ALBERT

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Widner, B., Kido Soule, M. C., Ferrer-González, F. X., Moran, M. A., & Kujawinski, E. B. Quantification of amine- and alcohol-containing metabolites in saline samples using pre-extraction benzoyl chloride derivatization and ultrahigh performance liquid chromatography tandem mass spectrometry (UHPLC MS/MS). Analytical Chemistry, 93(11), (2021): 4809-4817, https://doi.org/10.1021/acs.analchem.0c03769.

Description: Dissolved metabolites serve as nutrition, energy, and chemical signals for microbial systems. However, the full scope and magnitude of these processes in marine systems are unknown, largely due to insufficient methods, including poor extraction of small, polar compounds using common solid-phase extraction resins. Here, we utilized pre-extraction derivatization and ultrahigh performance liquid chromatography electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) to detect and quantify targeted dissolved metabolites in seawater and saline culture media. Metabolites were derivatized with benzoyl chloride by their primary and secondary amine and alcohol functionalities and quantified using stable isotope-labeled internal standards (SIL-ISs) produced from 13C6-labeled benzoyl chloride. We optimized derivatization, extraction, and sample preparation for field and culture samples and evaluated matrix-derived biases. We have optimized this quantitative method for 73 common metabolites, of which 50 cannot be quantified without derivatization due to low extraction efficiencies. Of the 73 metabolites, 66 were identified in either culture media or seawater and 45 of those were quantified. This derivatization method is sensitive (detection limits = pM to nM), rapid (∼5 min per sample), and high throughput.

Description: Funding included the Gordon and Betty Moore Foundation (Award GBMF5503 to M.A.M. and E.B.K.), Simons Foundation International (Award 409923 to E.B.K.), and the National Science Foundation (Award 1656311 to M.A.M.).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ralston, D. K., Yellen, B., & Woodruff, J. D. Watershed suspended sediment supply and potential impacts of dam removals for an estuary. Estuaries and Coasts, (2021), https://doi.org/10.1007/s12237-020-00873-3.

Description: Observations and modeling are used to assess potential impacts of sediment releases due to dam removals on the Hudson River estuary. Watershed sediment loads are calculated based on sediment-discharge rating curves for gauges covering 80% of the watershed area. The annual average sediment load to the estuary is 1.2 Mt, of which about 0.6 Mt comes from side tributaries. Sediment yield varies inversely with watershed area, with regional trends that are consistent with substrate erodibility. Geophysical and sedimentological surveys in seven subwatersheds of the Lower Hudson were conducted to estimate the mass and composition of sediment trapped behind dams. Impoundments were classified as (1) active sediment traps, (2) run-of-river sites not actively trapping sediment, and (3) dammed natural lakes and spring-fed ponds. Based on this categorization and impoundment attributes from a dam inventory database, the total mass of impounded sediment in the Lower Hudson watershed is estimated as 4.9 ± 1.9 Mt. This represents about 4 years of annual watershed supply, which is small compared with some individual dam removals and is not practically available given current dam removal rates. More than half of dams impound drainage areas less than 1 km2, and play little role in downstream sediment supply. In modeling of a simulated dam removal, suspended sediment in the estuary increases modestly near the source during discharge events, but otherwise effects on suspended sediment are minimal. Fine-grained sediment deposits broadly along the estuary and coarser sediment deposits near the source, with transport distance inversely related to settling velocity.

Description: This work was sponsored by the National Estuarine Research Reserve System Science Collaborative, which is funded by the National Oceanic and Atmospheric Administration and managed by the University of Michigan Water Center (NAI4NOS4190145). Additional support for participating graduate and undergraduates was provided by the Northeast Climate and Adaptation Center and the Hudson River Fund. Additional support for DKR was provided by the Hudson River Foundation (Grant No. 003/19A). Data from sediment cores that were collected in association with this manuscript are archived here: https://doi.org/10.7275/dh3v-0x33.

