This study demonstrated that a 5 Gy X-ray dose accumulated over 6 weeks during a longitudinal micro-CT study had no significant effects on the pulmonary and myocardial tissue of C57BL/6 mice. As a result, the many advantages of micro-CT imaging, including rapid acquisition of high-resolution, isotropic images in free-breathing mice, can be taken advantage of in longitudinal studies without concern for negative dose-related effects.

In this paper we discuss some of the effects of using "unidexterous" worldsheet superfields, which satisfy worldsheet differential constraints ∂ = Λ = 0 = ∂ = | Υ and so are partly on-shell, i.e., on half-shell. Most notably, this results in a stratification of the field space that reminds of "brane-world" geometries. Linear dependence on such superfields provides a worldsheet generalization of the super-Zeeman effect. In turn, non-linear dependence yields additional left-right asymmetric dynamical constraints on the propagating fields, again in a stratified fashion. PACS: 11.30.Pb, 12.60.Jv Introduction, Results and SynopsisSupersymmetry has been studied for almost four decades [1,2,3,4], but still seems to harbor novel features. In particular, worldsheet supersymmetry is unique among supersymmetric field theories in that the Lorentz group is abelian Spin(1, 1) U(1). This permits the definition of the twistedchiral superfields [5], and a whole host of supersymmetry representations not possible in higherdimensional spacetimes [6]; see Eqs. (1.2b)-(1.2c) for two that we will need herein: the lefton and rightons superfields, denoted Λ and Υ, respectively.In superfield formulations of supersymmetry it is not uncommon that some of the component fields, called auxiliary, end up having algebraic equations of motion. It is routinely assumed that such algebraic equations may be solved for, and their solutions substituted back into the Lagrangians, thereby obtaining an equivalent but simpler description of the model.It is our main purpose to point out that this is not as straightforward as it may seem, that it may well impose rather non-standard dynamical constraints on the model, and may well result in stratifying the field space of the model into regions (strata) of varying dimensions and dynamics. As worldsheet models are most often used in superstring theory and suitable subsets of the field space are identified as the effective, "real" spacetime, worldsheet models with such stratified field space would seem to provide a natural Lagrangian framework for "brane-world"-like geometries.The remainder of this section offers a basic review of (1, 1|2, 2)-superspace notation, with a few technical details deferred to Appendix A. Section 2 employs this to derive some simple consequences of using lefton superfields Λ, and section 3 showcases these results in a few simple but nontrivial examples. Section 4 collects our conclusions.

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Purpose To noninvasively characterize the ligament strain in the hip capsule using a novel CT-based imaging technique. Methods The superior iliofemoral ligament (SIFL), inferior iliofemoral ligament (IIFL), ischiofemoral ligament (IFL) and pubofemoral ligament (PFL) were identified and beaded in seven cadavers. Specimens were mounted on a joint motion simulator within an O-arm CT scanner in − 15°, 0°, 30°, 60°, and 90° of flexion. 3 Nm of internal rotation (IR) and external rotation (ER) were applied and CT scans obtained. Strains were calculated by comparing bead separation in loaded and unloaded conditions. Repeated-measures ANOVA was used to evaluate differences in strain within ligaments between hip positions. Results For the SIFL, strain significantly decreased in IR at 30° (p = 0.045) and 60° (p = 0.043) versus 0°. For ER, there were no significant position-specific changes in strain (n.s.). For the IIFL, strain decreased in IR and increased in ER with no significant position-specific differences. For the IFL, strain increased with IR and decreased with ER with no significant position-specific differences. Finally, in the PFL there was a significant flexion angle-by-load interaction (p < 0.001; ES = 0.566), with peak strains noted at 60˚, however pair-wise comparisons failed to identify significant differences between positions (n.s.). Strain decreased in ER, with no significant position-specific differences. Conclusion The SIFL and IIFL limit hip external rotation with greater effect in higher flexion angles, while the IFL and PFL limit hip internal rotation. Following hip arthroscopy, consideration should be given to restricting external rotation as traditional capsulotomies cause injury to the SIFL and IIFL.