bluuebunny/crossref_metadata_2025_split huggingface dataset:
RETRACTED ARTICLE: Property evaluations of coir fibres for use as reinforcement in composites
Authors: Madueke Chioma Ifeyinwa , Kolawole Funsho , Tile Joseph 
Published: February 2021

AbstractThe density, tensile properties at different gauge lengths, Weibull modulus, and water absorption at elevated temperatures of coir fibres of Sri Lanka are presented. The tensile strength and stiffness of these fibres were found to decrease by 51.0 and 68.0% respectively as the gauge length of the coir fibres increased from 20 to 100 mm at a constant cross-head displacement rate of 1 mm/minute. The elongation at break of these fibres increased from 33.3 to 62.5% as the gauge length increased from 20 to 100 mm. The porosity of the fibres is in the range of 32.9–48.1% with an average pore count of 130–475 and average cell diameter of 6.8–13.7 µm within the studied diameter range of 0.162–0.313 mm. The porosity of coir fibres was found to increase as the diameter increased. TGA and scanning electron microscopy of failed samples were conducted to analyse the failure modes and to observe the trend in changes in the mechanical properties.
Evidence for strong relations between the upper Tagus loess formation (central Iberia) and the marine atmosphere off the Iberian margin during the last glacial period
Authors: Wolf Daniel , Kolb Thomas , Ryborz Karolin , Heinrich Susann , Schäfer Imke , Calvo Ruben , Sanchez Jesus , Hambach Ulrich , Zech Roland , Zöller Ludwig , Faust Dominik 
Published: February 2021

AbstractDuring glacial times, the North Atlantic region was affected by serious climate changes corresponding to Dansgaard-Oeschger cycles that were linked to dramatic shifts in sea temperature and moisture transfer to the continents. However, considerable efforts are still needed to understand the effects of these shifts on terrestrial environments. In this context, the Iberian Peninsula is particularly interesting because of its close proximity to the North Atlantic, although the Iberian interior lacks paleoenvironmental information so far because suitable archives are rare. Here we provide an accurate impression of the last glacial environmental developments in central Iberia based on comprehensive investigations using the upper Tagus loess record. A multi-proxy approach revealed that phases of loess formation during Marine Isotope Stage (MIS) 2 (and upper MIS 3) were linked to utmost aridity, coldness, and highest wind strengths in line with the most intense Greenland stadials also including Heinrich Events 3–1. Lack of loess deposition during the global last glacial maximum (LGM) suggests milder conditions, which agrees with less-cold sea surface temperatures (SST) off the Iberian margin. Our results demonstrate that geomorphological system behavior in central Iberia is highly sensitive to North Atlantic SST fluctuations, thus enabling us to reconstruct a detailed hydrological model in relation to marine–atmospheric circulation patterns.
The figure of the abducted Acholi girl: nation-building, gender, and children born into the LRA in Uganda
Authors: Stewart Beth W. 
Published: February 2021

AbstractBased on analysis of newspapers and secondary sources, this article examines the gendered construction of the national imagery of the war between the Ugandan government and the Lord's Resistance Army (LRA) in an effort to expand current conceptual understanding of the exclusion experienced by children born of forced marriage inside the LRA. Uganda developed as a militarised and masculine post-colony and yet nation-building for President Museveni involved crafting a national imagery that drew upon development discourses of gender and children to position himself as the benevolent father of the nation. Invoking Veena Das’ ‘figure of the abducted woman’, I argue that the Ugandan government mobilised the figure of the abducted Acholi girl to legitimise both its governance and the war. The article concludes that the resulting narrative provided no legitimate social or political space in the national imagery for the children of the abducted girls.
Practices of development assistance and climate change mitigation in reshaping the Mozambican REDD+ strategy
Authors: Virtanen Pekka , Palmujoki Eero 
Published: February 2021