Description: Gashydrate, auch „brennendes Eis“ genannt, sind faszinierende, eisähnliche Feststoffe, die aus Wasser- und Gasmolekülen aufgebaut sind und weltweit an allen aktiven und passiven Kontinentalhängen und in Permafrostgebieten vorkommen. Doch ihr unauffälliges Erscheinungsbild täuscht: Die Einschlussverbindungen können beachtliche Mengen Methangas enthalten. Daher besteht einerseits die Hoffnung auf einen möglichen neuen Energieträger und andererseits die Sorge um eine nicht zu unterschätzende Quelle an klimaschädlichem Methangas. Gashydrate, hat die neueste Forschung gezeigt, bieten zudem in vielen Bereichen industrieller Anwendung eine durchaus vielversprechende Alternative zu konventionellen Verfahren. Das vorliegende Buch gibt eine Einführung in die physikalisch-chemischen Grundlagen der Hydratbildung und die Strukturen der Gashydratphasen. Basierend auf diesem grundlegenden Verständnis erklärt es die natürlichen Gashydratvorkommen und zeichnet mögliche Methoden des Abbaus und der Gewinnung von Methangas auf. Es beleuchtet Risiken, die von den Gashydratvorkommen in der Natur ausgehen könnten, und führt in die Möglichkeiten der Nutzung dieser Einschlussverbindungen in verschiedenen industriellen Anwendungsbereichen wie z.B. der Aufbereitung von Abwässern oder der Speicherung von Gasen ein. Zielgruppe dieser kompakten Einführung in die verschiedenen Aspekte der Gashydratforschung sind Studierende der Chemie und Geowissenschaften, Ingenieure, Techniker oder auch Wissenschaftler.

Description: Global population projections foresee the biggest increase to occur in Africa with most of the available uncultivated land to ensure food security remaining on the continent. Simultaneously, greenhouse gas emissions are expected to rise due to ongoing land use change, industrialisation, and transport amongst other reasons with Africa becoming a major emitter of greenhouse gases globally. However, distinct knowledge on greenhouse gas emissions sources and sinks as well as their variability remains largely unknown caused by its vast size and diversity and an according lack of observations across the continent. Thus, an environmental research infrastructure—as being setup in other regions—is more needed than ever. Here, we present the results of a design study that developed a blueprint for establishing such an environmental research infrastructure in Africa. The blueprint comprises an inventory of already existing observations, the spatial disaggregation of locations that will enable to reduce the uncertainty in climate forcing’s in Africa and globally as well as an overall estimated cost for such an endeavour of about 550 M€ over the next 30 years. We further highlight the importance of the development of an e-infrastructure, the necessity for capacity development and the inclusion of all stakeholders to ensure African ownership.

Description: The female flowers (“cones”) of the hop plant (Humulus L.) produce compounds that contribute to the flavor and other properties of beer. Hop leaves and cones produce many of the same compounds, which also confer agronomic traits such as insect and disease resistance. Targeted and untargeted ultraperformance liquid chromatography-quadrupole time-of-flight–mass spectrometry with Waters MSE technology (UPLC-QTof-MSE) metabolomics were used to compare leaf phytochemical compositions of greenhouse-grown southwestern American wild Humulus neomexicanus (A. Nelson and Cockerell) Rydb. against a group of commercial hop cultivars consisting of both pure European Humulus lupulus L. and European–North American hybrids. Principal component analysis showed a clear distinction in chemical profiles between the two groups. H. neomexicanus leaves had a significantly higher content of total α acids (p = 4.4 × 10–9), total bitter acids (p = 2.6 × 10–6), cohumulone (p = 1.0 × 10–13), humulone + adhumulone (p = 9.1 × 10–4), and the prenylflavonoids xanthohumol (p = 0.013) and desmethylxanthohumol (p = 0.029) as well as significantly higher densities of glandular trichomes (p = 1.3 × 10–6), the biosynthetic site of those compounds. Most flavonol glycosides measured were also significantly more abundant in H. neomexicanus (p = 1.5 × 10–22 to 0.0027), whereas phenolic acids were consistently, but generally nonsignificantly (p 〉 0.05), more abundant in the cultivars. The higher bitter acid, prenylflavonoid, and flavonol glycoside content of H. neomexicanus leaves may help to confer more favorable insect and disease-resistance properties.

Description: Iron is an indispensable metabolic cofactor in both pro- and eukaryotes, which engenders a natural competition for the metal between bacterial pathogens and their human or animal hosts. Bacteria secrete siderophores that extract Fe3+ from tissues, fluids, cells, and proteins; the ligand gated porins of the Gram-negative bacterial outer membrane actively acquire the resulting ferric siderophores, as well as other iron-containing molecules like heme. Conversely, eukaryotic hosts combat bacterial iron scavenging by sequestering Fe3+ in binding proteins and ferritin. The variety of iron uptake systems in Gram-negative bacterial pathogens illustrates a range of chemical and biochemical mechanisms that facilitate microbial pathogenesis. This document attempts to summarize and understand these processes, to guide discovery of immunological or chemical interventions that may thwart infectious disease.

