CALCULATION OF CONVERSION COEFFICIENTS FOR VOXELIZED PHANTOMS FOR CRITICALITY ACCIDENT DOSIMETRY.

In the event of a criticality accident, not only the maximal doses received by the victims must be determined but it is also crucial to evaluate the doses to the different organs. With a neutron component, morphology is a key parameter in the organ dose calculation. As the simulation tools can be time consuming to proceed, especially if morphology is taken into account, for all the victims, it may be very useful to have a database of conversion coefficients that allow to obtain the organ doses from the dose measured in the dosemeter for different kinds of morphology. In this paper, we present a study performed to evaluate such conversion coefficients using voxelized anthropomorphic phantoms. These coefficients take into account two crucial parameters having an impact on the dose at the organs: the orientation of the victim in the radiation field and the morphology, that is to say the body mass index of the different victims.

Combined microscopy and molecular analyses show phloem occlusions and cell wall modifications in tomato leaves in response to 'Candidatus Phytoplasma solani'.

Callose deposition, phloem-protein conformational changes and cell wall thickening are calcium-mediated occlusions occurring in the plant sieve elements in response to different biotic and abiotic stresses. However, the significance of these structures in plant-phytoplasma interactions requires in-depth investigations. We adopted a novel integrated approach, based on the combined use of microscopic and molecular analyses, to investigate the structural modifications induced in tomato leaf tissues in presence of phytoplasmas, focusing on vascular bundles and on the occlusion structures. Phloem hyperplasia and string-like arrangement of xylem vessels were found in infected vascular tissue. The diverse occlusion structures were differentially modulated in the phloem in response to phytoplasma infection. Callose amount was higher in midribs from infected plants than in healthy ones. Callose was observed at sieve plates but not at pore-plasmodesma units. A putative callose synthase gene encoding a protein with high similarity to Arabidopsis CalS7, responsible for callose deposition at sieve plates, was upregulated in symptomatic leaves, indicating a modulation in the response to stolbur infection. P-proteins showed configuration changes in infected sieve elements, exhibiting condensation of the filaments. The transcripts for a putative P-protein 2 and a sieve element occlusion-related protein were localized in the phloem but only the first one was modulated in the infected tissues.

Assessment of xylem phenology: a first attempt to verify its accuracy and precision.

This manuscript aims to evaluate the precision and accuracy of current methodology for estimating xylem phenology and tracheid production in trees. Through a simple approach, sampling at two positions on the stem of co-dominant black spruce trees in two sites of the boreal forest of Quebec, we were able to quantify variability among sites, between trees and within a tree for different variables. We demonstrated that current methodology is accurate for the estimation of the onset of xylogenesis, while the accuracy for the evaluation of the ending of xylogenesis may be improved by sampling at multiple positions on the stem. The pattern of variability in different phenological variables and cell production allowed us to advance a novel hypothesis on the shift in the importance of various drivers of xylogenesis, from factors mainly varying at the level of site (e.g., climate) at the beginning of the growing season to factors varying at the level of individual trees (e.g., possibly genetic variability) at the end of the growing season.

Affect and outcome in short-term group therapy for loss.

Affect and work variables were monitored for 12 of 16 groups involved in a controlled outcome study of psychoanalytically oriented short-term group therapy. Groups were conducted by experienced therapists for outpatients who experienced difficulties adapting to personal losses through death, separation, or both. Postsessional ratings of positive and negative affect were provided by individual patients, therapists, and other patients. Psychodynamic work was rated independently using a content analysis system. Patients who had experienced separation were more inhibited in their affective expression. Rating sources agreed that positive affect increased over time. Direct relationships were found between positive affect and favorable outcome. Concerning negative affect, the strongest predictors of favorable outcome involved the interaction of affect and work. Implications of these findings are discussed in terms of the cathartic hypothesis.