ABSTRACTThis paper studies how the practices of climate change governance and development assistance have reshaped the Reducing Emissions from Deforestation and Forest Degradation (REDD) process in Mozambique. We look at how the original goals of the Mozambican REDD+ strategy changed in the interplay of different governance-related practices, both those originating locally and nationally, and those coming from international organisations. The paper is based on the frameworks of multilevel governance and practice theory. We identify six combinations of practices that are relevant in the REDD+ programmes and projects. Three of them are incorporated in the general idea of sustainability, including practices of promoting environmental conservation, economic growth and social justice/development, while the remaining three practices are connected to climate-mitigation practices, for which the frame is defined in the United Nations Framework Convention on Climate Change.
Polygenic association between attention-deficit/hyperactivity disorder liability and cognitive impairments
Authors: Vainieri Isabella , Martin Joanna , Rommel Anna-Sophie , Asherson Philip , Banaschewski Tobias , Buitelaar Jan , Cormand Bru , Crosbie Jennifer , Faraone Stephen V. , Franke Barbara , Loo Sandra K. , Miranda Ana , Manor Iris , Oades Robert D. , Purves Kirstin L. , Ramos-Quiroga J. Antoni , Ribasés Marta , Roeyers Herbert , Rothenberger Aribert , Schachar Russell , Sergeant Joseph , Steinhausen Hans-Christoph , Vuijk Pieter J. , Doyle Alysa E. , Kuntsi Jonna 
Published: February 2021

AbstractBackgroundA recent genome-wide association study (GWAS) identified 12 independent loci significantly associated with attention-deficit/hyperactivity disorder (ADHD). Polygenic risk scores (PRS), derived from the GWAS, can be used to assess genetic overlap between ADHD and other traits. Using ADHD samples from several international sites, we derived PRS for ADHD from the recent GWAS to test whether genetic variants that contribute to ADHD also influence two cognitive functions that show strong association with ADHD: attention regulation and response inhibition, captured by reaction time variability (RTV) and commission errors (CE).MethodsThe discovery GWAS included 19 099 ADHD cases and 34 194 control participants. The combined target sample included 845 people with ADHD (age: 8–40 years). RTV and CE were available from reaction time and response inhibition tasks. ADHD PRS were calculated from the GWAS using a leave-one-study-out approach. Regression analyses were run to investigate whether ADHD PRS were associated with CE and RTV. Results across sites were combined via random effect meta-analyses.ResultsWhen combining the studies in meta-analyses, results were significant for RTV (R2 = 0.011, β = 0.088, p = 0.02) but not for CE (R2 = 0.011, β = 0.013, p = 0.732). No significant association was found between ADHD PRS and RTV or CE in any sample individually (p > 0.10).ConclusionsWe detected a significant association between PRS for ADHD and RTV (but not CE) in individuals with ADHD, suggesting that common genetic risk variants for ADHD influence attention regulation.
Investigation of longitudinal friction characteristics of an omnidirectional wheel via LuGre model
Authors: Şahin Osman Nuri , Dede Mehmet İsmet Can 
Published: February 2021

SUMMARYIn recent years, omnidirectional wheels have found more applications in the design of automated guided vehicles (AGV). In this work, LuGre friction model is used for an omnidirectional wheel. A test setup that includes a single omnidirectional wheel is designed and constructed to identify the model parameters. With the help of the constructed test setup, the longitudinal friction characteristic of the omnidirectional wheel is obtained, and the model is verified via validation tests. In addition, for the first time, the effect of lateral frictional force on longitudinal motion is examined for an omnidirectional wheel through experiments.
Food after the COVID-19 Pandemic and the Case for Change Posed by Alternative Food: A Case Study of the American Midwest
Authors: Robinson Jennifer Meta , Mzali Leila , Knudsen Daniel , Farmer James , Spiewak Ruta , Suttles Shellye , Burris Mecca , Shattuck Annie , Valliant Julia , Babb Angela 
Published: February 2021

Abstract

Non-Technical Summary
In this paper, we focus on the disruption that the current pandemic has created within the US industrial food system. We suggest that the pandemic has provided an opening for small producers. Attending to small-scale responses to the pandemic can guide policy and public investments towards a more just and sustainable future for food.

Technical Summary
Building on the IPES-Food Communique of April 2020, we examine the many ways in which the US industrial food system faltered during the ongoing COVID-19 pandemic. Using Regime Theory as a guide, we suggest that such a catastrophic crisis may create significant opportunities for an emergent food regime. Drawing from our research and participant observation in the US Midwest, we examine changes in the food system occasioned by the pandemic that foreshadow a new food regime. We suggest several blockages and risks to this new regime and suggest policies that would make transition smoother to a more just and sustainable food system.

