bluuebunny/crossref_metadata_2025 huggingface dataset:
The prevalence of pathological findings identified by next day abdominal ultrasound in patients discharged from the emergency department
Authors: Cargnelli Stephanie , Thompson Cameron , Dear Taylor , Sandre Aislinn , Borgundvaag Bjug , McLeod Shelley L.
Published: August 2019

Objective

A common strategy for managing emergency department (ED) patients with low-risk abdominal pain is to discharge them home and arrange for next day outpatient ultrasound for further assessment. The objective was to determine the proportion of outpatient ultrasounds with findings requiring intervention within 14 days.

Methods

This was a retrospective chart review of non-pregnant patients ages 18 to 40 years, presenting to an academic ED (annual census 65,000) with an abdominal complaint for whom the emergency physician arranged an outpatient (next day) abdominal ultrasound.

Results

Of the 299 included patients, 252 (84.3%) were female and mean (SD) age was 28.4 (6.0) years. Twenty-three (7.7%) patients had ultrasounds requiring intervention within 14 days of imaging. Of these, eight (34.8%) had appendicitis, five (21.7%) had cholecystitis, four (17.4%) had urological pathology, three (13.0%) had gynecological pathology, and three (13.0%) had gastrointestinal diagnoses. Of note, 14 (60.9%) patients requiring follow-up or intervention within 14 days had symptoms that improved or resolved at the time of the outpatient ultrasound. For the 277 (92.6%) patients not requiring intervention, 117 (42.2%) had improved, 89 (32.1%) were unchanged, 50 (18.1%) had resolved, and 5 (1.8%) had worsened symptoms at the time of the follow-up ultrasound. Of the non-intervention patients, 13 (4.7%) went on to have alternative imaging, including magnetic resonance imaging, computed tomography, and a sonohysterogram.

Conclusions

Next-day ultrasound imaging remains a good way of identifying patients with serious pathology not appreciated at the time of their ED visit.
KABOOM: an agent-based model for simulating cognitive style in team problem solving
Authors: Lapp Samuel , Jablokow Kathryn , McComb Christopher
Published: August 2019

The performance of a design team is influenced by each team member’s unique cognitive style – i.e., their preferred manner of managing structure as they solve problems, make decisions, and seek to bring about change. Cognitive style plays an important role in how teams of engineers design and collaborate, but the interactions of cognitive style with team organization and processes have not been well studied. The limitations of small-scale behavioral experiments have led researchers to develop computational models for simulating teamwork; however, none have modeled the effects of individuals’ cognitive styles. This paper presents the Kirton Adaption–Innovation Inventory agent-based organizational optimization model (KABOOM), the first agent-based model of teamwork to incorporate cognitive style. In KABOOM, heterogeneous agents imitate the diverse problem-solving styles described by the Kirton Adaption-Innovation construct, which places each individual somewhere along the spectrum of cognitive style preference. Using the model, we investigate the interacting effects of a team’s communication patterns, specialization, and cognitive style composition on design performance. By simulating cognitive style in the context of team problem solving, KABOOM lays the groundwork for the development of team simulations that reflect humans’ diverse problem-solving styles.
High-repetition-rate ( kHz) targets and optics from liquid microjets for high-intensity laser–plasma interactions
Authors: George K. M. , Morrison J. T. , Feister S. , Ngirmang G. K. , Smith J. R. , Klim A. J. , Snyder J. , Austin D. , Erbsen W. , Frische K. D. , Nees J. , Orban C. , Chowdhury E. A. , Roquemore W. M.
Published: August 2019

High-intensity laser–plasma interactions produce a wide array of energetic particles and beams with promising applications. Unfortunately, the high repetition rate and high average power requirements for many applications are not satisfied by the lasers, optics, targets, and diagnostics currently employed. Here, we aim to address the need for high-repetition-rate targets and optics through the use of liquids. A novel nozzle assembly is used to generate high-velocity, laminar-flowing liquid microjets which are compatible with a low-vacuum environment, generate little to no debris, and exhibit precise positional and dimensional tolerances. Jets, droplets, submicron-thick sheets, and other exotic configurations are characterized with pump–probe shadowgraphy to evaluate their use as targets. To demonstrate a high-repetition-rate, consumable, liquid optical element, we present a plasma mirror created by a submicron-thick liquid sheet. This plasma mirror provides etalon-like anti-reflection properties in the low field of 0.1% and high reflectivity as a plasma, 69%, at a repetition rate of 1 kHz. Practical considerations of fluid compatibility, in-vacuum operation, and estimates of maximum repetition rate are addressed. The targets and optics presented here demonstrate a potential technique for enabling the operation of laser–plasma interactions at high repetition rates.
Advances in the Radiocarbon Analysis of Carbon dioxide at the NERC Radiocarbon Facility (East Kilbride) using Molecular sieve Cartridges
Authors: Garnett M H , Newton Josephine-Anne , Ascough P L
Published: August 2019

