bluuebunny/crossref_metadata_2025 huggingface dataset:
Image-guided radiation therapy using computed tomography in radiotherapy
Authors: Fung Winky Wing Ki , Wu Vincent Wing Cheung
Published: November 2010

The sharp dose gradients in intensity-modulated radiation therapy increase the treatment sensitivity to various inter- and intra-fractional uncertainties, in which a slight anatomical change may greatly alter the actual dose delivered. Image-guided radiotherapy refers to the use of advanced imaging techniques to precisely track and correct these patient-specific variations in routine treatment. It can also monitor organ changes during a radiotherapy course. Currently, image-guided radiotherapy using computed tomography has gained much popularity in radiotherapy verification as it provides volumetric images with soft-tissue contrast for on-line tracking of tumour. This article reviews four types of computed tomography-based image guidance systems and their working principles. The system characteristics and clinical applications of the helical, megavoltage, computed tomography, and kilovoltage, cone-beam, computed tomography systems are discussed, given that they are currently the most commonly used systems for radiotherapy verification. This article also focuses on the recent techniques of soft-tissue contrast enhancement, digital tomosynthesis, four-dimensional fluoroscopic image guidance, and kilovoltage/megavoltage, in-line cone-beam imaging. These evolving systems are expected to take over the conventional two-dimensional verification system in the near future and provide the basis for implementing adaptive radiotherapy.
A qualitative focus group study to explore the information, support and communication needs of women receiving adjuvant radiotherapy for primary breast cancer
Authors: Hendry J.A.
Published: November 2010

Purpose: This study aimed to explore the patient’s experience of the radiotherapy pathway with a view to improving patient-centred services.

Methods: Women’s views about the radiotherapy pathway were gathered through a focus group. Focus groups have been used extensively in qualitative research to gather rich meaningful data. A thematic analysis of the transcript identified areas of importance for the women, which could be used to direct service improvement.

Results: Five main themes emerged: information, communication and support, dignity and individualised care, service accessibility and staff relationships. Generally, staff were viewed as professionals and the radiotherapy service well run although women did identify several unmet needs during radiotherapy. Lack of information and perceived time constraints of busy staff was revealed. However women did feel treated with dignity, respect and as individuals. ‘End-of-treatment’ was a particular focus; women felt dedicated time with staff would enable discussion, information giving and support around this vulnerable time. In addition, women felt that communication barriers and time constraints influenced the information and support they experienced during radiotherapy.

Conclusion: The use of a focus group enabled service users to identify clear areas for improvement at a local level. Priorities include information, communication and support and the ‘end-of-treatment’.
Comparison of three-dimensional conformal irradiation techniques for prostate cancer using a low-energy (6 MV) photon beam
Authors: Armpilia Christina , Antypas Christos , Zygogianni Anna , Balafouta Myrsini , Kouvaris John , Sandilos Panagiotis
Published: November 2010

Purpose: To evaluate composite coplanar and non-coplanar three-dimensional conformal techniques (3D-CRT) for external-beam prostate radiotherapy using a low-energy (6 MV) photon beam.

Methods and Materials: For treatment-planning purposes, three different planning target volumes (PTV) were defined for ten patients with prostate cancer and as follows: PTV1 (pelvis), PTV2 (prostate + seminal vesicles + 1 cm margin) and PTV3 (prostate + 1 cm margin). Conformal techniques of 2, 3, 4, 5 (coplanar) and 6 (non-coplanar) field techniques have been considered and combined to produce five different plan combinations (i.e. techniques A, B, C, D and E). Treatment plans were generated with a prescription dose of 75 Gy to PTV3, 65 Gy to PTV2 and 45 Gy to PTV1 and were assessed on the basis of 3D dose distributions and dose-volume histograms (DVHs). Normal tissue-dose constraints for the relevant organs at risk (OARs), that is, rectum, bladder and femoral heads, were also considered.

Results: Findings show that all five treatment-plan combinations result in adequate PTV coverage and acceptable OAR irradiated volumes. The greatest rectal spacing in the high-dose region is achieved by technique C; all techniques achieve this, except for technique A, and give approximately the same fraction of volume (of rectum) that receives a dose of 50 Gy (V50) and 60 Gy (V60). When considering the bladder, techniques B, D and E give the best bladder sparing with small absolute differences, whereas technique A results in the lowest dose for femoral heads. Technique E appears to give the best compromise for all three considered OARs, provided the PTV is adequately covered.

Conclusions: Even though the optimum photon-beam energy for conformal prostate radiotherapy is greater than 10 MV, our study shows that a good sparing of OAR can be achieved even with a lower-energy beam (6 MV) and the appropriate plan combination and that the dose to prostate can be as high as 75 Gy.
Influence of catheters on predicted tumour control probability and severity of acute genitourinary toxicity during high-dose-rate brachytherapy prostate boost
Authors: Tunio Mutahir , Hashmi Altaf , Rafi Mansoor , Mohsin Rehan , Zameer Asad
Published: November 2010

Purpose: High-dose-rate brachytherapy (HDR) boost is an effective method for dose escalation when treating prostate cancer. Optimal number and location of catheters play key role in radiation dose delivery. We studied the impact of catheters and associated trauma on the dose uncertainties and urethral toxicity.

Methods and Materials: Between July 2008 to August 2009, 50 patients with prostate cancer were treated with 46 Gy of external irradiation of whole pelvis (2 Gy per fraction) and two HDR brachytherapy fractions (each 14 Gy) at the end of 10 fractions of external beam. All brachytherapy implants were planned using real-time, ultrasound-based planning system. Variables were prostate and urethral volumes, number of catheters and their mean distance from base of bladder and dose volume histogram parameters. All data were collected during first implant only. The toxicities were graded according to Radiation Therapy Oncology Group Toxicity Criteria. Statistical analysis was done on SPSS version 17.0.

