MRI radiomic features are independently associated with overall survival in soft tissue sarcoma

Purpose: Soft tissue sarcomas (STS) represent a heterogeneous group of diseases, and selection of individualized treatments remains a challenge. The goal of this study was to determine whether radiomic features extracted from magnetic resonance (MR) images are independently associated with overall survival (OS) in STS. Methods and Materials: This study analyzed 2 independent cohorts of adult patients with stage II-III STS treated at center 1 (N = 165) and center 2 (N = 61). Thirty radiomic features were extracted from pretreatment T1-weighted contrast-enhanced MR images. Prognostic models for OS were derived on the center 1 cohort and validated on the center 2 cohort. Clinical-only (C), radiomics-only (R), and clinical and radiomics (C+R) penalized Cox models were constructed. Model performance was assessed using Harrell\u27s concordance index. Results: In the R model, tumor volume (hazard ratio [HR], 1.5) and 4 texture features (HR, 1.1-1.5) were selected. In the C+R model, both age (HR, 1.4) and grade (HR, 1.7) were selected along with 5 radiomic features. The adjusted c-indices of the 3 models ranged from 0.68 (C) to 0.74 (C+R) in the derivation cohort and 0.68 (R) to 0.78 (C+R) in the validation cohort. The radiomic features were independently associated with OS in the validation cohort after accounting for age and grade (HR, 2.4; Conclusions: This study found that radiomic features extracted from MR images are independently associated with OS when accounting for age and tumor grade. The overall predictive performance of 3-year OS using a model based on clinical and radiomic features was replicated in an independent cohort. Optimal models using clinical and radiomic features could improve personalized selection of therapy in patients with STS

Detection of two dissimilar chronic wasting disease isolates in two captive Rocky Mountain elk (\u3ci\u3eCervus canadensis\u3c/i\u3e) herds: Two distinctive chronic wasting disease isolates identified in captive elk

Chronic wasting disease (CWD) continues to spread in both wild and captive cervid herds in North America and has now been identified in wild reindeer and moose in Norway, Finland and Sweden. There is limited knowledge about the variety and characteristics of isolates or strains of CWD that exist in the landscape and their implications on wild and captive cervid herds. In this study, we evaluated brain samples from two captive elk herds that had differing prevalence, history and timelines of CWD incidence. Site 1 had a 16-year history of CWD with a consistently low prevalence between 5% and 10%. Twelve of fourteen naïve animals placed on the site remained CWD negative after 5 years of residence. Site 2 herd had a nearly 40-year known history of CWD with long-term environmental accrual of prion leading to nearly 100% of naïve animals developing clinical CWD within two to 12 years. Obex samples of several elk from each site were compared for CWD prion strain deposition, genotype in prion protein gene codon 132, and conformational stability of CWD prions. CWD prions in the obex from site 2 had a lower conformational stability than those from site 1, which was independent of prnp genotype at codon 132. These findings suggest the existence of different CWD isolates between the two sites and suggest potential differential disease attack rates for different CWD strains

Pionium Production in the Cooler

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Conserved Responses in a War of Small Molecules between a Plant-Pathogenic Bacterium and Fungi

Small-molecule signaling is one major mode of communication within the polymicrobial consortium of soil and rhizosphere. While microbial secondary metabolite (SM) production and responses of individual species have been studied extensively, little is known about potentially conserved roles of SM signals in multilayered symbiotic or antagonistic relationships. Here, we characterize the SM-mediated interaction between the plant-pathogenic bacterium Ralstonia solanacearum and the two plant-pathogenic fungi Fusarium fujikuroi and Botrytis cinerea. We show that cellular differentiation and SM biosynthesis in F. fujikuroi are induced by the bacterially produced lipopeptide ralsolamycin (synonym ralstonin A). In particular, fungal bikaverin production is induced and preferentially accumulates in fungal survival spores (chlamydospores) only when exposed to supernatants of ralsolamycin-producing strains of R. solanacearum. Although inactivation of bikaverin biosynthesis moderately increases chlamydospore invasion by R. solanacearum, we show that other metabolites such as beauvericin are also induced by ralsolamycin and contribute to suppression of R. solanacearum growth in vitro. Based on our findings that bikaverin antagonizes R. solanacearum and that ralsolamycin induces bikaverin biosynthesis in F. fujikuroi, we asked whether other bikaverin-producing fungi show similar responses to ralsolamycin. Examining a strain of B. cinerea that horizontally acquired the bikaverin gene cluster from Fusarium, we found that ralsolamycin induced bikaverin biosynthesis in this fungus. Our results suggest that conservation of microbial SM responses across distantly related fungi may arise from horizontal transfer of protective gene clusters that are activated by conserved regulatory cues, e.g., a bacterial lipopeptide, providing consistent fitness advantages in dynamic polymicrobial networks

