bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Women from Georgia and Contiguous States Who Obtained Abortions in Georgia, 1994–2016
Authors: Shapiro Rachel , Erhardt-Ohren Blake , Rochat Roger
Published: January 2020

Objectives

To determine trends for Georgia and contiguous state residents seeking abortions in Georgia between 1994 and 2016.

Methods

We analyzed aggregate vital statistics data, collected in Georgia, on Georgia residents (n = 675,995) and contiguous state residents (Alabama, Florida, North Carolina, South Carolina, Tennessee) (n = 76,232) obtaining abortion and delivery services in Georgia between 1994 and 2016. We examined demographic, pregnancy, and abortion characteristics using counts, ratios, and χ2 tests of proportion.

Results

Of the data analyzed, 10.1% of all abortions were for contiguous state residents. The number of abortions in Georgia for contiguous state residents increased 35.3% from 1994 to 2016 (from n = 3115 to n = 4216) while it decreased for Georgia residents by 11.1% (from n = 32,934 to n = 29,264). Contiguous state residents exhibited a higher abortion ratio (1115) compared to Georgia women (224). These populations exhibited statistically significant differences across all variables and time points. Both populations demonstrated similar trends in ethnicity, race, education, marital status, and age. However, contiguous state residents were more likely to obtain an abortion at ≥ 20 weeks gestational age (13.8%) and obtained a lower proportion of suction curettage abortions (60.0%) and a higher proportion of dilation and evacuation procedures (31.9%). They were also less likely to be primigravid.

Conclusions for Practice

Women from neighboring states seek abortions in Georgia later in gestation and may therefore lack affordable, safe, early abortion care in their home states. Understanding trends in travel for abortion can allow providers and policymakers to better respond to the needs of patients.
Correlation of Elastohydrodynamic Friction with Molecular Structure of Highly Refined Hydrocarbon Base Oils
Authors: Kim Hak Mook , Spikes Hugh
Published: January 2020

The molecular compositions of a range of low viscosity hydrocarbon base oils spanning API Groups II to IV have been quantified using 13C NMR and correlated with base oil elastohydrodynamic (EHD) friction. A strong correlation has been found between the proportions of paraffin, linear and branched carbons and EHD friction, with a high proportion of linear and paraffinic carbon atoms contributing to low-EHD friction but branched carbons contributing to high-EHD friction. Correlation equations have been developed to predict EHD friction based on base oil composition. At very high temperature and low pressure, this correlation breaks down as the lubricant in the contact does not reach sufficiently high shear stress for shear thinning to occur. For Group IV polyalphaolefin, the correlation must be extended to account for the very high proportion of linear carbons originating from linear alkene oligomerization. The correlations developed in this study can be used to guide the design of low-EHD friction base oils.
Fast, robust, and accurate monocular peer-to-peer tracking for surgical navigation
Authors: Strzeletz Simon , Hazubski Simon , Moctezuma José-Luis , Hoppe Harald
Published: January 2020

Purpose

This work presents a new monocular peer-to-peer tracking concept overcoming the distinction between tracking tools and tracked tools for optical navigation systems. A marker model concept based on marker triplets combined with a fast and robust algorithm for assigning image feature points to the corresponding markers of the tracker is introduced. Also included is a new and fast algorithm for pose estimation.

Methods

A peer-to-peer tracker consists of seven markers, which can be tracked by other peers, and one camera which is used to track the position and orientation of other peers. The special marker layout enables a fast and robust algorithm for assigning image feature points to the correct markers. The iterative pose estimation algorithm is based on point-to-line matching with Lagrange–Newton optimization and does not rely on initial guesses. Uniformly distributed quaternions in 4D (the vertices of a hexacosichora) are used as starting points and always provide the global minimum.

Results

Experiments have shown that the marker assignment algorithm robustly assigns image feature points to the correct markers even under challenging conditions. The pose estimation algorithm works fast, robustly and always finds the correct pose of the trackers. Image processing, marker assignment, and pose estimation for two trackers are handled in less than 18 ms on an Intel i7-6700 desktop computer at 3.4 GHz.

Conclusion

The new peer-to-peer tracking concept is a valuable approach to a decentralized navigation system that offers more freedom in the operating room while providing accurate, fast, and robust results.
Cortical 3-hinges could serve as hubs in cortico-cortical connective network
Authors: Zhang Tuo , Li Xiao , Jiang Xi , Ge Fangfei , Zhang Shu , Zhao Lin , Liu Huan , Huang Ying , Wang Xianqiao , Yang Jian , Guo Lei , Hu Xiaoping , Liu Tianming
Published: January 2020

Mapping the relation between cortical convolution and structural/functional brain architectures could provide deep insights into the mechanisms of brain development, evolution and diseases. In our previous studies, we found a unique gyral folding pattern, termed a 3-hinge, which was defined as the conjunction of three gyral crests. The uniqueness of the 3-hinge was evidenced by its thicker cortex and stronger fiber connections than other gyral regions. However, the role that 3-hinges play in cortico-cortical connective architecture remains unclear. To this end, we conducted MRI studies by constructing structural cortico-cortical connective networks based on a fine-granular cortical parcellation, the parcels of which were automatically labeled as 3-hinge, 2-hinge (ordinary gyrus) or sulcus. On human brains, 3-hinges possess significantly higher degrees, strengths and betweennesses than 2-hinges, suggesting that 3-hinges could serve more like hubs in the cortico-cortical connective network. This hypothesis gains supports from human functional network analyses, in which 3-hinges are involved in more global functional networks than ordinary gyri. In addition, 3-hinges could serve as ‘connector’ hubs rather than ‘provincial’ hubs and they account for a dominant proportion of nodes in the high-level ‘backbone’ of the network. These structural results are reproduced on chimpanzee and macaque brains, while the roles of 3-hinges as hubs become more pronounced in higher order primates. Our new findings could provide a new window to the relation between cortical convolution, anatomical connection and brain function.
Trocar Site HERnias After Bariatric Laparoscopic Surgery (HERBALS): a Prospective Cohort Study
Authors: Karampinis Ioannis , Lion Eliette , Hetjens Svetlana , Vassilev Georgi , Galata Christian , Reissfelder Christoph , Otto Mirko
Published: January 2020