Description: While thousands of environmental metagenomes have been mined for the presence of novel biosynthetic gene clusters, such computational predictions do not provide evidence of their in vivo biosynthetic functionality. Using fluorescent in situ enzyme assay targeting carrier proteins common to polyketide (PKS) and nonribosomal peptide synthetases (NRPS), we applied fluorescence-activated cell sorting to tunicate microbiome to enrich for microbes with active secondary metabolic capabilities. Single-cell genomics uncovered the genetic basis for a wide biosynthetic diversity in the enzyme-active cells and revealed a member of marine Oceanospirillales harboring a novel NRPS gene cluster with high similarity to phylogenetically distant marine and terrestrial bacteria. Interestingly, this synthase belongs to a larger class of siderophore biosynthetic gene clusters commonly associated with pestilence and disease. This demonstrates activity-guided single-cell genomics as a tool to guide novel biosynthetic discovery.

Description: The aim of this study is to improve our knowledge of the attenuation structure in the Southern Apennines using a new amplitude ratio tomography method (Phillips et al., Geophys Res Lett 32(21): L21301, 2005) applied on both direct and coda envelope measurements derived from 150 events recorded by 47 stations of the Istituto Nazionale di Geofisica e Vulcanologia National Seismic Network (Rete Sismica Nazionale Centralizzata). The twodimensional (2-D) analysis allows us to take into account lateral crustal variations and heterogeneities of this region. Using the same event and station distribution, we also applied a simple 1-D methodology, and the performance of the 1-D and 2-D path assumptions is tested by comparing the average interstation variance for the path-corrected amplitudes using coda and direct waves. In general, coda measurement results are more stable than using direct waves when the same methodology is applied. Using the 2-D approach, we observe more stable results for both waves. However, the improvement is quite small, probably because the crustal heterogeneity is weak. This means that, for this region, the 1-D path assumption is a good approximation of the attenuation characteristics of the region. A comparison between Q tomography images obtained using direct and coda amplitudes shows similar results, consistent with the geology of the region. In fact, we observe low Q along the Apennine chain toward the Tyrrhenian Sea and higher values to the east, in correspondence with the Gargano zone that is related to the Apulia Carbonate Platform. Finally, we compared our results with the coda Q values proposed by Bianco et al. (Geophys J Int 150:10–22, 2002) for the same region. The good agreement validates our results as the authors used a completely independent methodology.

Description: Published

Description: 355–365

Description: 1T. Struttura della Terra

Description: JCR Journal

Description: Poás is a complex stratovolcano with an altitude of 2,708 m asl, located in the Cordillera Volcánica Central of Costa Rica. Prior to 2017, the last three historical eruptions occurred on 7 February 1834, between January and May 1910 and during the period 1953-1955. Very few literature exists on the 1834 eruption. The only references state that it was an important event, that ash reached 〉53 km W-SW of Poás, and that it harmed the grasslands around the volcano. Related deposits of this eruption suggest phreatic activity, which launched bombs and blocks. Moreover, there is evidence of pyroclastic flow deposits near the crater. The 1910 eruption is better described. Despite the fact that ash fall is only reported near the volcano, a volume of the deposit of 1.6 x 107 m3 is estimated. Deposits of the eruption are white in color with many hydrothermally altered, and minor presence of juvenile fragments (vesicular lapilli). The eruption is classified as vulcanian, with deposits of ash fall and pyroclastic flows close to the crater. A Volcano Explosivity Index 3 (VEI 3) is estimated. The eruption affected agriculture. The 1953-1955 eruptions had a longer duration. Various ash fall deposits at several sites are reported. Deposits of this eruption, easily distinguished in the field, are black scoria lapilli, bombs with, sometimes fusiform, bread crust textures. In the eastern sector of the crater bombs can reach meters in size; such large bombs near the eruption centre at one side suggest the inclination of the eruptive conduct, or an asymmetrical vent-crater system. Inside the crater a 40 m-high dome and a lava flow were extruded during the eruption. Towards the east side of the current Laguna Caliente crater lake, relicts of a 8.5 m thick lava pool are found. During the entire eruptive episode, the acid lake presumably lacked. The eruption is described to be of a mixed type: strombolian, phreatomagmatic, vulcanian and dome extrusion eruptions. Considering the characteristics of this eruption, the height of the eruption column, ejected volume (2.1 x 107  m3), and its presumed duration, a VEI 3 is estimated. The eruptions damaged agricultural activity (including cattle), and forced the spontaneous evacuation of some people. In April 2017 magmatic eruptions followed a decade-long period of intense phreatic activity. These eruptions destroyed the 1953-1955 Dome and led to the complete dry out of Laguna Caliente. Pyroclastic cones and sulphur volcanism manifested at the bottom of the former crater lake bottom. The 2017 eruption severely affected touristic activities at and near Poás, with an estimated economic loss of 20 million dollars. By May-August 2018 Laguna Caliente reappeared. The volcanic hazards related to the three studied historical eruptions are: pyroclastic flows (at least 1 km from the eruptive centre, including reaching the current mirador sector), ballistics (bomb ejections up to 2 km from the emission centre), dispersion and fall of pyroclasts (tens of kms), gas emission and acid rain, dispersed by WSW dominant winds, and lahars in most of the river canyons SW of the volcano.  