Measurement of Inclusive Spin Structure Functions of the Deuteron

We report the results of a new measurement of spin structure functions of the deuteron in the region of moderate momentum transfer ($Q^2$ = 0.27 -- 1.3 (GeV/c)$^2$) and final hadronic state mass in the nucleon resonance region ($W$ = 1.08 -- 2.0 GeV). We scattered a 2.5 GeV polarized continuous electron beam at Jefferson Lab off a dynamically polarized cryogenic solid state target ($^{15}$ND$_3$) and detected the scattered electrons with the CEBAF Large Acceptance Spectrometer (CLAS). From our data, we extract the longitudinal double spin asymmetry $A_{||}$ and the spin structure function $g_1^d$. Our data are generally in reasonable agreement with existing data from SLAC where they overlap, and they represent a substantial improvement in statistical precision. We compare our results with expectations for resonance asymmetries and extrapolated deep inelastic scaling results. Finally, we evaluate the first moment of the structure function $g_1^d$ and study its approach to both the deep inelastic limit at large $Q^2$ and to the Gerasimov-Drell-Hearn sum rule at the real photon limit ($Q^2 \to 0$). We find that the first moment varies rapidly in the $Q^2$ range of our experiment and crosses zero at $Q^2$ between 0.5 and 0.8 (GeV/c)$^2$, indicating the importance of the $\Delta$ resonance at these momentum transfers.Comment: 13 pages, 8 figures, ReVTeX 4, final version as accepted by Phys. Rev.

Deeply virtual and exclusive electroproduction of omega mesons

The exclusive omega electroproduction off the proton was studied in a large kinematical domain above the nucleon resonance region and for the highest possible photon virtuality (Q2) with the 5.75 GeV beam at CEBAF and the CLAS spectrometer. Cross sections were measured up to large values of the four-momentum transfer (-t < 2.7 GeV2) to the proton. The contributions of the interference terms sigma_TT and sigma_TL to the cross sections, as well as an analysis of the omega spin density matrix, indicate that helicity is not conserved in this process. The t-channel pi0 exchange, or more generally the exchange of the associated Regge trajectory, seems to dominate the reaction gamma* p -> omega p, even for Q2 as large as 5 GeV2. Contributions of handbag diagrams, related to Generalized Parton Distributions in the nucleon, are therefore difficult to extract for this process. Remarkably, the high-t behaviour of the cross sections is nearly Q2-independent, which may be interpreted as a coupling of the photon to a point-like object in this kinematical limit.Comment: 15 pages,19 figure

Compton Scattering from \u3csup\u3e4\u3c/sup\u3eHe at 61 MeV

The Compton scattering cross section from 4He has been measured with high statistical accuracy over a scattering angle range of 40∘−159∘ using a quasimonoenergetic 61-MeV photon beam at the High Intensity Gamma-Ray Source. The data are interpreted using a phenomenological model sensitive to the dipole isoscalar electromagnetic polarizabilities (αs and βs) of the nucleon. These data can be fit with the model using values of αs and βs that are consistent with the currently accepted values. These data will serve as benchmarks of future calculations from effective field theories and lattice quantum chromodynamics

Q2Q^2 Dependence of Quadrupole Strength in the γ∗p→Δ+(1232)→pπ0\gamma^*p\to\Delta^+(1232)\to p \pi^0 Transition

Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the $Q^2$ dependence of the magnetic ($M_{1+}$), electric ($E_{1+}$), and scalar ($S_{1+}$) multipoles in the $\gamma^* p \to \Delta^+ \to p \pi^0$ transition. We report new experimental values for the ratios $E_{1+}/M_{1+}$ and $S_{1+}/M_{1+}$ over the range $Q^2$= 0.4-1.8 GeV$^2$, extracted from precision $p(e,e 'p)\pi^{\circ}$ data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role.Comment: 5 pages, 5 figures, 1 table. To be published in Phys. Rev. Lett. (References, figures and table updated, minor changes.