Background

The exact prevalence of trocar site hernias after bariatric procedures is not yet known. Recent metaanalysis data indicated concerning rates of up to 25%. We conducted a prospective cohort study to estimate the prevalence and analyze the role of fascia closure in the development of trocar hernias.

Method

A total of 365 patients who were operated for obesity in our department between 2009 and 2018 were included. All patients were invited for a follow-up ultrasonography scan in order to detect abdominal wall defects. The role of intraoperative fascia closure in the development of trocar site hernias was evaluated, and a logistic regression analysis was performed to detect potential risk factors.

Results

The overall prevalence of trocar hernias detected by ultrasonography was 34%. The prevalence of abdominal wall defects in patients who received a fascia closure was 37% compared with 34% in patients who did not receive a fascia closure (p = 0.37). The only factor that was associated with a higher risk for trocar site hernias was high excessive weight loss (p = 0.05).

Conclusion

Trocar site hernias are an underestimated complication of minimally invasive, multiportal bariatric surgery, and the prevalence of asymptomatic hernias is probably higher than initially expected. In this study, fascia closure did not protect against trocar hernias. However, opposing evidence from similar trials suggests closing the fascia. This clinical problem should therefore be further assessed in a prospective randomized setting.
Comparison study on potential syngas produced by mild thermoconversion of microalgal residues through proton nuclear magnetic resonance and thermogravimetric analysis-fourier transform infrared spectroscopy
Authors: Li Shuangfei , Liu Liangxu , Cheng Jay Jiayang , Yang Xuewei
Published: January 2020

This paper presented a mechanism study of syngas production through lipid-extracted microalgal residues by investigating how the structure of these residues affected the pyrolysis characteristics. The results showed that both Chlorella sorokiniana 21 and Monoraphidium 3s35 residues could be pyrolyzed efficiently at low temperatures from 120 to 380 °C, with a final residue of less than 22.75%. Hemicellulose with carboxyl groups was the main component of both microalgal residues, most likely contributing to the production of the C=O compounds and carbon monoxide (CO). A large amount of CHO, CH2O, and CH3O (60.09% in total) was observed from C. sorokiniana 21, which was 1.58 times more than that from Monoraphidium 3s35. Pyrolysis of the C. sorokiniana 21 residue yielded more C=O and CHn compounds with less activation energy (52.97–58.57 kJ mol−1) and a higher reaction rate (0.105% s−1) than that of Monoraphidium 3s35. The different pyrolysis characteristics between the two microalgal residues might be attributed to structural variations.
Multiple hormone secretion may indicate worse prognosis in patients with ectopic Cushing’s syndrome
Authors: Lase Ieva , Strele Ieva , Grönberg Malin , Kozlovacki Gordana , Welin Staffan , Janson Eva Tiensuu
Published: January 2020

Purpose

Ectopic Cushing’s syndrome (ECS) caused by an ACTH secreting neuroendocrine neoplasm (NEN) is a rare and challenging condition. We aimed to detect predictive and prognostic parameters for ECS patients identified from a retrospective, comprehensive cohort of NENs treated at a tertiary referral center.

Methods

Medical records of 886 patients with NENs were reviewed. We identified 51 patients with ECS (33 females/18 men); mean age 52 ± 15 years (SD). Clinical parameters including symptoms, biochemical markers, and survival were extracted and further analyzed.

Results

The primary tumor was located in the thorax (n = 28) or pancreas (n = 15) or was of unknown primary origin (n = 8). In 30 patients, tumor and ECS were diagnosed simultaneously. In 12 patients, the NEN diagnosis preceded ECS development, with a median time of 43.5 months (range: 9–96), and 10 of these showed radiological tumor progression at ECS diagnosis. Twenty-one patients had multiple hormone secretion, which correlated with shorter overall survival (OS), p = 0.012 (HR 2.4 (95% CI 1.2–4.9)), as did high morning cortisol, p = 0.037 (HR 2.3 (1.0–5.2)), higher tumor grade, p = 0.044 (HR 2.3 (1.0–5.1)), and diabetes, p = 0.050 (HR 2.4 (1.0–6.0)).

