The soundscape of the Anthropocene ocean Duarte, Carlos M; Chapuis, Lucille; Collin, Shaun P ...
Science (American Association for the Advancement of Science),
02/2021, Volume:
371, Issue:
6529
Journal Article
Peer reviewed
Open access
Oceans have become substantially noisier since the Industrial Revolution. Shipping, resource exploration, and infrastructure development have increased the anthrophony (sounds generated by human ...activities), whereas the biophony (sounds of biological origin) has been reduced by hunting, fishing, and habitat degradation. Climate change is affecting geophony (abiotic, natural sounds). Existing evidence shows that anthrophony affects marine animals at multiple levels, including their behavior, physiology, and, in extreme cases, survival. This should prompt management actions to deploy existing solutions to reduce noise levels in the ocean, thereby allowing marine animals to reestablish their use of ocean sound as a central ecological trait in a healthy ocean.
Recent studies have shown that many aprotic electrolytes used in lithium–air batteries are not stable against superoxide and peroxide species formed upon discharge and charge. However, the stability ...of polymers often used as binders and as electrolytes is poorly understood. In this work, we select a number of polymers heavily used in the Li–air/Li-ion battery literature, and examine their stability, and the changes in molecular structure in the presence of commercial Li2O2. Of the polymers studied, poly(acrylonitrile) (PAN), poly(vinyl chloride) (PVC), poly(vinylidene fluoride) (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), and poly(vinylpyrrolidone) (PVP) are reactive and unstable in the presence of Li2O2. The presence of the electrophilic nitrile group in PAN allows for nucleophilic attack by Li2O2 at the nitrile carbon, before further degradation of the polymer backbone. For the halogenated polymers, the presence of the electron-withdrawing halogens and adjacent α and β hydrogen atoms that become electron-deficient due to hyperconjugation makes PVC, PVDF, and PVDF-HFP undergo dehydrohalogenation reactions with Li2O2. PVP is also reactive, but with much slower kinetics. On the other hand, the polymers poly(tetrafluoroethylene) (PTFE), Nafion, and poly(methyl methacrylate) (PMMA) appear stable against nucleophilic Li2O2 attack. The lack of labile hydrogen atoms and the poor leaving nature of the fluoride group allow for the stability of PTFE and Nafion, while the methyl and methoxy functionalities in PMMA reduce the number of potential reaction pathways for Li2O2 attack in PMMA. Poly(ethylene oxide) (PEO) appears relatively stable, but may undergo some cross-linking in the presence of Li2O2. Knowledge gained from this work will be essential in selecting and developing new polymers as stable binders and solid or gel electrolytes for lithium–air batteries.
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IJS, KILJ, NUK, PNG, UL, UM
Abstract
The emergence of forests on Earth (~385 million years ago, Ma)
1
has been linked to an order-of-magnitude decline in atmospheric CO
2
levels and global climatic cooling by altering ...continental weathering processes, but observational constraints on atmospheric CO
2
before the rise of forests carry large, often unbound, uncertainties. Here, we calibrate a mechanistic model for gas exchange in modern lycophytes and constrain atmospheric CO
2
levels 410–380 Ma from related fossilized plants with bound uncertainties of approximately ±100 ppm (1 sd). We find that the atmosphere contained ~525–715 ppm CO
2
before continents were afforested, and that Earth was partially glaciated according to a palaeoclimate model. A process-driven biogeochemical model (COPSE) shows the appearance of trees with deep roots did not dramatically enhance atmospheric CO
2
removal. Rather, shallow-rooted vascular ecosystems could have simultaneously caused abrupt atmospheric oxygenation and climatic cooling long before the rise of forests, although earlier CO
2
levels are still unknown.
Statistical modeling of experimental and simulation databases has enabled the development of an accurate predictive capability for deuterium-tritium layered cryogenic implosions at the OMEGA laser V. ...Gopalaswamy et al.,Nature 565, 581 (2019). In this letter, a physics-based statistical mapping framework is described and used to uncover the dependencies of the fusion yield. This model is used to identify and quantify the degradation mechanisms of the fusion yield in direct-drive implosions on OMEGA. The yield is found to be reduced by the ratio of laser beam to target radius, the asymmetry in inferred ion temperatures from the ℓ = 1 mode, the time span over which tritium fuel has decayed, and parameters related to the implosion hydrodynamic stability. When adjusted for tritium decay and ℓ = 1 mode, the highest yield in OMEGA cryogenic implosions is predicted to exceed 2 × 1014 fusion reactions.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
The oxidation kinetics of Li(2)O(2) was studied in a carbonate-free electrolyte using electrodes consisting of non-catalyzed and catalyzed Vulcan carbon (VC) and chemically synthesized Li(2)O(2) ...particles. VC and Au nanoparticles supported on VC (Au/C) were fairly inactive for catalyzing the oxidation of Li(2)O(2), where oxidation currents greater than 10 mA g(carbon)(-1) were found only at voltages equal to and greater than 4.0 V vs. Li (V(Li)). Pt and Ru nanoparticles supported on VC (Pt/C and Ru/C) could significantly increase the kinetics of Li(2)O(2) oxidation, where Li(2)O(2) could be removed largely at voltages below 4 V(Li). In addition, Pt/C and Ru/C showed quick initiation of Li(2)O(2) oxidation in contrast to VC and Au/C.
