Improving target delineation on 4-dimensional CT scans in stage I NSCLC using a deformable registration tool

INTRODUCTION: Correct target definition is crucial in stereotactic radiotherapy for lung tumors. We evaluated use of deformable registration (DR) for target contouring on 4-dimensional (4D) CT scans. MATERIALS AND METHODS: Three clinicians contoured gross tumor volume (GTV) in an end-inspiration phase of 4DCT of 6 patients on two occasions. Two clinicians contoured GTVs in all phases of 4DCT and on maximum intensity projections (MIP). The initial GTV was auto-propagated to 9 other phases using a B-spline algorithm (VelocityAI). Internal target volumes (ITVs) generated were (i) ITV(10manual) encompassing all physician-contoured GTVs, (ii) ITV-MIP(optimized) from MIP after review of individual 4DCT phases, (iii) ITV(10deformed) encompassing auto-propagated GTVs using DR, and (iv) ITV(10deformed-optimized), from an ITV(10deformed) target that was modified to form a 'clinically optimal' ITV. Volume-overlaps were scored using Dice's Similarity Coefficients (DSCs). RESULTS: Intra-clinician GTV reproducibility was greater than inter-clinician reproducibility (mean DSC 0.93 vs. 0.88, p<0.0004). In five of 6 patients, ITV-MIP(optimized) differed from the ITV(10deformed-optimized). In all patients, the DSC between ITV(10deformed-optimized) and ITV(10deformed) was higher than that between ITV(10deformed-optimized) and ITV-MIP(optimized) (p<0.02 T-test). CONCLUSION: ITVs created in stage I tumors using DR were closer to 'clinically optimal' ITVs than was the case with a MIP-modified approach

Interference correlations between like pions in the reaction K-p→K-pπ+π+π-π- at 8.25 GeV/c

We have observed correlations in the transverse momentum of pion pairs with like and unlike charge produced in 8.25 GeV/c K-p→K-pπ+π+π-π- interaction. We found that a Bose-Einstein interference effect accounts partially for these correlations. Evidence is presented indicating that the correlations observed in the above reaction can be described by the reflections from the occurence of physical resonances. © 1983 Springer-Verlag

Biogeographical implications of a new mouse-sized fossil bandicoot (Marsupialia: Peramelemorphia) occupying a dasyurid-like ecological niche across Australia

We describe Bulungu palara gen. et sp. nov., a new fossil peramelemorphian (bandicoot), based on a single well-preserved skull and additional dental specimens from Late Oligocene to Middle Miocene (Faunal Zones A-C) limestone deposits at the Riversleigh World Heritage Property, Queensland, and two dental specimens from the Early-Middle Miocene Kutjamarpu Local Fauna, South Australia. This is the first fossil peramelemorphian species to be reported from more than a single fossil fauna, with its inferred distribution extending from north-western Queensland (modern latitude ∼19°S) to north-eastern South Australia (modern latitude ∼28°S). The presence of Bulungu palara in Riversleigh Faunal Zones A, B and C and in the Kutjamarpu Local Fauna supports the current interpretation that these faunas span similar ages, namely Late Oligocene-Middle Miocene. Phylogenetic analyses of an expanded 74 morphological character dataset using maximum parsimony and Bayesian approaches, both with and without a molecular scaffold, consistently place Bulungu and the Oligo-Miocene forms Galadi and Yarala outside crown-group Peramelemorphia. These analyses also fail to support a close relationship between the Pliocene Ischnodon australis (previously considered the oldest known representative of the extant peramelemorphian family Thylacomyidae) and the modern thylacomyid genus Macrotis. With an estimated body mass of ∼130 g, Bulungu palara is smaller than any known Recent bandicoot from Australia, although some modern New Guinean species are similar in size. The small size and craniodental morphology of B. palara suggest that it was predominantly or exclusively insectivorous, perhaps ecologically similar to small New Guinean dasyurids such as Murexechinus melanurus. Together with the small-bodied (< 100 g), insectivorous Yarala burchfieldi and large-bodied (∼900 g), faunivorous Galadi speciosus, Bulungu palara demonstrates that Oligo-Miocene Australian peramelemorphians filled ecological niches that today are mostly occupied by dasyurids, and that a major faunal turnover event occurred at some point after the Middle Miocene

Experimental tests of the factorisation of Regge trajectories in the proton fragmentation region

We present double differential cross sections for the reactions K- + p → π± + anything at 8.25 GeV/c. Using published data for reactions K+ + p→ π- + anything and p + p → π+ anything we predict the differential cross sections for γ + p → π- + anything, π- + p → π- + anything and π- + p → π+ + anything in the target fragmentation region based on factorisation of the pomeron and Regge trajectories. Our predictions agree with the experimental data and support the hypothesis of factorisation of the Regge trajectories in the target fragmentation region. © 1973

A study of inclusive reactions K-p → K0 + X0 and K-p → K*- (890) + X+ at 8.25 GeV/c

The inclusive reactions K-p → K0 + X0 and K-p → K*- (890) + X+ are studied in detail at 8.25 GeV/c. The most prominent experimental features are discussed in connection with a triple-Regge behavior and, where relevant, compared with the corresponding data of K+p at the same energy. Evidence for pseudoscalar exchange dominance at small t′ and low missing mass is suggested by the density matrix element analysis of K*- (890). The natural- and unnatural-parity contributions to the cross section in the helicity frame indicate characteristics of absorptive behavior. © 1973

High transverse momentum and baryon exchange

Data are presented on the average transverse momentum of pions produced in events selected so as to enhance the baryon exchange contribution. High values are found compared with unselected events having only a small baryon exchange contribution. © 1972

A study of the low-mass part of the (Kππ) system in the reaction K-p→K-pπ+π- at 8.25 GeV/c

The low-mass (Kππ) system of the reaction K-p → K-pπ+π- at 8.25 GeV/c is studied. The cross-section of this reaction is (0.97± ±0.04) mb. The dependence of the cross-section on the proton-proton momentum transfer shows broadening of the diffraction peak with respect to increasing (Kππ) mass. The production of two-body and three-body resonances is discussed with respect to their occurrence in the four longitudinal-momentum phase space sectors of pl(π+)vs. pl(π-). This allows to separate the three-body low-mass systems (Kππ) and (pππ), which can be produced diffractively, from the other quasi-two-body processes whose production mechanism is meson exchange. In order to discuss what spin-parity contributions can be distinguished in the lowmass (Kππ) system, the D-moments of the angular distributions of the (Kππ) system with respect to variation of its effective mass and to variation of the possible analyser directions are carried out. The result is that, in addition to the dominant JP=1+ content, there is a clearly identifiable JP=0- contribution to the low-mass (Kππ) system. This contribution can be estimated to be 10% by an analysis of the density of events in the Dalitz plot, which gives also that the ρ production amplitude with respect to the K*(890) production amplitude decreases with increasing (Kππ) mass. This result is in agreement with an analysis of the reaction K+p→ K+pπ+π-. In the Appendix are given the properties of the D-moments and their predictability or suppression with respect to various spin-parity contributions. © 1974 Società Italiana di Fisica