Description: Published

Description: 261-299

Description: 1V. Storia eruttiva

Description: We present an interdisciplinary review of the observed and projected variations in atmospheric and oceanic circulation within the southwestern South Atlantic focused on basin-scale processes driven by climate change, and their potential impact on the regional fisheries. The observed patterns of atmospheric circulation anomalies are consistent with anthropogenic climate change. There is strong scientific evidence suggesting that the Brazil Current is intensifying and shifting southwards during the past decades in response to changes in near-surface wind patterns, leading to intense ocean warming along the path of the Brazil Current, the South Brazil Bight, and in the Río de la Plata. These changes are presumably responsible for the poleward shift of commercially important pelagic species in the region and the long-term shift from cold-water to warm-water species in industrial fisheries of Uruguay. Scientific and traditional knowledge shows that climate change is also affecting small-scale fisheries. Long-term records suggest that mass mortalities decimated harvested clam populations along coastal ecosystems of the region, leading to prolonged shellfishery closures. More frequent and intense harmful algal blooms together with unfavorable environmental conditions driven by climate change stressors affect coastal shellfisheries, impact economic revenues, and damage the livelihood of local communities. We identify future modelling needs to reduce uncertainty in the expected effects of climate change on marine fisheries. However, the paucity of fisheries data prevents a more effective assessment of the impact of climate change on fisheries and hampers the ability of governments and communities to adapt to these changes.

Description: The relation between macroseismic intensity and ground shaking makes it possible to transform instrumental Ground Motion Parameters (GMPs) in macroseismic intensity and vice versa, and is therefore useful for making comparisons between estimates of seismic hazard determined in terms of GMPs and macroseismic intensity, and for other engineering and seismological applications. Empirical relationships between macroseismic intensity and different recorded GMPs for the Italian territory are presented in this paper. The coefficients are calibrated using a dataset of horizontal geometrical mean GMPs, i.e. peak ground acceleration (PGA), peak ground velocity (PGV), spectral acceleration (SA) at 0.2, 0.3, 1.0 and 2.0 s from the ITalian ACcelerometric Archive (ITACA; Luzi et al. 2019), and macroseismic intensity at Mercalli-Cancani-Sieberg (MCS) scale from the database DBMI15 (Locati et al. 2019). A dataset was obtained that corresponds to 240 pairs of macroseismic intensity-GMPs from 67 Italian earthquakes in the time window 1972-2016 with moment magnitude ranging from 4.2 to 6.8 and macroseismic intensity in the range [2, 10-11]. The final dataset is developed correlating strong motion stations and macroseismic intensity observations generally within 2 km from each other, but the associations is manually validated through the expert opinion. The adopted functional form is non-linear predicting macroseismic intensity as a function of LogGMPs and vice versa by performing separate regressions. The set of empirical conversion relationships GMP-I MCS -GMP and the associated standard deviations are compared with previous models. The results of an illustrative PSHA, obtained using a new seismogenic zonation (Santulin et al. 2017), proposed as one of the inputs of the new Italian seismic hazard model (Meletti et al. 2017), are used to analyse and compare seismic hazard assessment in terms of PGA and the related seismic hazard map in terms of macroseismic intensity (MCS) obtained using the empirical relationships here proposed for the PGA.