Social Media Summary (120 characters)
What will food be like after the pandemic? This new study outlines an alternative food system emerging in the American Midwest.
Evidence of Subproton‐Scale Magnetic Holes in the Venusian Magnetosheath
Authors: Goodrich Katherine A. , Bonnell John W. , Curry Shannon , Livi Roberto , Whittlesey Phyllis , Mozer Forrest , Malaspina David , Halekas Jasper , McManus Michael , Bale Stuart , Bowen Trevor , Case Anthony , Dudok de Wit Thierry , Goetz Keith , Harvey Peter , Kasper Justin , Larson Davin , MacDowall Robert , Pulupa Marc , Stevens Michael 
Published: February 2021

AbstractDepressions in magnetic field strength, commonly referred to as magnetic holes, are observed ubiquitously in space plasmas. Subproton‐scale magnetic holes with spatial scales smaller than or on the order of a proton gyroradius, are likely supported by electron current vortices, rotating perpendicular to the ambient magnetic field. While there are numerous accounts of subproton‐scale magnetic holes within the Earth’s magnetosphere, there are few, if any, reported observations in other space plasma environments. We present the first evidence of subproton‐scale magnetic holes in the Venusian magnetosheath. During Parker Solar Probe’s first Venus Gravity Assist, the spacecraft crossed the planet’s bow shock and subsequently observed the Venusian magnetosheath. The FIELDS instrument suite onboard the spacecraft achieved magnetic and electric field measurements of magnetic hole structures. The electric fields associated with magnetic depressions are consistent with electron current vortices with amplitudes on the order of 1 μA/m2.
New Insights Into the Heterogeneity of the Lithosphere‐Asthenosphere System Beneath South China From Teleseismic Body‐Wave Attenuation
Authors: Deng Yangfan , Byrnes Joseph S. , Bezada Maximiliano 
Published: February 2021

AbstractTeleseismic body‐wave attenuation provides an independent constraint on the architecture of the lithosphere‐asthenosphere system. We obtain the first map of teleseismic attenuation across South China, which correlates well with previous estimates of lithospheric thickness. The weakest attenuation occurs in the Sichuan Basin, where continental lithosphere is thick, and in the adjacent Chuandian region, which we attribute to delaminated lithosphere, or lithosphere strengthened by an ancient plume based on comparison with previous studies. Smaller batches of remnant or delaminated lithosphere may cause local minima along the eastern coast. Pronounced negative anomalies occur in the Hengyang, Jianghan and Nanchang basins, motivating the hypothesis that the basins occur where locally strong blocks within the lithosphere resisted the pervasive deformation of South China. The strongest attenuation occurs in a broad region in the vicinity of the Hainan plume, which is consistent with high temperatures and possibly partial melt in the upper mantle.
Circulation Over the South‐East Greenland Shelf and Potential for Liquid Freshwater Export: A Drifter Study
Authors: Duyck Elodie , De Jong Marieke Femke 
Published: February 2021

AbstractFreshwater input into deep convection regions could affect the overturning circulation. With a set of 15 Consortium for Advanced Research for the Transport of Hydrocarbon in the Environment (CARTHE) drifters and 15 Surface Velocity Program (SVP) drifters, we investigate the circulation over the south‐east Greenland shelf and the potential for off‐shelf freshwater export. Part of the East Greenland Current flow is steered into the East Greenland Coastal Current immediately upstream of Sermilik Trough. Between the trough and Cape Farewell, two separate cores are visible. Just past Cape Farewell drifters are redistributed into a shelfbreak core and a slow eddying shelf flow. A coastal core is reestablished downstream. Exchanges between the shelfbreak and coastal flows take place both on the east and west Greenland shelf, allowing fresher water to be diverted away from the coast. Five of 15 shallower CARTHE drifters were exported, mainly at Cape Farewell. CARTHE motion shows a higher correlation with local winds, which are more favorable for off‐shelf transport in this area.
A Possible Mechanism on the Detachment Between a Subauroral Proton Arc and the Auroral Oval
Authors: Zhou Su , Luan Xiaoli , Burch J. L. , Yao Zhonghua , Han De‐Sheng , Tian Chenjing , Chen Yuqing , Zhang Jin , Yu Xiaoyan , Dai Tianjun 
Published: February 2021

