Impulsively Generated Linear and Non-linear Alfven Waves in the Coronal Funnels

We present simulation results of the impulsively generated linear and non-linear Alfv\'en waves in the weakly curved coronal magnetic flux-tubes (coronal funnels) and discuss their implications for the coronal heating and solar wind acceleration. We solve numerically the time-dependent magnetohydrodynamic (MHD) equations to obtain the temporal signatures of the small (linear) and large-amplitude (non-linear) Alfv\'en waves in the model atmosphere of expanding open magnetic field configuration (e.g., coronal funnels) by considering a realistic temperature distribution. We compute the maximum transversal velocity of both linear and non-linear Alfv\'en waves at different heights in the coronal funnel, and study their response in the solar corona during the time of their propagation. We infer that the pulse-driven non-linear Alfv\'en waves may carry sufficient wave energy fluxes to heat the coronal funnels and also to power the solar wind that originates in these funnels. Our study of linear Alfv\'en waves show that they can contribute only to the plasma dynamics and heating of the funnel-like magnetic flux-tubes associated with the polar coronal holes.Comment: 16 pages of the text and 3 figure

Nucleon-deuteron scattering with Δ-isobar excitation: Perturbation theory

A perturbative approach for the description of elastic and inelastic nucleon-deuteron scattering is developed. Its validity is discussed. The aim of the perturbative approach is the isolation of details of different reaction mechanisms. The dynamics is based on a two-baryon potential allowing for the excitation of a nucleon to a Δ isobar. The coupled-channel potential yields an effective three-nucleon force in three-nucleon scattering. The purely nucleonic reference potential is the charge-dependent CD-Bonn potential

Terminologia Anatomica and its practical usage: pitfalls and how to avoid them

In 2016, the Federative International Programme for Anatomical Terminology tentatively approved the updated and extended version of anatomical terminology that replaced the previous version of Terminologia Anatomica (1998). This modern version has already appeared in new editions of leading anatomical atlases and textbooks, including Netter’s Atlas of Human Anatomy, even though it was originally available only as a draft and the final version is different. We believe that updated and extended versions of anatomical terminology are important and they can be a powerful tool in communication between anatomists and other specialists around the world. In general, the new version uses more precise and adequate anatomical terms and many segments, including the part dealing with the nervous system, which is also known as the Terminologia Neuroanatomica, have been considerably improved. Nevertheless, some segments have not been extended or modernised, while other parts have been modified considerably, thereby posing a challenge to those who prefer the traditional version of Latin terminology because a number of official names for bones, muscles, organs and blood vessels have been changed. Whilst most of these changes seem to be inspired by a long anatomical tradition and thus cannot come as a surprise to anyone in the field, other modifications are characterised by terminological innovativeness. Selected new and unexpected changes that might cause confusion among those who prefer traditional anatomical terms and definitions are discussed here

303. Image registration – precise quality assessment of radiotherapy without necessity of showing corresponding points in simulation and portal images

PurposeEnabling the quality assessment of radiotherapy to be made in daily practice, using the new software tool to analyze the simulation and portal images.MethodIn the registration of the anatomical structures as well as the irradiation fields, the features used as landmarks are the edges. The significant edge fragments must be chosen manually, but without showing any specific corresponding points. Field edges marked with wires in the simulation image are found fully automatically with the original combination of a dedicated line edge detector and a version of hierarchical, combined Hough transform. The registration is guided by the robust accuracy criterion using the modified Hausdorff distance measure. The only parameter of the measure – quantile rank, or share of data used in comparison – is not fixed, but evolves from 1 to 0 during the optimization of the accuracy. This has two advantages. 1: The user can choose the result found for the share corresponding to the actual share of erroneous data in the images, which can be seen only after the results for all the possible ranks are known. 2: The algorithm can avoid the local minima. The registration takes few seconds on a typical PC. The method has been implemented in a software tool which supports the complete process of measurement, and has been tested in clinical triais with positive result.ConclusionsThe modified Hausdorff distance measure with evolving rank is a good and efficient registration accuracy measure for quality assessment of radiotherapy based on the comparison of portal and simulation images