Results: The mean number of catheters implanted was 12.38 (8–19), and number of attempts per needle to achieve desired position was 1.6 (range = 0–5). Mean distance between the catheters tips to contrast filled bladder was 3.2 mm (1–8 mm) after the adjustment. Distances >5 mm showed lower doses to prostate and lower predicted tumour control probability (TCP) (p < 0.01). No correlation was found between numbers of catheters implanted, attempts per catheter and severity of acute genitourinary (GU) toxicity. Significant correlation was found between severity of acute GU toxicity and urethral V130, V150 (p < 0.001).

Conclusion: Dose decline and subsequently lower TCP were seen for the greater distances between the needles and bladder. Acute GU toxicity increased with higher urethral, but severity of acute GU toxicity does not increase with increase in prostate/urethral volumes, number of catheters needles and attempts.
Three‐dimensional finite difference saturated‐unsaturated flow modeling with nonorthogonal grids using a coordinate transformation method
Authors: An Hyunuk , Ichikawa Yutaka , Tachikawa Yasuto , Shiiba Michiharu
Published: November 2010

Study of the saturated‐unsaturated flow in porous media is of interest in many branches of science and engineering. Among the various numerical simulation methods available, the finite difference method is advantageous because it offers simplicity of discretization. This method has been widely used for simulating saturated‐unsaturated flows. However, the simulation of geometrically complex flow domains requires the use of high‐resolution grids in conventional finite difference models because conventional finite difference discretization assumes an orthogonal coordinate system. This makes a finite difference model computationally less efficient than other numerical models that can treat nonorthogonal grids, such as the finite element model and finite volume model. To overcome this disadvantage, we use a coordinate transformation method and develop a multidimensional finite difference model for simulating saturated‐unsaturated flows; this model can treat nonorthogonal grids. The cross‐derivative terms derived by the coordinate transformation method are evaluated explicitly for ease of coding. Therefore, a 7 point stencil is used for implicit terms in the iterative calculation, as in the case of conventional finite difference models with an orthogonal grid. We assess the performance of the proposed model by carrying out test simulations. We then compare the simulation results with dense grid solutions in order to evaluate the numerical accuracy of the proposed model. To examine the performance of the proposed model, we draw a comparison between the simulation results obtained using the proposed model and the results obtained by using (1) a model in which all terms are considered fully implicitly, (2) a finite element model, and (3) a conventional finite difference model with a high‐resolution orthogonal grid.
Stratus cloud supersaturations
Authors: Hudson James G. , Noble Stephen , Jha Vandana
Published: November 2010

A wide range of California coastal stratus cloud droplet concentrations (Nc) were compared with CCN spectra to provide numerous estimates of cloud supersaturations (S). These revealed the predicted decrease of S with higher CCN concentrations (NCCN). A significant result was frequent stratus cloud S significantly above 0.3%, especially for more maritime NCCN and Nc (i.e., <300 cm−3). This means that much smaller and more numerous particles than previously considered interact with the most important clouds for the indirect aerosol effect.
Susceptibility of human and murine Chlamydia trachomatis serovars to granulocyte‐ and epithelium‐derived antimicrobial peptides
Authors: Chong‐Cerrillo C. , Selsted M.E. , Peterson E.M. , De La Maza L.M.
Published: November 2010

Abstract: Four antimicrobial peptides, protegrin‐1, RTD‐1, cryptdin‐4, and indolicidin, were tested for their ability to inhibit the in vitro growth of Chlamydia trachomatis serovars E, L2, and mouse pneumonitis (MoPn). In general, protegrin‐1 was found to have the strongest anti‐chlamydial activity. Overall, of the three serovars tested, L2 was the most susceptible while MoPn was the most resistant to these peptides.
In vivo structure–activity studies on the dark‐color‐inducing neurohormone of locusts
Authors: Grach C. , Wang Y. , Barda Y. , Gilon C. , Pener M.P.
Published: November 2010

Abstract: In the 11‐residue long dark‐color‐inducing neurohormone (DCIN =  [His7]‐corazonin), of locusts, from residue 2 to residue 11, one amino acid at each time was substituted by d‐phenylalanine (d‐Phe). The dark‐color‐inducing effect of these peptides was investigated in comparison with unaltered DCIN by a bioassay based on nymphs of a DCIN‐deficient albino mutant of the migratory locust, Locusta migratoria. Substitution of any single amino acid by d‐Phe always reduced the activity, but did not abolish it completely. Maximum inactivation was obtained after substitution of Gln4, Ser6, or Trp9. The latter two residues are within the partial sequence ‐Ser‐Xxx‐Gly‐Trp‐ (Xxx = His in the DCIN) that seems to be important for the dark‐color‐inducing activity, as found also in another study (Insect Biochem. Mol. Biol. 32, 2002, 909). Gln4, however, is outside of this partial sequence. Minimal, although still considerable, inactivation occurred after substitution of Gly8, Phe3, or Asn11, despite the fact that Gly8 is within the ‐Ser‐Xxx‐Gly‐Trp‐ partial sequence. In conclusion, no single active core was found, indicating that the whole sequence of the DCIN is necessary to induce maximum darkening effect. No difference was found in the activity of the peptides in which Gly8 was substituted by d‐Phe or by l‐Phe. Therefore the ‐Ser‐Xxx‐Gly‐Trp‐ partial sequence does not seem to be stabilized by a type II β‐turn. Nevertheless, existence of another kind of turn that includes this partial sequence is feasible. A single unsuccessful attempt was made to discover an antagonist to the DCIN.
On the nucleotide distribution in bacterial DNA sequences
Authors: Sobottka Marcelo , Hart Andrew Glenn
Published: November 2010