AbstractSubauroral proton arcs are a type of terrestrial auroral phenomena, which are often detached equatorially from the auroral oval. This work presents evolution of a subauroral proton arc using observations of the Special Sensor Ultraviolet Spectrographic Imager and Special Sensor J (SSJ) on board Defense Meteorological Satellite Program (DMSP) spacecraft. The arc was observed in the afternoon sector and was located within 60°–70° geomagnetic latitude during the recovery phase of a moderate magnetic storm with the minimum SYM‐H index of −55 nT. Particle measurements from DMSP F17/SSJ indicate that the arc was detached from the normal oval and produced by energetic ring current ions with energies above 10 keV. These energetic ions were likely scattered into the magnetic loss cone by electromagnetic ion cyclotron waves in the frequency range between 0.1 and 0.5 Hz, as confirmed by Pc1 waves derived from the observations of a ground station. Continuous auroral observations directly show that the subauroral proton arc was detached from the oval during evolution. Following a northward interplanetary magnetic field turning, the auroral oval moved toward higher latitudes. We propose that the equatorward edge of the auroral oval is less influenced by the convection electric field, and thus moves more slowly than the poleward edge. This mechanism is proposed for producing a separation between the equatorward and poleward parts of the auroral oval, with the former evolving into the subauroral proton arc.
Saturn's Nightside Ring Current During Cassini's Grand Finale
Authors: Provan G. , Bradley T. J. , Bunce E. J. , Cowley S. W. H. , Cao H. , Dougherty M. , Hunt G. J. , Roussos E. , Staniland N. R. , Tao C. 
Published: February 2021

AbstractDuring Cassini's Grand Finale proximal orbits, the spacecraft traversed the nightside magnetotail to ∼21 Saturn radii. Clear signatures of Saturn's equatorial current sheet are observed in the magnetic field data. An axisymmetric model of the ring current is fitted to these data, amended to take into account the tilt of the current layer by solar wind forcing, its teardrop‐shaped nature and the magnetotail and magnetopause fringing fields. Variations in ring current parameters are examined in relation to external driving of the magnetosphere by the solar wind and internal driving by the two planetary period oscillations (PPOs), and compared with previous dawn and dayside observations. We find that the relative phasing of the PPOs determines the ring current's response to solar wind conditions. During solar wind compressions when the PPOs are in antiphase, a thick partial ring current is formed on the nightside, dominated by hot plasma injected by tail reconnection. This partial ring current should close partly via magnetopause currents and possibly via field‐aligned currents into the ionosphere. However, during solar wind compressions when the PPOs are in phase, this partial ring current is not detected. During solar wind rarefactions an equatorial “magnetodisc” configuration is observed in the dayside/dawn/nightside regions, with similar total currents flowing at these local times. During very quiet intervals of prolonged solar wind rarefaction, a thin current sheet with an enhanced current density is formed, indicative of a ring current dominated by cool, dense, Enceladus water group ions.
Alpine Ice‐Core Evidence of a Large Increase in Vanadium and Molybdenum Pollution in Western Europe During the 20th Century
Authors: Arienzo Monica M. , Legrand Michel , Preunkert Susanne , Stohl Andreas , Chellman Nathan , Eckhardt Sabine , Gleason Kelly E. , McConnell Joseph R. 
Published: February 2021

