Navigating Potential Hype and Opportunity in Governing Marine Carbon Removal

As the technical and political challenges of land-based carbon dioxide removal (CDR) approaches become more apparent, the oceans may be the new “blue” frontier for carbon drawdown strategies in climate governance. Drawing on lessons learnt from the way terrestrial carbon dioxide removal emerged, we explore increasing overall attention to marine environments and mCDR projects, and how this could manifest in four entwined knowledge systems and governance sectors. We consider how developments within and between these “frontiers” could result in different futures—where hype and over-promising around marine carbon drawdown could enable continued time-buying for the carbon economy without providing significant removals, or where reforms to modeling practices, policy development, innovation funding, and legal governance could seek co-benefits between ocean protection, economy, and climate

From Behavior to Genes, and Back Again.

The aim of this thesis was to use forward and reverse genetics to explore the contribution of unknown and known genes to the touch-evoked escape behaviors belonging to zebrafish (Danio rerio). A forward genetic screen identified two mutants that displayed abnormal touch-evoked escape behaviors. The first mutant touchdown (tdo) lacked sensitivity to light touch, but responded to noxious stimuli. tdo mutants were shown to result from mutations in the gene encoding for TRPM7, an ion channel with an attached kinase. A combination of electrophysiological and molecular techniques revealed that ion channel function was sufficient to restore sensitivity to light touch within excitable mechanosensitive neurons. Therefore TRPM7 is a candidate for a vertebrate mechanoreceptor responsible for sensitivity to light touch. The second mutant identified from our forward genetic screen non-active (nav) initiated escape contractions, but failed to swim in response to touch. nav mutants were shown to result from mutations in the gene encoding NaV1.6 that abolished channel activity. Electrophysiological recordings revealed that NaV1.6 is required to turn on a locomotor network capable of generating rudimentary swimming. Furthermore the requirement of NaV1.6 to turn this network might be its contribution of a persistent sodium current which is known to facilitate repetitive firing in other neurons. Finally the cloning and characterization of the ATP-gated P2X receptor subunits P2X1 through P2X5.2 from zebrafish demonstrated that two subunits (P2X1 and P2X5.1) form functional homomeric receptors in contrast to previous reports. The use of reverse genetics (antisense knockdown) allowed the rejection of the hypothesis that signaling through P2X receptors is essential for myogenesis.Ph.D.NeuroscienceUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/60889/1/selow_1.pd

THE EFFECT OF STEP WIDTH CONTROL ON LOAD CARRIAGE ECONOMY

The purpose of this study was to assess the influence of step width on load carriage economy. Fifteen healthy volunteers (age = 25 ± 3 years; stature = 1.78 ± 0.07 m; body mass = 73.6 ± 10.1 kg) completed three trials in a randomised order. Each trial differed by load carriage method and involved walking on a force-instrumented at 3km.h-1 with 0, 3, 12 and 20 kg. This protocol was then repeated with step width controlled to each participant’s preferred unloaded width. Relative load carriage economy was measured using the Extra Load Index (ELI). Load carriage economy was significantly worse in the head loading method compared to the other two method with step width uncontrolled (p = 0.02) and controlled (p = 0.02). For the trials where step width was uncontrolled, there was a significant difference in step width from unloaded walking between the different loading methods (p = 0.01) but no significant difference between load mass (p = 0.39). There was no difference in ELI between preferred and controlled step widths. Based on the data presented here, moderate alterations in step width caused by load carriage do not appear to influence load carriage economy

Characterization of the Zebrafish Glycine Receptor Family Reveals Insights Into Glycine Receptor Structure Function and Stoichiometry

To study characterization of zebrafish glycine receptors (zGlyRs), we assessed expression and function of five α- and two ß-subunit encoding GlyR in zebrafish. Our qPCR analysis revealed variable expression during development, while in situ hybridizations uncovered expression in the hindbrain and spinal cord; a finding consistent with the reported expression of GlyR subunits in these tissues from other organisms. Electrophysiological recordings using Xenopus oocytes revealed that all five α subunits form homomeric receptors activated by glycine, and inhibited by strychnine and picrotoxin. In contrast, ß subunits only formed functional heteromeric receptors when co-expressed with α subunits. Curiously, the second transmembranes of both ß subunits were found to lack a phenylalanine at the sixth position that is commonly associated with conferring picrotoxin resistance to heteromeric receptors. Consistent with the absence of phenylalanines at the sixth position, heteromeric zGlyRs often lacked significant picrotoxin resistance. Subsequent efforts revealed that resistance to picrotoxin in both zebrafish and human heteromeric GlyRs involves known residues within transmembrane 2, as well as previously unknown residues within transmembrane 3. We also found that a dominant mutation in human GlyRα1 that gives rise to hyperekplexia, and recessive mutations in zebrafish GlyRßb that underlie the bandoneon family of motor mutants, result in reduced receptor function. Lastly, through the use of a concatenated construct we demonstrate that zebrafish heteromeric receptors assemble with a stoichiometry of 3α:2ß. Collectively, our findings have furthered our knowledge regarding the assembly of heteromeric receptors, and the molecular basis of ß subunit-conferred picrotoxin resistance. These results should aid in future investigations of glycinergic signaling in zebrafish and mammals

Risk–risk governance in a low-carbon future: Exploring institutional, technological, and behavioral tradeoffs in climate geoengineering pathways

