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To study the potential consequences of differences in the evaluation of variable versus uniform relative biological effectiveness calculations in proton radiotherapy for prostate cancer.Experimental data with proton beams suggest that relative biological effectiveness increases with linear energy transfer. This relation also depends on thePhenomenological models clearly predict higher relative biological effectiveness values compared to microdosimetric kinetic model, that seems to approach to the constant value of 1.1 adopted in the clinics, at least for low linear energy transfer values achieved in typical prostate proton plans. All models predict a higher increase of the relative biological effectiveness-weighted dose for the prostate tumor than for the rest of structures involved due to its lower

Stem-and-leaf displays have been widely taught since John W. Tukey publicized them energetically in the 1970s. They remain useful for many distributions of small or modest size, especially for showing fine structure such as digit preference. Stata's implementation stem produces typed text displays and has some inevitable limitations, especially for comparison of two or more displays. One can re-create stem-and-leaf displays with a few basic Stata commands as scatterplots of stem variable versus position on line with leaves shown as marker labels. Comparison of displays then becomes easy and natural using scatter, by(). Back-to-back presentation of paired displays is also possible. I discuss variants on standard stem-and-leaf displays in which each distinct value is a stem, each distinct value is its own leaf, or axes are swapped. The problem shows how one can, with a few lines of Stata, often produce standard graph forms from first principles, allowing in turn new variants. I also present a new program, stemplot, as a convenience tool.

SUMMARYCertain tiger moths (Arctiidae) defend themselves against bats by phonoresponding to their echolocation calls with trains of ultrasonic clicks. The dogbane tiger moth, Cycnia tenera, preferentially phonoresponds to the calls produced by attacking versus searching bats, suggesting that it either recognizes some acoustic feature of this phase of the bat's echolocation calls or that it simply reacts to their increased power as the bat closes. Here, we used a habituation/generalization paradigm to demonstrate that C. tenera responds neither to the shift in echolocation call frequencies nor to the change in pulse duration that is exhibited during the bat's attack phase unless these changes are accompanied by either an increase in duty cycle or a decrease in pulse period. To separate these features, we measured the moth's phonoresponse thresholds to pulsed stimuli with variable versus constant duty cycles and demonstrate that C. tenerais most sensitive to echolocation call periods expressed by an attacking bat. We suggest that, under natural conditions, C. tenera identifies an attacking bat by recognizing the pulse period of its echolocation calls but that this feature recognition is influenced by acoustic power and can be overridden by unnaturally intense sounds.

International audience; The aim of this study was to investigate the metabolic responses to variable versus constant-intensity (CI) during 20-km cycling on subsequent 5-km running performance. Ten triathletes, not only completed one incremental cycling test to determine maximal oxygen uptake and maximal aerobic power (MAP), but also three various cycle-run (C–R) combinations conducted in outdoor conditions. During the C–R sessions, subjects performed first a 20-km cycletime trial with a freely chosen intensity (FCI, ~80% MAP) followed by a 5-km run performance. Subsequently, triathletes were required to perform in a random order, two C–R sessions including either a CI, corresponding to the mean power of FCI ride, or a variable-intensity (VI) during cycling with power changes ranging from 68 to 92% MAP, followed immediately by a 5-km run. Metabolic responses and performances were measured during the C–R sessions. Running performance was significantly improved after CI ride (1118 ± 72 s) compared to those after FCI ride (1134 ± 64 s) or VI ride (1168 ± 73 s) despite similar metabolic responses and performances reported during the three cycling bouts. Moreover, metabolic variables were not significantly different between the run sessions in our triathletes. Given the lack of significant differences in metabolic responses between the C–R sessions, the improvement in running time after FCI and CI rides compared to VI ride suggests that other mechanisms, such as changes in neuromuscular activity of peripheral skeletal muscle or muscle fatigue, probably contribute to the influence of power output variation on subsequent running performance.

In this paper we study optimal harvesting of the Norwegian spring-spawning herring stock. The biological model is described by a discrete time age-structured model. The optimal harvesting patterns are studied numerically and the results show that when using a linear cost function and constant price in the optimisation model, the optimal harvesting pattern is pulse fishing. However, optimal constant fishing effort gives only slightly lower profit. Moreover, when price is made responsive to harvest the optimal harvesting strategy is substantially smoothed.

For networks with large scale integration of wind farms this paper demonstrates a significant difference between the transient behavior of variable speed wind systems that adopt doubly fed induction generators with a four quadrant ac-to-ac converter connected to the rotor windings (DFIG) and a fixed speed wind system, where the conventional cage induction generator is used. The reason for this difference is explained, and it is shown that the phenomenon is due to the ability of the two dedicated rotor current regulators of the DFIG to control the electrical torque and reactive power quickly and accurately. This difference is clearly observed after a severe fault (short circuit) occurrence. It will be demonstrated that the adjustable speed generator (DFIG) enhances system stability in power networks.

Purpose: To evaluate the effects of variable versus constant dose rate in volumetric modulated arc (VMAT) treatment planning for prostate cases. Method and Materials:A retrospective investigation on fifteen prostate cases was performed. Two dosimetrically identical linacs were commissioned in Pinnacle TPS. One machine was variable dose rate capable, while the other was constant dose rate capable for VMAT planning purposes. PTVs and OARs (rectum and bladder) were delineated for each case. Two VMAT plans were generated per case: each comprised of a single arc and comparing variable to constant dose rate. Both plans were normalized such that 95% of the PTV was covered by the same prescription dose. Plan quality was evaluated by several dose indices used as DVH objectives in the inverse optimization. In addition, dose inhomogeneity across the PTV was tallied together with MUs and estimated treatment times. Variable dose rare plans were used as reference. Results: The majority of rectum and bladder doses to 10%, 20%, and 40% of the OAR volumes differed by less than 3% between the two plans plans. Even for the cases with larger than 3% deviation the constant dose rate plans were clinically acceptable. Dose inhomogeneity across the PTV however was larger for constant dose rate plans, where for 80% of the cases it was over 3%, while it was within 3% for all variable dose rate cases. The MUs for the two delivering modes were comparable, while the treatment times differed three‐fold. Conclusions: The results indicate that variable and constant dose rate VMAT plans for prostate carcinoma result in comparable target coverage and OAR sparing. Nonetheless, the constant dose rate plans exhibit higher dose inhomogeneity across the target and the clinical applicability should be carefully evaluated for the potential hotspots in undesired location.