It is probable that the distributional structure of DNA sequences arises from the accumulation of many successive stochastic events such as nucleotide deletions, insertions, substitutions and elongations [1, 2, 3, 4, 5, 6, 7]. Although the existence of long-range correlations in non-coding portions of DNA sequences is well established [8, 9, 10, 11], first order Markov chains might well capture aspects of their nucleotide distributions [12]. Here we propose a hidden Markov model based on a coupling of an urn process with a Markov chain to approximate the distributional structure of primitive DNA sequences. Then, by supposing that a bacterial DNA sequence can be derived from uniformly distributed mutations of some primitive DNA, we use the model to explain and predict some distributional properties of bacterial DNA sequences. The distributional properties intrinsic to the model were compared to statistical estimates from 1049 bacterial DNA sequences. In particular, the proposed model provides another possible theoretical explanation for Chargaff’s second parity rule for short oligonucleotides [13, 14].
Assessing performance of conservation-based Best Management Practices: Coarse vs. fine-scale analysis
Authors: Piechnik Denise , Goslee Sarah , Veith Tamie
Published: November 2010

Background/Questions/Methods

Animal agriculture in the Spring Creek watershed of central Pennsylvania contributes sediment to the stream and ultimately to the Chesapeake Bay. Best Management Practices (BMPs) such as stream bank buffers are intended to intercept sediment moving from heavy-use areas toward the stream. The placement of BMPs on a farm is generally based on untested assumptions about flow paths. Most often, a straight-line distance from the heavy-use area to the stream is assumed to be correct. Our objective was to compare the straight-line path to hydrologic flow paths calculated from fine-, medium- and coarse-grained Digital Elevation Models (DEMs; 1m, 10m, 30m) for 471 mapped heavy-use points within 100m of the stream. The 30m DEMs are the most widely available and require the least processing time. We anticipated that the flow path distance would be longer than the straight-line distance in all cases, that the finest resolution would lead to the most accurate measurement, but that the difference might not be great enough to justify the increased costs. Understanding the changes in path length and direction calculated using more complex methods and higher-resolution source data will enable us to make recommendations on methods to be used in developing conservation management plans.

Results/Conclusions

The medium-(10m DEM) and fine-resolution data (1m DEM) had the smallest differences between the hydrologic flow path and straight-line path: median differences in path length of 20 m for both the 1m and 10m DEMs, and 51m for the 30m DEM. Hydrologic flow paths were significantly longer than straight-line paths for all three scales; BMP placement based on straight-line distances may not be the most effective. Although the overall difference was significantly positive, calculations on the 30m DEMs sometimes produced straight-line paths that were longer than the hydrologic flow paths, apparently due to inaccuracies in the data. Where fine-scale DEMs are available, BMPs might be more effectively situated by considering the corresponding drainage pathways. The very different results produced at the three scales demonstrate that using the finest-grained elevation data may substantially improve placement of BMPs intended to mitigate for heavy animal use areas. The use of 30m DEMs for this purpose should be avoided. Fine-grained data such as 1m-resolution LiDAR-derived DEMs are available for Pennsylvania through PAMAP, and can be incorporated in the planning stages of BMP placement ultimately resulting in reducing agricultural sediment and nutrient loadings into local watersheds and the Chesapeake Bay.
Comparison of the solid‐phase fragment condensation and phase‐change approaches in the synthesis of salmon I calcitonin
Authors: Gatos D. , Tzavara C.
Published: November 2010

Abstract:Salmon I calcitonin was synthesized using both phase‐change and conventional solid‐phase fragment condensation (SPFC) approaches, utilizing the Rink amide linker (Fmoc‐amido‐2,4‐dimethoxybenzyl‐4‐phenoxyacetic acid) combined with 2‐chlorotrityl resin and the Fmoc/tBu(Trt)‐based protection scheme. Phase‐change synthesis, performed by the selective detachment of the fully protected C‐terminal 22‐mer peptide‐linker from the resin and subsequent condensation in solution with the N‐terminal 1–10 fragment, gave a product of slightly less purity (85 vs. 92%) than the corresponding synthesis on the solid‐phase. In both cases salmon I calcitonin was easily obtained in high purity.
Topography of the neurotensin (NT)(8−9) binding site of human NT receptor‐1 probed with NT(8–13) analogs
Authors: Lundquist IV J.T. , Büllesbach E.E. , Golden P.L. , Dix T.A.
Published: November 2010