Conclusions

Multiple hormone secretion, high morning cortisol, higher tumor grade, and diabetes were correlated with shorter OS. Development of ECS in patients with a non-functioning NEN may indicate tumor progression. Multiple hormone secretion should be considered as a bad prognostic sign in ECS patients and should lead to intensified clinical management.
Automated Vehicle Handover Interface Design: Focus Groups with Learner, Intermediate and Advanced Drivers
Authors: Clark Jediah R. , Stanton Neville A. , Revell Kirsten M. A.
Published: January 2020

Conditionally and highly automated vehicles will require drivers to take control as a result of a non-emergency, such as a geographical, terrain, capability or design boundary. It is anticipated that these events will provide the driver with a sufficient amount of time to prepare themselves for the transition of control. This study explores conditionally and highly automated vehicle transitions of control by asking how drivers of differing skill levels (learner, intermediate and advanced) approach the task of designing an interface responsible for making transitions safer, more usable and more efficient. Three focus groups generated detailed designs for vehicle-to-driver transitions in an 1-h and a 10-min “out-of-the-loop” scenarios and transitions from driver to vehicle. Results show great variation in the approaches taken by each skill group (e.g., the reliance on visual interfaces for awareness assist and viewpoints on issues such as multimodal displays). Customization was a common theme throughout, with drivers desiring the option to adjust alert timings and modalities in which information is displayed. This paper presents these designs along with a detailed comparison of group designs and implements distributed situation awareness theory to discuss findings and draw conclusions.
A counterexample to the Liouville property of some nonlocal problems
Authors: Brasseur Julien , Coville Jérôme
Published: January 2020

In this paper, we construct a counterexample to the Liouville property of some nonlocal reaction-diffusion equations of the form

\int \limits_{\mathbb{R}^{N} \setminus K}J(x−y)\:(u(y)−u(x))\mathrm{d}y + f(u(x)) = 0,\:x \in \mathbb{R}^{N} \setminus K,

where

K \subset \mathbb{R}^{N}

is a bounded compact set, called an “obstacle”, and

f

is a bistable nonlinearity. When

K

is convex, it is known that solutions ranging in

[0,1]

and satisfying

u(x)\rightarrow 1

as

|x|\rightarrow \infty

must be identically 1 in the whole space. We construct a nontrivial family of simply connected (non-starshaped) obstacles as well as data

f

and

J

for which this property fails.
COMPACT WEIGHTED COMPOSITION OPERATORS BETWEEN -SPACES
Authors: LO CHING-ON , LOH ANTHONY WAI-KEUNG
Published: January 2020

We provide complete characterisations for the compactness of weighted composition operators between two distinct $L^{p}$-spaces, where $1\leq p\leq \infty$. As a corollary, when the underlying measure space is nonatomic, the only compact weighted composition map between $L^{p}$-spaces is the zero operator.
OVERPARTITIONS RELATED TO THE MOCK THETA FUNCTION
Authors: LIN BERNARD L. S.
Published: January 2020

Recently, Brietzke, Silva and Sellers [‘Congruences related to an eighth order mock theta function of Gordon and McIntosh’, J. Math. Anal. Appl.479 (2019), 62–89] studied the number $v_{0}(n)$ of overpartitions of $n$ into odd parts without gaps between the nonoverlined parts, whose generating function is related to the mock theta function $V_{0}(q)$ of order 8. In this paper we first present a short proof of the 3-dissection for the generating function of $v_{0}(2n)$. Then we establish three congruences for $v_{0}(n)$ along certain progressions which are subsequences of the integers $4n+3$.
INEQUALITIES FOR DRAGOMIR’S MAPPINGS VIA STIELTJES INTEGRALS
Authors: SZOSTOK TOMASZ
Published: January 2020

We present some inequalities for the mappings defined by Dragomir [‘Two mappings in connection to Hadamard’s inequalities’, J. Math. Anal. Appl.167 (1992), 49–56]. We analyse known inequalities connected with these mappings using a recently developed method connected with stochastic orderings and Stieltjes integrals. We show that some of these results are optimal and others may be substantially improved.
Evaluation of role of concentration and molecular weight of oat β-glucan
in determining effect of viscosity on plasma glucose and insulin following
an oral glucose load
Authors: Wood P. J. , Beer M. U. , Butler G.
Published: January 2020

Data from clinical studies established that there was an inverse linear
relationship between measures of postprandial blood glucose and insulin
responses to an oral glucose load, consumed in a drink, and the logarithm of
viscosity of the drink. These data have been re-analysed using concentration
and molecular weight as the dependent variables. Molecular weight (M) of the
β-glucans used was determined using high-performance size exclusion
chromatography equipped with a triple detector system of right angle light
scattering, viscometry and refractive index. A significant relationship
between changes in peak blood glucose and a combination of logarithm of the
concentration and logarithm of M was found.
Disrupted upregulation of salience network connectivity during acute stress in siblings of schizophrenia patients
Authors: van Leeuwen Judith M. C. , Vinkers Christiaan H. , Vink Matthijs , Kahn René S. , Joëls Marian , Hermans Erno J.
Published: January 2020

Background

An adaptive neural stress response is essential to adequately cope with a changing environment. It was previously argued that sympathetic/noradrenergic activity during acute stress increases salience network (SN) connectivity and reduces executive control network (ECN) connectivity in healthy controls, with opposing effects in the late aftermath of stress. Altered temporal dynamics of these networks in response to stress are thought to play a role in the development of psychopathology in vulnerable individuals.

Methods

We exposed male healthy controls (n = 40, mean age = 33.9) and unaffected siblings of schizophrenia patients (n = 39, mean age = 33.2) to the stress or control condition of the trier social stress test and subsequently investigated resting state functional connectivity of the SN and ECN directly after and 1.5 h after stress.

Results

Acute stress resulted in increased functional connectivity within the SN in healthy controls, but not in siblings (group × stress interaction pfwe < 0.05). In the late aftermath of stress, stress reduced functional connectivity within the SN in both groups. Moreover, we found increased functional connectivity between the ECN and the cerebellum in the aftermath of stress in both healthy controls and siblings of schizophrenia patients.