Radiocarbon (14C) analysis of carbon dioxide (CO2) provides unique information on the age, turnover and source of this important greenhouse gas, raising the prospect of novel scientific investigations into a range of natural and anthropogenic processes. To achieve these measurements, cartridges containing zeolite molecular sieves are a reliable and convenient method for collecting CO2 samples. At the NERC Radiocarbon Facility (East Kilbride) we have been refining our molecular sieve methods for over twenty years to achieve high-quality, reproducible and precise measurements. At the same time, we have been developing novel field sampling methods to expand the possibilities in collecting gas from the atmosphere, soil respiration and aquatic environments. Here, we present our latest improvements to cartridge design and procedures. We provide the results of tests used to verify the methods using known 14C content standards, demonstrating reliability for sample volumes of 3 mL CO2 (STP; 1.6 mg C) collected in cartridges that had been prepared at least three months earlier. We also report the results of quality assurance standards processed over the last two years, with results for 22 out of 23 international 14C standards being within measurement uncertainty of consensus values. We describe our latest automated procedures for the preparation of cartridges prior to use.
JOHN LOCKE AND THE TOLERATION OF CATHOLICS: A NEW MANUSCRIPT
Authors: WALMSLEY J. C. , WALDMANN FELIX
Published: August 2019

The following Communication presents a newly discovered manuscript by John Locke. The manuscript dates from 1667–8 and it deserves notice as the most significant example of Locke's thought on the toleration of Catholics prior to theEpistola de tolerantia(1689). The manuscript, entitledReasons for tolerateing Papists equally with others, reveals Locke's engagement with Sir Charles Wolseley'sLiberty of conscience, the magistrates interest(1668) and significantly informs the compositional history of Locke'sEssay concerning toleration(1667–8).
Bank Branching Deregulation and the Syndicated Loan Market
Authors: Keil Jan , Müller Karsten
Published: August 2019

How do changes in banking regulation affect the syndicated loan market? Because branch networks and loan syndication both enable banks to diversify geographical credit risk, we investigate the staggered implementation of the Riegle–Neal Interstate Branching and Banking Efficiency Act of 1994. Exploiting that the act only changed the legal framework for out-of-state commercial banks, we find that branching deregulation decreased syndicated loan issuance but spurred bilateral lending to corporations. Consistent with a supply-driven substitution effect, this shift is also reflected in interest rate spreads. Our results suggest that changes to banking regulation can substantially alter credit allocation across loan types.
Molecular characterization and identification of digenean larval stages in Aylacostoma chloroticum (Prosobranchia: Thiaridae) from a neotropical floodplain
Authors: Onaca F.M.T. , da Graça R.J. , Fabrin T.M.C. , Takemoto R.M. , de Oliveira A.V.
Published: August 2019

Digeneans (Trematoda: Digenea) are endoparasites that present a complex life cycle, generally involving an intermediate invertebrate host and a vertebrate host. There is limited information about which species of molluscs may act as intermediate hosts in the upper Paraná River floodplain (UPRF), where Aylacostoma chloroticum can be considered a potential candidate. The study of digeneans in this region is important because some of these parasites are potentially zoonotic, and, therefore, are relevant to public health. However, the correct identification of these organisms during the larval stages is difficult because of the lack of morphologically diagnostic characteristics. The objective of this study was to identify and molecularly characterize the larval stages of digeneans found in A. chloroticum in the UPRF, using the mitochondrial marker of subunit I of cytochrome c oxidase and the 28S nuclear marker. The molluscs were examined in the laboratory and three morphotypes of cercariae were found. DNA was extracted from the specimens obtained and was then amplified and sequenced. The morphotypes exhibited high genetic similarities with Pseudosellacotyla, Paralecithodendrium and Philophthalmus, indicating that these organisms belong to these genera. This is the first record of larval stages of these genera in molluscs collected in the UPRF.
Decomposing the effects of childhood adversity on later-life depression among Europeans: a comparative analysis by gender
Authors: Verropoulou Georgia , Serafetinidou Eleni , Tsimbos Cleon
Published: August 2019

The aims of the present study are twofold: first, to examine the importance of socio-economic disadvantage, adverse experiences and poor health in childhood on later-life depression by sex and, second, to discern the direct and indirect effects of childhood circumstances using a decomposition technique. Data are derived from Waves 2 and 3 of the Survey of Health, Ageing and Retirement in Europe (SHARE). The methods involve use of logistic regression models and a decomposition approach. The findings indicate that childhood socio-economic status (SES) for both genders and cognitive function for men have only a significant direct effect, consistent with the critical period model. Childhood health for men and poor parental mental health for women are nearly fully mediated by adulthood and later-life circumstances, a fact in line with the pathway model. Poor childhood health, parental excessive alcohol consumption and cognitive function for women and adverse experiences for men have both significant direct and indirect effects, consistent with both models. Mediating factors include poor adulthood and later-life health, socio-economic adversity and stress; adulthood and later-life SES mediate early life health and adverse experiences more strongly for men, whereas stress seems to mediate early life adverse experiences to a greater extent among women. Intervening policies should address childhood adversity while considering the differential vulnerability of men and women.
Particle-in-cell simulations of current loss in magnetically insulated transmission line with inductive helical support
Authors: Luo Wei , Li Yongdong , Wang Hongguang , Guo Fan , Zou Wenkang , Zhang Pengfei , Zhang Lei , Gu Yu , Zhang Jianwei
Published: August 2019

