bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards a transdimensional home: home-making in the narrations of Norwegians of Turkish descent
Authors: Nikielska-Sekula Karolina
Published: January 2021

Building on current scholarship and empirical evidence from the research conducted by the author on Norwegian Turkish communities in the city of Drammen, Norway, this paper discusses the process of home-making by the descendants of Turkish immigrants in Norway, the so-called second- and third-generation. By doing so it develops a model of a transdimensional home that attempts to embrace the multiple and seemingly contradictory meanings and reflections of home involving eight dimensions identified in the narrations of the respondents: spatial, material, relational, home as routines and protection, home as origin, sensorial home, gendered relationships at home, and rejection from home. The model of a transdimensional home highlights people’s emotional and practical balancing acts between the ancestral country of origin and the place they live in. It aims at grasping the dynamics between these dimensions, approaching home as occurring at their intersection. It also underlines the processual character of the making of home in relation to the surrounding circumstances.
Analysis of loess landslide mechanism and numerical simulation stabilization on the Loess Plateau in Central China
Authors: Xie Wan-li , Guo Qianyi , Wu Jason Y. , Li Ping , Yang Hui , Zhang Maosheng
Published: January 2021

Loess landslides have complicated deformation mechanisms. Accurately describing the internal failure deformation of loess landslides and establishing a theoretical method of landslide instability evaluation for the prevention of subsequent landslides have become important topics in western development project construction in China. This paper presents a case study of the Zhonglou Mountain landslide in Shaanxi Province, China. Based on field investigation results, a two-dimensional stability analysis model was constructed using the finite element method. Taking the deformation characteristics of the landslide as the research basis, the distribution laws of the displacement, stress, and shear strain of this landslide were identified with the strength reduction finite element numerical simulation method. Additionally, the safety factor was evaluated under normal and storm conditions. The numerical simulation results show that the horizontal tensile stress of the landslide was mainly distributed in the middle and upper parts of the landslide under normal conditions, while the vertical tensile stress was distributed near the sliding surface. Under heavy rainfall, the sliding force increased, and the anti-sliding force and anti-sliding section decreased; the location of the maximum shear strain shifted down from the middle and upper parts of the landslide body to the area with a shear crack, and the plastic shear strain area expanded along nearly the entire the sliding surface, leading to the occurrence of a landslide. Thus, the use of anti-slide piles to stabilize the landslide was proposed and tested. Monitoring points were arranged along the sliding surface to evaluate the displacement, stress, and strain responses. The on-site observation results agreed with the modeling results. The use of anti-slide piles was demonstrated to be an effective stabilization method for the Zhonglou Mountain landslide.
Chemical Compositions in Salinity Waterflooding of Carbonate Reservoirs: Theory
Authors: Yutkin M. P. , Radke C. J. , Patzek T. W.
Published: January 2021

Higher oil recovery after waterflood in carbonate reservoirs is attributed to increasing water wettability of the rock that in turn relies on complicated surface chemistry. In addition, calcite mineral reacts with aqueous solutions and can alter substantially the composition of injected water by mineral dissolution. Carefully designed chemical and/or brine flood compositions in the laboratory may not remain intact while the injected solutions pass through the reactive reservoir rock. This is especially true for a low-salinity waterflood process, where some finely tuned brine compositions can improve flood performances, whereas others cannot. We present a 1D reactive transport numerical model that captures the changes in injected compositions during water flow through porous carbonate rock. We include highly coupled bulk aqueous and surface carbonate-reaction chemistry, detailed reaction and mass transfer kinetics, 2:1 calcium ion exchange, and axial dispersion. At typical calcite reaction rates, local equilibrium is established immediately upon injection. In SI, we validate the reactive transport model against analytic solutions for rock dissolution, ion exchange, and longitudinal dispersion, each considered separately. Accordingly, using an open-source algorithm (Charlton and Parkhurst in Comput Geosci 37(10):1653–1663, 2011. 10.1016/j.cageo.2011.02.005), we outline a design tool to specify chemical/brine flooding formulations that correct for composition alteration by the carbonate rock. Subsequent works compare proposed theory against experiments on core plugs of Indiana limestone and give examples of how injected salinity compositions deviate from those designed in the laboratory for water-wettability improvement.
Susan Lynn Williams: the Life of an Exceptional Scholar, Leader, and Friend (1951–2018)
Authors: Dennison William C. , Bracken Matthew E. S. , Brown Maria , Bruno John F. , Carlton James T. , Carpenter Robert C. , Carruthers Tim J. B. , Dethier Megan N. , Duarte Carlos M. , Fisher Thomas R. , Fourqurean James W. , Grosberg Richard K. , Hamdan Leila J. , Heck Ken L. , Howard Dan J. , Hughes A. Randall , Hughes Brent B. , Kendrick Gary A. , Kenworthy W. Judson , Mars Frank , McRoy C. Peter , Naylor Rosamond L. , Nyden Bruce , Ogden John C. , Olyarnik Suzanne , Orth Robert J. , Short Frederick T. , Sorte Cascade J. B. , Stachowicz John J. , Strong Donald R. , Sur Christine , Waycott Michelle
Published: January 2021

