Trace-metaldynamics in response of increase CO₂ and iron availability in a coastal mesocosm experiment

A mesocosm experiment was performed in the Raunefjord (Norway) to study changes in dissolved Cu (dCu) and Fe (dFe), and in the elemental composition of particles during an Emiliania huxleyi dominated bloom. The CO2 treatments consisted of present (LC; 390 ppmV) and predicted levels (HC; 900 ppmV) and iron conditions were created with the addition of the siderophore desferoxamine B (DFB). Our results showed the DFB addition enhanced the solubility of Fe in this fjord environment. Initially, dFe was comparable among treatments but after the addition, the HC and/or +DFB treatments presented higher levels and finally, the only ones maintaining high dFe were the +DFB treatments. Unlike dCu presented indistinguishable levels in all mesocosms over time. Particulate metals were normalised to P and Al to evaluate the relative influence of biotic and abiotic sources. The Fe:P ratios decreased with time and compared to published phytoplankton ratios suggest Fe storage. On the other hand, Fe:Al ratios were relatively closer to the crustal ratios suggesting that the abiotic source was more important for this metal. Trends for other metals will be discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Creating Edinburgh:Diffracting interdisciplinary education in the contemporary city

This article follows an experimental interdisciplinary undergraduate course into the busy, unpredictable space of the contemporary city. It locates practice-based research of interdisciplinary higher education in a dynamic learning environment, which is comprised of unpredictable connections between disciplinary perspectives. Following Karen Barad, the aim is to diffract interdisciplinary higher education in order to recognise and work with a multiplicity of meaning and experience. This article explores an alternative to the dominant model of challenge-based learning in the interdisciplinary classroom. Creating Edinburgh: The Interdisciplinary City is an undergraduate elective offered by Edinburgh Futures Institute at the University of Edinburgh. It provides students with opportunities to explore the city of Edinburgh in small groups, comprised of students from a wide range of degree programmes. Groups are invited to engage with a selection of themed fieldwork topics throughout the 11 weeks of the course, visiting specific sites and responding to a series of tasks and questions. These include topics such as Sustainability, Decolonisation and Wildness, which are presented as interdisciplinary field topics to explore, rather than problems to solve. This article develops a research methodology that sets out to travel with students as they navigate their way through the city during their weekly field trips. Combining first-hand autoethnographic accounts with walking interviews, it offers an insight into interdisciplinary learning and teaching in the expanded field of the contemporary city. Conceiving urban space as an assemblage of digital and non-digital objects, events and activities, members of the research team accompany students during their fieldwork, equipped with audio recorders, cameras and notebooks. The documents of these research journeys are then diffracted within a new materialist framework. The article concludes with questions and prompts for working with the agency and affordances of a field-based education practice

Financing Sustainable Value Creation

Addressing the contribution of EU financial markets to unsustainable business practices is vital to realising the EU’s commitments on sustainability. In this chapter, we assess recent EU legislative progress in this field. We argue that legislative and regulatory mechanisms in the field of financial regulation are progressing too slowly to meet the EU’s self-imposed targets for sustainability. We argue that, on current trajectories, a fundamental recalibration of reform efforts is required in relation to financial system participants if a reduction in the funding of activities that cause damage to the environment and to the social foundation of humanity is to be achieved. To this end, we provide a menu of rapid and meaningful policy interventions.Peer reviewe

ENHANCING THE APPLICATION AND MEASUREMENT OF RELATIONSHIP QUALITY IN FUTURE IT OUTSOURCING STUDIES

Studies have emphasised the importance of a strong relationship between a client and vendor to ensure positive IT Outsourcing (ITO) outcomes. To measure and assess this relationship strength, a construct known as Relationship Quality (ReQ) has been widely used in the ITO context. However, recent studies have highlighted the inconsistent and even contradictory application of this construct in previous studies raising concern over its validity. To address this matter, we conducted a critical literature analysis to systematically examine how ReQ has been applied in previous ITO studies. The findings from our review highlight three important knowledge gaps with the current ITO studies: 1) lack of rich qualitative studies investigating ReQ that is complex and subjective in nature; 2) inappropriate application of economic and strategic based theoretical lenses; 3) lack of differentiation between ReQ attributes. This study provides a number of recommendations to enhance the application and measurement of ReQ in future ITO studies. The next step of the study will address the three identified knowledge gaps. This study offers important implications to both theory and practice