High inductive helical support provides a solution to controlling the alignment error of inner electrodes in magnetically insulated transmission lines (MITLs). Three-dimensional particle-in-cell simulations were performed to examine the current loss mechanism and the effects of structural parameters on electron flow in an MITL with a helical inductor. An empirical expression related to the ratio of electron current loss to anode current and the ratio of anode current to self-limited current was obtained. Electron current loss caused by helical inductor with different structures was displayed. The results indicate that the current loss in an MITL, near an inductive helical support, comprises both the inductor current and the electron current loss. The non-uniform structure and current of a helical inductor cause an abrupt change in the magnetic field near the helical support, which leads to anomalous behavior and current loss of electron flow. In addition, current loss in the inductive helical-supported MITL is negligible when the inductance of the support is sufficiently high. This work facilitates the estimation of electron current loss caused by the inductive helical support in MITLs.
Optimal Feet-Forces’ and Torque Distributions of Six-Legged Robot Maneuvering on Various Terrains
Authors: Mahapatra Abhijit , Roy Shibendu Shekhar , Pratihar Dilip Kumar
Published: August 2019

An analytical model with coupled dynamics for a realistic six-legged robotic system locomoting on various terrains has been developed, and its effectiveness has been proven through computer simulations and validated using virtual prototyping tools and real experiment. The approach is new and has not been attempted before. This study investigated the optimal feet-forces’ distributions under body force and foot–ground interaction considering compliant contact and friction force models for the feet undergoing slip. The kinematic model with 114 implicit constraints in 3D Cartesian space has been transformed in terms of generalized coordinates with a reduced explicit set of 24 constrained equations using kinematic transformations. The nonlinear constrained inverse dynamics model of the system has been formulated as a coupled dynamical problem using Newton–Euler method with realistic environmental conditions (compliant foot–ground contact, impact, and friction) and computed using optimization techniques due to its indeterminate nature. One case study has been carried out to validate the analytical data with the simulated ones executed in MSC.ADAMS® (Automated Dynamic Analysis of Mechanical Systems), while the other case study has been conducted to validate the analytical and simulated data with the experimental ones. In both these cases, results are found to be in close agreement, which proves the efficacy of the model.
Comparing Changes and Transitions of Home Care Clients in Retirement Homes and Private Homes
Authors: Poss Jeffrey , Sinn Chi-Ling , Grinchenko Galina , Salam-White Lialoma , Hirdes John
Published: August 2019

Long-stay home care clients mostly reside in private homes or retirement homes, and the type of residence may influence risk factors for long-term care placement. This multi-state analytic study uses RAI-Home Care and administrative data from the Hamilton Niagara Haldimand Brant Local Health Integration Network to model conceptualized states of risk at baseline through a 13-month follow-up period. Modifiable risk factors in these states were client loneliness or depressive symptoms, and caregiver distress. A higher adjusted likelihood of being discharged deceased was found for the lowest-risk clients in retirement homes. Adjusting for client, service, and caregiver characteristics, retirement home residency was associated with higher likelihood of placement in a long-term care home; reduced caregiver distress; and increased client loneliness/depression. As an alternative to private home settings as the location for aging in place among these long-stay home care clients, retirement home residency represents some trade-offs between client and informal caregiver.
Fuzzy approach for production planning by using a three-dimensional printing-based ubiquitous manufacturing system
Authors: Chen Tin-Chih Toly
Published: August 2019

A ubiquitous manufacturing (UM) system is used in manufacturing for obtaining the Internet of things solutions and provides location-based manufacturing services. Human-induced uncertainty and early termination are two complications that hamper the effectiveness of an UM system based on three-dimensional (3D) printing. To resolve these complications, several solutions were considered in this study. First, fuzzy-valued parameters were defined to determine uncertainty. Subsequently, slack was derived to determine whether to restart an early terminated 3D printing process in the same 3D printing facility. Consequently, two optimization models – a fuzzy mixed-integer linear programming model and a fuzzy mixed-integer quadratic programming model – were developed in this study. Based on the two optimization models, a fuzzy 3D printing-based UM system that considers uncertainty and early termination was developed. The effectiveness of the proposed methodology was tested by conducting a regional experiment. The experimental results revealed that the proposed methodology could shorten the average cycle time by 9% and could enable 3D printing facilities to make real-time, online reprinting decisions.
Establishment of a protocol for the isolation of ovarian preantral follicles derived from collared peccaries (Pecari tajacu)
Authors: Campos Lívia Batista , Silva Andréia Maria da , Moreira Samara Sandy Jeronimo , Santos Caio Sergio , Apolinário Carlos Alexandre de Carvalho , Saraiva Márcia Viviane Alves , Oliveira Moacir Franco de , Silva Alexandre Rodrigues
Published: August 2019

