bluuebunny/crossref_metadata_2025_split huggingface dataset:
Internal Morphological Effects of Growth Hormone Transgenesis in Coho Salmon
Authors: Gaffney L. P. , Watson B. M. , Oakes J. D. , Devlin R. H. 
Published: September 2018

AbstractEffects of growth hormone (GH) overexpression on internal morphology were examined in homozygous and hemizygous GH transgenic Coho Salmon Oncorhynchus kisutch aided by clearing and staining and magnetic resonance imaging methodologies. Morphological effects of transgenesis were observed in pin bones in fast‐growing hemizygous transgenic salmon, in vertebral column and swim bladder deformities in homozygotes, and as nonproportional modifications to some cranial structures examined among groups. These data provide further examples of the complex pleiotropic effects arising from GH overexpression in transgenic salmon.
Interrogating Depictions of Disability in Children's Picturebooks
Authors: Kleekamp Monica C. , Zapata Angie 
Published: September 2018

AbstractDiverse classroom libraries offer opportunities for students to not only see themselves represented in books but also encounter lived experiences and perspectives that are different from their own. As classrooms increasingly include learners with cognitively and physically diverse abilities, teachers are faced with the challenge of selecting literature with humanizing depictions of individuals with disability labels. Historically, portrayals of disabilities in children's literature have included themes of pity and exclusion. In this article, the authors introduce a framework that educators can employ when selecting inclusive literature for their classroom libraries. Using this framework, the authors analyzed three sample picture books that teachers might also share with students to help them read with and against these texts. As a whole, this article offers a starting point for teachers beginning the process of creating inclusive spaces that foster the multitude of ways that students come to be, know, and learn.
Emerging evolutionary paradigms in antibiotic discovery
Authors: Chevrette Marc G , Currie Cameron R 
Published: September 2018

AbstractAntibiotics revolutionized medicine and remain its cornerstone. Despite their global importance and the continuous threat of resistant pathogens, few antibiotics have been discovered in recent years. Natural products, especially the secondary metabolites of Actinobacteria, have been the traditional discovery source of antibiotics. In nature, the chemistry of antibiotic natural products is shaped by the unique evolution and ecology of their producing organisms, yet these influences remain largely unknown. Here, we highlight the ecology of antibiotics employed by microbes in defensive symbioses and review the evolutionary processes underlying the chemical diversity and activity of microbe-derived antibiotics, including the dynamics of vertical and lateral transmission of biosynthetic pathways and the evolution of efficacy, targeting specificity, and toxicity. We argue that a deeper understanding of the ecology and evolution of microbial interactions and the metabolites that mediate them will allow for an alternative, rational approach to discover new antibiotics.
Variability of Spatter Morphology in Pyroclastic Deposits in Southern Idaho, as Correlated to Thermal Conditions and Eruptive Environment
Authors: Rader E. , Kobs Nawotniak S. , Heldmann J. 
Published: September 2018

AbstractTo investigate the thermal conditions of spatter eruptions on Earth, other planets, and moons we measured and categorized the physical characteristics of clasts in spatter deposits in Southern Idaho, USA. Physical characteristics of clasts, such as aspect ratio and degree of welding, are influenced by the style of eruption, distance from the vent, and lava properties. The correlation between morphological characteristics and the degree of fusion constrains thermal conditions of unwitnessed spatter‐producing eruptions on Earth and extraterrestrial volcanoes. We categorize spatter deposits into three groups, as defined by their emplacement conditions: primary vent, distal (spatter exposed in noneruptive cracks on the flanks of primary vents), and hornito (secondary spatter from a nonprimary cone); and show the variability of clast morphology within the three categories. Primary vent deposits typically show a wide range of fused perimeters between clasts (18–82%), lower aspect ratios (0.20–0.49), and larger void space, both between clasts (4–21%) and within clasts (referred to as hollow cores, up to 93%). Hornitos typically have less fusion (14–22%) between clasts, higher aspect ratios (0.45–0.49), and lower proportions of void space (6–10%). Distal outcrops are easily distinguished by the lack of void space (<8%) and the very high aspect ratio of clasts (close to 1). When chemical composition and outcrop proximity are accounted for, the accumulation rate appears to be primarily responsible for spatter clast morphology. Our results are based on field measurements of clasts; however, digital imagery could be used to categorize and interpret pyroclastic deposits in planetary systems by robotic spacecraft.
Deciphering the Role of Water Column Redoxclines on Methylmercury Cycling Using Speciation Modeling and Observations From the Baltic Sea
Authors: Soerensen A. L. , Schartup A. T. , Skrobonja A. , Bouchet S. , Amouroux D. , Liem‐Nguyen V. , Björn E. 
Published: September 2018