Conclusions

The results show profound differences between siblings of schizophrenia patients and controls during acute stress. Siblings lacked the upregulation of neural resources necessary to quickly and adequately cope with a stressor. This points to a reduced dynamic range in the sympathetic response, and may constitute a vulnerability factor for the development of psychopathology in this at-risk group.
Modeling and Analysis of the Multiple Dynamic Coupling Effects of a Dual-arm Space Robotic System
Authors: Peng Jianqing , Xu Wenfu , Hu Zhonghua , Liang Bin , Wu Aiguo
Published: January 2020

A dual-arm space robot has large potentials in on-orbit servicing. However, there exist multiple dynamic coupling effects between the two arms, each arm, and the base, bringing great challenges to the trajectory planning and dynamic control of the dual-arm space robotic system. In this paper, we propose a dynamic coupling modeling and analysis method for a dual-arm space robot. Firstly, according to the conservation principle of the linear and angular momentum, the dynamic coupling between the base and each manipulator is deduced. The dynamic coupling factor is then defined to evaluate the dynamic coupling degree. Secondly, the dynamic coupling equations between the two arms, each arm, and the base are deduced, respectively. The dynamic coupling factor is suitable not only for single-arm space robots but also for multi-arm space robot systems. Finally, the multiple coupling effects of the dual-arm space robotic system are analyzed in detail through typical cases. Simulation results verified the proposed method.
Mobile-mediated dynamic assessment: A new perspective for second language development
Authors: Andujar Alberto
Published: January 2020

The present investigation analyses the potential of a pedagogical dynamic assessment (DA) approach to foster second language (L2) development through the use of a mobile instant messaging application. Students’ zone of actual and proximal development is observed through the use of a grammar and vocabulary level test and the use of the WhatsApp application respectively. Sixty students taking a B1 English course at the language centre of a Spanish university were studied. A mixed methods methodology was used to analyse the differences between two pre-existing groups (control and experimental), each consisting of 30 participants. Both groups received the same tuition and content, and students in the experimental group participated in a daily conversation in the application during a five-month period where negative feedback was provided by the teacher through the use of an inventory of prompts, from most implicit to most explicit. Throughout the research, pedagogical mobile-mediated DA became a central part of the students’ learning process, extending learning beyond the in-class time and becoming a constant source of L2 input and feedback. Moreover, results indicated that DA and dialogic mediation helped students reflect on their language performance, gradually requiring less explicit feedback and metalinguistic explanations.
Coenzyme Q10 administration has no effect on sICAM-1 and metabolic	parameters of pediatrics with type 1 diabetes mellitus
Authors: Serag Heba , El Wakeel Lamia , Adly Amira
Published: January 2020

Abstract. Background: Endothelial dysfunction (ED) plays a key role in the development and progression of microvascular and macrovascular complications in pediatrics with type 1 diabetes mellitus (T1DM). Coenzyme Q10 (CoQ10) is a nutraceutical with a known anti-inflammatory and anti-oxidant activity. This study was conducted to evaluate the potential effect of CoQ10 on ED and various metabolic parameters. Methods: This prospective randomized open-label pilot study was conducted on 49 T1DM pediatric patients. Seven healthy non-diabetic pediatric subjects who didn’t receive treatment were included as a control group. Eligible patients were randomly allocated into either group I (n = 25); received 100 mg of CoQ10 in addition to standard treatment or group II (n = 24); received standard treatment only. The levels of; soluble intracellular adhesion molecule-1 (sICAM-1), glycated hemoglobin (HbA1c), fasting blood glucose (FBG), lipid profile, serum creatinine and liver function tests were assessed for both groups at baseline and after 3 months of treatment. Results: At baseline, compared to an age-matched healthy control group sICAM-1 levels were significantly elevated in group II diabetic patients (276.5 (231.6–320.66) vs 221.8 (177.9–267.1 ng/ml), p = 0.042. After 3 months of treatment no significant difference was observed in sICAM-1, HbA1c, FBG, lipid profile, serum creatinine and liver function tests between the two study groups. A positive correlation was found between sICAM-1 and HbA1c throughout the study (r = 0.308, p = 0.0054). Conclusion: Administration of CoQ10 for 3 months in T1DM pediatric patients was well tolerated but had no favorable effect on ED or metabolic parameters.
Richard Mansergh Thorne (1942–2019)
Authors: Horne Richard , Tsurutani Bruce
Published: January 2020

A pioneering space plasma physicist who led the way in understanding how complex wave-particle interactions control Earth’s radiation belts and low-level auroral light emissions.
Scientists and Activists Examine Need for Climate Action
Authors: Showstack Randy
Published: January 2020

Scientists shouldn’t have to apologize for being advocates “for a fact-based, objective discourse over what is arguably the greatest threat that we face as a civilization.”
Ancient Assyrian Aurorae Help Astronomers Understand Solar Activity
Authors: Johnson-Groh Mara
Published: January 2020

Records of aurorae in Mesopotamia from 2,600 years ago are helping astronomers understand and predict solar activity today.
Hydromechanical Modeling of Fault Reactivation in the St. Gallen Deep Geothermal Project (Switzerland): Poroelasticity or Hydraulic Connection?
Authors: Zbinden Dominik , Rinaldi Antonio P. , Diehl Tobias , Wiemer Stefan
Published: January 2020