We compare the efficiency of mechanical or enzymatic methods, and their combination, for the isolation of ovarian preantral follicles (PFs) from collared peccaries. The ovaries from six females were subjected to the different methods investigated here. For the enzymatic method, ovary fragments were exposed to collagenase type IV in TCM-HEPES medium; the mechanical procedure was based on ovarian cortex dissociation by using a scalpel blade. The residual solution obtained after the mechanical isolation was subjected to the enzymatic procedure. The number of isolated PFs was quantified and classified as primordial, primary, or secondary; their viability was assessed using trypan blue dye assay. To confirm the results, PFs derived from the most efficient method were evaluated for integrity using scanning electron microscopy (SEM) and subjected to a 24 h in vitro culture for subsequent evaluation of viability by using fluorescent probes. A higher number of PFs (P < 0.05) was obtained from the enzymatic method (961.7 ± 132.9) in comparison with the mechanical method (434.3 ± 88.9), but no difference was observed between the two methods and their combination (743.2 ± 92.8). The trypan blue assay showed that the enzymatic method (98.7 ± 0.6%) provided the highest percentage of viable follicles (P < 0.05). Furthermore, SEM confirmed the ultrastructural integrity of the surface architecture of peccary PFs isolated by the enzymatic procedure; epifluorescence microscopy was used to confirm their viability (86.0%). In conclusion, we suggest that the enzymatic method investigated here is useful for the isolation of viable ovarian PFs from collared peccaries.
Semi-automated speckle-tracking for quantitative right ventricular assessment in children and adolescents
Authors: McCloud Aron K. , Lowisz Joanna , Roberson David A. , Lefaiver Cheryl A. , Penk Jamie S.
Published: August 2019

Background:

Assessment of right ventricular size and function is an important part of the clinical cardiac evaluation; however, these quantitative measures are challenging by echocardiography. Automated software could be useful in place of manual measurements and qualitative assessment. This study evaluates a semi-automated software by comparing automated to manual measures in normal children.

Methods:

Neonates to adolescents with normal echocardiograms were prospectively enrolled. Measurements were performed using manual techniques and semi-automated software (EchoInsight®, Epsilon Imaging, Ann Arbor, Michigan, United States of America). Right ventricular measurements included end-diastolic and end-systolic area, fractional area change, chamber dimensions, and tricuspid annular plane systolic excursion. Agreement between manual and semi-automated measures was compared.

Results:

Echocardiograms for 233 patients were included in the analysis. Intra- and inter-observer reliabilities for semi-automated measures were good with intraclass correlation coefficients all over 0.9 and 0.85, respectively. There was very strong correlation between manual and semi-automated methods for areas and dimensions (r = 0.93–0.99) and low bias (1.4–10.8%). For functional measures, tricuspid annular plane systolic excursion measures correlated well (r = 0.84), but fractional area change did not (r = 0.50). Both demonstrated significant bias (33.5–43.0%). The semi-automated method consistently underestimated fractional area change with a mean of 26.6% versus a manual mean of 36.1%.

Conclusions:

The semi-automated software is capable of generating quantitative right ventricular measures in children with good reliability. The software demonstrates very good correlation and low bias when compared to manual methods for right ventricular areas and dimensions. There is a significant difference between manual and semi-automated techniques for the functional measures.
Tackling challenges of neural purchase stage identification from imbalanced twitter data
Authors: Adel Heike , Chen Francine , Chen Yan-Ying
Published: August 2019

Twitter and other social media platforms are often used for sharing interest in products. The identification of purchase decision stages, such as in the AIDA model (Awareness, Interest, Desire, and Action), can enable more personalized e-commerce services and a finer-grained targeting of advertisements than predicting purchase intent only. In this paper, we propose and analyze neural models for identifying the purchase stage of single tweets in a user’s tweet sequence. In particular, we identify three challenges of purchase stage identification: imbalanced label distribution with a high number of non-purchase-stage instances, limited amount of training data, and domain adaptation with no or only little target domain data. Our experiments reveal that the imbalanced label distribution is the main challenge for our models. We address it with ranking loss and perform detailed investigations of the performance of our models on the different output classes. In order to improve the generalization of the models and augment the limited amount of training data, we examine the use of sentiment analysis as a complementary, secondary task in a multitask framework. For applying our models to tweets from another product domain, we consider two scenarios: for the first scenario without any labeled data in the target product domain, we show that learning domain-invariant representations with adversarial training is most promising, while for the second scenario with a small number of labeled target examples, fine-tuning the source model weights performs best. Finally, we conduct several analyses, including extracting attention weights and representative phrases for the different purchase stages. The results suggest that the model is learning features indicative of purchase stages and that the confusion errors are sensible.
A Heretic in the Schoenberg Circle: Roberto Gerhard's First Engagement with Twelve-Tone Procedures inAndantino
Authors: ALONSO TOMÁS DIEGO
Published: August 2019

Shortly before finishing his studies with Arnold Schoenberg, Roberto Gerhard composedAndantino, a short piece in which he used for the first time a compositional technique for the systematic circulation of all pitch classes in both the melodic and the harmonic dimensions of the music. He modelled this technique on the tri-tetrachordal procedure in Schoenberg's Prelude from the Suite for Piano, Op. 25 but, unlike his teacher, Gerhard treated the tetrachords as internally unordered pitch-class collections. This decision was possibly encouraged by his exposure from the mid-1920s onwards to Josef Matthias Hauer's writings on ‘trope theory’. Although rarely discussed by scholars,Andantinooccupies a special place in Gerhard's creative output for being his first attempt at ‘twelve-tone composition’ and foreshadowing the permutation techniques that would become a distinctive feature of his later serial compositions. This article analysesAndantinowithin the context of the early history of twelve-tone music and theory.
Why We Love Michelle: Understanding Public Support for First Lady Michelle Obama
Authors: Elder Laurel , Frederick Brian
Published: August 2019