The effects of ocean acidification and siderophore additions on trace-metal dynamics during an Emiliania Huxleyi- dominated bloom in a coastal mesocosm experiment

The combined impacts of high CO2 and changes in trace metal availability on plankton remain largely unknown. A 22 days mesocosm experiment was carried out in the Raunefjord, off Bergen, Norway (June 2012) to investigate the interactive effects of increased CO2 and changes in iron availability in the pelagic community. Twelve mesocosms covered by PAR and UVR transparent lids were used. The CO2 treatments consisted of present (LC; 390 ppmV) and predicted levels for year 2100 (HC; 900 ppmV). On day 7, half of the mesocoms were amended with the siderophore desferoxamine B (DFB) at 70 nM (final concentration). We studied changes in dissolved Cu (dCu) and Fe (dFe), and in the elemental composition of particles. Dissolved Fe and dCu were measured by chemiluminescence flow injection analysis, while particulate metals were determined by high-resolution inductively coupled mass spectrometry. The metals were normalised to P and Al to evaluate the relative influence of biotic and abiotic sources. Samples were taken throughout a bloom of the coccolithophore E. huxleyi. Further details will be discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Evidence for the production of copper-complexing ligands by marine phytoplankton in the subarctic northeast Pacific

The availability and toxicity of copper (Cu) to marine phytoplankton involve complexation of Cu by dissolved organic ligands of uncertain origin and structure. As part of a GEOTRACES process study we used immobilized copper(II)-ion affinity chromatography (IMAC) to isolate and obtain information about the distribution and potential sources of Cu-complexing ligands along Line P in the subarctic northeast Pacific. Filtered seawater samples were collected from up to five stations during cruises in June 2016, June 2017, August 2017, and September 2018. Copper ligand concentrations were consistently higher at coastal station P4 than at other stations, particularly in surface waters. Ligand concentrations in the upper 40 m at station P26 increased between 2016 and 2018 following the 2014–2016 warming anomaly in the northeast Pacific, whereas an increase in ligand concentration from June to August 2017 coincided with seasonal increases in dissolved organic carbon (DOC) and net community production. At all stations, the depth of highest ligand concentration and maximum chlorophyll concentration coincided. A positive linear correlation between ligand and chlorophyll concentrations suggests that marine phytoplankton are a significant source of Cu ligands along Line P. The lower than expected ligand concentrations at station P26 in June 2016 are consistent with changes in phytoplankton ecology associated with the 2014–2016 warming anomaly. Comparing results from coastal and oceanic waters with those obtained previously in the Canadian Arctic suggests that terrigenous organic matter and marine humic substances contribute to the pool of Cu ligands captured by IMAC

Effect of iron limitation on the cadmium to phosphorus ratio of natural phytoplankton assemblages from the Southern Ocean

There is considerable interest in the biogeochemical cycling of cadmium (Cd) and phosphate (PO4) in surface waters, driven in part by the ongoing development of a paleonutrient proxy that utilizes Cd preserved in fossil planktonic foraminifera to determine past PO4 utilization efficiencies in ocean surface waters. The present article reports the results of a field study into the effects of Fe limitation on the Cd : P composition of natural assemblages of marine phytoplankton in the Antarctic Zone of the Pacific sector of the Southern Ocean. Iron enrichment to shipboard incubation bottles led to increases in community growth rate and final biomass. After 10.7 d of incubation, the climax community was dominated by large diatoms of the genus Fragillariopsis, Pseudonitzschia, and Nitzschia. Direct measurements of phytoplankton metal : P ratios from controlled shipboard experiments indicate that Cd : P, Co: P, and Zn : P ratios decreased from control values with increasing initial dissolved Fe concentrations in the incubation bottles, by factors of ~2–10 at highest Fe additions. We suggest that the effect of Fe limitation on resident diatoms is to decrease growth rate, leading to elevated cellular Cd content. The dissolved Cd : P ratio in iron-limited surface waters of the Southern Ocean may, therefore, respond to the supply of Fe to the resident phytoplankton community, which has implications for the developing paleonutrient proxy. We suggest that the biological uptake of Cd and P is independent of the dissolved Cd: PO4 ratio. As a consequence, the results argue against the use of empirical Rayleigh fractionation models or models with fixed phytoplankton uptake ratios to account for regional variability in surface water dissolved Cd : PO4