Susan Lynn Williams (1951–2018) was an exceptional marine ecologist whose research focused broadly on the ecology of benthic nearshore environments dominated by seagrasses, seaweeds, and coral reefs. She took an empirical approach founded in techniques of physiological ecology. Susan was committed to applying her research results to ocean management through outreach to decision-makers and resource managers. Susan’s career included research throughout the USA in tropical, temperate, and polar regions, but she specialized in tropical marine ecology. Susan’s scholarship, leadership, and friendship touched many people, leading to this multi-authored paper. Susan’s scholarship was multi-faceted, and she excelled in scientific discovery, integration of scientific results, application of science for conservation, and teaching, especially as a mentor to undergraduate and graduate students and postdoctoral scholars. Susan served in a variety of leadership positions throughout her career. She embodied all facets of leadership; leading by example, listening to others, committing to the “long haul,” maintaining trust, and creating a platform for all to shine. Susan was an important role model for women in science. Susan was also a loyal friend, maintaining friendships for many decades. Susan loved cooking and entertaining with friends. This paper provides an overview of the accomplishments of Susan in the broad categories of scholarship, leadership, and friendship.
Bridging the gap: the case for an ‘Incompletely Theorized Agreement’ on AI policy
Authors: Stix Charlotte , Maas Matthijs M.
Published: January 2021

Recent progress in artificial intelligence (AI) raises a wide array of ethical and societal concerns. Accordingly, an appropriate policy approach is urgently needed. While there has been a wave of scholarship in this field, the research community at times appears divided amongst those who emphasize ‘near-term’ concerns and those focusing on ‘long-term’ concerns and corresponding policy measures. In this paper, we seek to examine this alleged ‘gap’, with a view to understanding the practical space for inter-community collaboration on AI policy. We propose to make use of the principle of an ‘incompletely theorized agreement’ to bridge some underlying disagreements, in the name of important cooperation on addressing AI’s urgent challenges. We propose that on certain issue areas, scholars working with near-term and long-term perspectives can converge and cooperate on selected mutually beneficial AI policy projects, while maintaining their distinct perspectives.
Exploring 'Unseen' Social Capital in Community Participation
Authors: Wong Sam
Published: January 2021

This volume argues that using social capital to eradicate poverty is unlikely to succeed because its mainstream approach mistakenly assumes that social capital necessarily benefits poor people. The inadequacy of that assumption, Sam Wong argues, calls for a reassessment of human motivations, institutional dynamics, and the complexity of structures in social capital building. Proposing a ‘pro-poor' perspective, in which poverty-specific outcomes are highlighted, he suggests an exploration of 'unseen' social capital is in order-not only to challenge the mainstream understanding of 'seen' social capital, but to demonstrate the need for everyday cooperation, which is shaped by social norms, influenced by conscious and unconscious motivations, and subject to changes in priority based on livelihood. A useful volume for both policy makers and practitioners, Exploring 'Unseen' Social Capital in Community Participation offers a fresh perspective in thinking about civic and social agency.
Their Footprints Remain
Authors: McKay Alex
Published: January 2021

By the end of the 19th century, British imperial medical officers and Christian medical missionaries had introduced Western medicine to Tibet, Sikkim, and Bhutan. Their Footprints Remain uses archival sources, personal letters, diaries, and oral sources in order to tell the fascinating story of how this once-new medical system became imbedded in the Himalayas. Of interest to anyone with an interest in medical history and anthropology, as well as the Himalayan world, this volume not only identifies the individuals involved and describes how they helped to spread this form of imperialist medicine, but also discusses its reception by a local people whose own medical practices were based on an entirely different understanding of the world.
The Politics of Justification
Authors: Green-Pedersen Christoffer
Published: January 2021

Christoffer Green-Pedersen's insightful examination of political party strategy in Europe reveals strong links between party consensus and policy retrenchment, arguing that the former allows governments to frame retrenchment in a way that justifies it to the electorate. In the Netherlands, Green-Pedersen shows, such consensus emerged in the mid-1980s, allowing the government to implement a number of welfare retrenchments; in Denmark, consensus did not emerge until the Social Democratic Party re-entered government in 1993, leading to less welfare-state retrenchment than in the Netherlands.
Constructing Iron Europe
Authors: Anastasiadou Irene
Published: January 2021

Although the years between the world wars were ones of diplomatic tension in Europe, they also saw the construction of countless miles of international railroads on the continent. In Constructing Iron Europe, Irene Anastasiadou examines this era of railroad building and argues that, contrary to most conventional histories which view railroad building as an aspect of nation- or empire-building the construction in this era was deliberately transnational, and ultimately aimed at tightening links between nations and constructing a closer-knit European community.
CRISPR-finder: A high throughput and cost-effective method to identify successfully edited Arabidopsis thaliana individuals
Authors: Symeonidi Efthymia , Regalado Julian , Schwab Rebecca , Weigel Detlef
Published: January 2021

