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The Materials Management and Minimization program is developing fuel designs to replace highly enriched fuel with fuels of low enrichment. Swelling is an important irradiation behavior that needs to be well understood. Data from high resolution thickness measurements performed on U-7Mo dispersion fuel plates with Al-Si alloy matrices that were irradiated at high power is sparse. This paper reports the results of detailed thickness measurements performed on two dispersion fuel plates that were irradiated at relatively high power to high fission densities in the Advanced Test Reactor in the same RERTR-9B experiment. Both plates were irradiated to similar fission densities, but one was irradiated at a higher power than the other. The goal of this work is to identify any differences in the swelling behavior when fuel plates are irradiated at different powers to the same fission densities. Based on the results of detailed thickness measurments, more swelling occurs when a U-7Mo dispersion fuel with Al-3.5Si matrix is irradiated to a high fission density at high power compared to one irradiated at a lower power to high fission density.

Introduction The impact of time to treatment on clinical outcome is an established precept in infectious disease but is not established in peritoneal dialysis–related peritonitis (PDRP). Methods In a prospective multicenter study of PDRP, symptom-to-contact time (SC), contact-to-treatment time (CT), defined as the time from health care presentation to initial antibiotic, and symptom-to-treatment time (ST) were determined. Results One hundred sixteen patients had 159 episodes of PDRP. Median SC for all episodes was 5.0 hours (first to third quartile [Q1–Q3]: 1.3–13.9); CT, 2.3 hours (Q1–Q3: 1.2–4.0); and ST, 9.0 hours (Q1–Q3: 4.7–25.3). Thirty-eight (23.9%) patient episodes (28 catheter removals and 10 deaths) met the primary composite outcome of PD failure at 30 days (PD-fail). The risk of PD-fail increased by 5.5% for each hour of delay of administration of antibiotics (odds ratio [OR] for CT: 1.055; 95% confidence interval [CI]: 1.005–1.109; P = 0.032). Neither SC (OR: 1.00; 95% CI: 0.99–1.01; P = 0.74) nor ST (OR: 1.00; 95% CI: 0.99–1.01; P = 0.48) was associated with PD-fail. In a multivariable analysis, only CT for presentation to a hospital-based facility compared with a community facility (OR: 1.068; 95% CI: 1.013–1.126; P = 0.015) and female sex (OR: 2.4; 95% CI: 1.1–5.4; P = 0.027) were independently associated with PD-fail. Each hour of delay in administering antibacterial therapy from the time of presentation to a hospital facility increased the risk of PD failure or death by 6.8%. Discussion Strategies targeted to expedited antibiotic treatment should be implemented to improve outcomes from PDRP.

The interaction between perception and action represents one of the pillars of human evolutionary success. Our interactions with the surrounding world involve a variety of behaviors, almost always including movements of the eyes and hands. Such actions rely on neural mechanisms that must process an enormous amount of information in order to generate appropriate motor commands. Yet, compared to the great advancements in the field of perception for cognition, the neural underpinnings of how we control our movements, as well as the interactions between perception and motor control, remain elusive. With this research topic we provide a framework for: (1) the perception of real objects and shapes using visual and haptic information, (2) the reference frames for action and perception, and (3) how perceived target properties are translated into goal-directed actions and object manipulation. The studies in this special issue employ a variety of methodologies that include behavioral kinematics, neuroimaging, transcranial magnetic stimulation, and patient cases. Here we provide a brief summary and commentary on the articles included in this research topic.

Australia’s “Direct Action” climate change policy relies on purchasing greenhouse gas abatement from projects undertaking approved abatement activities. Management of soil organic carbon (SOC) in agricultural soils is an approved activity, based on the expectation that land use change can deliver significant changes in SOC. However, there are concerns that climate, topography and soil texture will limit changes in SOC stocks. This work analyses data from 1482 sites surveyed across the major agricultural regions of Eastern Australia to determine the relative importance of land use vs. other drivers of SOC. Variation in land use explained only 1.4% of the total variation in SOC, with aridity and soil texture the main regulators of SOC stock under different land uses. Results suggest the greatest potential for increasing SOC stocks in Eastern Australian agricultural regions lies in converting from cropping to pasture on heavy textured soils in the humid regions.

Increasing soil organic carbon (SOC) storage in agricultural soils through changes to management may help to mitigate rising greenhouse gas emissions and sustain agricultural productivity and environmental conditions. However, in order to improve assessment of the potential for increasing SOC storage in the agricultural lands of Victoria, Australia, further information is required on current SOC levels and how they are related to environmental conditions, soil properties and agricultural management. Therefore, we measured stocks of SOC at 615 sites in pasture and cropping systems in Victoria, encompassing eight regions, five soil orders and four management classes (continuous cropping, crop–pasture rotation, sheep or beef pasture, and dairy pasture), and explored relationships between the C stocks and environment, soil and management. The results showed an extremely wide range in SOC, from 2 to 239 t C/ha (0–30 cm). Most of this variation was attributable to climate; almost 80% of the variation in SOC stock was related to annual rainfall or vapour pressure deficit (i.e. humidity). Texture-related soil properties accounted for a small, additional amount of variation in SOC. After accounting for climate, differences in SOC between management classes were small and often not significant. Management practices such as stubble retention, minimum cultivation, perennial pasture species, rotational grazing and fertiliser inputs were not significantly related to SOC stock. The relationships between SOC and environment, soil and management were scale-dependent. Within individual regions, the apparent influence of climate and soil properties on SOC stock varied, and in some regions, much of the variation in SOC stock remained unexplained. The results suggest that, across Victoria, there is a general hierarchy of influence on SOC stock: climate > soil properties > management class > management practices.

Despite considerable research, predicting how soil organic carbon (SOC) in grain production systems will respond to conservation management practices, such as reduced tillage, residue retention and alternative rotations, remains difficult because of the slowness of change and apparent site specificity of the effects. We compared SOC stocks (equivalent soil mass to ~0–0.3 m depth) under various tillage, residue management and rotation treatments in three long-term (12-, 28- and 94-year-old) field experiments in two contrasting environments (Mallee and Wimmera regions). Our hypotheses were that SOC stocks are increased by: (1) minimum tillage rather than traditional tillage; (2) continuous cropping, rather than crop–fallow rotations; and (3) phases of crop or pasture legumes in rotations, relative to continuous cropping with cereals. We found that zero tillage and stubble retention increased SOC in some circumstances (by up to 1.5 Mg C ha–1, or 8%) but not in others. Inclusion of bare fallow in rotations reduced SOC (by 1.4–2.4 Mg C ha–1, or 8–12%) compared with continuous cropping. Including a pulse crop (field pea, where the grain was harvested) in rotations also increased SOC in some instances (by ~6–8 Mg C ha–1, or 29–35%) but not in others. Similarly, leguminous pasture (medic or lucerne) phases in rotations either increased SOC (by 3.5 Mg C ha–1, or 21%) or had no significant effect compared with continuous wheat. Inclusion of a vetch green manure or unfertilised oat pasture in the rotation did not significantly increase SOC compared with continuous wheat. The responses in SOC to these management treatments were likely to be due, in part, to differences in nitrogen and water availability (and their effects on carbon inputs and decomposition) and, in part, to other, unidentified, interactions. We conclude that the management practices examined in the present study may not reliably increase SOC on their own, but that significant increases in SOC are possible under some circumstances through the long-term use of multiple practices, such as stubble retention + zero tillage + legume N input + elimination of fallow. The circumstances under which increases in SOC can be achieved require further investigation.