After eight years as the first lady of the United States, Michelle Obama left the White House beloved in the eyes of many Americans. Being well liked by Americans is not in and of itself an unusual phenomenon for first ladies. What is remarkable about the love so many Americans expressed toward First Lady Michelle Obama is that she was able to maintain high favorable evaluations through a period of political, social, and electoral acrimony that made high approval ratings for national political figures increasingly unlikely. By drawing on a wealth of aggregate data drawn from the Roper Center for Public Opinion Research archives and individual-level public opinion data drawn from the 2012 American National Election Studies survey as well as original survey data, this article identifies several important forces behind Michelle Obama's popularity.
Pkd1-targeted mutation reveals a role for the Wolffian duct in autosomal dominant polycystic kidney disease
Authors: Tee J. B. , Dnyanmote A. V. , Lorenzo M. K. , Lee O. R. , Grisaru S. , Suk M. , Acott P. D.
Published: August 2019

Several life-threatening diseases of the kidney have their origins in mutational events that occur during embryonic development. In this study, we investigate the role of the Wolffian duct (WD), the earliest embryonic epithelial progenitor of renal tubules, in the etiology of autosomal dominant polycystic kidney disease (ADPKD). ADPKD is associated with a germline mutation of one of the two Pkd1 alleles. For the disease to occur, a second event that disrupts the expression of the other inherited Pkd1 allele must occur. We postulated that this secondary event can occur in the pronephric WD. Using Cre-Lox recombination, mice with WD-specific deletion of one or both Pkd1 alleles were generated. Homozygous Pkd1-targeted deletion in WD-derived tissues resulted in mice with large cystic kidneys and serologic evidence of renal failure. In contrast, heterozygous deletion of Pkd1 in the WD led to kidneys that were phenotypically indistinguishable from control in the early postnatal period. High-throughput sequencing, however, revealed underlying gene and microRNA (miRNA) changes in these heterozygous mutant kidneys that suggest a strong predisposition toward developing ADPKD. Bioinformatic analysis of this data demonstrated an upregulation of several miRNAs that have been previously associated with PKD; pathway analysis further demonstrated that the differentially expressed genes in the heterozygous mutant kidneys were overrepresented in signaling pathways associated with maintenance and function of the renal tubular epithelium. These results suggest that the WD may be an early epithelial target for the genetic or molecular signals that can lead to cyst formation in ADPKD.
Association between birth weight and childhood cardiovascular disease risk factors in West Virginia
Authors: Umer Amna , Hamilton Candice , Cottrell Lesley , Giacobbi Peter , Innes Kim , Kelley George A. , Neal William , John Collin , Lilly Christa
Published: August 2019

The reported associations between birth weight and childhood cardiovascular disease (CVD) risk factors have been inconsistent. In this study, we investigated the relationship between birth weight and CVD risk factors at 11 years of age. This study used longitudinally linked data from three cross-sectional datasets (N= 22,136) in West Virginia; analysis was restricted to children born full-term (N= 19,583). The outcome variables included resting blood pressure [systolic blood pressure (SBP), diastolic blood pressure (DBP)] and lipid profile [total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, non-HDL, and triglycerides (TG)]. Multiple regression analyses were performed, adjusting for child’s body mass index (BMI), sociodemographics, and lifestyle characteristics. Unadjusted analyses showed a statistically significant association between birth weight and SBP, DBP, HDL, and TG. When adjusted for the child’s BMI, the association between birth weight and HDL [b= 0.14 (95% CI: 0.11, 0.18) mg/dl per 1000 g increase] and between birth weight and TG [b= –0.007 (–0.008, –0.005) mg/dl per 1000 g increase] remained statistically significant. In the fully adjusted model, low birth weight was associated with higher LDL, non-HDL, and TGs, and lower HDL levels. The child’s current BMI at 11 years of age partially (for HDL, non-HDL, and TG) and fully mediated (for SBP and DBP) the relationship between birth weight and select CVD risk factors. While effects were modest, these risk factors may persist and amplify with age, leading to potentially unfavorable consequences in later adulthood.
Guidewire perforation and compartment syndrome after lower extremity	angioplasty
Authors: Ganesan Krishanth , Tan Janice Ser Huey , Kumar Pradesh
Published: August 2019

Summary: Chronic total occlusion remains one of the most challenging lesions to treat despite continuing developments in medical devices and increasing operator experience. Guidewire perforation complications are being increasingly observed. Early recognition and timely institution of appropriate treatment are essential to prevent potentially devastating sequelae.
Very Slow Rotation of Earth's Inner Core From 1971 to 1974
Authors: Vidale John E.
Published: August 2019

