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The common approach to crystal-plasticity finite element modeling for load-bearing prediction of metallic structures involves the simulation of simplified grain morphology and substructure detail. This paper details a methodology for predicting the structure–property effect of as-manufactured microstructure, including true grain morphology and orientation, on cyclic plasticity, and fatigue crack initiation in biomedical-grade CoCr alloy. The methodology generates high-fidelity crystal-plasticity finite element models, by directly converting measured electron backscatter diffraction metal microstructure grain maps into finite element microstructural models, and thus captures essential grain definition for improved microstructure–property analyses. This electron backscatter diffraction-based method for crystal-plasticity finite element model generation is shown to give approximately 10% improved agreement for fatigue life prediction, compared with the more commonly used Voronoi tessellation method. However, the added microstructural detail available in electron backscatter diffraction–crystal-plasticity finite element did not significantly alter the bulk stress–strain response prediction, compared to Voronoi tessellation–crystal-plasticity finite element. The new electron backscatter diffraction-based method within a strain-gradient crystal-plasticity finite element model is also applied to predict measured grain size effects for cyclic plasticity and fatigue crack initiation, and shows the concentration of geometrically necessary dislocations around true grain boundaries, with smaller grain samples exhibiting higher overall geometrically necessary dislocations concentrations. In addition, minimum model sizes for Voronoi tessellation–crystal-plasticity finite element and electron backscatter diffraction–crystal-plasticity finite element models are proposed for cyclic hysteresis and fatigue crack initiation prediction. This publication has emanated from research conducted with the financial support of Science Foundation Ireland under Grant number 16/RC/3872. For the purpose of Open Access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. The authors wish to acknowledge the Irish Centre for High-End Computing (ICHEC) for the provision of computational facilities and support. The microstructure 668 characterization work is supported by the University of Limerick, which is highly appreciated. The 669 authors would also like to acknowledge Dr P. J. Ashton for the helpful discussion. peer-reviewed

OBJECTIVES The use of ‘extended criteria’ donor hearts and reconditioned hearts from donation after circulatory death has corresponded with an increase in primary graft dysfunction, with ischaemia–reperfusion injury being a major contributing factor in its pathogenesis. Limiting ischaemia–reperfusion injury through optimising donor heart preservation may significantly improve outcomes. We sought to review the literature to evaluate the evidence for this. METHODS A review of the published literature was performed to assess the potential impact of organ preservation optimisation on cardiac transplantation outcomes. RESULTS Ischaemia–reperfusion injury is a major factor in myocardial injury during transplantation with multiple potential therapeutic targets. Innate survival pathways have been identified, which can be mimicked with pharmacological conditioning. Although incompletely understood, discoveries in this domain have yielded extremely encouraging results with one of the most exciting prospects being the synergistic effect of selected agents. Ex situ heart perfusion is an additional promising adjunct. CONCLUSIONS Cardiac transplantation presents a unique opportunity to perfuse the whole heart before, or immediately after, the onset of ischaemia, thus maximising the potential for global cardioprotection while limiting possible systemic side effects. While clinical translation in the setting of myocardial infarction has often been disappointing, cardiac transplantation may afford the opportunity for cardioprotection to finally deliver on its preclinical promise.

Soft robots are notoriously hard to control. This is partly due to the scarcity of models and simulators able to capture their complex continuum mechanics, resulting in a lack of control methodologies that take full advantage of body compliance. Currently available methods are either too computational demanding or overly simplistic in their physical assumptions, leading to a paucity of available simulation resources for developing such control schemes. To address this, we introduce Elastica, an open-source simulation environment modeling the dynamics of soft, slender rods that can bend, twist, shear, and stretch. We couple Elastica with five state-of-the-art reinforcement learning (RL) algorithms (TRPO, PPO, DDPG, TD3, and SAC). We successfully demonstrate distributed, dynamic control of a soft robotic arm in four scenarios with both large action spaces, where RL learning is difficult, and small action spaces, where the RL actor must learn to interact with its environment. Training converges in 10 million policy evaluations with near real-time evaluation of learned policies.

asean has not collectively responded to the Rakhine crisis since 2017 from the perspective of the Responsibility to Protect (R2P) principle and has failed to put a stop to the atrocities against the Rohingyas in Myanmar. This article argues that there is less support in the region for invoking the non-interference principle in dealing with Myanmar on the Rohingya issue even as some members have called for its relaxation and use of constructive engagement instead. As international pressure in pursuit of justice and accountability increased, so did calls from within the region for asean to do more beyond just providing humanitarian assistance to affected communities in Rakhine. Even so, asean consciously avoids pressing too hard on the issue of accountability as this could force the government and the military in Myanmar to totally disengage with asean and the international community on the Rakhine crisis, as well as push Nay Pyi Daw further into China’s embrace and thus undermine asean’s strategic interests in the region.

