Magnetic field tracking with MCNP5.

With the introduction of continuous-energy heavy charged particle transport in MCNP5, the need for tracking charged particles in a magnetic field becomes increasingly important. Two methods for including magnetic field effects on charged particles are included in the proton transport version of the code. The first technique utilises transfer maps produced by the beam dynamics simulation and analysis code COSY INFINITY. This method is fast and accurate; however, its use is limited to void cells only and to ensembles of particles with a fairly small energy spread. The second technique, particle ray tracing, is based on an algorithm adopted from the MARS transport code. This method can be applied to both void and material cells and is valid over a very large range of particle energies. Results from tracking particles in a quadrupole 'identity lens' using the two techniques are compared.

Proton radiography applications with MCNP5.

A modified version of MCNP5 has been developed to treat continuous-energy proton transport. This work is summarised in companion papers by Hughes et al. and Bull et al. (in these proceedings). An intrinsic part of this development effort has involved testing, verification and validation of a capability for simulating proton radiographs. This paper presents the results of calculations simulating various different test objects and the effects of alternative physics models. The significant physics processes include elastic scattering, multiple coulomb scattering, collisional energy-loss and straggling, magnetic fields and attenuation owing to nuclear interactions. Comparisons with experimental data are presented.

Micropropagation of Phytolacca dodecandra through shoot-tip and nodal cultures.

A procedure for micropropagation of endod (Phytolacca dodecandra) is described. BA at 0.44 µM produced 3.1 new shoots per expiant in six weeks using shoot tips. Nodal expiants, however, produced up to 4.7 shoots per explant on medium with 0.44 µM BA and 0.27 µM GA,. IBA at 0.49 µM induced 90% rooting with minimal callus. Plantlets were successfully transferred to the greenhouse and some staminate clones produced flowers after six months.

Similarities between lidar inversion algorithms.

This Letter demonstrates that there is a link between the double ended inversion method and the forward or the reverse inversion method, with a known relationship between extinction and backscatter.

Double-ended lidar technique for aerosol studies.

The technique of inverting a single-ended lidar return to obtain range-dependent atmospheric extinction coefficients requires an assumption concerning the relationship between the volumetric backscatter and extinction coefficients. By comparing the powers returned from a volume common to each of two lidars located at opposite ends of a propagation path the need for this relationship can be eliminated, and the extinction coefficient is determined as a function of position between the two lidars. If the lidars are calibrated, the backscatter coefficients and their relationship to extinction can then be determined as a function of position. We present measurements obtained with two lidars which were operated reciprocally over a slant path of ~1 km during reduced visibility conditions. The measured extinction and backscatter coefficients determined by this method provide the boundary value inputs to both the forward and reverse integration algorithms for inverting the single-ended lidar returns. The accuracies by which both singleended integration schemes can reproduce the double-ended measurements are examined by allowing the ratio of backscatter to extinction coefficients to be either constant or varying with position between the two lidars as measured.

Cervical spine movement during orotracheal intubation.

We measured cervical spine movement during orotracheal intubation in 16 anesthetized patients without neck injury. Comparisons were made using straight and curved laryngoscope blades without stabilization, Philadelphia collar stabilization, and in-line stabilization by an assistant. There was cervical spine movement in all cases. There was no significant difference in movement without stabilization when comparing straight and curved laryngoscope blades (P = .8536). There was no significant decrease in movement when a Philadelphia collar was applied (P = 1.000). There was a significant decrease in movement when in-line stabilization was applied (P = 0.0056). Although none of the methods tested totally prevented cervical spine movement during orotracheal intubation, the least movement was obtained by the use of in-line stabilization by an assistant. The type of laryngoscope blade used or application of a Philadelphia collar did not reduce movement significantly.

Sensitivity of a lidar inversion algorithm to parameters relating atmospheric backscatter and extinction.

A solution of the single-scattering lidar equation requires a relationship between the coefficients of backscatter beta(r) and extinction sigma(r) to be of the form beta(r) = C2sigma(r)k, where C2 and k are parameters independent of range r. The sensitivity of a particular lidar inversion algorithm to uncertainties in C2 and k is investigated using a measured lidar return which indicated the atmosphere to be essentially horizontally homogeneous during a reduced visibility condition. Starting with the measured power returned as a function of range, extinction coefficients and average visibilities are calculated using the inversion algorithm for different values of C2 and k and compared with those inferred from the lidar return using the slope method. The calculated extinction coefficients (and visibilities) were found to be extremely sensitive to uncertainties in C2. This questions the usefulness of the lidar inversion algorithm for aerosol extinction applications when the air mass characteristics change along the measurement path.

Traumatic disruption of the brachiocephalic artery.

We report the case of a patient presenting with blunt chest and head injuries. Initial emergency department evaluation revealed a pulmonary contusion and suspected closed head injuries. Computed tomographic scan of the head was unremarkable. An angiogram performed to further investigate the nature of his head injuries revealed a disruption of the brachiocephalic artery. The lesion was surgically repaired in the operating room and the patient was moved to the intensive care unit, where he remained comatose and died from complications of his head and chest injuries on the seventh post-operative day. The pathophysiology and clinical manifestations of injuries to the brachiocephalic artery are discussed.