Genome editing with the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR associated protein) system allows mutagenesis of a targeted region of the genome using a Cas endonuclease and an artificial guide RNA. Both because of variable efficiency with which such mutations arise and because the repair process produces a spectrum of mutations, one needs to ascertain the genome sequence at the targeted locus for many individuals that have been subjected to mutagenesis. We provide a complete protocol for the generation of amplicons up until the identification of the exact mutations in the targeted region. CRISPR-finder can be used to process thousands of individuals in a single sequencing run. We successfully identified an ISOCHORISMATE SYNTHASE 1 mutant line in which the production of salicylic acid was impaired compared to the wild type, as expected. These features establish CRISPR-finder as a high-throughput, cost-effective and efficient genotyping method of individuals whose genomes have been targeted using the CRISPR/Cas9 system.
Mapping Urban “Mixing” and Intercommunal Relations in Late Ottoman Jerusalem: A Neighborhood Study
Authors: Campos Michelle U.
Published: January 2021

Although Ottoman cities long have been recognized as sites of significant ethnic and religious heterogeneity, very little scholarship exists that documents or analyzes patterns of residential sorting, be it segregation, the physical separation of groups from each other in the urban landscape, or its opposite, integration. GIS mapping of the Ottoman censuses of Jerusalem illuminates these urban patterns and reveals the importance of scale when considering this question. Even the most “integrated” neighborhood on the aggregate level reveals “segregated” zones of clustering and concentration at the smaller scales of quadrant, street, and building. At the same time, the proximity and exposure of residents to each other reveals how very porous boundaries were in the neighborhood. In order to understand how and why the city developed such a complex spatial pattern, qualitative sources like newspapers, memoirs, and court records are a necessary supplement to demographic records. This approach allows for a comprehensive outlining of the economic, legal, religious, and cultural factors and forces contributing to both segregation and integration in an Ottoman city. It also points to a multidisciplinary reconstruction of the social space of an historic neighborhood.
Do you see what I mean?: Using mobile eye tracking to capture parent–child dynamics in the context of anxiety risk
Authors: MacNeill Leigha A. , Fu Xiaoxue , Buss Kristin A. , Pérez-Edgar Koraly
Published: January 2021

Temperamental behavioral inhibition (BI) is a robust endophenotype for anxiety characterized by increased sensitivity to novelty. Controlling parenting can reinforce children's wariness by rewarding signs of distress. Fine-grained, dynamic measures are needed to better understand both how children perceive their parent's behaviors and the mechanisms supporting evident relations between parenting and socioemotional functioning. The current study examined dyadic attractor patterns (average mean durations) with state space grids, using children's attention patterns (captured via mobile eye tracking) and parental behavior (positive reinforcement, teaching, directives, intrusion), as functions of child BI and parent anxiety. Forty 5- to 7-year-old children and their primary caregivers completed a set of challenging puzzles, during which the child wore a head-mounted eye tracker. Child BI was positively correlated with proportion of parent's time spent teaching. Child age was negatively related, and parent anxiety level was positively related, to parent-focused/controlling parenting attractor strength. There was a significant interaction between parent anxiety level and child age predicting parent-focused/controlling parenting attractor strength. This study is a first step to examining the co-occurrence of parenting behavior and child attention in the context of child BI and parental anxiety levels.
Sperm chromatin protamination influences embryo development in unsexed and sexed bull semen
Authors: Silva Thiago Velasco Guimarães , Santana Priscila Di Paula Bessa , Souza Eduardo Baia de , Lima Ana Júlia Mota de , Santos Caroline de Araújo , Almeida Nathália Nogueira da Costa , Brito Vanessa Cunha de , Gonçalves Arnaldo Algaranhar , Rolim Filho Sebastião Tavares , Cordeiro Marcela da Silva , Santos Simone do Socorro Damasceno , Miranda Moysés dos Santos , Ohashi Otávio Mitio
Published: January 2021

Sex selection through sperm sorting offers advantages in regards selection pressure in high-producing livestock. However, the sex-sorting process results in sperm membrane and DNA damage that ultimately decrease fertility. We hypothesized that given the role of protamines in DNA packaging, protamine deficiency could account, at least partially, for the DNA damage observed following sperm sex sorting. To test this, we compared protamine status between unsexed and sexed spermatozoa from two bulls using the fluorochrome chromomycin A3 (CMA3) and flow cytometry. Then, we assessed embryo development followingin vitrofertilization (IVF) using the same sperm treatments. Overall, sperm protamination was not different between sexed and unsexed semen. However, one of the two bulls displayed higher rates of protamine deficiency for both unsexed and sexed semen (P< 0.05). Moreover, unsexed semen from this bull yielded lower blastocyst (P< 0.05) and blastocyst hatching rates than unsexed sperm from the other bull. CMA3-positive staining was negatively correlated with cleavage (R285.1,P= 0.003) and blastocyst hatching (R287.6,P= 0.006) rates in unsexed semen. In conclusion, while the sex-sorting process had no effect on sperm protamine content, we observed a bull effect for sperm protamination, which correlated to embryo development rates following IVF.
Wind, Convection and Fetch Dependence of Gas Transfer Velocity in an Arctic Sea‐Ice Lead Determined From Eddy Covariance CO2 Flux Measurements
Authors: Prytherch J. , Yelland M. J.
Published: January 2021