Exploring heterogeneity in the economic impacts of solar geoengineering is a fundamental step towards understanding the risk tradeoff associated with a geoengineering option. To evaluate impacts of ...solar geoengineering and greenhouse gas-driven climate change on equal terms, we apply macroeconomic impact models that have been widely applied to climate change impacts assessment. Combining historical evidence with climate simulations of mean annual temperature and precipitation, we project socio-economic outcomes under high anthropogenic emissions for stylized climate scenarios in which global temperatures are stabilized or over-cooled by blocking solar radiation. We find impacts of climate changes on global GDP-per-capita by the end of the century are temperature-driven, highly dispersed, and model dependent. Across all model specifications, however, income inequality between countries is lower with solar geoengineering. Consistent reduction in inter-country inequality can inform discussions of the distribution of impacts of solar geoengineering, a topic of concern in geoengineering ethics and governance debates.
The concept of sustainability has received much attention since the publication of
Our Common Future by the World Commission on Environment and Development in 1987. Despite the institutionalisation ...of sustainability principles through legislation and policy around the world, progress in implementing sustainable development actions has been slow. The very open-ended definition of sustainable development provided in these documents, and the “language” used has made interpretation of what is required for implementation controversial. “Principles” of sustainable development have been developed to provide further guidance for implementation, but sustainability remains a contested and value-laden concept. Yet there is increasing recognition that the present development paths around the world are clearly
not sustainable into the future and that we need urgently to address this
unsustainability. Water use has become a prominent issue through broad acceptance that its use in many situations, including southeast Australia and cities such as Sydney, is unsustainable. This paper provides a broad introduction to the development of the concept of sustainability, barriers to implementation of sustainable development, and the application of sustainable development principles to water provision for a city such as Sydney, with emphasis on the use of recycled water.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK
Abstract
Anthropogenic noise is a recognized global pollutant, affecting a wide range of nonhuman animals. However, most research considers only whether noise pollution has an impact, ignoring that ...individuals within a species or population exhibit substantial variation in responses to stress. Here, we first outline how intrinsic characteristics (e.g., body size, condition, sex, and personality) and extrinsic factors (e.g., environmental context, repeated exposure, prior experience, and multiple stressors) can affect responses to environmental stressors. We then present the results of a systematic search of the anthropogenic-noise literature, identifying articles that investigated intraspecific variation in the responses of nonhuman animals to noise. This reveals that fewer than 10% of articles (51 of 589) examining impacts of noise test experimentally for intraspecific variation in responses; of those that do, more than 75% report significant effects. We assess these existing studies to determine the current scope of research and findings to-date, and to provide suggestions for good practice in the design, implementation, and reporting of robust experiments in this field. We close by explaining how understanding intraspecific variation in responses to anthropogenic noise is crucial for improving how we manage captive animals, monitor wild populations, model species responses, and mitigate effects of noise pollution on wildlife. Our aim is to stimulate greater knowledge and more effective management of the harmful consequences of this global pollutant.
To understand fully how noise pollution affects animals, we must consider differences between individuals. Less than 10% of published experimental studies on noise effects investigate variation due either to individual characteristics (such as size and sex) or external factors (such as current context or previous exposure). We explain how greater consideration of individual variation is vital for understanding man-made noise as a global pollutant and for developing mitigation strategies to protect animals.
In direct-drive inertial confinement fusion, the laser bandwidth reduces the laser imprinting seed of hydrodynamic instabilities. The impact of varying bandwidth on the performance of direct-drive ...DT-layered implosions was studied in targets with different hydrodynamic stability properties. The stability was controlled by changing the shell adiabat from (αF ≃ 5) (more stable) to (αF ≃ 3.5) (less stable). Herein these experiments show that the performance of lower adiabat implosions improves considerably as the bandwidth is raised indicating that further bandwidth increases, beyond the current capabilities of OMEGA, would be greatly beneficial. These results suggest that the future generation of ultra-broadband lasers could enable achieving high convergence and possibly high gains in direct drive ICF.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
Advances in peri-operative care of surgical oncology patients result in shorter hospital stays. Earlier discharge may bring benefits, but complications can occur while patients are recovering at ...home. Electronic patient-reported outcome (ePRO) systems may enhance remote, real-time symptom monitoring and detection of complications after hospital discharge, thereby improving patient safety and outcomes. Evidence of the effectiveness of ePRO systems in surgical oncology is lacking. This pilot study evaluated the feasibility of a real-time electronic symptom monitoring system for patients after discharge following cancer-related upper gastrointestinal surgery.
A pilot study in two UK hospitals included patients who had undergone cancer-related upper gastrointestinal surgery. Participants completed the ePRO symptom-report at discharge, twice in the first week and weekly post-discharge. Symptom-report completeness, system actions, barriers to using the ePRO system and technical performance were examined. The ePRO surgery system is an online symptom-report that allows clinicians to view patient symptom-reports within hospital electronic health records and was developed as part of the eRAPID project. Clinically derived algorithms provide patients with tailored self-management advice, prompts to contact a clinician or automated clinician alerts depending on symptom severity. Interviews with participants and clinicians determined the acceptability of the ePRO system to support patients and their clinical management during recovery.
Ninety-one patients were approached, of which 40 consented to participate (27 male, mean age 64 years). Symptom-report response rates were high (range 63-100%). Of 197 ePRO completions analysed, 76 (39%) triggered self-management advice, 72 (36%) trigged advice to contact a clinician, 9 (5%) triggered a clinician alert and 40 (20%) did not require advice. Participants found the ePRO system reassuring, providing timely information and advice relevant to supporting their recovery. Clinicians regarded the system as a useful adjunct to usual care, by signposting patients to seek appropriate help and enhancing their understanding of patients' experiences during recovery.
Use of the ePRO system for the real-time, remote monitoring of symptoms in patients recovering from cancer-related upper gastrointestinal surgery is feasible and acceptable. A definitive randomised controlled trial is needed to evaluate the impact of the system on patients' wellbeing after hospital discharge.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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