Abstract: A series of neurotensin (NT)(8–13) analogs featuring substitution of the Arg8and/or Arg9residues with non‐natural cationic amino acids was synthesized and evaluated for binding to the human NT receptor‐1 (hNTR‐1). The modifications were designed to probe specific steric and electrostatic requirements in the N‐terminal cationic region of NT(8–13) for receptor binding as a general evaluation of the feasibility of incorporating minor structural changes into a peptide at a crucial polar receptor binding site. Many of the non‐natural amino acids are more or less isosteric to Arg but more lipophilic as a result of addition of alkyl groups or through removal or replacement of NH character with methylene or methyl substituents, whereas others vary the distance between the cation and the α–amino acid carbon. Substitution of Arg8withNG‐alkylated Arg derivatives or homolysine (Hlys) maintained the subnanomolar affinity of NT(8–13) to the hNTR‐1. Position 8 incorporation of Hlys produced the most favorable primary amine side‐chain substitution to date. Moderate losses in affinity observed with position 9 substitutions were attributed to adverse steric effects. Doubly substituted [Hlys8, DAB9]NT(8–13), in which DAB is 2,4‐diaminobutyric acid, was also prepared and tested as the shorter side‐chain of DAB is known to be favored in position 9 of NT(8–13). This analog maintained 60% of NT(8–13) binding affinity making it the most favoreddes‐guanidinium‐containing analog known. These results demonstrate that adequate receptor binding affinity can be maintained over a structural range of Arg analogs, thus providing a range of peptides expected to exhibit altered pharmacokinetic properties. From the standpoint of the hNTR‐1 cationic binding sites, these results help to map out the structural stringency inherent in the formation of a tight binding complex with NT(8–13) and related analogs.
Topographies of plasma-hardened surfaces of poly(dimethylsiloxane)
Authors: Görrn Patrick , Wagner Sigurd
Published: November 2010

We studied the formation of surface layers hardened by plasma-enhanced oxidation of the silicone elastomer poly(dimethylsiloxane). We explored the largest parameter space surveyed to date. The surface layers may wrinkle, crack, or both, under conditions that at times are controlled by design, but more often have been discovered by trial-and-error. We find four distinct topographies: flat/wrinkled/cracked/cracked and wrinkled. Each topography is clearly separated in the space of plasma dose versus plasma pressure. We analyzed wrinkle amplitude and wavelength by atomic force microscopy in the tapping mode. From these dimensions we calculated the elastic modulus and thickness of the hard surface layer, and inferred a graded hardness, by employing a modified theoretical model. Our main result is the identification of the parameters under which the technologically important pure wrinkled, crack-free topography is obtained.
On the characteristics of the interaction between two dust-acoustic solitary waves in a magnetized dusty plasma and two-temperature ions
Authors: El-Labany S. K. , El-Shamy E. F. , Shokry M.
Published: November 2010

The interaction between two dust-acoustic solitary waves (DASWs) in a three-dimensional magnetized dusty plasma has been investigated theoretically, using the extended Poincaré–Lighthill–Kuo method. The analytical phase shifts after the interaction of the two solitary waves are derived. The effects of two types of isothermal ions, oblique collision of DASWs, the number densities of ions species to the density of charged dust grains ratio, the effective temperature of ions to the electron temperature ratio, and the adiabatic ratio of specific heats on the phase shifts are discussed. The results show that these parameters have strong effects on the phase shifts and the trajectories of two DASWs after collision.
Constant pressure ab initio molecular dynamics with discrete variable representation basis sets
Authors: Ma Zhonghua , Tuckerman Mark
Published: November 2010

The use of discrete variable representation (DVR) basis sets within ab initio molecular dynamics calculations allows the latter to be performed with converged energies and, more importantly, converged forces. In this paper, we show how to carry out ab initio molecular dynamics calculations in the isothermal-isobaric ensemble with fully flexible simulation boxes within the DVR basis set framework. In particular, we derive the appropriate DVR based expression for the pressure tensor when the electronic structure is represented using Kohn–Sham density functional theory, and we examine the convergence of this expression as a function of the basis set size. An illustrative example using 64 silicon atoms in a fully flexible box using a combination of the Martyna–Tobias–Klein [Martyna et al., J. Chem. Phys. 101, 4177 (1994)] and Car–Parrinello [Car and Parinello, Phys. Rev. Lett. 55, 2471 (1985)] algorithms is presented to demonstrate the efficacy of the approach.
Flute instability and the associated radial transport in the tandem mirror with a divertor mirror cell
Authors: Katanuma I. , Yagi K. , Haraguchi Y. , Ichioka N. , Masaki S. , Ichimura M. , Imai T.
Published: November 2010

The flute instability and the associated radial transport are investigated in the tandem mirror with a divertor mirror cell (the GAMMA10 A-divertor) with help of computer simulation, where GAMMA10 is introduced [Inutake et al., Phys. Rev. Lett. 55, 939 (1985)]. The basic equations used in the simulation were derived on the assumption of an axisymmetric magnetic field. So the high plasma pressure in a nonaxisymmetric minimum-B anchor mirror cell, which is important for the flute mode stability, is taken into account by redefining the specific volume of a magnetic field line. It is found that the flute modes are stabilized by the minimum-B magnetic field even with a divertor mirror although its stabilizing effects are weaker than that without the divertor mirror. The flute instability enhances the radial transport by intermittently repeating the growing up and down of the Fourier amplitude of the flute instability in time.
Low-temperature crystal structure, specific heat, and dielectric properties of lithium tetraborate Li2B4O7
Authors: Senyshyn A. , Schwarz B. , Lorenz T. , Adamiv V. T. , Burak Ya. V. , Banys J. , Grigalaitis R. , Vasylechko L. , Ehrenberg H. , Fuess H.
Published: November 2010

Coherent neutron powder diffraction experiments were carried out together with specific heat, dilatometry, and dielectric spectroscopy studies on Li2B4O7 enriched with B11 isotope to 99.3% at low temperatures. Neither traces of phase transformations nor discontinuous changes in physical properties were observed. Negative thermal expansion, anomalous thermal behavior of selected interatomic distances/angles, isotropic displacement parameters on specific sites as well as dielectric constant were discussed in terms of dynamic lithium disorder.
Optical alignment of the exciton in ZnO nanoparticles
Authors: Chassaing P.-M. , Balocchi A. , Amand T. , Saint-Macary L. , Kahn M. L. , Chaudret B. , Marie X.
Published: November 2010