The air‐water exchange of trace gases such as CO2 is usually parameterized in terms of a gas transfer velocity, which can be derived from direct measurements of the air‐sea gas flux. The transfer velocity of poorly soluble gases is driven by near‐surface ocean turbulence, which may be enhanced or suppressed by the presence of sea ice. A lack of measurements means that air‐sea fluxes in polar regions, where the oceanic sink of CO2 is poorly known, are generally estimated using open‐ocean transfer velocities scaled by ice fraction. Here, we describe direct determinations of CO2 gas transfer velocity from eddy covariance flux measurements from a mast fixed to ice adjacent to a sea‐ice lead during the summer‐autumn transition in the central Arctic Ocean. Lead water CO2 uptake is determined using flux footprint analysis of water‐atmosphere and ice‐atmosphere flux measurements made under conditions (low humidity and high CO2 signal) that minimize errors due to humidity cross‐talk. The mean gas transfer velocity is found to have a quadratic dependence on wind speed: k660 = 0.179 U102, which is 30% lower than commonly used open‐ocean parameterizations. As such, current estimates of polar ocean carbon uptake likely overestimate gas exchange rates in typical summertime conditions of weak convective turbulence. Depending on the footprint model chosen, the gas transfer velocities also exhibit a dependence on the dimension of the lead, via its impact on fetch length and hence sea state. Scaling transfer velocity parameterizations for regional gas exchange estimates may therefore require incorporating lead width data.
Global Distribution of Three Types of Drop Size Distribution Representing Heavy Rainfall From GPM/DPR Measurements
Authors: Ryu Jihoon , Song Hwan‐Jin , Sohn Byung‐Ju , Liu Chao
Published: January 2021

In this study, Gaussian mixture model clustering analysis was carried out to examine characteristics of Global Precipitation Measurement (GPM) Dual‐frequency Precipitation Radar (DPR)‐retrieved mass‐weighted mean diameter (Dm), and normalized intercept parameter (Nw) of the drop size distribution (DSD) for heavy rainfalls (>10 mm h−1) for 6 years (2014–2019). Three objective DSD types – continental, oceanic deep, and oceanic shallow convective types – emerged. The means and standard deviations of Dm and Nw obtained for the three types are in good agreement with various ground‐based observations, indicating that global view of DSD characteristics can be obtained from DPR‐derived DSD parameters. Global distributions of occurrence and contribution of each DSD type to total heavy rainfall are produced for the first time, which will help examine the dominant DSD type, its contribution to total heavy rainfall, and composition of different convective types in the rainfall system at a given location.
New Directional Wave Satellite Observations: Towards Improved Wave Forecasts and Climate Description in Southern Ocean
Authors: Aouf L. , Hauser D. , Chapron B. , Toffoli A. , Tourain C. , Peureux C.
Published: January 2021

In spite of continuous improvements of ocean wave models in the last decades, large errors still remain in particular under strongly forced conditions, often encountered in the Southern Ocean, where strong westerly winds generate some of the fiercest waves on Earth in almost unlimited fetch conditions. The newly launched China‐France Oceanography SATellite (CFOSAT) provides directional spectra of ocean waves for both wind seas and swells. Compared to Synthetic Aperture Radar (SAR), it can resolve shorter wavelengths in all directions, which dominate in non‐fully developed wind waves. Here, the assimilation of these CFOSAT wavenumber components is proved to bring more accurate predictions of wave growth compared to the assimilation of significant wave height alone. A notable reduction of model bias is found in the Southern Ocean, especially in the Pacific Ocean sector. Results further exhibit a downward shift of the wave age, consistent with theoretical wave growth curves.
Double‐ITCZ as an Emergent Constraint for Future Precipitation Over Mediterranean Climate Regions in the North Hemisphere
Authors: Dong Lu , Leung L. Ruby , Lu Jian , Song Fengfei
Published: January 2021

The semiarid Mediterranean climate regions feature wet winter and dry summer, distinct from most other regions on Earth. In response to warming, climate models project increased precipitation in US Southwest (USSW) and decreased in Mediterranean basin (MED) during winter, but with marked uncertainty. Using a multimodel ensemble, we found that models with excessive double Intertropical Convergence Zone (ITCZ) biases tend to exaggerate the precipitation increase over USSW and understate the precipitation decrease over MED in the future. These relationships are attributed to the atmospheric circulation changes driven by the increased tropical rainfall and the weaker slowdown of the Atlantic Meridional Overturning Circulation under warming, respectively. Constraining the present‐day double‐ITCZ with observations, the projected wetting over USSW is reduced to no change and the drying over MED is intensified by 32%. A relative reduction in future precipitation has profound societal and economic implications for these regions already under severe water stress.
Periodic Bedrock Ridges at the ExoMars 2022 Landing Site: Evidence for a Changing Wind Regime
Authors: Silvestro S. , Pacifici A. , Salese F. , Vaz D.A. , Neesemann A. , Tirsch D. , Popa C.I. , Pajola M. , Franzese G. , Mongelluzzo G. , Ruggeri A.C. , Cozzolino F. , Porto C. , Esposito F.
Published: January 2021