Description: Published

Description: 5143–5164

Description: 6T. Studi di pericolosità sismica e da maremoto

Description: JCR Journal

Description: This chapter is arguably the most complete compilation of sulfur volcanism of any given volcano on Earth: Poás. Sulfur volcanism at Poás is described in historical literature since 1828, and in scientific literature since the 1960’s. We first classify the various manifestations of sulfur volcanism at crater lake bearing volcanoes (subaerial and sublacustrine sulfur pools, sulfur spherules, flows, cones/hornitos, and sweat, and pyroclastic and burning sulfur), based on work by Japanese pioneers of the early 1900s. Their first observations and models have passed the test of time and still stand as theories today. Comparing the sulfur volcanism at Poás with the one at other (55) volcanoes, it is honest to say that only White Island (New Zealand) and Kawah Ijen (Indonesia) are the only ones comparable with Poás, being the most dynamic of them all.

Description: Published

Description: 45-78

Description: 4V. Processi pre-eruttivi

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in McLean, C., & Kujawinski, E. B. AutoTuner: high fidelity and robust parameter selection for metabolomics data processing. Analytical Chemistry, 92(8), (2020): 5724-5732, doi:10.1021/acs.analchem.9b04804.

Description: Untargeted metabolomics experiments provide a snapshot of cellular metabolism but remain challenging to interpret due to the computational complexity involved in data processing and analysis. Prior to any interpretation, raw data must be processed to remove noise and to align mass-spectral peaks across samples. This step requires selection of dataset-specific parameters, as erroneous parameters can result in noise inflation. While several algorithms exist to automate parameter selection, each depends on gradient descent optimization functions. In contrast, our new parameter optimization algorithm, AutoTuner, obtains parameter estimates from raw data in a single step as opposed to many iterations. Here, we tested the accuracy and the run-time of AutoTuner in comparison to isotopologue parameter optimization (IPO), the most commonly used parameter selection tool, and compared the resulting parameters’ influence on the properties of feature tables after processing. We performed a Monte Carlo experiment to test the robustness of AutoTuner parameter selection and found that AutoTuner generated similar parameter estimates from random subsets of samples. We conclude that AutoTuner is a desirable alternative to existing tools, because it is scalable, highly robust, and very fast (∼100–1000× speed improvement from other algorithms going from days to minutes). AutoTuner is freely available as an R package through BioConductor.

Description: We thank Titus Brown and Ben Temperton for advice on the algorithm validation, Arthur Eschenlauer for constructive feedback on the software design, Krista Longnecker for continuous support and discussions, Gabriel Leventhal for mathematics advice, the users of AutoTuner for debugging help through Github, and David Angeles-Albores and two anonymous reviewers for critical feedback on the manuscript. Funding support included the National GEM Consortium and NSF graduate research program fellowships (C.M.) and grants from the MIT Microbiome Center (Award 6936800, E.B.K.) and the Simons Foundation (Award ID #509034, E.B.K.).

Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Zeng, L., Schmitt, R. W., Li, L., Wang, Q., & Wang, D. Forecast of summer precipitation in the Yangtze River Valley based on South China Sea springtime sea surface salinity. Climate Dynamics, 53(9-10), (2019): 5495-5509, doi: 10.1007/s00382-019-04878-y.

Description: As a major moisture source, the South China Sea (SCS) has a significant impact on the summer precipitation over China. The ocean-to-land moisture transport generates sea surface salinity (SSS) anomalies that can be used to predict summer precipitation on land. This study illustrates a high correlation between springtime SSS in the central SCS and summer precipitation over the middle and lower Yangtze River Valley (the YRV region). The linkage between spring SSS in the central SCS and summer YRV precipitation is established by ocean-to-land moisture transport by atmospheric processes and land–atmosphere soil moisture feedback. In spring, oceanic moisture evaporated from the sea surface generates high SSS in the central SCS and directly feeds the precipitation over southern China and the YRV region. The resulting soil moisture anomalies last for about 3 months triggering land–atmosphere soil moisture feedback and modulating the tropospheric moisture content and circulation in the subsequent summer. Evaluation of the atmospheric moisture balance suggests both a dynamic contribution (stronger northward meridional winds) and a local thermodynamic contribution (higher tropospheric moisture content) enhance the summer moisture supply over the YRV, generating excessive summer precipitation. Thus, spring SSS in the SCS can be utilized as an indicator of subsequent summer precipitation over the YRV region, providing value for operational climate prediction and disaster early warning systems in China.