In 2013, fluid injection during the St. Gallen deep geothermal project, Switzerland, induced hundreds of seismic events, including a
 3.5 earthquake on a fault hundreds of meters away from the well. Recent studies have suggested the direct pressure effect through permeable hydraulic connections and poroelastic effects as possible mechanisms for inducing seismicity on distant faults. In St. Gallen, operational, seismic, and earthquake data are available to investigate the underlying physical mechanisms using a numerical model. The results show that Coulomb stress changes at the fault can be 3 orders of magnitude greater when a hydraulic connection is present. Combining this with several field observations, we conclude that the direct pressure effect was more likely the predominant mechanism behind the seismicity induced in St. Gallen. The detection of hydraulic connections may be important for future projects as pressure can be driven far from the well and reactivate remote faults.
Causes and Climatic Consequences of the Impact Winter at the Cretaceous‐Paleogene Boundary
Authors: Tabor Clay R. , Bardeen Charles G. , Otto‐Bliesner Bette L. , Garcia Rolando R. , Toon Owen B.
Published: January 2020

Prolonged periods of low light and cold temperatures at Earth's surface are hypothesized effects of the end‐Cretaceous asteroid impact. However, debate remains about the causes and consequences of this “impact winter.” We perform simulations of the Chicxulub impact with an Earth system model that can simulate the evolution of extreme aerosol loading to quantify the climatic responses to emissions (soot, sulfur, and dust) associated with the impact winter. We show that all impact winter emissions can drastically reduce surface temperature and precipitation. However, only soot emission from impact‐driven firestorms is capable of reducing light to below the photosynthetic threshold for many months. Therefore, our results suggest that widespread fires may have been necessary to produce the observed pattern of marine extinction across the Cretaceous‐Paleogene boundary. We identify polar coasts and the surrounding open oceans as regions likely to have experienced the least climatic, and biotic, disruption from the impact winter.
Rapid Export of Waters Formed by Convection Near the Irminger Sea's Western Boundary
Authors: Le Bras I. A.‐A. , Straneo F. , Holte J. , de Jong M. F. , Holliday N. P.
Published: January 2020

The standard view of the overturning circulation emphasizes the role of convection, yet for waters to contribute to overturning, they must not only be transformed to higher densities but also exported equatorward. From novel mooring observations in the Irminger Sea (2014–2016), we describe two water masses that are formed by convection and show that they have different rates of export in the western boundary current. Upper Irminger Sea Intermediate Water appears to form near the boundary current and is exported rapidly within 3 months of its formation. Deep Irminger Sea Intermediate Water forms in the basin interior and is exported on longer time scales. The subduction of these waters into the boundary current is consistent with an eddy transport mechanism. Our results suggest that light intermediate waters can contribute to overturning as much as waters formed by deeper convection and that the export time scales of both project onto overturning variability.
Underestimated Change of Wet‐Bulb Temperatures Over East and South China
Authors: Freychet N. , Tett S.F.B. , Yan Z. , Li Z.
Published: January 2020

Wet‐bulb temperature (TW), which combines dry‐bulb temperature and relative humidity (RH), is a key variable for human health and heat stress because in hot environments evaporation is the main process by which bodies cool down. For this study, we use two independent RH data sets: a new homogenized network of daily ground observations in China and the recent ERA5 reanalysis, for which we highlight the need to apply humidity correction. Based on these data sets, we show that Chinese wet‐bulb temperatures since 1980 have increased largely due to a rise in dry‐bulb temperatures while RH has remained approximately constant. We also find that TW change has been previously underestimated due to humidity bias in reanalysis and nonhomogenized observation where RH was decreasing sharply after 2000s, greatly limiting changes in TW.
Glacial Earthquakes and Precursory Seismicity Associated With Thwaites Glacier Calving
Authors: Winberry J. Paul , Huerta Audrey D. , Anandakrishnan Sridhar , Aster Richard C. , Nyblade Andrew A. , Wiens Douglas A.
Published: January 2020

We observe two (~MS3) long‐period (10–30 s) seismic events that originate from the terminus of Thwaites Glacier, Antarctica. Serendipitous acquisition of satellite images confirm that the seismic events were glacial earthquakes generated during the capsizing of icebergs. The glacial earthquakes were preceded by 6 days of discrete high‐frequency seismic events that can be observed at distances exceeding 250 km. The high‐frequency seismicity displays an increasing rate of occurrence, culminating in several hours of sustained tremor coeval with the long‐period events. A series of satellite images collected during this precursory time period show that the high‐frequency events and tremor are the result of accelerating growth of ancillary fractures prior to the culminating calving event. This study indicates that seismic data have the potential to elucidate the processes by which Thwaites Glacier discharges into the ocean, thus improving our ability to constrain future sea level rise.
Two Decades of Ocean Acidification in the Surface Waters of the Beaufort Gyre, Arctic Ocean: Effects of Sea Ice Melt and Retreat From 1997–2016
Authors: Zhang Y. , Yamamoto‐Kawai M. , Williams W.J.
Published: January 2020