Wind‐formed features are abundant in Oxia Planum (Mars), the landing site of the 2022 ExoMars mission, which shows geological evidence for a past wet environment. Studies of aeolian bedforms at the landing site were focused on assessing the risk for rover trafficability, however their potential in recording climatic fluctuations has not been explored. Here we show that the landing site experienced multiple climatic changes in the Amazonian, which are recorded by an intriguing set of ridges that we interpret as Periodic Bedrock Ridges (PBRs). Clues for a PBR origin result from ridge regularity, defect terminations, and the presence of preserved megaripples detaching from the PBRs. PBR orientation differs from superimposed transverse aeolian ridges pointing toward a major change in wind regime. Our results provide constrains on PBR formation mechanisms and offer indications on paleo winds that will be crucial for understanding the landing site geology.
In Situ Investigation of Fluid‐Rock Interactions at Ångstrom Resolution
Authors: Barsotti Elizabeth , Qin Ziqiang , Piri Mohammad
Published: January 2021

The flow of aqueous phases through porous media shapes the world. It changes the courses of rivers, erodes mountainsides, dissolves historical monuments, builds caves, regulates the carbon cycle, and changes porosity in aquifers and hydrocarbon reservoirs. Despite the significance of this process both to natural phenomena and human endeavors, fundamental insight into the mechanisms that drive it at the Ångstrom scale is scarce. Here, we employ environmental transmission electron microscopy (ETEM) to visualize interactions between water and various types of porous media, including sandstone, limestone, and dolostone samples, at Ångstrom resolution in real time. Unlike other techniques presented in the literature, ETEM allows for direct visualization of both the aqueous phase and the porous media. As expected, dissolution and recrystallization were observed to significantly impact the shapes, sizes, and interconnectivities of the pores in the rocks. However, for the first time, we provide direct in situ experimental evidence that adsorption‐induced strain can also significantly impact the above‐mentioned parameters, especially in micropores. In some cases, adsorption was observed to reduce effective pore size by more than 60%. The magnitude of the change in pore size was found to vary with pore wall mineralogy and pore geometry. This work presents the first direct Ångstrom‐resolution observations of liquid adsorption films and adsorption‐induced strain.
Spatiotemporal Development and Dissipation of Hypoxia Induced by Variable Wind‐Driven Shelf Circulation off the Pearl River Estuary: Observational and Modeling Studies
Authors: Li Dou , Gan Jianping , Hui Chiwing , Yu Liuqian , Liu Zhiqiang , Lu Zhongming , Kao Shuh‐ji , Dai Minhan
Published: January 2021

Observations reveal the high spatiotemporal variability of the hypoxia in the western and eastern coastal transition zones (WCTZ and ECTZ) off the Pearl River Estuary (PRE). We utilized data from cruise observations, buoy mooring, and a three‐dimensional model based on ROMS to investigate the hypoxia variability response to the typical synoptic variation of the summer monsoon, i.e., from prevailing upwelling‐favorable wind (UFW), the ensuing episodic upwelling relaxation (URW), downwelling (DFW), to downwelling relaxation wind (DRW). During the UFW, we found that the northeastward shelf current converges with nutrient‐rich river plume, forms strong stratification, and provides hubs for depositing detritus for hypoxia to develop in the CTZ. The ensuing URW and DFW forcing alters the transport to advect the plume and detritus westward, weakens vertical mixing, and enhances hypoxia in the WCTZ. Correspondingly, opposite conditions occur in the ECTZ as the plume veers westward during the URW and DFW. Contrarily, the weakening westward transport during the DRW forcing restores the biophysical conditions to their states when there is an UFW event. We found that varying wind‐driven circulation interacts with the plume to jointly regulate the transport of nutrient and detritus, water vertical mixing, and residence time, and, thus, the hypoxia variability in the CTZ. The variability of hypoxia in the CTZ is less controlled by the river discharges once biogeochemical conditions become saturated. Our study illustrates the biophysical control of hypoxia variability that is frequently observed in estuaries and coastal oceans.
A Global, Multiproduct Analysis of Coastal Marine Heatwaves: Distribution, Characteristics, and Long‐Term Trends
Authors: Marin Maxime , Feng Ming , Phillips Helen E. , Bindoff Nathaniel L.
Published: January 2021

Major marine heatwave (MHW) events have caused catastrophic impacts on coastal marine ecosystems. However, to date there has not been a global assessment of MHWs in coastal areas where rich marine ecosystems are at risk. Here, we combine four satellite Sea Surface Temperature (SST) products to quantify the distribution, characteristics, and decadal trend of coastal MHWs, using an ensemble approach. Hotspots of MHW stress, defined as yearly cumulative intensity, were found to be concentrated in mid latitude coasts like the Mediterranean Sea, Japan Sea, and Tasman Sea, as well as the north‐eastern coast of the United States. We found a global increase in coastal MHW frequency and duration during the past 25 years by 1–2 events per decade and 5–10 days per decade, respectively, with regional distribution closely related to decadal climate variability. Increases in frequency and duration of MHWs has led to large increases of cumulative intensity and yearly cumulative intensity, particularly in mid‐latitudes and hotspot regions. Long‐term changes in mean SST were the main driver of the observed trends of coastal MHWs, while internal variability was important for explaining local decreases in MHW metrics such as along the south‐eastern Pacific coast. MHW average metrics and trends were consistent across all four products used in this analysis, giving high confidence in the results. However, important differences between products were observed for MHW mean intensity, which was well correlated to SST variability, suggesting sensitivity of this metric to the specific SST data set and demonstrating a need for an ensemble approach to MHW analysis.
An Overview of Atmospheric Features Over the Western North Atlantic Ocean and North American East Coast – Part 1: Analysis of Aerosols, Gases, and Wet Deposition Chemistry
Authors: Corral Andrea F. , Braun Rachel A. , Cairns Brian , Gorooh Vesta Afzali , Liu Hongyu , Ma Lin , Mardi Ali Hossein , Painemal David , Stamnes Snorre , van Diedenhoven Bastiaan , Wang Hailong , Yang Yang , Zhang Bo , Sorooshian Armin
Published: January 2021