The phloem is a key player in whole plant functioning-transporting carbon from sites of production to sites of demand-and is likely influenced by drought due to its dependence on water for generating pressure-driven bulk flow transport. Yet, phloem functioning during drought remains largely unknown due to a lack of experimental studies. Here, we use a phloem-bleeding species, Ricinus communis, to investigate phloem loss-of-function in the context of leaf physiological processes, the mechanisms of phloem turgor maintenance during drought, and the role of turgor in phloem loss-of-function. We found that the solute concentration in the phloem sap doubled over the drought, which allowed phloem turgor to be maintained past the point at which leaves have reached permanent stomatal closure. We also found that phloem turgor did not decline before bleeding ceased, which suggests that phloem bleeding ceassation (interpreted as the cessation of transport) occurred when the phloem still had turgor. In sum, our findings highlight the robustness of phloem functioning, with important implications for forecasting whole-plant carbon dynamics and drought-induced tree mortality.

Polyethylene glycol (PEG)–based conformal coating (CC) encapsulation of transplanted islets is a promising β cell replacement therapy for the treatment of type 1 diabetes without chronic immunosuppression because it minimizes capsule thickness, graft volume, and insulin secretion delay. However, we show here that our original CC method, the direct method, requiring exposure of islets to low pH levels and inclusion of viscosity enhancers during coating, severely affected the viability, scalability, and biocompatibility of CC islets in nonhuman primate preclinical models of type 1 diabetes. We therefore developed and validated in vitro and in vivo, in several small- and large-animal models of type 1 diabetes, an augmented CC method—emulsion method—that achieves hydrogel CCs around islets at physiological pH for improved cytocompatibility, with PEG hydrogels for increased biocompatibility and with fivefold increase in encapsulation throughput for enhanced scalability.

Past research has explored coach developers’ practice and called for learner-centred coach education provision. However, understanding of how “learner-centred” policies are reproduced in practice remains partial. In response, a multiple methods case study explored three introductory coach education courses. The Bernsteinian concept of “framing” was introduced to coach education research for the first time, and used to examine how coach developers implemented “learner-centred” policy. A composite creative non-fiction narrative revealed courses have: (1) A high volume of strongly framed assessment; (2) A wide range of strongly framed content; and (3) Coach developers who attempt to weakly frame pedagogic practice. Findings highlight tensions between being “learner-centred” and covering content and assessment that were prescribed by stakeholders in the coach education system. This study provides a significant contribution by connecting policy to practice, and highlighting the challenges of implementing learner-centred education policy.

Walsh (2020) underscores how dementia leads to a cognitive transformative experience, which can result in a change in preferences, values, and beliefs. This transformation supports placing greater ...

To conclude that there is enough or not enough evidence demonstrating that deep brain stimulation (DBS) causes unintended postoperative personality changes is an epistemic problem that should be answered on the basis of established, replicable, and valid data. If prospective DBS recipients delay or refuse to be implanted because they are afraid of suffering from personality changes following DBS, and their fears are based on unsubstantiated claims made in the neuroethics literature, then researchers making these claims bear great responsibility for prospective recipients' medical decisions and subsequent well-being. Our article “Deflating the ‘DBS causes personality’ bubble” reported an increase in theoretical neuroethics publications suggesting putative DBS-induced changes to personality, identity, agency, autonomy, authenticity and/or self (PIAAAS) and a critical lack of supporting primary empirical studies. This special issue of Neuroethics brings together responses to our initial publication, with our own counter-responses organized according to common themes. We provide a brief summary for each commentary and its main criticisms as well as a discussion of the way in which these responses can: 1) help clarify the meaning of PIAAAS, suggesting supplementary frameworks for understanding the impact of DBS on PIAAAS; 2) provide further empirical evidence of PIAAAS by presenting results from the researchers’ own work; and/or 3) offer a critique of our research approach and/or findings. Unintended postoperative putative changes to PIAAAS remain a critical ethical concern. It is beyond dispute that we need to develop reliable empirical and conceptual instruments able to measure complex cognitive, affective, and behavioural changes in order to investigate whether they are attributable to DBS alone.

Coronavirus disease 2019 (COVID‐19), the worst pandemic in more than a century, has claimed >125,000 lives worldwide to date. Emerging predictors for poor outcomes include advanced age, male sex, preexisting cardiovascular disease, and risk factors including hypertension, diabetes, and, more recently, obesity. This article posits new obesity‐driven predictors of poor COVID‐19 outcomes, over and above the more obvious extant risks associated with obesity, including cardiometabolic disease and hypoventilation syndrome in intensive care patients. This article also outlines a theoretical mechanistic framework whereby adipose tissue in individuals with obesity may act as a reservoir for more extensive viral spread, with increased shedding, immune activation, and cytokine amplification. This paper proposes studies to test this reservoir concept with a focus on specific cytokine pathways that might be amplified in individuals with obesity and COVID‐19. Finally, this paper underscores emerging therapeutic strategies that might benefit subsets of patients in which cytokine amplification is excessive and potentially fatal.