The exciton spin dynamics of zinc oxide nanoparticles (NPs) of sizes ranging from 2.3 to 6.6 nm has been studied by time-resolved photoluminescence. Following a quasiresonant linearly polarized excitation, the exciton photoluminescence of an ensemble of NPs exhibits a linear polarization of 15%, demonstrating the optical alignment of exciton in zinc oxide NPs. Within the accuracy of our experimental setup, no decay time of the linear polarization is observed on the exciton lifetime scale, reflecting an exciton spin relaxation time longer than 1 ns.
Efficient data averaging for spin noise spectroscopy in semiconductors
Authors: Müller Georg M. , Römer Michael , Hübner Jens , Oestreich Michael
Published: November 2010

Spin noise spectroscopy (SNS) is the perfect tool to investigate electron spin dynamics in semiconductors at thermal equilibrium. We simulate SNS measurements which utilize real-time fast Fourier transformation instead of an ordinary spectrum analyzer and show that ultrafast digitizers with low resolution enable surprisingly sensitive, high bandwidth SNS in the presence of strong optical background shot noise. The simulations reveal that optimized input load at the digitizer is crucial for efficient spin noise detection while the resolution of the digitizer, i.e., the bit depth, influences the sensitivity rather weakly.
Microwave inductance of thin metal strips
Authors: Steinberg Katrin , Scheffler Marc , Dressel Martin
Published: November 2010

We have measured the frequency-dependent, complex impedance of thin metal strips in a broad range of microwave frequencies (45 MHz to 20 GHz). The spectra are in good agreement with theoretical predictions of an RCL model. The resistance, inductance, and capacitance, which govern the microwave response, depend on the strip width and thickness as well as on the strip and substrate materials. While the strip resistance scales inversely with the cross section, the inductance depends on the width of the strip but not on the thickness (in the limit of small thickness).
Structural, magnetic, electrical transport properties, and reversible room-temperature magnetocaloric effect in antipervoskite compound AlCMn3
Authors: Wang B. S. , Lin J. C. , Tong P. , Zhang L. , Lu W. J. , Zhu X. B. , Yang Z. R. , Song W. H. , Dai J. M. , Sun Y. P.
Published: November 2010

We report the structural, magnetic, electrical transport properties, and magnetocaloric effect (MCE) of antipervoskite compound AlCMn3. It exhibits a second-order ferromagnetic–paramagnetic phase transition around (TC) 287 K. The electronic resistivity (ρ) shows a good metallic behavior except for a slope change around TC. At lower temperatures (below 130 K), ρ∝T2 indicates that the electron-electron scatterings domain. At evaluated temperatures (130–270 K), ρ is linear dependence on temperature, implying that the phonon scatterings boost up greatly. Furthermore, a broad distribution of the magnetic entropy change (−ΔSM) peak is found to about 100 K with the magnetic field change ΔH=45 kOe. The relative cooling power are ∼137 J/kg and ∼328 J/kg (or ∼68 K2 and ∼162 K2) with ΔH=20 kOe and 45 kOe, respectively. All these values are comparable with the typical MCE associated with a second-order transition. It suggests that AlCMn3 may be considered as a candidate material for near room-temperature magnetic refrigeration because of: (i) the large full width at half peak of the −ΔSM-T curve, (ii) no hysteresis losses, (iii) the near room-temperature working temperature, and (iv) the low-cost and innoxious raw materials. Moreover, it is found that the simple theoretical model which only considering the magnetoelastic and magnetoelectronic couplings couldn’t account well for the observed MCE in antiperovskite AlCMn3.
Mechanical stiffening, bistability, and bit operations in a microcantilever
Authors: Venstra Warner J. , Westra Hidde J. R. , van der Zant Herre S. J.
Published: November 2010

We investigate the nonlinear dynamics of microcantilevers. We demonstrate mechanical stiffening of the frequency response at large amplitudes, originating from the geometric nonlinearity. At strong driving the cantilever amplitude is bistable. We map the bistable regime as a function of drive frequency and amplitude, and suggest several applications for the bistable microcantilever, of which a mechanical memory is demonstrated.
Magnetohydrodynamic instability in plasmas with intrinsic magnetization
Authors: Bychkov Vitaly , Modestov Mikhail , Marklund Mattias
Published: November 2010

From a magnetofluid description with intrinsic magnetization, a new plasma instability is obtained. The plasma magnetization is produced by the collective electron spin. The instability develops in a nonuniform plasma when the electron concentration and temperature vary along an externally applied magnetic field. Alfvén waves play an important role in the instability. The instability properties are numerically investigated for a particular example of an ultrarelativistic degenerate plasma in exploding white dwarfs.
Crystal coherence length effects on the infrared optical response of MgO thin films
Authors: Ihlefeld J. F. , Ginn J. C. , Shelton D. J. , Matias V. , Rodriguez M. A. , Kotula P. G. , Carroll J. F. , Boreman G. D. , Clem P. G. , Sinclair M. B.
Published: November 2010