The Western North Atlantic Ocean (WNAO) and adjoining East Coast of North America are of great importance for atmospheric research and have been extensively studied for several decades. This broad region exhibits complex meteorological features and a wide range of conditions associated with gas and particulate species from many sources regionally and other continents. As Part 1 of a 2‐part paper series, this work characterizes quantities associated with atmospheric chemistry, including gases, aerosols, and wet deposition, by analyzing available satellite observations, ground‐based data, model simulations, and reanalysis products. Part 2 provides insight into the atmospheric circulation, boundary layer variability, three‐dimensional cloud structure, properties, and precipitation over the WNAO domain. Key results include spatial and seasonal differences in composition along the North American East Coast and over the WNAO associated with varying sources of smoke and dust and meteorological drivers such as temperature, moisture, and precipitation. Spatial and seasonal variations of tropospheric carbon monoxide and ozone highlight different pathways toward the accumulation of these species in the troposphere. Spatial distributions of speciated aerosol optical depth and vertical profiles of aerosol mass mixing ratios show a clear seasonal cycle highlighting the influence of different sources in addition to the impact of intercontinental transport. Analysis of long‐term climate model simulations of aerosol species and satellite observations of carbon monoxide confirm that there has been a significant decline in recent decades among anthropogenic constituents owing to regulatory activities.
Three‐Dimensional Distribution of Groundwater Residence Time Metrics in the Glaciated United States Using Metamodels Trained on General Numerical Simulation Models
Authors: Starn J. J. , Kauffman L. J. , Carlson C. S. , Reddy J. E. , Fienen M. N.
Published: January 2021

Residence time distribution (RTD) is a critically important characteristic of groundwater flow systems; however, it cannot be measured directly. RTD can be inferred from tracer data with analytical models (few parameters) or with numerical models (many parameters). The second approach permits more variation in system properties but is used less frequently than the first because large‐scale numerical models can be resource intensive. Using a novel automated approach, a set of 115 inexpensive general simulation models (GSMs) was used to create RTD metrics (fraction of young groundwater, defined as <65 years old; mean travel time of young fraction; median travel time of old fraction; and mean path length). GSMs captured the general trends in measured tritium concentrations in 431 wells. Boosted Regression Tree metamodels were trained to predict these RTD metrics using available wall‐to‐wall hydrogeographic digital sets as explanatory features. The metamodels produced a three‐dimensional distribution of predictions throughout the glacial system that generally matched with the numerical model RTD metrics. In addition to the expected importance of aquifer thickness and recharge rate in predicting RTD metrics, two new data sets, Multi‐Order Hydrologic Position (MOHP) and hydrogeologic terrane were important predictors. These variables by themselves produced metamodels with Nash‐Sutcliffe efficiency close to the full metamodel. Metamodel predictions showed that the volume of young groundwater stored in the glaciated United States is about 6,000 km3, or about 0.5% of globally stored young groundwater.
DNA Tracer Transport Through Porous Media—The Effect of DNA Length and Adsorption
Authors: Zhang Yuran , Hartung Marshall B. , Hawkins Adam J. , Dekas Anne E. , Li Kewen , Horne Roland N.
Published: January 2021

Artificial tracer testing is an effective technique to identify fluid flow pathways and characterize subsurface hydrological properties. Synthetic DNA tracers, available in virtually unlimited number of unique variations, enable multiwell tracer testing and have the potential to improve the characterization of groundwater flowpaths enormously. This study investigated the effect of DNA length (i.e., number of base pairs) and adsorption on DNA tracer transport via well‐controlled laboratory experiments. Nine unique synthetic double‐stranded DNA tracers were designed with varying lengths (90–200 base pairs) and flowed with reference solute tracers (bromide and lithium) through columns packed with glass beads or Ottawa sand. The peak arrivals of DNA tracers were earlier than bromide in the glass‐bead column test, yet significantly retarded in the sand column test. In a given porous medium, DNA length did not have noticeable effects on peak arrival or tracer dispersion. However, DNA tracer recovery increased with increasing DNA length in the glass‐bead column test but decreased with increasing DNA length in the sand column test, likely resulting from the corresponding trends in partition coefficients as revealed by tracer transport modeling. Such reversed trends in different porous media likely resulted from the different likelihoods for longer DNA to have multisegment attachment during transport. Our findings suggest that both DNA length and the surface properties of the porous medium have notable effects on DNA tracer transport and hence need to be considered carefully in future tracer test designs in terms of site selection, DNA sequence design and data interpretation.
Aberrant role of ALK in tau proteinopathy through autophagosomal dysregulation
Authors: Park Jisu , Choi Hyunwoo , Kim Young Doo , Kim Seo-Hyun , Kim Youbin , Gwon Youngdae , Lee Dong Young , Park Sung-Hye , Heo Won Do , Jung Yong-Keun
Published: January 2021

