Full aperture backscatter diagnostics for characterization of laser plasma instabilities at the extreme light infrastructure (ELI) beamlines.

We report on the commissioning of a full aperture backscatter diagnostics station for the kilojoule, nanosecond high repetition rate L4n laser operating at a wavelength of 527 nm at the Extreme Light Infrastructure (ELI) - Beamlines, Dolni Brezany, Czech Republic. Light scattered back from laser-plasma interaction into the cone of the final focusing lens is captured and split into different channels to measure the signatures of laser plasma instabilities from stimulated Brillouin scattering, stimulated Raman scattering, and two plasmon decay with respect to back scattered energy, its spectrum, and its temporal profile. The performance was confirmed in a commissioning experiment with more than 800 shots at laser intensities ranging from 0.5 × 1013 to 1.1 × 1015 W cm-2. These diagnostics are permanently installed at ELI Beamlines, and can be used to understand the details of laser-plasma interactions in experiments with kJ and 527 nm light. The large number of shots that can be collected in an experimental campaign will allow us to study the details of the laser-plasma interaction with a high level of confidence.

Sequence variation of ribosomal internal transcribed spacers (ITS) in commercially important Phytoseiidae mites.

Preliminary work is needed to assess the usefulness of different markers at different taxonomic scales when a new group is analyzed, such as the commercially important Phytoseiidae mites. We investigate here the level of sequence variation of the nuclear ribosomal spacers ITS 1 and 2 and the 5.8S gene in six species of Phytoseiidae: Neoseiulus culifornicus, N. fallacis, Euseius concordis, Metaseiulus occidentalis, Typhlodromus pyri and Phytoseiulus persimilis. As expected, the 5.8S gene (148 base pairs) is markedly conserved and displays little variation in between genera comparisons. ITS1 and ITS2 show contrasting patterns: while the ITS2 is short (80-89 bp) and shows little variation, the ITS1 is longer (303-404 bp) and is very variable in sequence. This fact compromises reliable nucleotide homologies when comparing the genera. The comparison of ITS1 sequence similarity at the species level might be useful for species identification, however, the value of ITS in taxonomic studies does not extend to the level of the family. The intraspecific variations of ITS were investigated in three species: N. californicus, N. fallacis and E. concordis. The first species has identical ITS1 sequences and the last two display low polymorphism (2 nucleotide substitutions). The ITS2 and 5.8S sequences were identical in all three subspecies comparisons.

[Evaluation of a computer graphic representation of echo-Doppler (Echotrace) in the assessment of atherosclerosis of the legs]. / Evaluation d'une représentation graphique de l'écho-Doppler (Echotrace) dans le bilan de l'athérosclérose des membres inférieurs.

The problems generally encountered in interpreting written reports of echo-Doppler examinations led us to develop a graphic software system to visualize the vascular network: Echotrace. The objective of the present work was to evaluate the reliability of Echotrace in patients with atherosclerosis of the lower limbs using arteriography as the standard for assessing sonographic findings. This prospective study was conducted in 29 consecutive patients. Nineteen strategic sites of the arterial network were investigated with duplex-scan and arteriography: lesions scores were attributed for each examination and data for a given site were compared. On the 551 sites compared, we found 26 disagreements including 23 concerning lesion quantification and 3 on localizations. There were also 21 minor disagreements with a single variation in the pathology score. The statistical comparisons could not be made on these scores so the results were compared with the arteriography data on the basis of therapeutic decision taking into account all the arterial lesions and the patient's general status. We observed a perfect agreement between the two imaging techniques in 12 patients, one disagreement which would not change the treatment in 15 patients and, in 2 patients, a disagreement which would modify treatment. This study demonstrated that graphic visualization of arterial lesions with Echotrace is a reliable, easy-to-interpret method.

[Echographic aspects of blood clots]. / Aspects échographiques des caillots sanguins.

The ultrasonic imaging of blood clots depends on the degree of compactness of the red cells which it contains. When the clot is densely compact, the number of targets struck by the ultrasound beam is large, and major diffusion occurs, providing a visible image. When the clot is less dense, there are insufficient targets and it is not possible to pick-up a reflected signal able to create a visible image. The former situation arises in the case of a recently-formed clot, whereas the latter occurs in ageing clots.