AbstractOxygen‐depleted areas are spreading in coastal and offshore waters worldwide, but the implication for production and bioaccumulation of neurotoxic methylmercury (MeHg) is uncertain. We combined observations from six cruises in the Baltic Sea with speciation modeling and incubation experiments to gain insights into mercury (Hg) dynamics in oxygen depleted systems. We then developed a conceptual model describing the main drivers of Hg speciation, fluxes, and transformations in water columns with steep redox gradients. MeHg concentrations were 2–6 and 30–55 times higher in hypoxic and anoxic than in normoxic water, respectively, while only 1–3 and 1–2 times higher for total Hg (THg). We systematically detected divalent inorganic Hg (HgII) methylation in anoxic water but rarely in other waters. In anoxic water, high concentrations of dissolved sulfide cause formation of dissolved species of HgII: HgS2H−(aq) and Hg (SH)20(aq). This prolongs the lifetime and increases the reservoir of HgII readily available for methylation, driving the high MeHg concentrations in anoxic zones. In the hypoxic zone and at the hypoxic‐anoxic interface, Hg concentrations, partitioning, and speciation are all highly dynamic due to processes linked to the iron and sulfur cycles. This causes a large variability in bioavailability of Hg, and thereby MeHg concentrations, in these zones. We find that zooplankton in the summertime are exposed to 2–6 times higher MeHg concentrations in hypoxic than in normoxic water. The current spread of hypoxic zones in coastal systems worldwide could thus cause an increase in the MeHg exposure of food webs.
Miocene to Holocene Marine Tephrostratigraphy Offshore Northern Central America and Southern Mexico: Pulsed Activity of Known Volcanic Complexes
Authors: Schindlbeck J. C. , Kutterolf S. , Freundt A. , Eisele S. , Wang K.‐L. , Frische M. 
Published: September 2018

AbstractWe studied the tephra inventory of 14 deep sea drill sites of three Deep Sea Drilling Project and Ocean Drilling Program legs drilled offshore Guatemala and El Salvador (Legs 67, 84, and 138) and one leg offshore Mexico (Leg 66). Marine tephra layers reach back from the Miocene to the Holocene. We identified 223 primary ash beds and correlated these between the drill sites, with regions along the volcanic arcs, and to specific eruptions known from land. In total, 24 correlations were established between marine tephra layers and to well‐known Quaternary eruptions from El Salvador and Guatemala. Additional 25 tephra layers were correlated between marine sites. Another 108 single ash layers have been assigned to source areas on land resulting in a total of 157 single eruptive events. Tephra layer correlations to independently dated terrestrial deposits provide new time markers and help to improve or confirm age models of the respective drill sites. Applying the respective sedimentation rates derived from the age models, we calculated ages for all marine ash beds. Hence, we also obtained new age estimates for eight known but so far undated large terrestrial eruptions. Furthermore, this enables us to study the temporal evolution of explosive eruptions along the arc, and we discovered five pulses of increased activity: (1) a pulse during the Quaternary, (2) a Pliocene pulse between 6 and 3 Ma, (3) a Late Miocene pulse between 10 and 7 Ma, (4) a Middle Miocene pulse between 17 and 11 Ma, and (5) an Early Miocene pulse (ca. >21 Ma).
Tropical Precipitation and Cross‐Equatorial Heat Transport in Response to Localized Heating: Basin and Hemisphere Dependence
Authors: White R. H. , McFarlane A. A. , Frierson D. M. W. , Kang S. M. , Shin Y. , Friedman M. 
Published: September 2018