Predicting Quality of Clinical Performance From Cardiology Fellowship Applications

Variables in cardiology fellowship applications have not been objectively analyzed against applicants\u27 subsequent clinical performance. We investigated possible correlations in a retrospective cohort study of 65 cardiology fellows at the Mayo Clinic (Rochester, Minn) who began 2 years of clinical training from July 2007 through July 2013. Application variables included the strength of comparative statements in recommendation letters and the authors\u27 academic ranks, membership status in the Alpha Omega Alpha Honor Medical Society, awards earned, volunteer activities, United States Medical Licensing Examination (USMLE) scores, advanced degrees, publications, and completion of a residency program ranked in the top 6 in the United States. The outcome was clinical performance as measured by a mean of faculty evaluation scores during clinical training. The overall mean evaluation score was 4.07 ± 0.18 (scale, 1-5). After multivariable analysis, evaluation scores were associated with Alpha Omega Alpha designation (β=0.13; 95% CI, 0.01-0.25; P=0.03), residency program reputation (β=0.13; 95% CI, 0.05-0.21; P=0.004), and strength of comparative statements in recommendation letters (β=0.08; 95% CI, 0.01-0.15; P=0.02), particularly in letters from residency program directors (β=0.05; 95% CI, 0.01-0.08; P=0.009). Objective factors to consider in the cardiology fellowship application include Alpha Omega Alpha membership, residency program reputation, and comparative statements from residency program directors

A call for refining the role of humic-like substances in the oceanic iron cycle

Primary production by phytoplankton represents a major pathway whereby atmospheric CO2 is sequestered in the ocean, but this requires iron, which is in scarce supply. As over 99% of iron is complexed to organic ligands, which increase iron solubility and microbial availability, understanding the processes governing ligand dynamics is of fundamental importance. Ligands within humic-like substances have long been considered important for iron complexation, but their role has never been explained in an oceanographically consistent manner. Here we show iron co-varying with electroactive humic substances at multiple open ocean sites, with the ratio of iron to humics increasing with depth. Our results agree with humic ligands composing a large fraction of the iron-binding ligand pool throughout the water column. We demonstrate how maximum dissolved iron concentrations could be limited by the concentration and binding capacity of humic ligands, and provide a summary of the key processes that could influence these parameters. If this relationship is globally representative, humics could impose a concentration threshold that buffers the deep ocean iron inventory. This study highlights the dearth of humic data, and the immediate need to measure electroactive humics, dissolved iron and iron-binding ligands simultaneously from surface to depth, across different ocean basins

Vouchers, Public School Response, and the Role of Incentives: Evidence from Florida

This paper analyzes the incentives and responses of public schools in the context of an educational reform. The literature on the effect of voucher programs on public schools typically focuses on student and mean school scores. This paper tries to go inside the black box to investigate some of the ways in which schools facing the Florida voucher program behaved. The program embedded vouchers in an accountability regime. Schools getting an “F” grade for the first time were exposed to the threat of vouchers, but did not face vouchers unless and until they got a second “F” within the next three years. In addition, “F,” being the lowest grade, exposed the threatened schools to stigma. Exploiting the institutional details of this program, I analyze the incentives built into the system and investigate the behavior of the threatened public schools facing these incentives. There is strong evidence that they did respond to incentives. Using highly disaggregated school-level data, a difference-in-differences estimation strategy, and a regression discontinuity analysis, I find that the threatened schools tended to focus more on students below the minimum criteria cutoffs rather than reading and math. These results are robust to controlling for differential preprogram trends, changes in demographic compositions, mean reversion, and sorting. The findings have important policy implications