nurseries reliably predict curly top resistant cultivars for commercial cultivation.
First Report of Plum pox virus on Plum in New York State
Authors: Snover-Clift K. L. , Clement P. A. , Jablonski R. , Mungari R. J. , Mavrodieva V. A. , Negi S. , Levy L.
Published: October 2007

Plum pox, also known as Sharka, is one of the more significant viral diseases of stone fruit trees such as plum, peach, and apricot. It was first reported in Europe in the early 1900s and more recently in Chile in 1992, the United States (Pennsylvania) in 1999, Canada (Ontario and Nova Scotia) in 2000, China in 2001, and Argentina in 2004. Plum pox virus (PPV) was recently detected in two plum (Prunus domestica) trees in an orchard in Niagara County, NY, located within 5 miles from a Canadian plum pox eradication zone. Typical symptoms of chlorotic rings and spots were observed on some of the leaves from these trees. No symptoms were reported prior to the survey collection in July 2006. Survey samples were screened for the presence of PPV by ELISA using the Agdia PPV (Agdia, Elkhart, IN) specific kit that recognizes all strains but C of PPV. Approximately 5% of the survey samples were additionally analyzed by a validated immunocapture reverse transcription (IC-RT)-PCR TaqMan assay in a Cepheid SmartCycler (Cepheid, Sunnyvale, CA). Both replicates of the two New York plum trees produced a positive ELISA reaction in two consecutive tests. The ELISA-positive samples also produced positive results when subjected to the real-time IC-RT-PCR test. The PPV-positive trees were sampled again and an additional 53 samples were collected from trees in the surrounding area. Suspect trees again tested positive, while all the trees in the surrounding area tested negative. The methods used for confirmation included two ELISA tests (Durviz [Valencia, Spain] DAS indirect monoclonal ELISA and Agdia DAS polyclonal ELISA). Confirmatory real-time IC-RT-PCR was performed using universal 3′ nontranslated region (NTR) primers (2,3) in a SYBR Green assay format and a coat protein (CP) primers/probe TaqMan assay (3,4). Further, the New York PPV isolate was identified as PPV D group using a subgroup specific conventional IC-RT-PCR (1). A 1.4-kb sequence fragment from the 3′ end of the New York PPV was sequenced (GenBank Accession No. DG 883816). Comparison of the sequence with the database confirmed this isolate as subgroup D and exhibited a high degree of identity with other PPV D accessions (PPV D Teycheney [Accession No. X16415]; Penn4 [Accession No. DQ465243] Cnd 123-1 [Accession No. AY9553267]; and Cnd 3 [Accession No. AY953262]). To our knowledge, this is the first report of PPV in New York.

References: (1) T. Candresse et al. Phytopathology. 88:198, 1998. (2) L. Levy et al. J. Virol. Methods. 49:295, 1994. (3) V. Mavrodieva and L. Levy. Acta Hortic. 657:141, 2004. (4) T. Wetzel et al. J.Virol. Methods 33:355, 1991.
Frequent Occurrence of Lettuce mosaic virus in Cape Daisy (Osteospermum sp.) in Tunisia
Authors: Gall O. Le , Svanella-Dumas L. , Fakhfakh H. , Marrakchi M. , Candresse T.
Published: October 2007

The potyvirus Lettuce mosaic virus (LMV) is a common pathogen of lettuce crops worldwide, but it also infects other Asteraceae spp. including ornamentals (2,3,4). Cape daisies (Osteospermum sp.) are widely grown perennial ornamentals reported to be natural hosts of LMV (2,4), which causes faint leaf mosaic and sometimes mild flower breaking. A preliminary observation of mosaic symptoms prompted a large-scale survey during the spring of 2005 in Cape daisies grown in the Tunis metropolitan area and the south of Tunisia (Djerba, Medenine). Two hundred seventy-one samples (Tunis: 14 sites, 219 samples; South: 9 sites, 52 samples) were randomly collected from nurseries, roadway plantings, and home gardens and analyzed. Ninety-three samples (Tunis: 40%, South: 12%; overall: 34%) showed distinct mosaic symptoms. LMV infection was verified by immuno-tissue printing on all collected samples (1), providing evidence for even higher infection levels (Tunis: 60%; South: 25%; overall: 56%). This technique, therefore, allowed the detection of symptomless infection in a significant proportion of samples. It should however, be stressed that symptoms can be very difficult to observe in water-stressed plants, a situation frequently observed in Tunisia. Subsequent PCR analysis with LMV-specific primers (1) of a subset of 24 symptomatic and tissue-print-positive samples confirmed LMV infection in all cases. This is to our knowledge, the first report of LMV infection in Cape daisies in Tunisia. The very high rate of infection observed suggests that these popular ornamentals might constitute a reservoir of LMV as previously reported in the United States (4).

References: (1) H. Fakhfakh et al. J. Plant Pathol. 83:3, 2001. (2) R. Jordan and M. Guaragna. (Abstr.) Phytopathology 96(suppl.):S56, 2006. (3) O. Le Gall. No. 399 in: Description of Plant Viruses. A. T. Jones et al., eds. CMI/AAB, Kew, Surrey, UK, 2003. (4) D. C. Opgenorth et al. Plant Dis. 75:751, 1991.
Phylogenetic Analysis of Downy Mildew Pathogens of Opium Poppy and PCR-Based In Planta and Seed Detection of Peronospora arborescens
Authors: Landa Blanca B. , Montes-Borrego Miguel , Muñoz-Ledesma Francisco J. , Jiménez-Díaz Rafael M.
Published: October 2007

Severe downy mildew diseases of opium poppy (Papaver somniferum) can be caused by Peronospora arborescens and P. cristata, but differentiating between the two pathogens is difficult because they share morphological features and a similar host range. In Spain, where severe epidemics of downy mildew of opium poppy have occurred recently, the pathogen was identified as P. arborescens on the basis of morphological traits. In this current study, sequence homology and phylogenetic analyses of the internal transcribed spacer regions (ITS) of the ribosomal DNA (rDNA) were carried out with DNA from P. arborescens and P. cristata from diverse geographic origins, which suggested that only P. arborescens occurs in cultivated Papaver somniferum in Spain. Moreover, analyses of the rDNA ITS region from 27 samples of downy-mildew-affected tissues from all opium-poppy-growing regions in Spain showed that genetic diversity exists within P. arborescens populations in Spain and that these are phylogenetically distinct from P. cristata. P. cristata instead shares a more recent, common ancestor with a range of Peronospora species that includes those found on host plants that are not members of the Papaveraceae. Species-specific primers and a PCR assay protocol were developed that differentiated P. arborescens and P. cristata and proved useful for the detection of P. arborescens in symptomatic and asymptomatic opium poppy plant parts. Use of these primers demonstrated that P. arborescens can be transmitted in seeds and that commercial seed stocks collected from crops with high incidence of the disease were frequently infected. Field experiments conducted in microplots free from P. arborescens using seed stocks harvested from infected capsules further demonstrated that transmission from seedborne P. arborescens to opium poppy plants can occur. Therefore, the specific-PCR detection protocol developed in this study can be of use for epidemiological studies and diagnosing the pathogen in commercial seed stocks; thus facilitating the sanitary control of the disease and avoidance of the pathogen distribution in seeds.