The objectives of this study are: (1) to verify whether using linear heat input alone is sufficient to predict the resulting microstructure of Ti6Al4V and (2) to demonstrate the potential of single-step process of functionally graded material using powder bed fusion. In laser powder bed fusion, linear heat input is defined as the ratio of laser power to scan speed. It is a key process variable that describes the unit energy input. Therefore, linear heat input has been extensively linked with the resulting microstructure. However, review of existing studies shows that when similar linear heat input was used, a marked difference in mechanical properties exists. Using proportionally changed laser power and scan speed in five zones, functionally graded specimens were fabricated in this study. All other parameters remain the same for these zones. Variation of microstructure and hardness across the five zones were obtained. This implies that linear heat input is not sufficient to determine the resulting microstructure and mechanical properties. The amplitude of laser power and scan speed has an effect on the resulting microstructure, so they need to be separately considered in future studies.

“How does one implement an ethical rule or norm to ensure that it fulfills its primary purpose?” (Sisk et al. 2020)Framed as the “ought-is” problem by Sisk et al. (2020), this remains a significant...

Addressing the prevalence of tick-borne disease requires robust chemical options as an integral component of Integrative Vector Management (IVM) program. Spatial repellency is a novel concept in tick bite prevention. To date, there is no standard for the evaluation of spatial repellency against ticks, despite the speculated value of volatilized chemicals in control systems. This study reports a novel vertical climb assay that was specifically created for the quantitative evaluation of spatial repellency in ticks. Controlled release devices (CRDs) were used to control the dispersion of multiple Active Ingredients (AIs) transfluthrin, metofluthrin, nootkatone, and DEET against adult females of three medically important tick species: Dermacentor variabilis, Amblyomma americanum, and Ixodes scapularis. Results of our study indicate significant associations between AI exposure and changing in tick climbing behavior when compared controls in the absence of the AI, from several perspectives, including changes in tick movement velocity, displacement, detachment, and rate of successful vertical climbing. Metofluthrin and transfluthrin caused strong reductions in host seeking activities against D. variabilis and A. americanum, while both demonstrated slightly weaker effects against I. scapularis. Further work is planned to evaluate spatial repellency in ticks in more natural environments and assess their potential in future tick control programs.

In this work, the suitability of basalt fibres for uni-directional composite material applications, and adhesion between the fibres and the matrix they are embedded in have been investigated. A single fibre fragmentation test was carried out on 13 µm diameter basalt fibres embedded in a dog-bone epoxy matrix. Photoelastic analysis was used to observe different fracture mechanisms in a single fibre composite sample and fibre breaks during testing. A theoretical model based on a Griffithâ s fracture mechanics approach was used to determine the fibre-matrix interfacial shear strength, which is a measurement of the level of adhesion between the fibre and the matrix. It was also used to predict the fibre fragment axial stress and the fragment interfacial shear stress, both as functions of axial position on the fibre. A finite element model was developed to simulate the fibre fracture process, and the redistribution of stresses in the fibre and the local region surrounding a fibre break. The developed experimental procedure was successful in that stress-induced birefringence was observed in the tested samples, as well as the characteristic shear stress light fringes that occur in the regions surrounding fibre fractures. Also, there were some similarities between the finite element model results and the theoretical predictions. The critical fibre length, lc was measured as 0.752 mm, whereas this value was calculated 0.6708 mm from finite element predicted interfacial shear stress distribution for fibre fragment. A combination of all three types of failure modes was recorded across the samples that were tested, while only a single failure mode was observed in the finite element model. According to the theoretical model, for a given set of parameters and constant stress with only the fibre length varying, the axial stress in the fibre reduces as the fibre gets smaller.In this work, the suitability of basalt fibres for uni-directional composite material applications, and adhesion between the fibres and the matrix they are embedded in have been investigated. A single fibre fragmentation test was carried out on 13 µm diameter basalt fibres embedded in a dog-bone epoxy matrix. Photoelastic analysis was used to observe different fracture mechanisms in a single fibre composite sample and fibre breaks during testing. A theoretical model based on a Griffithâ s fracture mechanics approach was used to determine the fibre-matrix interfacial shear strength, which is a measurement of the level of adhesion between the fibre and the matrix. It was also used to predict the fibre fragment axial stress and the fragment interfacial shear stress, both as functions of axial position on the fibre. A finite element model was developed to simulate the fibre fracture process, and the redistribution of stresses in the fibre and the local region surrounding a fibre break. The developed experimental procedure was successful in that stress-induced birefringence was observed in the tested samples, as well as the characteristic shear stress light fringes that occur in the regions surrounding fibre fractures. Also, there were some similarities between the finite element model results and the theoretical predictions. The critical fibre length, lc was measured as 0.752 mm, whereas this value was calculated 0.6708 mm from finite element predicted interfacial shear stress distribution for fibre fragment. A combination of all three types of failure modes was recorded across the samples that were tested, while only a single failure mode was observed in the finite element model. According to the theoretical model, for a given set of parameters and constant stress with only the fibre length varying, the axial stress in the fibre reduces as the fibre gets smaller. peer-reviewed 2023-04-11