The role of crystal coherence length on the infrared optical response of MgO thin films was investigated with regard to Reststrahlen band photon-phonon coupling. Preferentially (001)-oriented sputtered and evaporated ion-beam assisted deposited thin films were prepared on silicon and annealed to vary film microstructure. Film crystalline coherence was characterized by x-ray diffraction line broadening and transmission electron microscopy. The infrared dielectric response revealed a strong dependence of dielectric resonance magnitude on crystalline coherence. Shifts to lower transverse optical phonon frequencies were observed with increased crystalline coherence. Increased optical phonon damping is attributed to increasing granularity and intergrain misorientation.
Cell-free fusion of bacteria-containing phagosomes with endocytic compartments
Authors: Becken Ulrike , Jeschke Andreas , Veltman Katharina , Haas Albert
Published: November 2010

Uptake of microorganisms by professional phagocytic cells leads to formation of a new subcellular compartment, the phagosome, which matures by sequential fusion with early and late endocytic compartments, resulting in oxidative and nonoxidative killing of the enclosed microbe. Few tools are available to study membrane fusion between phagocytic and late endocytic compartments in general and with pathogen-containing phagosomes in particular. We have developed and applied a fluorescence microscopy assay to study fusion of microbe-containing phagosomes with different-aged endocytic compartments in vitro. This revealed that fusion of phagosomes containing nonpathogenic
Escherichia coli
with lysosomes requires Rab7 and SNARE proteins but not organelle acidification. In vitro fusion experiments with phagosomes containing pathogenic
Salmonella enterica
serovar Typhimurium indicated that reduced fusion of these phagosomes with early and late endocytic compartments was independent of endosome and cytosol sources and, hence, a consequence of altered phagosome quality.
Recognition and Molecular Discrimination of Severe and Mild PVYO Variants of Potato virus Y in Potato in New Brunswick, Canada
Authors: Nie Bihua , Singh Mathuresh , Sullivan Andrew , Singh Rudra P. , Xie Conghua , Nie Xianzhou
Published: November 2010

A field isolate of Potato virus Y (PVY) was collected in New Brunswick, Canada in 2007 due to unusual symptoms observed on different potato cultivars. To unveil the PVY strain identity, tobacco and potato bioassays, PVYO and PVYN-specific antibody-based enzyme-linked immunosorbent assays, and reverse-transcription polymerase chain reaction (PCR)-based genotyping were carried out. All the assays demonstrated that the isolate, designated as PVYO-FL in this study, belonged to the PVYO strain group. Greenhouse tests with the potato cvs. FL 1533 and Jemseg confirmed the severe nature of infection by PVYO-FL. The complete genome sequences of PVYO-FL and PVYO-RB, the latter a mild PVYO isolate, were determined. BLAST analysis revealed that the two isolates shared 97 and 98% sequence identities at the nucleotide and polyprotein levels, respectively. Further BLAST analysis unveiled that PVYO-FL shared 99.7% nucleotide sequence identity with PVYO-Oz, an isolate reported in New York, United States, whereas the PVYO-RB isolate shared 99.2% sequence identity with PVYO-139, a PVYO isolate reported in New Brunswick, Canada. A phylogenetic tree of available, full-length sequences of PVY isolates demonstrated two subgroups within the PVYO branch, one clustered with PVYO-RB and the other with PVYO-FL. Group-specific sense primers for differentiation of the two subgroups were developed and evaluated. A limited survey of potato tubers collected from a field plot at the Potato Research Centre, Agriculture and Agri-Food Canada, using the newly developed PCR primers, indicated that 65.3 and 2.4% of the PVYO-positive tubers were infected with PVYO isolates belonging to the PVYO-FL and PVYO-RB subgroups, respectively. Assessment of the pathogenicity of three representative isolates from each subgroup on the potato cv. Jemseg demonstrated that severe and mild symptoms were induced by the PVYO-FL-like and PVYO-RB-like isolates, respectively.
An alkylaminoquinazoline restores antibiotic activity in Gram-negative resistant isolates
Authors: Mahamoud Abdallah , Chevalier Jacqueline , Baitiche Milad , Adam Elissavet , Pagès Jean-Marie
Published: November 2010

To date, various bacterial drug efflux pump inhibitors (EPIs) have been described. They exhibit variability in their activity spectrum with respect to antibiotic structural class and bacterial species. Among the various 4-alkylaminoquinazoline derivatives synthesized and studied in this work, one molecule, 1167, increased the susceptibility of important human-pathogenic, resistant, Gram-negative bacteria towards different antibiotic classes. This 4-(3-morpholinopropylamino)-quinazoline induced an increase in the activity of chloramphenicol, nalidixic acid, norfloxacin and sparfloxacin, which are substrates of the AcrAB-TolC and MexAB-OprM efflux pumps that act in these multidrug-resistant isolates. In addition, 1167 increased the intracellular concentration of chloramphenicol in efflux pump-overproducing strains. The rate of restoration depended on the structure of the antibiotic, suggesting that different sites in the efflux pumps may be involved. A molecule exhibiting a morpholine functional group and a propyl extension of the side chain was more active.
Interstitial granulomatous dermatitis? An unusual presentation in the mucosa and periungual skin
Authors: NAKAMURA Naomi , ASAI Jun , DAITO Junko , TAKENAKA Hideya , KATOH Norito
Published: November 2010