Breakup in nucleon-deuteron scattering with Δ-isobar excitation

Breakup in nucleon-deuteron scattering is described. The description is based on a coupled-channel two-baryon potential that allows for the virtual excitation of a nucleon to a Δ isobar. The Coulomb interaction is not included. Channel coupling gives rise to an effective three-nucleon force. The three-particle scattering equations are solved by real-axis integration using a separable expansion of the two-baryon transition matrix. Examples for spin-averaged and spin-dependent observables are calculated and compared with experimental data

3/Evaluation of set-up deviations during the irradiation of patients suffering from breast cancer treated with two different techniques

PurposeTo present results of patient positioning during routine radiotherapy for patients treated after mastectomy and to compare the inaccuracies in patient set-up for this group of patients and for the patients treated after breast conserving therapy with tangential fields.Methods and materialsIn total, the analysis comprised 56 pairs of portal and simulator films for 14 consecutive patients treated following breast conserving therapy and 98 pairs of portal and simulator films for 20 consecutive patients treated after mastectomy. For the first group the tangential field technique (TF technique) was used, for the second the inverse hockey stick technique (IHS technique). The comparison of the treatment reproducibility obtained for both groups of patients was performed in terms of systematic and random error calculated for the whole groups and by the comparison of cumulative distribution of the length of the displacement vector.ResultsIn the IHS and TF techniques for medial and lateral fields, displacement larger than 5 mm occurred in 28.3%, 15.8% and 25.4% respectively. For the IHS technique, the systematic errors for lateral and cranial-caudal direction were 1.9 and 1.7 mm respectively (1 standard deviation – SD), the random errors for lateral and cranial-caudal direction were 2.0 and 2.5 mm. For the TF technique, the systematic errors for lateral and cranial-caudal direction were 2.6 and 1.3 mm for medial field and 3.7 and 0.7 mm for lateral fields respectively, the random errors for lateral and cranial-caudal direction were 2.2 and 1.0 mm for medial field and 2.9 and 1.1 for lateral field respectively. Rotations were negligible in the HIS technique. For the TF technique the systematic component and random component amounted to about 2.0 degrees (1 SD).ConclusionsBoth the inverse hockey stick and standard tangential techniques showed good reproducibility of patients set-up with respect to cranial-caudal direction. For the TF technique, the accuracy should be improved for the medial field with respect to the ventral-dorsal direction

Three- and Four-Body Scattering Calculations including the Coulomb Force

The method of screening and renormalization for including the Coulomb interaction in the framework of momentum-space integral equations is applied to the three- and four-body nuclear reactions. The Coulomb effect on the observables and the ability of the present nuclear potential models to describe the experimental data is discussed.Comment: Proceedings of the Critical Stability workshop, Erice, Sicily, October 2008, to be published in Few-Body System

Potential Tools for Eradicating HIV Reservoirs in the Brain: Development of Trojan Horse Prodrugs for the Inhibition of P-Glycoprotein with Anti-HIV-1 Activity

Combination antiretroviral therapy is the mainstay of HIV treatment, lowering plasma viral levels below detection. However, eradication of HIV is a major challenge due to cellular and anatomical viral reservoirs that are often protected from treatment by efflux transporters, such as P-glycoprotein (P-gp) at the blood–brain barrier (BBB). Herein we described a Trojan horse approach to therapeutic evasion of P-gp based on a reversibly linked combination of HIV reverse transcriptase and protease inhibitors. Potent inhibition of P-gp efflux in cells, including human brain endothelial cells, was observed with the linked heterodimeric compounds. In vitro regeneration of active monomeric drugs was observed in a reducing environment with these dimeric prodrugs, with the superior leaving group promoting more facile release from the tether. These release trends were mirrored in the efficacy of the in cyto anti-HIV-1 activity of the Trojan horse heterodimers