AbstractPollutants emitted by industrial processes are deposited across the landscape. Ice core records from mid‐latitude glaciers located close to emission sources document the history of local‐to‐regional pollution since preindustrial times. Such records underpin attribution of pollutants to specific emission sources critical to developing abatement policies. Previous ice core studies from the Alps document the overall magnitude and timing of pollution related to nitrogen and sulfur‐derived species, as well as a few metals including lead. Here, we used subannually resolved measurements of vanadium (V) and molybdenum (Mo) in two ice cores from Col du Dome (French Alps), as well as atmospheric transport and deposition modeling, to investigate sources of pollution in the free European troposphere. The noncrustal V and Mo (ncV, ncMo) components were calculated by subtracting the crustal component from the total concentration. These ice core results showed a 32‐fold increase in ncV and a 69‐fold increase in ncMo from the preindustrial era (pre‐1860) to the industrial concentration peaks. Anthropogenic V and Mo emissions in Europe were estimated using emission factors from oil and coal consumption and atmospheric transport and deposition modeling. When comparing ice core data to estimated anthropogenic V and Mo emissions in Europe, V was found to be sourced primarily from oil combustion emissions. Conversely, coal and oil combustion estimated emissions did not agree with the measured ice core Mo concentrations, suggesting that other anthropogenic Mo sources dominated coal‐burning emissions, particularly after the 1950s. Noncoal‐burning sources of Mo may include metallurgy although emission factors are poorly known.
Seasonal Precipitation and Soil Moisture Relationships Across Forests and Woodlands in the Southwestern United States
Authors: Koehn C. R. , Petrie M. D. , Bradford J. B. , Litvak M. E. , Strachan S. 
Published: February 2021

AbstractPrecipitation [P: mm] controls forest and woodland dynamics in the southwestern United States (SWUS) by altering soil moisture [θ: mm3 mm−3] availability, but the influence of P on θ is complex, varying across space and time. We evaluated seasonal P and θ relationships at shallow (0–20 cm) and intermediate (50 cm) soil depths for nine semiarid forest and woodland sites (56 total years), which comprised three elevation gradients in the SWUS. We developed time‐varying definitions of winter (snow accumulation), spring (moisture recharge), and summer (moisture deficit), and determined how these sites exhibited similar P influence on θ across depths in the soil profile, between seasons, and in seasons with above‐ and below‐average P. Higher elevation sites (>2,800 m) experienced greater winter P, longer springs, and shorter summers compared to lower elevation sites (<2,500 m). Seasons with above‐ and below‐average P reduced elevation‐associated differences. θ at 0–20 cm was generally decoupled from θ at 50 cm in seasons with average and below‐average P, imparted by differences in spring and summer rainfall versus winter snowfall. Notably, across‐season influence of θ (e.g., a season’s similarity to subsequent seasons) was high when the first season experienced above‐ or below‐average P, and the subsequent season experienced average P, illustrating an important temporal connection initiated by wet and dry conditions. These results illustrate similarities in P‐θ relationships across widely differing ecosystems in the SWUS, and elucidate how these relationships may be altered in a changing climate.
Diatoms in Hyporheic Sediments Trace Organic Matter Retention and Processing in the McMurdo Dry Valleys, Antarctica
Authors: Heindel Ruth C. , Darling Josh P. , Singley Joel G. , Bergstrom Anna J. , McKnight Diane M. , Lukkari Braeden M. , Welch Kathleen A. , Gooseff Michael N. 
Published: February 2021

AbstractIn low‐nutrient streams in cold and arid ecosystems, the spiraling of autochthonous particulate organic matter (POM) may provide important nutrient subsidies downstream. Because of its lability and the spatial heterogeneity of processing in hyporheic sediments, the downstream transport and fate of autochthonous POM can be difficult to trace. In Antarctic McMurdo Dry Valley (MDV) streams, any POM retained in the hyporheic zone is expected to be derived from surface microbial mats that contain diatoms with long‐lasting silica frustules. We tested whether diatom frustules can be used to trace the retention of autochthonous POM in the hyporheic zone and whether certain geomorphic locations promote this process. The accumulation of diatom frustules in hyporheic sediments, measured as biogenic silica, was correlated with loss‐on‐ignition organic matter and sorbed ammonium, suggesting that diatoms can be used to identify locations where POM has been retained and processed over long timescales, regardless of whether the POM remains intact. In addition, by modeling the upstream sources of hyporheic diatom assemblages, we found that POM was predominantly derived from N‐fixing microbial mats of the genus Nostoc. In terms of spatial variability, we conclude that the hyporheic sediments adjacent to the stream channel that are regularly inundated by daily flood pulses are where the most POM has been retained over long timescales. Autochthonous POM is retained in hyporheic zones of low‐nutrient streams beyond the MDVs, and we suggest that biogenic silica and diatom composition can be used to identify locations where this transfer is most prevalent.