The rate that Earth's inner core rotates relative to the mantle and crust has been debated for decades. Nonrotational processes, including internal deformation and flow in the outer core, have also been proposed to explain observed seismic changes. The observed changes thus far have been so inconsistent and weak as to hamper convincing interpretation. Here, we examine waves backscattered from within the inner core, which can more robustly evaluate rotation, from two nuclear tests 3 years apart in Novaya Zemlya, Russia. We have extended our previous analysis of these explosions using precise station corrections and the full Large Aperture Seismic Array, thus revealing how the time shifts depend on slowness and lag time and halving our rotation rate estimate. Our derived 0.07°/year inner core superrotation rate from 1971 to 1974 is more robust and slower than most previous estimates and may require interesting reinterpretations of localized signals previously interpreted as inner core rotation.
Advected Air Mass Reservoirs in the Downwind of Mountains and Their Roles in Overrunning Boundary Layer Depths Over the Plains
Authors: Pal Sandip , Lee Temple R.
Published: August 2019

Atmospheric boundary layer depths (BLDs) over continental sites have long been meticulously characterized. However, a downwind‐footprint concept for BLDs over plains under the impact of seasonally and spatially changing horizontal advection of BLDs off elevated terrains has remained unexplored. For the first time, we provide observational evidence of the impact of mountains on regional BLDs using 25‐years (1991–2015) of rawinsonde‐retrieved afternoon BLDs over 22 sites located in the mountains' (Rockies and Appalachians) downstream. Results suggest that mountain‐advected air mass, elevated terrains, and wind play a significant role in modulating BLD variability “miles away” from terrains. We found significant BLD contrasts over the plains (400–1,500 m) under mountain‐advected versus flatland‐advected flows pertaining to elevated mixed layers off the mountain ranges. The BLD contrasts were higher in the downwind of Rockies than the Appalachians, and higher BLD contrasts were observed in spring and summer (900–1,500 m) than in fall and winter (100–500 m). These findings will help build advanced parameterizations in models where BLD simulations around complex terrain still remain a hurdle.
Origin of Long‐Wavelength Magnetic Anomalies at Subduction Zones
Authors: Williams Simon E. , Gubbins David
Published: August 2019

Most subduction zones have associated long‐wavelength anomalies in the lithospheric magnetic field observed at satellite altitude. We model the 13 subduction zones defined by seismicity and seismic tomography using vertically integrated magnetizations that are increasing, level, or decreasing away from the trench. These mimic end members of a magnetized mantle wedge, a uniform layer, and a magnetized dipping lithospheric slab. They are added to a global model of vertically integrated magnetization based on continental and oceanic geology. We find the dipping slab places the anomaly too close to the trench, while the other two fit the data equally well and use the level model in the main part of the study. Anomalies at the Sunda, Aleutians, Cascadia, Central American, and Kamchatka‐Japan zones are well modeled by uniform magnetization of differing susceptibilities and spatial extents. We show the South American anomaly is weak because the magnetization lies mainly in the null space that produces no external potential magnetic field. There is no anomaly associated with the Ryukyu system, possibly because the present subduction started too recently for magnetization to have formed. The magnetic anomaly stretching down the Baja California peninsula is not present in the prediction because there is no seismicity on which to base a slab geometry, but recent tomography suggests a fossil slab there and we propose historic subduction as the origin of the Baja magnetic anomaly. Finally, we discuss the mineralogical origins of the magnetization and favor serpentinization of the region above the subducted plate.
Inclusion of Viscosity Into Classical Homogeneous Nucleation Theory for Water Bubbles in Silicate Melts: Reexamination of Bubble Number Density in Ascending Magmas
Authors: Nishiwaki Mizuki , Toramaru Atsushi
Published: August 2019

To evaluate the effect of melt viscosity on bubble nucleation, we formulated the homogeneous nucleation rate of water bubbles to explicitly include melt viscosity. The viscosity coefficient appears in the preexponential factor of the nucleation rate in terms of the Péclet number: the ratio of the bubble growth timescale by molecular diffusion and the viscous relaxation timescale. The preexponential factor is almost constant when viscosity is low (or a high Péclet number), whereas it linearly decreases with increasing viscosity (or a decreasing Péclet number) exceeding the crossover value of viscosity, under a given supersaturation. The crossover point depends on whether homogeneous or heterogeneous nucleation takes place. We numerically solved the evolution of bubble nucleation and growth processes in ascending magmas by using the new nucleation rate formula and a precise approximation of moment equations of the bubble size distribution function. The resultant bubble number density has two regimes, similar to the previous study, but the transition point between the diffusion‐controlled regime and the viscosity‐controlled regime moves to higher viscosity or higher decompression rates by 0.6 log units at the maximum. In the viscosity‐controlled regime, the effect of the better approximation of bubble size distribution moment equations reduces bubble number density by a few orders of magnitude compared with the previous study. As a result of compiling the past laboratory experimental data, it turned out that all the experiments are conducted under the conditions equivalent to the diffusion‐controlled regime. We propose an experimental condition to confirm the presence of the viscosity‐controlled regime.
How Does Seismic Rupture Accelerate? Observational Insights From Earthquake Source Time Functions
Authors: Renou Julien , Vallée Martin , Dublanchet Pierre
Published: August 2019

