Interobserver variability in target definition for stereotactic arrhythmia radioablation

Background: Stereotactic arrhythmia radioablation (STAR) is a potential new therapy for patients with refractory ventricular tachycardia (VT). The arrhythmogenic substrate (target) is synthesized from clinical and electro-anatomical information. This study was designed to evaluate the baseline interobserver variability in target delineation for STAR. Methods: Delineation software designed for research purposes was used. The study was split into three phases. Firstly, electrophysiologists delineated a well-defined structure in three patients (spinal canal). Secondly, observers delineated the VT-target in three patients based on case descriptions. To evaluate baseline performance, a basic workflow approach was used, no advanced techniques were allowed. Thirdly, observers delineated three predefined segments from the 17-segment model. Interobserver variability was evaluated by assessing volumes, variation in distance to the median volume expressed by the root-mean-square of the standard deviation (RMS-SD) over the target volume, and the Dice-coefficient. Results: Ten electrophysiologists completed the study. For the first phase interobserver variability was low as indicated by low variation in distance to the median volume (RMS-SD range: 0.02–0.02 cm) and high Dice-coefficients (mean: 0.97 ± 0.01). In the second phase distance to the median volume was large (RMS-SD range: 0.52–1.02 cm) and the Dice-coefficients low (mean: 0.40 ± 0.15). In the third phase, similar results were observed (RMS-SD range: 0.51–1.55 cm, Dice-coefficient mean: 0.31 ± 0.21). Conclusions: Interobserver variability is high for manual delineation of the VT-target and ventricular segments. This evaluation of the baseline observer variation shows that there is a need for methods and tools to improve variability and allows for future comparison of interventions aiming to reduce observer variation, for STAR but possibly also for catheter ablation

Photoelectron and threshold photoelectron valence spectra of pyridine

The pyridine molecule has been examined by the means of photoelectron and threshold photoelectron spectroscopies. Ionization energies were determined for both outer and inner valence orbitals and new adiabatic values were also resolved. Vibronic structure associated with several states was assigned mainly to be due to C-C stretches and ring bends. Additionally a Rydberg state converging to 7b2 state was ascribed. The data shown here are in a good agreement with previous results and brings some new insights into the electronic structure of this biologically and astrochemically relevant and important molecule

Sequence analysis of the ribosomal Internal Transcribed Spacers region in spider mites (Prostigmata: Tetranychidae) occurring in citrus orchards in Eastern Spain: use for species discrimination

Tetranychus urticae is a polyphagous mite which is an important pest of citrus worldwide. This mite can be found feeding on many plant species occurring in the citrus agrosystem moving from weeds to trees. Because field samples consist of a mixture of different Tetranychidae species, as a first step necessary to further implement population characterization of T. urticae, species-discriminating criteria based on molecular techniques are needed. In this study, the nucleotide variation of the Internal Transcribed Spacers (ITS) 1 and 2 and the intergenic 5.8S fragment of nuclear ribosomal DNA of T. urticae, T. turkestani, T. evansi, T. ludeni and P. citri, have been determined. Results demostrate that for these species, the rDNA ITS2 regions are much more conserved than the corresponding rDNA ITS1. The high homogeneity of the ITS2 sequence observed among the specimens of T. urticae obtained from the same eco-region makes this DNA-sequience an excellent tool for species discrimination. ITS sequences differentiate not only species but also specimens from different geographical origin. Furthemore, PCR-RFLP analysis of the ITS2 proved adequate for a quick screening of high numbers of field sample

Potential distribution of the invasive mite Tetranychus evansi (Tetranychidae) in the Mediterraean region

Predicting the potential geographical distribution of a species is particularly useful for pests with strong invasive abilities. Tetranychus evansi, possibly native of South America, is a spider mite recognized as a pest of solanaceous crops. This mite is considered as an invasive species in Africa and Europe and has been recorded in many parts of the world. To define the potential global distribution of the species, a CLIMEX model distribution was developed using: i) South American records, ii) laboratory life‐history parameters and iii) exotic records. The model results fitted the known distribution of T.evansi Except for some dry locations host plants develop only with irrigation. High temperatures, dry and wet stresses play a role in limiting the spread of the mite in the tropics, Whereas in a large part of North America and Europe, the distribution of T.evansi appears to be limited essentially by cold stress. A distribution map is provided for the global potential distribution of T.evansi. The Mediterranean region is of particular interest because it is the main area where tomato is grown in open fields in Europe. According to the model, the Mediterranean region will be colonized in exorably by the pest. However, model results indicate a mite distribution being limited to coastal areas

Sequence analysis of the ribosomal internal transcribed spacers region in spider mites (Prostigmata: Tetranychidae) occurring in citrus orchards in Eastern Spain: use for species discrimination

Correspondence to Mónica Hurtado Ruiz, Departament de Ciències Agràries i del Medi Natural, Universitat Jaume I, Campus del Riu Sec, E-12071-Castelló de la Plana, Spain. Email: [email protected] Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699International audienceTetranychus urticae is a polyphagous mite which is an important pest of citrus worldwide. This mite can be found feeding on many plant species occurring in the citrus agrosystem moving from weeds to trees. Because field samples consist of a mixture of different Tetranychidae species, as a first step necessary to further implement population characterisation of T. urticae, species-discriminating criteria based on molecular techniques are needed. In this study, the nucleotide variation of the internal transcribed spacers (ITS) 1 and 2 and the intergenic 5.8S fragment of nuclear rDNA of T. urticae, Tetranychus turkestani, Tetranychus evansi, Tetranychus ludeni and Panonychus citri have been determined. Results demonstrate that for these species, the rDNA ITS2 regions are much more conserved than the corresponding rDNA ITS1. The high homogeneity of the ITS2 sequence observed among the specimens of T. urticae obtained from the same ecoregion makes this DNA sequence an excellent tool for species discrimination. ITS sequences differentiate not only species but also specimens from different geographical origin. Furthermore, polymerase chain reaction–restriction fragment length polymorphism analysis of the ITS2 proved adequate for a quick screening of high numbers of field sample