Proteinopathy in neurodegenerative diseases is typically characterized by deteriorating activity of specific protein aggregates. In tauopathies, including Alzheimer’s disease (AD), tau protein abnormally accumulates and induces dysfunction of the affected neurons. Despite active identification of tau modifications responsible for tau aggregation, a critical modulator inducing tau proteinopathy by affecting its protein degradation flux is not known. Here, we report that anaplastic lymphoma kinase (ALK), a receptor tyrosine kinase, is crucial for the tau-mediated AD pathology. ALK caused abnormal accumulation of highly phosphorylated tau in the somatodendritic region of neurons through its tyrosine kinase activity. ALK-induced LC3-positive axon swelling and loss of spine density, leading to tau-dependent neuronal degeneration. Notably, ALK activation in neurons impaired Stx17-dependent autophagosome maturation and this defect was reversed by a dominant-negative Grb2. In a Drosophila melanogaster model, transgenic flies neuronally expressing active Drosophila Alk exhibited the aggravated tau rough eye phenotype with retinal degeneration and shortened lifespan. In contrast, expression of kinase-dead Alk blocked these phenotypes. Consistent with the previous RNAseq analysis showing upregulation of ALK expression in AD [1], ALK levels were significantly elevated in the brains of AD patients showing autophagosomal defects. Injection of an ALK.Fc-lentivirus exacerbated memory impairment in 3xTg-AD mice. Conversely, pharmacologic inhibition of ALK activity with inhibitors reversed the memory impairment and tau accumulation in both 3xTg-AD and tauC3 (caspase-cleaved tau) transgenic mice. Together, we propose that aberrantly activated ALK is a bona fide mediator of tau proteinopathy that disrupts autophagosome maturation and causes tau accumulation and aggregation, leading to neuronal dysfunction in AD.
Prediction of short-term antidepressant response using probabilistic graphical models with replication across multiple drugs and treatment settings
Authors: Athreya Arjun P. , Brückl Tanja , Binder Elisabeth B. , John Rush A. , Biernacka Joanna , Frye Mark A. , Neavin Drew , Skime Michelle , Monrad Ditlev , Iyer Ravishankar K. , Mayes Taryn , Trivedi Madhukar , Carter Rickey E. , Wang Liewei , Weinshilboum Richard M. , Croarkin Paul E. , Bobo William V.
Published: January 2021

Heterogeneity in the clinical presentation of major depressive disorder and response to antidepressants limits clinicians’ ability to accurately predict a specific patient’s eventual response to therapy. Validated depressive symptom profiles may be an important tool for identifying poor outcomes early in the course of treatment. To derive these symptom profiles, we first examined data from 947 depressed subjects treated with selective serotonin reuptake inhibitors (SSRIs) to delineate the heterogeneity of antidepressant response using probabilistic graphical models (PGMs). We then used unsupervised machine learning to identify specific depressive symptoms and thresholds of improvement that were predictive of antidepressant response by 4 weeks for a patient to achieve remission, response, or nonresponse by 8 weeks. Four depressive symptoms (depressed mood, guilt feelings and delusion, work and activities and psychic anxiety) and specific thresholds of change in each at 4 weeks predicted eventual outcome at 8 weeks to SSRI therapy with an average accuracy of 77% (p = 5.5E-08). The same four symptoms and prognostic thresholds derived from patients treated with SSRIs correctly predicted outcomes in 72% (p = 1.25E-05) of 1996 patients treated with other antidepressants in both inpatient and outpatient settings in independent publicly-available datasets. These predictive accuracies were higher than the accuracy of 53% for predicting SSRI response achieved using approaches that (i) incorporated only baseline clinical and sociodemographic factors, or (ii) used 4-week nonresponse status to predict likely outcomes at 8 weeks. The present findings suggest that PGMs providing interpretable predictions have the potential to enhance clinical treatment of depression and reduce the time burden associated with trials of ineffective antidepressants. Prospective trials examining this approach are forthcoming.
Acclimation and adaptation to elevated pCO2 increase arsenic resilience in marine diatoms
Authors: Xu Dong , Schaum Charlotte-Elisa , Li Bin , Chen Yanan , Tong Shanying , Fu Fei-Xue , Hutchins David A , Zhang Xiaowen , Fan Xiao , Han Wentao , Wang Yitao , Ye Naihao
Published: January 2021