Observation of the seismic process for a large earthquake population is of key interest to detect potential magnitude‐dependent behaviors and, more generally, to quantify how seismic rupture develops. In contrast with studies focusing on the first radiated waves, we here propose to characterize the growing phase leading to the main seismic moment release episode(s), which we refer to as the development phase. Our analysis uses the 2,221 teleseismic source time functions (STFs) of shallow dip‐slip earthquakes provided by the global SCARDEC database and consists in measuring the moment acceleration during the development phase at prescribed moment rates. This approach is therefore insensitive to hypocentral time uncertainties and aims at quantifying how seismic ruptures accelerate, independently of when they accelerate. Our results first show that rupture acceleration does not exhibit any magnitude‐dependent signal emerging above the intrinsic measurements variability. We thus use the full STF catalog to characterize the moment rate
of the development phase and show that, on average,
with nd equal to 2.7. This time evolution therefore does not follow the steady t2 growth expected for classical circular crack models, which indicates that stress drop and/or rupture velocity transiently vary during the development phase. We finally illustrate with a synthetic STF catalog that, due to initial rupture variability, approaches based on hypocentral time are not expected to fully characterize the behavior of the development phase.
Pacific Water Pathway in the Arctic Ocean and Beaufort Gyre in Two Simulations With Different Horizontal Resolutions
Authors: Hu Xianmin , Myers Paul G. , Lu Youyu
Published: August 2019

A set of numerical simulations (with horizontal resolutions of 1/4° and 1/12°) is conducted to study the Pacific Water pathway in the Arctic Ocean and the freshwater content in Beaufort Gyre. Passive tracer tags the Pacific Water entering through Bering Strait into the Arctic Ocean and further reveals its circulation routes and spatial distribution. Both the 1/4° and 1/12° simulations show Pacific Water mainly follows the Transpolar Drift over the integration period of 2002–2016, with a limited amount being able to flow eastward along the Alaskan coast to enter the Canadian Arctic Archipelago. However, the circulation pattern of Pacific Water within the Beaufort Gyre is quite different with a stronger and tighter anticyclonic circulation in the 1/12° simulation corresponding to the difference in freshwater content. The 1/12° simulation successfully reproduces the overall recent increasing trend in the freshwater content in the Beaufort Gyre, while the 1/4° simulation fails to maintain the high freshwater content state after 2007. Budget analysis suggests that this difference in Beaufort Gyre freshwater storage is mainly caused by lateral advection. The lateral freshwater flux is decomposed into two components due to the slow‐varying circulation and mesoscale eddies. The difference in the capability to resolve eddies in the two simulations causes the difference in the temporal evolution of both components of the lateral flux.
Interacting Effects of Plant Invasion, Climate, and Soils on Soil Organic Carbon Storage in Coastal Wetlands
Authors: Yang Ren‐Min
Published: August 2019

Coastal wetland soils store large amounts of organic carbon, which is becoming vulnerable to environmental changes such as exotic species invasion and climate change. Soil organic carbon (SOC) is also related to soil biogeochemical factors. To understand the mechanisms of these changes in regulating SOC, it is necessary to characterize the direct and indirect effects of exotic species invasion, climate, and soil variables on SOC. We used a structural equation model to identify the key driving mechanisms of SOC storage to a depth of 1 m at 15 sites on the East China coast, whereSpartina alternifloraLoisel. (S. alterniflora) invasion has significantly influenced SOC storage. The model revealed several patterns that are expected to explain the enhanced SOC storage.Spartina alterniflorainvasion had a direct effect on SOC storage mainly due to its impacts on biomass production. Temperature had an important influence on SOC storage and the subsurface SOC content. SOC storage was also related to the interacting effects ofS. alterniflorainvasion and soil biogeochemical properties such as soil salinity, fine soil fraction, and bulk density. The relative contribution of SOC in the topsoil to SOC storage at a depth of 1 m decreased over time, while the contribution increased for the SOC below the surface. These results highlight the interactions amongS. alterniflorainvasion, climate, and soil properties in regulating SOC dynamics. Our results imply that the relative importance of vertical patterns to SOC storage associated withS. alterniflorainvasion and temperature fluctuations will change over time.
Inhibition of IRE1α RNase activity reduces NLRP3 inflammasome assembly and processing of pro-IL1β
Authors: Talty Aaron , Deegan Shane , Ljujic Mila , Mnich Katarzyna , Naicker Serika D. , Quandt Dagmar , Zeng Qingping , Patterson John B. , Gorman Adrienne M. , Griffin Matthew D. , Samali Afshin , Logue Susan E.
Published: August 2019

The inflammasome is a multiprotein complex assembled in response to Pathogen Associated Molecular Patterns (PAMPs) and Danger Associated Molecular Patterns (DAMPs). Inflammasome activation occurs through a two-step mechanism, with the first signal facilitating priming of inflammasome components while the second signal triggers complex assembly. Once assembled, the inflammasome recruits and activates pro-caspase-1, which in turn processes pro-interleukin (IL)-18 and pro-IL-1β into their bio-active forms. Owing to its key role in the regulation of innate immune responses, the inflammasome has emerged as a therapeutic target for the treatment of inflammatory conditions. In this study we demonstrate that IRE1α, a key component of the Unfolded Protein Response, contributes to assembly of the NLRP3 inflammasome. Blockade of IRE1α RNase signaling lowered NLRP3 inflammasome assembly, caspase-1 activation and pro-IL-1β processing. These results underscore both the importance and potential therapeutic relevance of targeting IRE1α signaling in conditions of excessive inflammasome formation.
Directed self-assembly of a helical nanofilament liquid crystal phase for use as structural color reflectors
Authors: Park Wongi , Ha Taewoo , Kim Teun-Teun , Zep Anna , Ahn Hyungju , Shin Tae Joo , Sim Kyung Ik , Jung Taek Sun , Kim Jae Hoon , Pociecha Damian , Gorecka Ewa , Yoon Dong Ki
Published: August 2019

