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AbstractPurposeWe evaluated the impact of random and whole‐bank multileaf collimator (MLC) delivery errors on dosimetric delivery accuracy in the Imaging and Radiation Oncology Core (IROC) phantom audits, as well as differences in delivery accuracy between the IROC phantom prescription and typical clinical fraction sizes.Methods and MaterialsPlans were created for the IROC IMRT head and neck (H&N) and SBRT spine phantoms. MLC leaf errors were introduced into the plans: random shifts between −2 and 2 mm, and whole bank shifts of 0.5, 1, and 2 mm. Plans were recalculated and delivered on a Varian Truebeam, and the log files were analyzed using Mobius Fx software. A second study examined the impact of fraction size on MLC position accuracy and corresponding dose delivery accuracy. The standard IROC phantom prescriptions (∼6 Gy) were scaled to the extremes of 2 Gy for H&N and 27 Gy for spine. All plans (original and scaled) were delivered on a Varian Truebeam and 21EX machine.ResultsRandom MLC positioning errors produced small average dose deviations in the PTV of up to −2.8% for H&N and 0.7% for spine. Whole‐bank MLC shifts resulted in larger average PTV dose deviations up to 8% for H&N and 7.1% for spine. The Varian 21EX irradiations had greater MLC root mean square (RMS) error than Truebeam plans. Plans with smaller prescriptions (and faster leaf motion) had greater MLC RMS errors, but plan accuracy was not affected dosimetrically – all results remained within 1% regardless of fraction size.ConclusionsBoth random and whole bank MLC shifts caused dose deviations in the IROC phantoms that were comparable to clinical results previously found in the literature. Deviations measured with ion chambers were well matched with delivery log file analysis. Smaller dose‐per‐fraction prescriptions caused larger MLC RMS errors that were detected with log files, but were clinically insignificant compared to the dosimetric accuracy of the plan.

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• Pub. Date : 2025
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Plasmopara viticola causes grape downy mildew, one of the most notorious diseases of cultivated grapes that damage vineyards worldwide. The pathogen secretes various effector molecules to infect and modulate the host biological processes. In this study, we aimed to evaluate the roles of KPvRxLR27, an arginine–any amino acid–leucine–arginine (RxLR) effector isolated from P. viticola JN-9 from Jeonju (South Korea) with respect to the reported Bcl-2-associated X and inverted formin1in inducing cell death in non-host Nicotiana benthamiana and resistant grape host cultivars via Agrobacterium-mediated transient transformation. We found that, KPvRxLR27 induced programmed cell death in N. benthamiana and rapid hypersensitive response in resistant grape cultivars. Agroinfiltration assay revealed that putative N-glycosylation at the N¹⁸⁶ amino acid sequence and nuclear localization signal motifs at the C-terminus were critical for the effector’s cell death-inducing activity of KPvRxLR27. Overexpression assay revealed that KPvRxLR27 was abundantly expressed in the plasma membrane and nuclear regions and activated the accumulation of reactive oxygen species in N. benthamiana. Moreover, KPvRxLR27 expression was significantly delayed in the resistant cultivar than in the susceptible cultivar. Our results suggest KPvRxLR27 as a potential avirulence gene recognized by the host receptors to activate the host immune response-associated genes, providing valuable insights to enhance the pathogen resistance of commercial cultivars.

• Book : 41(1)
• Pub. Date : 2025
• Page : pp.28-37
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AbstractPurposeThis work describes a single institution experience of commissioning a real‐time target tracking and beam control system, known as comprehensive motion management, for a 1.5 T Elekta MR‐Linac.MethodsAnatomical tracking and radiation beam control were tested using the MRI4D Quasar motion phantom. Multiple respiratory breathing traces were modeled across a range of realistic regular and irregular breathing patterns ranging between 10 and 18 breaths per minute. Each of the breathing traces was used to characterize the anatomical position monitoring (APM) accuracy, and beam latency, and to quantify the dosimetric impact of both parameters during a respiratory‐gated delivery using EBT3 film dosimetry. Additional commissioning tasks were performed to verify the dosimetric constancy during beam gating and to expand our existing quality assurance program.ResultsIt was determined that APM correctly predicted the 3D position of a dynamically moving tracking target to within 1.5 mm for 95% of the imaging frames with no deviation exceeding 2 mm. Among the breathing traces investigated, the mean latency ranged between −21.7 and 7.9 ms with 95% of all observed latencies within 188.3 ms. No discernable differences were observed in the relative profiles or cumulative output for a gated beam relative to an ungated beam with minimal dosimetric impact observed due to system latency. Measured dose profiles for all gated scenarios retained a gamma pass rate of 97% or higher for a 3%/2 mm criteria relative to a theoretical gated dose profile without latency or tracking inaccuracies.ConclusionMRI‐guided target tracking and automated beam delivery control were successfully commissioned for the Elekta Unity MR‐Linac. These gating features were shown to be highly accurate with an effectively small beam latency for a range of regular and irregular respiratory breathing traces.

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• Book : 23(1)
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Abstract The origin and authenticity of artifacts unearthed outside controlled archaeological excavations pose challenges for archaeologists, especially when they do not fit established patterns in the archaeological record. This article presents a detailed analysis of a stone stela discovered in non-professional circumstances on the Great Hungarian Plain. The stela’s engraved design, previously unknown in the regional archaeological record, closely resembles that of a slab in the Gavrinis passage grave in Bretagne, France. In addition to the provenance of the rock, our investigations specifically focused on the identification of the find context and the authenticity of the engravings. The results thus far support the engravings’ authenticity and suggest that the stela was removed from a Yamnaya kurgan and repurposed several millennia later. We argue that the Kevermes stela testifies to complex dynamics of long-distance mobility and cultural exchange in Europe during the late fourth and the first half of the third millennium BC.

• Book : 11(1)
• Pub. Date : 2025
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