Anthropogenic CO2 uptake drives ocean acidification and so decreases the calcium carbonate (CaCO3) saturation state (Ω). Undersaturation of surface water with respect to aragonite‐type CaCO3 was first reported for 2008 in the Canada Basin, preceding other open ocean basins. This study reveals interannual variation of Ω in the surface Canada Basin before and after 2008. A rapid decrease of Ω occurred during 2003–2007 at a rate of −0.09 year−1, 10 times faster than other open oceans. This was due to melting and retreat of sea ice, which diluted surface water and enhanced air‐sea CO2 exchange. After 2007, Ω did not further decrease, despite increasing atmospheric CO2 and continued sea ice retreat. A weakened dilution effect from sea ice melt and stabilized air‐sea CO2 disequilibrium state is the main reason for this stabilization of Ω. Aragonite undersaturation has been observed for the last 11 years, and aragonite‐shelled organisms may be threatened.
Modeling the Posteruptive Deformation at Okmok Based on the GPS and InSAR Time Series: Changes in the Shallow Magma Storage System
Authors: Xue Xueming , Freymueller Jeff , Lu Zhong
Published: January 2020

Based on the unscented Kalman filter, we develop a time‐dependent inversion filter combining Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) time series observations for modeling volcano deformation. We use the Variance Component Estimation method as means to assign the relative weights for GPS and InSAR data. Then we use the inversion filter to model the posteruptive deformation at Okmok volcano, Alaska. We find that a Mogi source at 3–4 km depth fits the InSAR data well, while the best fit to the GPS data is an oblate spheroid source at about 2.5 km depth. Our final model consists of a shallow sill at ~0.9 km and a Mogi source at ~3.2 km depth, which well fit both the GPS and InSAR data simultaneously. We think the Mogi source obtained here is the same source account for the preeruptive deformation. The shallow sill is a new structure that was not seen before the 2008 eruption. From 2008 to 2019, we have observed five inflation episodes, each of which decays exponential in time. We find that the characteristic timescale of those inflation episodes decreases with respect to time. The total volume change from the two sources is 0.068 km3, which recovers 50–60% of the volume decrease during the 2008 eruption.
Recent Advances and Challenges of Waveform‐Based Seismic Location Methods at Multiple Scales
Authors: Li Lei , Tan Jingqiang , Schwarz Benjamin , Staněk František , Poiata Natalia , Shi Peidong , Diekmann Leon , Eisner Leo , Gajewski Dirk
Published: January 2020

Source locations provide fundamental information on earthquakes and lay the foundation for seismic monitoring at all scales. Seismic source location as a classical inverse problem has experienced significant methodological progress during the past century. Unlike the conventional traveltime‐based location methods that mainly utilize kinematic information, a new category of waveform‐based methods, including partial waveform stacking, time reverse imaging, wavefront tomography, and full waveform inversion, adapted from migration or stacking techniques in exploration seismology has emerged. Waveform‐based methods have shown promising results in characterizing weak seismic events at multiple scales, especially for abundant microearthquakes induced by hydraulic fracturing in unconventional and geothermal reservoirs or foreshock and aftershock activity potentially preceding tectonic earthquakes. This review presents a comprehensive summary of the current status of waveform‐based location methods, through elaboration of the methodological principles, categorization, and connections, as well as illustration of the applications to natural and induced/triggered seismicity, ranging from laboratory acoustic emission to field hydraulic fracturing‐induced seismicity, regional tectonic, and volcanic earthquakes. Taking into account recent developments in instrumentation and the increasing availability of more powerful computational resources, we highlight recent accomplishments and prevailing challenges of different waveform‐based location methods and what they promise to offer in the near future.
Fault Dips Figured in Kīlauea’s Caldera Collapse
Authors: Shultz David
Published: January 2020

Large-volume volcanic eruptions can create instabilities in the ground above magma chambers, leading to massive collapses and telltale calderas.
Observational Data Validate Models of Sun’s Influence on Earth
Authors: Shultz David
Published: January 2020

Using a combination of independent models and observations over multiple timescales, scientists verify two important models that gauge the amount of solar radiation Earth receives.
Integrating Input to Forge Ahead in Geothermal Research
Authors: Rozansky Robert , McKittrick Alexis
Published: January 2020

A road map for a major geothermal energy development initiative determines proposed priorities and goals by integrating input from stakeholders, data, and technological assessments.
The Ice Giant Spacecraft of Our Dreams
Authors: Cartier Kimberly
Published: January 2020

Scientists imagined some innovative technologies that could enhance a future mission to Uranus or Neptune.
Rolling Rocks Reveal Recent Moonquakes
Authors: Lee Jack
Published: January 2020

Using satellite images of the lunar surface, scientists find trails left by boulders shaken loose by seismic activity.
Binocular Astronomy
Authors: Dickinson Dave
Published: January 2020

Explore the night sky with your own two eyes and a touch of magnification.
Amazon Fires Contribute to Andean Glacier Melting
Authors: Allen Michael
Published: January 2020

New research finds that black carbon emissions produced by fires in the Amazon cause glaciers in the Andes to absorb more sunlight and melt more.
Barbara Romanowicz Receives 2019 William Bowie Medal
Authors:   AGU
Published: January 2020

Barbara Romanowicz was awarded the 2019 William Bowie Medal at AGU’s Fall Meeting 2020 Honors Ceremony, held on 11 December 2019 in San Francisco, Calif. The medal is for “outstanding contributions for fundamental geophysics and for unselfish cooperation in research.”
Forests Respond to Volcanic Emissions
Authors: Petersen Kate
Published: January 2020

Researchers propose using volcanoes to study forests and forests to study volcanoes.
Long non-coding RNA DLGAP1-AS1 facilitates tumorigenesis and epithelial–mesenchymal transition in hepatocellular carcinoma via the feedback loop of miR-26a/b-5p/IL-6/JAK2/STAT3 and Wnt/β-catenin pathway
Authors: Lin Ye , Jian Zhixiang , Jin Haosheng , Wei Xiangling , Zou Xiongfeng , Guan Renguo , Huang Jianfeng
Published: January 2020