AbstractA heat source is applied to different surface locations in a fully coupled climate model to study the cross‐equatorial energy transport and tropical precipitation responses. Remarkably different tropical precipitation responses are seen, varying from a large shift toward, to a small shift away from, the heated hemisphere. These differences are dominated by changes in top‐of‐atmosphere radiation, with some contribution from changes in ocean cross‐equatorial heat flux. The atmospheric fraction of the total cross‐equatorial heat flux is consistently larger for Northern Hemisphere (NH) heating relative to Southern Hemisphere heating. This results in a larger tropical rainfall shift in response to NH heating. Positive shortwave radiative feedbacks, associated with a burn‐off of low clouds in the North Pacific, also amplify the tropical rainfall response to NH heating. The Pacific Ocean dominates the ocean response to Southern Hemisphere heating, while the Atlantic Ocean dominates the ocean response to NH heating.
Greenland Submarine Melt Water Observed in the Labrador and Irminger Sea
Authors: Rhein Monika , Steinfeldt Reiner , Huhn Oliver , Sültenfuß Jürgen , Breckenfelder Tilia 
Published: September 2018

AbstractHelium and Neon distributions from 1994 to 2015 are used to identify and quantify submarine melt water (SMW) from the Greenland Ice Sheet in the Labrador and Irminger Sea. SMW fractions >0.2% (maximum 0.62 ± 0.075%) are confined in the upper 400 m of the Greenland shelf and slope and account for 12 ± 6% of the total east Greenland freshwater flux. SMW is embedded in water of different mixtures of cold and fresh Polar Water and warm and saline Atlantic Water. The resulting salinity range from that mixture exceeds the effect of SMW addition by one order of magnitude. Up to now, SMW is not detectable in the formation region of the Labrador Sea Water. Episodically, He and Ne excess anomalies are found in the deep ocean, probably introduced by the East Greenland Current spill jets.
Dispersion Aerosol Indirect Effect in Turbulent Clouds: Laboratory Measurements of Effective Radius
Authors: Chandrakar K. K. , Cantrell W. , Kostinski A. B. , Shaw R. A. 
Published: September 2018

AbstractCloud optical properties are determined not only by the number density nd and mean radius
of cloud droplets but also by the shape of the droplet size distribution. The change in cloud optical depth with changing nd, due to the change in distribution shape, is known as the dispersion effect. Droplet relative dispersion is defined as
. For the first time, a commonly used effective radius parameterization is tested in a controlled laboratory environment by creating a turbulent cloud. Stochastic condensation growth suggests d independent of nd for a nonprecipitating cloud, hence nearly zero albedo susceptibility due to the dispersion effect. However, for size‐dependent removal, such as in a laboratory cloud or highly clean atmospheric conditions, stochastic condensation produces a weak dispersion effect. The albedo susceptibility due to turbulence broadening has the same sign as the Twomey effect and augments it by order 10%.
Continued Emissions of the Ozone‐Depleting Substance Carbon Tetrachloride From Eastern Asia
Authors: Lunt M. F. , Park S. , Li S. , Henne S. , Manning A. J. , Ganesan A. L. , Simpson I. J. , Blake D. R. , Liang Q. , O'Doherty S. , Harth C. M. , Mühle J. , Salameh P. K. , Weiss R. F. , Krummel P. B. , Fraser P. J. , Prinn R. G. , Reimann S. , Rigby M. 
Published: September 2018

AbstractCarbon tetrachloride (CCl4) is an ozone‐depleting substance, accounting for about 10% of the chlorine in the troposphere. Under the terms of the Montreal Protocol, its production for dispersive uses was banned from 2010. In this work we show that, despite the controls on production being introduced, CCl4 emissions from the eastern part of China did not decline between 2009 and 2016. This finding is in contrast to a recent bottom‐up estimate, which predicted a significant decrease in emissions after the introduction of production controls. We find eastern Asian emissions of CCl4 to be 16 (9–24) Gg/year on average between 2009 and 2016, with the primary source regions being in eastern China. The spatial distribution of emissions that we derive suggests that the source distribution of CCl4 in China changed during the 8‐year study period, indicating a new source or sources of emissions from China's Shandong province after 2012.
Ion Cyclotron Waves Rippling Ballooning/InterChange Instability Heads
Authors: Panov E. V. , Pritchett P. L. 
Published: September 2018