Description: This research has been supported by the National Natural Science Foundation of China (Nos. 41776025, 41476014, 41606030, 41806027, 41806035). RWS was supported by NSF Grant ICER-1663704. LL was supported by NSF-ICER-1663138. QW was also sponsored by the Pearl River S&T Nova Program of Guangzhou (201906010051). LZ was also supported by the Innovation Academy of South China Sea Ecology and Environmental Engineering (ISEE), Chinese Academy of Sciences, and the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou).

Description: Author Posting. © American Chemical Society, 2020. This is an open access article published under an ACS AuthorChoice License. The definitive version was published in Chemical Research in Toxicology, 33(4), (2020): 860-879, doi:10.1021/acs.chemrestox.9b00476.

Description: The Ah receptor (AHR) has been studied for almost five decades. Yet, we still have many important questions about its role in normal physiology and development. Moreover, we still do not fully understand how this protein mediates the adverse effects of a variety of environmental pollutants, such as the polycyclic aromatic hydrocarbons (PAHs), the chlorinated dibenzo-p-dioxins (“dioxins”), and many polyhalogenated biphenyls. To provide a platform for future research, we provide the historical underpinnings of our current state of knowledge about AHR signal transduction, identify a few areas of needed research, and then develop concepts such as adaptive metabolism, ligand structural diversity, and the importance of proligands in receptor activation. We finish with a discussion of the cognate physiological role of the AHR, our perspective on why this receptor is so highly conserved, and how we might think about its cognate ligands in the future.

Description: This review is dedicated in memory of the career of Alan Poland, one of the truly great minds in pharmacology and toxicology. This work was supported by the National Institutes of Health Grants R35-ES028377, T32-ES007015, P30-CA014520, P42-ES007381, and U01-ES1026127, The UW SciMed GRS Program, and The Morgridge Foundation. The authors would like to thank Catherine Stanley of UW Media Solutions for her artwork.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Finke, K., Jimenez-Esteve, B., Taschetto, A. S., Ummenhofer, C. C., Bumke, K., & Domeisen, D. I., V. Revisiting remote drivers of the 2014 drought in South-Eastern Brazil. Climate Dynamics, (2020), doi:10.1007/s00382-020-05442-9.

Description: South-Eastern Brazil experienced a devastating drought associated with significant agricultural losses in austral summer 2014. The drought was linked to the development of a quasi-stationary anticyclone in the South Atlantic in early 2014 that affected local precipitation patterns over South-East Brazil. Previous studies have suggested that the unusual blocking was triggered by tropical Pacific sea surface temperature (SST) anomalies and, more recently, by convection over the Indian Ocean related to the Madden–Julian Oscillation. Further investigation of the proposed teleconnections appears crucial for anticipating future economic impacts. In this study, we use numerical experiments with an idealized atmospheric general circulation model forced with the observed 2013/2014 SST anomalies in different ocean basins to understand the dominant mechanism that initiated the 2014 South Atlantic anticyclonic anomaly. We show that a forcing with global 2013/2014 SST anomalies enhances the chance for the occurrence of positive geopotential height anomalies in the South Atlantic. However, further sensitivity experiments with SST forcings in separate ocean basins suggest that neither the Indian Ocean nor tropical Pacific SST anomalies alone have contributed significantly to the anomalous atmospheric circulation that led to the 2014 South-East Brazil drought. The model study rather points to an important role of remote forcing from the South Pacific, local South Atlantic SSTs, and internal atmospheric variability in driving the persistent blocking over the South Atlantic.

Description: K.F. was partially supported by the GEOMAR Marine Meteorology research area. Support to D.D. and B.J-E. from the Swiss National Science Foundation through project PP00P2_170523 is gratefully acknowledged. This research was supported by a Research Fellowship by the Alexander von Humboldt Foundation and the Early Career Scientist Endowed Fund and The George E. Thibault Early Career Scientist Fund to C.C.U. A.S.T. is supported by the Australian Research Council FT160100495. Open access funding provided by Swiss Federal Institute of Technology Zurich.