Deliberations are underway to utilize increasingly radical technological options to help address climate change and stabilize the climatic system. Collectively, these options are often referred to as “climate geoengineering.” Deployment of such options, however, can create wicked tradeoffs in governance and require adaptive forms of risk management. In this study, we utilize a large and novel set of qualitative expert interview data to more deeply and systematically explore the types of risk–risk tradeoffs that may emerge from the use of 20 different climate geoengineering options, 10 that focus on carbon dioxide or greenhouse gas removal, and 10 that focus on solar radiation management and reflecting sunlight. We specifically consider: What risks does the deployment of these options entail? What types of tradeoffs may emerge through their deployment? We apply a framework that clusters risk–risk tradeoffs into institutional and governance, technological and environmental, and behavioral and temporal dimensions. In doing so, we offer a more complete inventory of risk–risk tradeoffs than those currently available within the respective risk-assessment, energy-systems, and climate-change literatures, and we also point the way toward future research gaps concerning policy, deployment, and risk management

Determining our climate policy future: expert opinions about negative emissions and solar radiation management pathways

Negative emissions technologies and solar radiation management techniques could contribute towards climate stability, either by removing carbon dioxide from the atmosphere and storing it permanently or reflecting sunlight away from the atmosphere. Despite concerns about them, such options are increasingly being discussed as crucial complements to traditional climate change mitigation and adaptation. Expectations around negative emissions and solar radiation management and their associated risks and costs shape public and private discussions of how society deals with the climate crisis. In this study, we rely on a large expert survey (N = 74) to critically examine the future potential of both negative emission options (e.g., carbon dioxide removal) and solar radiation management techniques. We designed a survey process that asked a pool of prominent experts questions about (i) the necessity of adopting negative emissions or solar radiation management options, (ii) the desirability of such options when ranked against each other, (iii) estimations of future efficacy in terms of temperature reductions achieved or gigatons of carbon removed, (iv) expectations about future scaling, commercialization, and deployment targets, and (v) potential risks and barriers. Unlike other elicitation processes where experts are more positive or have high expectations about novel options, our results are more critical and cautionary. We find that some options (notably afforestation and reforestation, ecosystem restoration, and soil carbon sequestration) are envisioned frequently as necessary, desirable, feasible, and affordable, with minimal risks and barriers (compared to other options). This contrasts with other options envisaged as unnecessary risky or costly, notably ocean alkalization or fertilization, space-based reflectors, high-altitude sunshades, and albedo management via clouds. Moreover, only the options of afforestation and reforestation and soil carbon sequestration are expected to be widely deployed before 2035, which raise very real concerns about climate and energy policy in the near- to mid-term

Coupling for climate intervention: Sectoral and sustainability couplings for carbon removal and solar geoengineering pathways

Solar geoengineering and negative-emissions technologies are attracting greater attention as prospective ways to tackle and mitigate the worst impacts of climate change. Until now, such options have rarely been examined in a comprehensive manner. Rather, insofar as this has been done, research focused on one or the other, rather than considering a portfolio contribution and, more often, has taken a sectoral approach that looks at the options germane to the agriculture or energy sectors, but not in relation to climate change. Arguing for the need for a wider lens, the current article aims to understand the kinds of couplings and linkages most germane for the effectiveness of a particular option. In specific, we employed a novel dataset garnered from a large expert-interview exercise (N = 125) to conceptualize and consider crucial couplings to solar radiation management and carbon dioxide removal at many levels (across different sectors, differing dimensions of sustainability, productive or destructive impacts, and direct and indirect relationships). Our analysis thereby provides insights into the understanding of climate transitions by explicitly considering the most salient couplings in general as well as how, and to what extent, the various options relate to each other, as a portfolio for climate intervention, and together to climate mitigation and adaptation

Undone science in climate interventions: Contrasting and contesting anticipatory assessments by expert networks

In global climate governance, anticipatory assessments map future options and pathways, in light of prospective risks and uncertainties, to inform present-day planning. Using data from 125 interviews, we ask: How are foundational experts contesting the conduct of anticipatory assessment of carbon removal and solar geoengineering – as two emerging but controversial strategies for engaging with climate change and achieving Net Zero targets? We find that efforts at carbon removal and solar geoengineering assessment leverage and challenge systems modeling that has become dominant in mapping and communicating future climate impacts and mitigation strategies via IPCC reports. Both suites of climate intervention have become stress-tests for the capacity of modeling to assess socio-technical strategies with complex, systemic dimensions. Meanwhile, exploring societal dimensions demands new modes of disciplinary expertise, qualitative and deliberative practices, and stakeholder inclusion that modelling processes struggle to incorporate. Finally, we discuss how the patterns of expert contestation identified in our results speak to multiple fault-lines within ongoing debates on reforming global environmental assessments, and highlights key open questions to be addressed

Isolated Scaphoid Dislocation From Low-Energy Wrist Trauma

Isolated scaphoid dislocation is an extremely rare injury typically caused by high-energy trauma. We present the first observed case of isolated scaphoid dislocation resulting from a non-traumatic injury of the wrist in power-grip tension in a patient with a questionable history of Marfan Syndrome. A 20-yearold right-hand dominant man presented to the emergency department with right wrist pain and deformation after carrying a table. The patient reported a possible history of Marfan Syndrome, but it had never been definitively diagnosed. Imaging revealed radial dislocation of the scaphoid. Bedside closed reduction was performed followed by outpatient ligament reconstruction with return to normal activities at 6 months. Early diagnosis and management lead to an improved prognosis for isolated scaphoid dislocation. Regardless of patient history or mechanism of injury, treatment options include closed reduction, percutaneous fixation, and/or open reduction with internal fixation and ligamentous reconstructio