AbstractA dawnward drifting Ballooning/InterChange Instability (BICI) head is identified and studied using high‐resolution Time History of Events and Macroscale Interactions during Substorms observations at XGSM≈−11RE on 15 February 2008 between 10:18 UT and 10:30 UT and compared with particle‐in‐cell simulation run results for a charged current sheet. A prediction of the earlier particle‐in‐cell simulation for a neutral sheet, that duskward drifting BICI heads are subject to a current‐driven ion cyclotron instability, is found to be true also for dawnward drifting BICI heads in the charged sheet simulations. This specific prediction and the Time History of Events and Macroscale Interactions during Substorms data indicate the presence of electromagnetic ion cyclotron wave activity that ripples the background BICI head shape. The waves propagated azimuthally with δEy/δBz≈4.5VA. The waves are found in a region of the strongest differential drift between the electrons and ions, suggesting that the drift generated the waves.
Roles of Flow Braking, Plasmaspheric Virtual Resonances, and Ionospheric Currents in Producing Ground Pi2 Pulsations
Authors: Takahashi Kazue , Hartinger Michael D. , Vellante Massimo , Heilig Balázs , Lysak Robert L. , Lee Dong‐Hun , Smith Charles W. 
Published: September 2018

AbstractIn one model, Pi2 pulsations are driven pulse by pulse by fast mode pulses that are launched as periodic bursty bulk flows brake when they approach the Earth. We have examined this model by analyzing data from multiple spacecraft and ground magnetometers for a Pi2 pulsation event. During the event, which started at ∼2226 UT on 8 November 2014, Time History of Events and Macroscale Interactions during Substorms (THEMIS)‐D detected an ∼2‐min‐period plasma bulk flow oscillation in the near‐Earth magnetotail, while THEMIS‐E and Van Allen Probes‐B, both located on the nightside just earthward of the electron plasmapause, detected a Pi2 pulsation consisting of a 10‐mHz oscillation in the azimuthal component of the electric field and a 19‐mHz oscillation in the compressional component of the magnetic field. On the ground, magnetic field oscillations containing both frequencies were observed both on the nightside and on the dayside. The nightside observations indicated that the pulsation had a radially standing structure, which is consistent with plasmaspheric virtual resonances (PVRs) excited in a magnetohydrodynamic simulation assuming an impulsive energy source. Cross‐spectral analysis of the magnetotail flow oscillation and the Pi2 pulsation indicated low coherence between them. These results suggest that the flow oscillation contributed to the Pi2 pulsation as a broadband energy source and that only the spectral components matching the PVR frequencies were detected with well‐defined frequencies. Ionospheric currents connected to the PVRs may be responsible for the appearance of the pulsation on the dayside.
The Breakdown of the Fluid Approximation for Electrons in a Plasma Wake
Authors: Wang Joseph , Hu Yuan 
Published: September 2018

AbstractA comparative study using a fluid‐based analytic solution, hybrid particle‐ion fluid‐electron particle‐in‐cell (PIC), and fully kinetic PIC is carried out to examine a collisionless, mesothermal plasma flow over a large, unbiased plate. We find that the plasma wake may be characterized into two regions based on the electron characteristics: a fluid electron expansion region and a kinetic electron expansion region. In the fluid electron expansion region, the electrons may be considered to be an equilibrium fluid and all the three approaches lead to a similar result. In the kinetic electron expansion region, the local electron velocity distributions are strongly non‐Maxwellian and the commonly used fluid approximation for electrons breaks down. The results also show that the error of the hybrid PIC simulation strongly correlates with a nonequilibrium parameter based on the weighted deviation of the electron velocity distribution from the equilibrium.
Dual‐Isotope Constraints on Seasonally Resolved Source Fingerprinting of Black Carbon Aerosols in Sites of the Four Emission Hot Spot Regions of China
Authors: Fang Wenzheng , Du Ke , Andersson August , Xing Zhenyu , Cho Chaeyoon , Kim Sang‐Woo , Deng Junjun , Gustafsson Örjan 
Published: September 2018