Arsenic pollution is a widespread threat to marine life, but the ongoing rise pCO2 levels is predicted to decrease bio-toxicity of arsenic. However, the effects of arsenic toxicity on marine primary producers under elevated pCO2 are not well characterized. Here, we studied the effects of arsenic toxicity in three globally distributed diatom species (Phaeodactylum tricornutum, Thalassiosira pseudonana, and Chaetoceros mulleri) after short-term acclimation (ST, 30 days), medium-term exposure (MT, 750 days), and long-term (LT, 1460 days) selection under ambient (400 µatm) and elevated (1000 and 2000 µatm) pCO2. We found that elevated pCO2 alleviated arsenic toxicity even after short acclimation times but the magnitude of the response decreased after mid and long-term adaptation. When fed with these elevated pCO2 selected diatoms, the scallop Patinopecten yessoensis had significantly lower arsenic content (3.26–52.83%). Transcriptomic and biochemical analysis indicated that the diatoms rapidly developed arsenic detoxification strategies, which included upregulation of transporters associated with shuttling harmful compounds out of the cell to reduce arsenic accumulation, and upregulation of proteins involved in synthesizing glutathione (GSH) to chelate intracellular arsenic to reduce arsenic toxicity. Thus, our results will expand our knowledge to fully understand the ecological risk of trace metal pollution under increasing human activity induced ocean acidification.
Bodo saltans(Kinetoplastida) is dependent on a novelParacaedibacter-like endosymbiont that possesses multiple putative toxin-antitoxin systems
Authors: Midha Samriti , Rigden Daniel J , Siozios Stefanos , Hurst Gregory D D , Jackson Andrew P
Published: January 2021

Bacterial endosymbiosis has been instrumental in eukaryotic evolution, and includes both mutualistic, dependent and parasitic associations. Here we characterize an intracellular bacterium inhabiting the flagellated protist Bodo saltans (Kinetoplastida). We present a complete bacterial genome comprising a 1.39 Mb circular chromosome with 40.6% GC content. Fluorescent in situ hybridisation confirms that the endosymbiont is located adjacent to the nuclear membrane, and a detailed model of its intracellular niche is generated using serial block-face scanning electron microscopy. Phylogenomic analysis shows that the endosymbiont belongs to the Holosporales, most closely related to other α-proteobacterial endosymbionts of ciliates and amoebae. Comparative genomics indicates that it has a limited metabolism and is nutritionally host-dependent. However, the endosymbiont genome does encode diverse symbiont-specific secretory proteins, including a type VI secretion system and three separate toxin-antitoxin systems. We show that these systems are actively transcribed and hypothesize they represent a mechanism by which B. saltans becomes addicted to its endosymbiont. Consistent with this idea, attempts to cure Bodo of endosymbionts led to rapid and uniform cell death. This study adds kinetoplastid flagellates to ciliates and amoebae as hosts of Paracaedibacter-like bacteria, suggesting that these antagonistic endosymbioses became established very early in Eukaryotic evolution.
Environmental stress destabilizes microbial networks
Authors: Hernandez Damian J , David Aaron S , Menges Eric S , Searcy Christopher A , Afkhami Michelle E
Published: January 2021

Environmental stress is increasing worldwide, yet we lack a clear picture of how stress disrupts the stability of microbial communities and the ecosystem services they provide. Here, we present the first evidence that naturally-occurring microbiomes display network properties characteristic of unstable communities when under persistent stress. By assessing changes in diversity and structure of soil microbiomes along 40 replicate stress gradients (elevation/water availability gradients) in the Florida scrub ecosystem, we show that: (1) prokaryotic and fungal diversity decline in high stress, and (2) two network properties of stable microbial communities—modularity and negative:positive cohesion—have a clear negative relationship with environmental stress, explaining 51–78% of their variation. Interestingly, pathogenic taxa/functional guilds decreased in relative abundance along the stress gradient, while oligotrophs and mutualists increased, suggesting that the shift in negative:positive cohesion could result from decreasing negative:positive biotic interactions consistent with the predictions of the Stress Gradient Hypothesis. Given the crucial role microbiomes play in ecosystem functions, our results suggest that, by limiting the compartmentalization of microbial associations and creating communities dominated by positive associations, increasing stress in the Anthropocene could destabilize microbiomes and undermine their ecosystem services.
A likelihood ratio approach for identifying three-quarter siblings in genetic databases
Authors: Galván-Femenía Iván , Barceló-Vidal Carles , Sumoy Lauro , Moreno Victor , de Cid Rafael , Graffelman Jan
Published: January 2021

The detection of family relationships in genetic databases is of interest in various scientific disciplines such as genetic epidemiology, population and conservation genetics, forensic science, and genealogical research. Nowadays, screening genetic databases for related individuals forms an important aspect of standard quality control procedures. Relatedness research is usually based on an allele sharing analysis of identity by state (IBS) or identity by descent (IBD) alleles. Existing IBS/IBD methods mainly aim to identify first-degree relationships (parent–offspring or full siblings) and second degree (half-siblings, avuncular, or grandparent–grandchild) pairs. Little attention has been paid to the detection of in-between first and second-degree relationships such as three-quarter siblings (3/4S) who share fewer alleles than first-degree relationships but more alleles than second-degree relationships. With the progressively increasing sample sizes used in genetic research, it becomes more likely that such relationships are present in the database under study. In this paper, we extend existing likelihood ratio (LR) methodology to accurately infer the existence of 3/4S, distinguishing them from full siblings and second-degree relatives. We use bootstrap confidence intervals to express uncertainty in the LRs. Our proposal accounts for linkage disequilibrium (LD) by using marker pruning, and we validate our methodology with a pedigree-based simulation study accounting for both LD and recombination. An empirical genome-wide array data set from the GCAT Genomes for Life cohort project is used to illustrate the method.