The fabrication of molecular structures with a desired morphology, e.g., nanotubes, nanoribbons, nanosprings, and sponges, is essential for the advancement of nanotechnology. Unfortunately, realization of this objective is expensive and complicated. Here, we report that irradiating a film comprising azobenzene derivatives with UV light produces oriented arrays of helical nanofilaments via the photoisomerization-induced Weigert effect. As a result, structural colors are observed due to the extrinsic chiral reflection in the visible wavelength range, and the reflected color can be tuned by adjusting the molecular length of the azobenzene derivative. This simple fabrication method can be used for fabricating large, reversible, and patternable color reflectors, providing a new platform for interference-based structural coloration as it exists in nature, such as morpho butterflies, green-winged teal, and various beetles.
The cost of obtaining rewards enhances the reward prediction error signal of midbrain dopamine neurons
Authors: Tanaka Shingo , O’Doherty John P. , Sakagami Masamichi
Published: August 2019

Midbrain dopamine neurons are known to encode reward prediction errors (RPE) used to update value predictions. Here, we examine whether RPE signals coded by midbrain dopamine neurons are modulated by the cost paid to obtain rewards, by recording from dopamine neurons in awake behaving monkeys during performance of an effortful saccade task. Dopamine neuron responses to cues predicting reward and to the delivery of rewards were increased after the performance of a costly action compared to a less costly action, suggesting that RPEs are enhanced following the performance of a costly action. At the behavioral level, stimulus-reward associations are learned faster after performing a costly action compared to a less costly action. Thus, information about action cost is processed in the dopamine reward system in a manner that amplifies the following dopamine RPE signal, which in turn promotes more rapid learning under situations of high cost.
Ice sheets matter for the global carbon cycle
Authors: Wadham J. L. , Hawkings J. R. , Tarasov L. , Gregoire L. J. , Spencer R. G. M. , Gutjahr M. , Ridgwell A. , Kohfeld K. E.
Published: August 2019

The cycling of carbon on Earth exerts a fundamental influence upon the greenhouse gas content of the atmosphere, and hence global climate over millennia. Until recently, ice sheets were viewed as inert components of this cycle and largely disregarded in global models. Research in the past decade has transformed this view, demonstrating the existence of uniquely adapted microbial communities, high rates of biogeochemical/physical weathering in ice sheets and storage and cycling of organic carbon (>104 Pg C) and nutrients. Here we assess the active role of ice sheets in the global carbon cycle and potential ramifications of enhanced melt and ice discharge in a warming world.
Separate lanes for adding and reading in the white matter highways of the human brain
Authors: Grotheer Mareike , Zhen Zonglei , Lerma-Usabiaga Garikoitz , Grill-Spector Kalanit
Published: August 2019

Math and reading involve distributed brain networks and have both shared (e.g. encoding of visual stimuli) and dissociated (e.g. quantity processing) cognitive components. Yet, to date, the shared vs. dissociated gray and white matter substrates of the math and reading networks are unknown. Here, we define these networks and evaluate the structural properties of their fascicles using functional MRI, diffusion MRI, and quantitative MRI. Our results reveal that there are distinct gray matter regions which are preferentially engaged in either math (adding) or reading, and that the superior longitudinal and arcuate fascicles are shared across the math and reading networks. Strikingly, within these fascicles, reading- and math-related tracts are segregated into parallel sub-bundles and show structural differences related to myelination. These findings open a new avenue of research that examines the contribution of sub-bundles within fascicles to specific behaviors.
The structure of a polygamous repressor reveals how phage-inducible chromosomal islands spread in nature
Authors: Ciges-Tomas J. Rafael , Alite Christian , Humphrey Suzanne , Donderis J. , Bowring Janine , Salvatella Xavier , Penadés José R. , Marina Alberto
Published: August 2019

Stl is a master repressor encoded by Staphylococcus aureus pathogenicity islands (SaPIs) that maintains integration of these elements in the bacterial chromosome. After infection or induction of a resident helper phage, SaPIs are de-repressed by specific interactions of phage proteins with Stl. SaPIs have evolved a fascinating mechanism to ensure their promiscuous transfer by targeting structurally unrelated proteins performing identically conserved functions for the phage. Here we decipher the molecular mechanism of this elegant strategy by determining the structure of SaPIbov1 Stl alone and in complex with two structurally unrelated dUTPases from different S. aureus phages. Remarkably, SaPIbov1 Stl has evolved different domains implicated in DNA and partner recognition specificity. This work presents the solved structure of a SaPI repressor protein and the discovery of a modular repressor that acquires multispecificity through domain recruiting. Our results establish the mechanism that allows widespread dissemination of SaPIs in nature.