AbstractDespite much recent efforts, the emission sources of black carbon (BC) aerosols―central input to understanding and predicting environmental and climate impact―remain highly uncertain. Here we present observational δ13C/Δ14C‐based constraints on the sources of BC aerosols over the four seasons in each of the four key hot spot emission regions of China: Beijing‐Tianjin‐Hebei (BTH‐Wuqing; where Wuqing is the sampling location), Yangtze River Delta (YRD‐Haining), Pearl River Delta (PRD‐Zhongshan), and Sichuan Basin (SC‐Deyang). Overall, BC loadings were highest in winter, yet elevated loadings were also observed in other seasons, for example, spring at SC‐Deyang and fall at PRD‐Zhongshan. Annually, the dominant BC sources were coal (50 ± 20%) for BTH‐Wuqing, liquid fossil for YRD‐Haining (46 ± 8%) and PRD‐Zhongshan (48 ± 18%), whereas liquid fossil (42 ± 17%) and biomass burning (41 ± 14%) equally affected SC‐Deyang. There is also different but distinct seasonalities in BC sources for the different sites. As an example, for BTH‐Wuqing coal burning increased from summer to winter, while summer and spring BTH‐Wuqing were more influenced by liquid fossil. In contrast, for YRD‐Haining, the relative importance of emission sources was more constant over the year. These quantitative observational constraints on source‐seasonality of BC aerosols in receptor sites located in China's four key economic zones highlight that regulatory control on BC aerosol emissions from different fuels should consider both seasonal and regional variations. Our results also suggest that models on estimates of BC‐induced climate and air quality should consider variations over both regional and seasonal scales.
Isolating and Reconstructing Key Components of North Atlantic Ocean Variability From a Sclerochronological Spatial Network
Authors: Reynolds D. J. , Hall I. R. , Slater S. M. , Mette M. J. , Wanamaker A. D. , Scourse J. D. , Garry F. K. , Halloran P. R. 
Published: September 2018

AbstractOur understanding of North Atlantic Ocean variability within the coupled climate system is limited by the brevity of instrumental records and a deficiency of absolutely dated marine proxies. Here we demonstrate that a spatial network of marine stable oxygen isotope series derived from molluscan sclerochronologies (δ18Oshell) can provide skillful annually resolved reconstructions of key components of North Atlantic Ocean variability with absolute dating precision. Analyses of the common δ18Oshell variability, using principal component analysis, highlight strong connections with tropical North Atlantic and subpolar gyre (SPG) sea surface temperatures and sea surface salinity in the North Atlantic Current (NAC) region. These analyses suggest that low‐frequency variability is dominated by the tropical Atlantic signal while decadal variability is dominated by variability in the SPG and salinity transport in the NAC. Split calibration and verification statistics indicate that the composite series produced using the principal component analysis can provide skillful quantitative reconstructions of tropical North Atlantic and SPG sea surface temperatures and NAC sea surface salinities over the industrial period (1864–2000). The application of these techniques with extended individual δ18Oshell series provides powerful baseline records of past North Atlantic variability into the unobserved preindustrial period. Such records are essential for developing our understanding of natural climate variability in the North Atlantic Ocean and the role it plays in the wider climate system, especially on multidecadal to centennial time scales, potentially enabling reduction of uncertainties in future climate predictions.
Direction Finding for Radio Transmitters With Mini Interferometric Network
Authors: Qu X. , Xu X. , Wang S. , Li J. , Zhu W. , Fang G. 
Published: September 2018

AbstractIn this paper, we present the design and deployment of a broadband interferometric mini array. The network with five electromagnetic signal detectors deployed over an area about 1 km2 is applied here to record 20‐ to 70‐kHz vertical electric fields emitted by radio transmitters in very low frequency/low‐frequency band. Furthermore, interferometric imaging algorithm is employed to evaluate the elevation angles and azimuth angles of the electromagnetic radiation source. It is found that the deviation between expected azimuth and the mean value of calculated azimuth is less than 0.2° with standard deviation of 3.55°. The experiment results indicate that the mini array may provide benefits in determining the precise locations of electromagnetic radiation sources.