Hepatocellular carcinoma (HCC) is one of the most common and lethal malignancies worldwide, and epithelial–mesenchymal transition (EMT) is a crucial factor affecting HCC progression and metastasis. Long noncoding RNAs (lncRNAs) have been validated to act as critical regulators of biological processes in various tumors. Herein, we attempted to elucidate the uncharacterized function and mechanism of lncRNA DLGAP1-AS1 in regulating tumorigenesis and EMT of HCC. In our study, DLGAP1-AS1 was shown to be upregulated in HCC cell lines and capable to promote HCC progression and EMT. Besides, DLGAP1-AS1 was proven to serve as a molecular sponge to sequester the HCC-inhibitory miRNAs, miR-26a-5p and miR-26b-5p, thus enhancing the level of an oncogenic cytokine IL-6, which could activate JAK2/STAT3 signaling pathway and reciprocally elevate the transcriptional activity of DLGAP1-AS1, thus forming a positive feedback loop. Moreover, we elaborated that the cancerogenic effects of DLGAP1-AS1 in HCC cells could be effectuated via activating Wnt/β-catenin pathway by positively regulating CDK8 and LRP6, downstream genes of miR-26a/b-5p. In conclusion, our results demonstrated the detailed molecular mechanism of DLGAP1-AS1 in facilitating HCC progression and EMT in vitro and in vivo, and suggested the potentiality of DLGAP1-AS1 as a therapeutic target for HCC.
Targeting alkaline ceramidase 3 alleviates the severity of nonalcoholic steatohepatitis by reducing oxidative stress
Authors: Wang Kai , Li Chuanjiang , Lin Xinxin , Sun Hang , Xu Ruijuan , Li Qingping , Wei Yiran , Li Yiyi , Qian Jianping , Liu Cuiting , Zhang Qifan , Yu Sheng , Cui Zhonglin , Huang Xixin , Zhu Bili , Zhou Jie , Mao Cungui
Published: January 2020

Overload of palmitic acids is linked to the dysregulation of ceramide metabolism in nonalcoholic steatohepatitis (NASH), and ceramides are important bioactive lipids mediating the lipotoxicity of palmitic acid in NASH. However, much remains unclear about the role of ceramidases that catalyze the hydrolysis of ceramides in NASH. By analyzing the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) database, we found that alkaline ceramidase 3 (ACER3) is upregulated in livers of patients with NASH. Consistently, we found that Acer3 mRNA levels and its enzymatic activity were also upregulated in mouse livers with NASH induced by a palmitate-enriched Western diet (PEWD). Moreover, we demonstrated that palmitate treatment also elevated Acer3 mRNA levels and its enzymatic activity in mouse primary hepatocytes. In order to investigate the function of Acer3 in NASH, Acer3 null mice and their wild-type littermates were fed a PEWD to induce NASH. Knocking out Acer3 was found to augment PEWD-induced elevation of C18:1-ceramide and alleviate early inflammation and fibrosis but not steatosis in mouse livers with NASH. In addition, Acer3 deficiency attenuated hepatocyte apoptosis in livers with NASH. These protective effects of Acer3 deficiency were found to be associated with suppression of hepatocellular oxidative stress in NASH liver. In vitro studies further revealed that loss of ACER3/Acer3 increased C18:1-ceramide and inhibited apoptosis and oxidative stress in mouse primary hepatocytes and immortalized human hepatocytes induced by palmitic-acid treatment. These results suggest that ACER3 plays an important pathological role in NASH by mediating palmitic-acid-induced oxidative stress.
A Wnt-mediated transformation of the bone marrow stromal cell identity orchestrates skeletal regeneration
Authors: Matsushita Yuki , Nagata Mizuki , Kozloff Kenneth M. , Welch Joshua D. , Mizuhashi Koji , Tokavanich Nicha , Hallett Shawn A. , Link Daniel C. , Nagasawa Takashi , Ono Wanida , Ono Noriaki
Published: January 2020

Bone marrow stromal cells (BMSCs) are versatile mesenchymal cell populations underpinning the major functions of the skeleton, a majority of which adjoin sinusoidal blood vessels and express C-X-C motif chemokine ligand 12 (CXCL12). However, how these cells are activated during regeneration and facilitate osteogenesis remains largely unknown. Cell-lineage analysis using Cxcl12-creER mice reveals that quiescent Cxcl12-creER+ perisinusoidal BMSCs differentiate into cortical bone osteoblasts solely during regeneration. A combined single cell RNA-seq analysis demonstrate that these cells convert their identity into a skeletal stem cell-like state in response to injury, associated with upregulation of osteoblast-signature genes and activation of canonical Wnt signaling components along the single-cell trajectory. β-catenin deficiency in these cells indeed causes insufficiency in cortical bone regeneration. Therefore, quiescent Cxcl12-creER+ BMSCs transform into osteoblast precursor cells in a manner mediated by canonical Wnt signaling, highlighting a unique mechanism by which dormant stromal cells are enlisted for skeletal regeneration.
Cooperative excitonic quantum ensemble in perovskite-assembly superlattice microcavities
Authors: Zhou Chun , Zhong Yichi , Dong Hongxing , Zheng Weihao , Tan Jiqing , Jie Qi , Pan Anlian , Zhang Long , Xie Wei
Published: January 2020