Interstitial granulomatous dermatitis (IGD) is a reactive phenomenon accompanying disorders including autoimmune disease, lymphoproliferative disorders and drug reactions. Histologically, IGD shows a granulomatous infiltrate surrounding piecemeal fragmentation of collagen in the diffuse interstitium. IGD presents with linear cords, papules and plaques mainly on the trunk and extremities. Herein, we report a case with peculiar clinical features that were histopathologically consistent with IGD. A 74‐year‐old man presented with periungual painful erythema, nail deformity of all fingers and labial, penile and anal erosive erythema. Histopathological examination of the lesions showed interface dermatitis and a diffuse interstitial granulomatous infiltrate mainly composed of CD68‐positive histiocytes and lymphocytes. Degenerative collagen bundles were also observed in granulomas. C‐reactive protein and the white blood cell count were elevated, but further examinations did not reveal systemic inflammatory disorders such as autoimmune disease, lymphoproliferative disorder, inflammatory bowel disease or drug hypersensitivity. The lesions were successfully treated with oral and topical steroids.
Relative importance of sorption versus aggregation for organic matter storage in subsoil horizons of two contrasting soils
Authors: Moni C. , Rumpel C. , Virto I. , Chabbi A. , Chenu C.
Published: November 2010

Soil organic matter (OM) stabilization by the mineral phase can take place through sorption and aggregation. In this study we examined both of these processes, (i) organic carbon (OC) sorption onto clay‐sized particles and (ii) OC occlusion in silt‐size aggregates, with the objective of evaluating their relative importance in OM storage and stabilization in soil. We studied two loamy soil profiles (Haplic Luvisol and Plinthic Cambisol) currently under agricultural use down to a depth of 2 m. Our approach was based on two parallel fractionation methods using different dispersion intensities; these methods isolated a free clay fraction (non‐occluded) and a clay fraction occluded within water‐stable silt‐size aggregates. The two clay fractions were analysed for their C content and 14C activity. The proportion of sorbed OC was estimated as OC loss after hydrofluoric acid (HF) demineralization. Our results showed an important contribution to SOM stabilization by occlusion of OC into silt‐size aggregates with depth through both soil profiles. In the Haplic Luvisol, OC associated with clay and located in silt‐size aggregates accounted for 34–64% of the total soil OC, whereas in the Plinthic Cambisol this occluded material represented 34–40% of total OC. In the Haplic Luvisol, more OC was located in silt‐size aggregates than was sorbed onto clay‐size minerals, suggesting that silt‐size aggregation plays a dominant role in OC storage in this soil. In the Plinthic Cambisol, the abundance of sorbed OC increased with depth and contributed more to the stored C than that associated with silt‐size aggregates. Radiocarbon dating of both clay fractions (either occluded within silt‐size aggregates or not) suggests, in the case of the Plinthic Cambisol, a preferential stabilization of OC within silt‐size aggregates.
Tolerance to frost and ice encasement in cultivars of timothy and perennial ryegrass during winter
Authors: Höglind M. , Bakken A. K. , Jørgensen M. , Østrem L.
Published: November 2010

Ice encasement causes major winter damage in grasslands in coastal areas of Northern Scandinavia and may also affect grass performance in a future changing climate. Changes in ice‐encasement tolerance (LD50), frost tolerance (LT50) and water‐soluble carbohydrate (WSC) content were investigated in different cultivars of timothy and perennial ryegrass sampled at three sites with contrasting conditions. Timothy endured ice encasement for 40 d more than ryegrass (maximum LD50 63 vs. 20 d), and a cultivar originating from 69°N tolerated significantly longer periods in ice than a cultivar from 59°N. A similar relationship between cultivar origin and tolerance was observed for ryegrass. The higher LD50 in timothy compared with ryegrass seemed to be associated with a lower rate of change in WSC content during ice encasement, but no apparent relationship was found between WSC content at the start of encasement and plant survival in ice. A significant linear relationship was found between LD50 and LT50 of plants sampled in the field. A differing decline in frost tolerance during ice encasement for the species indicated that timothy is more resistant to dehardening under ice than ryegrass. This study contributes data and functional relationships needed to develop models of grass performance during winter.
Prophylaxis therapy in haemophilia A: current situation in Spain
Authors: LUCÍA J. F. , AZNAR J. A. , ABAD‐FRANCH L. , ESCUIN R. R. , JIMÉNEZ‐YUSTE V. , PÉREZ R. , BATLLE J. , BALDA I. , ALPEROVICH G. , PARRA R. ,   ON BEHALF OF THE SPANISH HAEMOPHILIA EPIDEMIOLOGICAL STUDY WORKING GROUP
Published: November 2010

Summary.  The Spanish Epidemiological Study in Haemophilia carried out in 2006 enrolled 2400 patients [2081–86.7% with haemophilia A (HA) and 319–13.3% with haemophilia B]; 465 of them (19.4%) were on prophylaxis. These rates were higher in patients with severe haemophilia (45.4%) and severe paediatric cases (72.5%). On the basis of information recorded in this study, we analysed the current situation of prophylaxis therapy administered to patients with HA in Spain, as well as their orthopaedic status. Prophylaxis was used in 399 (19.2%) patients with HA; such prophylaxis was primary (PP) in 20.3% and secondary (SP) in 75.9% of cases. Among severe HA patients, 313 (45.9%) were on prophylaxis (22.3% on PP and 74.7% on SP). Taking into account the patients’ age, 34.7% of severe HA adults were on prophylaxis (6% PP and 92.1% SP), whereas 71.5% of severe HA paediatric patients (40.5% PP and 55.4% SP) received this kind of treatment. Established haemophilic arthropathy (EHA) was detected in 142 from 313 severe HA patients (45.3%) on prophylaxis, but only in 2.9% of patients under PP vs. 59% of patients receiving SP. There was no EHA in adult severe HA patient on PP, whereas 70.4% on SP had joint damage (P < 0.00001). Among paediatric severe HA patients, EHA was detected in 3.3% under PP and 37.8% under SP (P < 0.00001). In conclusion, our data suggest that an early initiation of prophylaxis avoids EHA in the long‐term in patients with severe HA. We should emphasize the early onset of prophylaxis regimens.
Strategies to reduce transfusion acquired vCJD
Authors: Wallis J. P.
Published: November 2010