Description: It is a good method to utilize the grain size distribution curves and cumulative frequency curves of marine or river sediments to estimate the hydrodynamic conditions, transportation processes and sedimentary environment. However, researchers can only rely on Excel or Grapher to plot the curves one by one at the present day. The manual plotting procedures are complicated, and calculating the truncation points is time-consuming. To solve the aforementioned problems, we have developed a software tool to plot cumulative frequency curves and calculate the values of truncation points automatically. The software has the ability to plot curves of hundreds of samples accurately and rapidly, promoting researchers to analyze transport mechanisms and hydrodynamic environments. And it is convenient to apply the software to compare the processes of transportation and deposition between different samples.

Description: Marine macroalgae, seaweeds, are exceptionally prolific producers of halogenated natural products. Biosynthesis of halogenated molecules in seaweeds is inextricably linked to reactive oxygen species (ROS) signaling as hydrogen peroxide serves as a substrate for haloperoxidase enzymes that participate in the construction these halogenated molecules. Here, using red macroalga Asparagopsis taxiformis, a prolific producer of the ozone depleting molecule bromoform, we provide the discovery and biochemical characterization of a ROS-producing NAD(P)H oxidase from seaweeds. This discovery was enabled by our sequencing of Asparagopsis genomes, in which we find the gene encoding the ROS-producing enzyme to be clustered with genes encoding bromoform-producing haloperoxidases. Biochemical reconstitution of haloperoxidase activities establishes that fatty acid biosynthesis can provide viable hydrocarbon substrates for bromoform production. The ROS production haloperoxidase enzymology that we describe here advances seaweed biology and biochemistry by providing the molecular basis for decades worth of physiological observations in ROS and halogenated natural product biosyntheses.

Description: Fusarium oxysporum is a destructive root-infecting plant pathogen that causes significant yield losses in many economically important crop species. Hence, a deeper understanding of pathogen infection strategies is needed. With liquid chromatography-tandem mass spectrometry and gas chromatography-time of flight mass spectrometry platforms, we analyzed the metabolic changes in a time-course experiment with Arabidopsis accessions either resistant (Col-0) or susceptible (Ler-0) to isolates of Fusarium oxysporum forma specialis matthioli infection. We showed a concurrent effect of Fusarium-derived polyols and the mycotoxin beauvericin in the suppression of the immune response of susceptible hosts. A significant increase in oxidized glutathione in the resistant host was probably associated with effective reactive oxygen species-mediated resistance responses. Through a combination of targeted and untargeted metabolomics, we demonstrated the concurrent action of several Arabidopsis defense systems as well as the concurrent action of several virulence systems in the fungal attack of susceptible Arabidopsis.

Description: In times of accelerating climate change, species are challenged to respond to rapidly shifting environmental settings. Yet, faunal distribution and composition are still scarcely known for remote and little explored seas, where observations are limited in number and mostly refer to local scales. Here, we present the first comprehensive study on Eurasian-Arctic macrobenthos that aims to unravel the relative influence of distinct spatial scales and environmental factors in determining their large-scale distribution and composition patterns. To consider the spatial structure of benthic distribution patterns in response to environmental forcing, we applied Moran’s eigenvector mapping (MEM) on a large dataset of 341 samples from the Barents, Kara and Laptev Seas taken between 1991 and 2014, with a total of 403 macrobenthic taxa (species or genera) that were present in ≥ 10 samples. MEM analysis revealed three spatial scales describing patterns within or beyond single seas (broad: ≥ 400 km, meso: 100–400 km, and small: ≤ 100 km). Each scale is associated with a characteristic benthic fauna and environmental drivers (broad: apparent oxygen utilization and phosphate, meso: distance-to-shoreline and temperature, small: organic carbon flux and distance-to-shoreline). Our results suggest that different environmental factors determine the variation of Eurasian-Arctic benthic community composition within the spatial scales considered and highlight the importance of considering the diverse spatial structure of species communities in marine ecosystems. This multiple-scale approach facilitates an enhanced understanding of the impact of climate-driven environmental changes that is necessary for developing appropriate management strategies for the conservation and sustainable utilization of Arctic marine systems.