Perovskites—compounds with the CaTiO3-type crystal structure—show outstanding performance in photovoltaics and multiparameter optical emitters due to their large oscillator strength, strong solar absorption, and excellent charge-transport properties. However, the ability to realize and control many-body quantum states in perovskites, which would extend their application from classical optoelectronic materials to ultrafast quantum operation, remains an open research topic. Here, we generate a cooperative quantum state of excitons in a quantum dot ensemble based on a lead halide perovskite, and we control the ultrafast radiation of excitonic quantum ensembles by introducing optical microcavites. The stimulated radiation of excitonic quantum ensemble in a superlattice microcavity is demonstrated to not be limited by the classical population-inversion condition, leading to a picosecond radiative duration time to dissipate all of the in-phase dipoles. Such a perovskite-assembly superlattice microcavity with a tunable radiation rate promises potential applications in ultrafast, photoelectric-compatible quantum processors.
The epichaperome is a mediator of toxic hippocampal stress and leads to protein connectivity-based dysfunction
Authors: Inda Maria Carmen , Joshi Suhasini , Wang Tai , Bolaender Alexander , Gandu Srinivasa , Koren III John , Che Alicia Yue , Taldone Tony , Yan Pengrong , Sun Weilin , Uddin Mohammad , Panchal Palak , Riolo Matthew , Shah Smit , Barlas Afsar , Xu Ke , Chan Lon Yin L. , Gruzinova Alexandra , Kishinevsky Sarah , Studer Lorenz , Fossati Valentina , Noggle Scott A. , White Julie R. , de Stanchina Elisa , Sequeira Sonia , Anthoney Kyle H. , Steele John W. , Manova-Todorova Katia , Patil Sujata , Dunphy Mark P. , Pillarsetty NagaVaraKishore , Pereira Ana C. , Erdjument-Bromage Hediye , Neubert Thomas A. , Rodina Anna , Ginsberg Stephen D. , De Marco Garcia Natalia , Luo Wenjie , Chiosis Gabriela
Published: January 2020

Optimal functioning of neuronal networks is critical to the complex cognitive processes of memory and executive function that deteriorate in Alzheimer’s disease (AD). Here we use cellular and animal models as well as human biospecimens to show that AD-related stressors mediate global disturbances in dynamic intra- and inter-neuronal networks through pathologic rewiring of the chaperome system into epichaperomes. These structures provide the backbone upon which proteome-wide connectivity, and in turn, protein networks become disturbed and ultimately dysfunctional. We introduce the term protein connectivity-based dysfunction (PCBD) to define this mechanism. Among most sensitive to PCBD are pathways with key roles in synaptic plasticity. We show at cellular and target organ levels that network connectivity and functional imbalances revert to normal levels upon epichaperome inhibition. In conclusion, we provide proof-of-principle to propose AD is a PCBDopathy, a disease of proteome-wide connectivity defects mediated by maladaptive epichaperomes.
Genomic programming of IRF4-expressing human Langerhans cells
Authors: Sirvent Sofia , Vallejo Andres F. , Davies James , Clayton Kalum , Wu Zhiguo , Woo Jeongmin , Riddell Jeremy , Chaudhri Virendra K. , Stumpf Patrick , Nazlamova Liliya Angelova , Wheway Gabrielle , Rose-Zerilli Matthew , West Jonathan , Pujato Mario , Chen Xiaoting , Woelk Christopher H. , MacArthur Ben , Ardern-Jones Michael , Friedmann Peter S. , Weirauch Matthew T. , Singh Harinder , Polak Marta E.
Published: January 2020

Langerhans cells (LC) can prime tolerogenic as well as immunogenic responses in skin, but the genomic states and transcription factors (TF) regulating these context-specific responses are unclear. Bulk and single-cell transcriptional profiling demonstrates that human migratory LCs are robustly programmed for MHC-I and MHC-II antigen presentation. Chromatin analysis reveals enrichment of ETS-IRF and AP1-IRF composite regulatory elements in antigen-presentation genes, coinciding with expression of the TFs, PU.1, IRF4 and BATF3 but not IRF8. Migration of LCs from the epidermis is accompanied by upregulation of IRF4, antigen processing components and co-stimulatory molecules. TNF stimulation augments LC cross-presentation while attenuating IRF4 expression. CRISPR-mediated editing reveals IRF4 to positively regulate the LC activation programme, but repress NF2EL2 and NF-kB pathway genes that promote responsiveness to oxidative stress and inflammatory cytokines. Thus, IRF4-dependent genomic programming of human migratory LCs appears to enable LC maturation while attenuating excessive inflammatory and immunogenic responses in the epidermis.
Neural circuits underlying auditory contrast gain control and their perceptual implications
Authors: Lohse Michael , Bajo Victoria M. , King Andrew J. , Willmore Ben D. B.
Published: January 2020

Neural adaptation enables sensory information to be represented optimally in the brain despite large fluctuations over time in the statistics of the environment. Auditory contrast gain control represents an important example, which is thought to arise primarily from cortical processing. Here we show that neurons in the auditory thalamus and midbrain of mice show robust contrast gain control, and that this is implemented independently of cortical activity. Although neurons at each level exhibit contrast gain control to similar degrees, adaptation time constants become longer at later stages of the processing hierarchy, resulting in progressively more stable representations. We also show that auditory discrimination thresholds in human listeners compensate for changes in contrast, and that the strength of this perceptual adaptation can be predicted from physiological measurements. Contrast adaptation is therefore a robust property of both the subcortical and cortical auditory system and accounts for the short-term adaptability of perceptual judgments.