Variant Creutzfeldt–Jakob disease (vCJD) can be transmitted by transfusion. The risk depends on the number of infected donors in the community. An estimate of these numbers in a less genetically susceptible population, based on the epidemic seen so far, suggests a maximum of 300 more cases. From this, it is possible to predict a maximum of one transfusion acquired case in 3 years from plasma transfusion. Importation of plasma from outside the UK has been advocated to prevent these cases and would cost around £30 million per year. An alternative measure is to use the observed susceptibility and exposure to dietary vCJD by age, and to target low risk donors for the production of components such as fresh frozen plasma (FFP) and platelets. This will reduce the possible cases of plasma transfusion‐acquired vCJD at little or no extra cost to the health service.
Over‐expression of the triploid white poplar PtDrl01 gene in tobacco enhances resistance to tobacco mosaic virus
Authors: Zheng H.‐Q. , Zhang Q. , Li H.‐X. , Lin S.‐Z. , An X.‐M. , Zhang Z.‐Y.
Published: November 2010

A full‐length cDNA, designated as the Populus tomentosa disease resistance‐like 01 (PtDrl01) gene, was isolated from triploid white poplar [(Populus tomentosa × P. bolleana) × P. tomentosa]. The protein thought to be produced by the PtDrl01 gene contains a nuclear localisation sequence (NLS), a toll/interleukin‐1 receptor (TIR) homologue region, a nucleotide binding site (NBS) and a leucine‐rich repeat (LRR) domain. The protein also exhibits a considerable degree of homology to N‐like resistance proteins. Real‐time quantitative RT‐PCR analysis revealed that expression of the PtDrl01 gene in triploid white poplar leaves could be induced by two defence signalling molecules: methyl jasmonate (MeJA) and salicylic acid (SA). Over‐expression of the PtDrl01 gene in transgenic tobacco induced enhanced resistance to tobacco mosaic virus (TMV). Long‐term resistance from the PtDrl01 gene to TMV infection was also observed in transgenic tobacco plants. Additionally, over‐expression of the PtDrl01 gene resulted in transcriptional changes in genes expressing pathogenesis‐related proteins in transgenic tobacco under non‐stress conditions. These data strongly suggest that the PtDrl01 gene is involved in plant defence responses to pathogen infection.
Collective Migration in House Dust Mites
Authors: Mailleux Anne‐Catherine , Astudillo Fernandez Aina , Martin Gilles S. , Detrain Claire , Deneubourg Jean‐Louis
Published: November 2010

House dust mites (Dermatophagoides pteronyssinus) are widespread in the furniture and mattresses of homes throughout Eurasia. Because human occupation induces wide diurnal fluctuations in temperature and relative humidity, the most favourable locations for mites change constantly and they must migrate repeatedly. Here, we triggered and studied mites migration movements to a new area. Mites migrated from a starting arena to a second arena through a diamond‐shaped corridor offering a choice between two branches of equal length. In this article, we show that local air dryness and a distant water source were both necessary to trigger collective migration. Males and nymphs had a higher probability of migration than larvae and females. When migrating, although both branches initially appeared to be chosen equally, most mites eventually ended up choosing one particular branch. When about 50 or more mites had passed, there was an obvious choice of branch. We used a modelling approach to show that these data support the hypothesis that mites lay an attractive trail that is reinforced by followers. Consequently, the consistency of the collective choice is higher as the number of migrants grows. This article is the first to observe dust mite migration as a collective phenomenon.
Needle blight of pine caused by two species of Dothistroma in Hungary
Authors: Barnes I. , Kirisits T. , Wingfield M. J. , Wingfield B. D.
Published: November 2010

Dothistroma septosporumandD. pinicause the serious pine needle disease, Dothistroma needle blight (DNB). Of these,D. septosporumhas a global distribution, whileD. piniis known only from the USA, Russia, Ukraine and France. During a study ofD. septosporumisolates fromPinus nigrain Hungary, microsatellite markers revealed the presence of a secondDothistromaspecies. The aim of this study was to identify the DNB pathogens occurring in Hungary using four different molecular techniques. These included sequencing of the rDNA ITS region, a species‐specific ITS‐RFLP, mating type primers and a diagnostic microsatellite marker, Doth_A. Results showed that bothD. septosporumandD. pinioccur in Hungary and that both DNB pathogens were present on the same trees and in some cases, the same needles. Mating types MAT1 and MAT2 ofD. septosporumwere shown to be present in Hungary, but only the MAT2 ofD. piniwas found. In addition, examination of needles with DNB symptoms from Russia revealed the presence ofD. pinionPinus pallasianaandP. nigraas well as on a new host,Pinus mugo. The molecular markers applied in this study were sufficiently robust to identify and differentiate between the two DNB pathogens, both in culture and directly from needles. They will consequently be useful to document the geographical range and to monitor the spread ofD. septosporumandD. piniin future studies.
Chimaeras and the origins of the holopelagic annelids Typhloscolecidae and Lopadorhynchidae: a reply to Struck & Halanych (2010)
Authors: Nygren Arne , Pleijel Fredrik
Published: November 2010

Nygren, A. & Fredrik, P. (2010). Chimaeras and the origins of the holopelagic annelids Typhloscolecidae and Lopadorhynchidae: a reply to Struck & Halanych. —Zoologica Scripta, 40, 112–114.