bluuebunny/crossref_metadata_2025 huggingface dataset:
Rights Metaphors Across Hybrid Legal Languages, Such as Euro English and Legal Chinese
Authors: Mannoni Michele
Published: April 2021

This paper focuses on two legal languages such as the legal English developed by the European Union institutions (Euro English) and the legal Chinese of Mainland China, to study whether the mental representations and the embodied simulation created by the conceptual metaphors for the same Western concept,right, differ in any significant ways. By analysing the data contained in two large corpora, this study has found that, despite the common origin of the conceptrightin the two legal languages, they conceptualise it in a significantly different fashion. Finally, the findings of this study are read through the theoretical framework proposed for this special issue—hybridity and the Third Space. While it is somewhat straightforward to conceive of Euro English as a hybrid language, owing to the multilingual and supranational setting where it is used, this study has found that the Chinese legal language, too, is a hybrid language exhibiting linguistic features that intersect different belief systems.
Ten steps to 4C/ID: training differentiation skills in a professional development program for teachers
Authors: Frerejean Jimmy , van Geel Marieke , Keuning Trynke , Dolmans Diana , van Merriënboer Jeroen J. G. , Visscher Adrie J.
Published: April 2021

This paper describes how an interdisciplinary design team used the Four-Component Instructional Design (4C/ID) model and its accompanying Ten Steps design approach to systematically design a professional development program for teaching differentiation skills to primary school teachers. This description illustrates how insights from a cognitive task analysis into classroom differentiation skills were combined with literature-based instructional design principles to arrive at the training blueprint for workplace-based learning. It demonstrates the decision-making processes involved in the systematic design of each of the four components: learning tasks, supportive information, procedural information, and part-task practice. While the design process was time and resource-intensive, it resulted in a detailed blueprint of a five-month professional development program that strategically combines learning activities to stimulate learning processes that are essential for developing the complex skillproviding differentiated instruction in a mathematics lesson.
Cultural transposition of a thinking classroom: to conceive possible unthoughts in mathematical problem solving activity
Authors: Mellone Maria , Pacelli Tiziana , Liljedahl Peter
Published: April 2021

This study concerns a professional development course designed and implemented for prospective teachers, centred on a teaching method regarding problem-solving activity, namely, the Thinking Classroom. The study is framed in the theory of cultural transposition, a perspective about the encounter with teaching practices from different cultural/school contexts. Cultural aspects are considered crucial and this encounter between cultures is seen as an opportunity for actors to become aware of their own unthoughts, i.e., some of the ‘invisible’ cultural beliefs about teaching and learning absorbed by their own culture. According to this framework, we present the results from a questionnaire given to all the participants, and two case studies of prospective teachers involved in the professional development, in order to discuss the kind of unthoughts on which they have focused in thinking about this training experience.
Eye contact effect: The role of vagal regulation and reactivity, and self-regulation of attention
Authors: Niedźwiecka Alicja
Published: April 2021

Eye contact is a crucial aspect of social interactions that may enhance an individual’s cognitive performance (i.e. the eye contact effect) or hinder it (i.e. face-to-face interference effect). In this paper, I focus on the influence of eye contact on cognitive performance in tasks engaging executive functions. I present a hypothesis as to why some individuals benefit from eye contact while others do not. I propose that the relations between eye contact and executive functioning are modulated by an individual’s autonomic regulation and reactivity and self-regulation of attention. In particular, I propose that individuals with more optimal autonomic regulation and reactivity, and more effective self-regulation of attention benefit from eye contact. Individuals who are less well regulated and over- or under-reactive and who do not employ effective strategies of self-regulation of attention may not benefit from eye contact and may perform better when eye contact is absent. I present some studies that justify the proposed hypothesis and point to a method that could be employed to test them. This approach could help to better understand the complex mechanisms underlying the individual differences in participant’s cognitive performance during tasks engaging executive functions.
Meta-analysis of nanoparticle albumin-bound paclitaxel used as neoadjuvant chemotherapy for operable breast cancer based on individual patient data (JBCRG-S01 study)
Authors: Futamura Manabu , Oba Mari , Masuda Norikazu , Bando Hiroko , Okada Morihito , Yamamoto Yutaka , Kin Takanori , Saeki Toshiaki , Nagashima Takeshi , Kuwayama Takashi , Toh Uhi , Hirano Akira , Inokuchi Masafumi , Yamagami Kazuhiko , Mizuno Yutaka , Kojima Yasuyuki , Nakayama Takahiro , Yasojima Hiroyuki , Ohno Shinji
Published: April 2021

Background

Nanoparticle albumin-bound paclitaxel (nab-PTX), a novel taxane formulation, was developed to avoid cremophor/ethanol-associated toxicities including peripheral neuropathy and hypersensitivity. At least 35 phase II studies using combined nab-PTX and anthracycline in neoadjuvant settings are registered in Japan. We analyzed the efficacy and safety of nab-PTX based on patient characteristics in these studies.

Methods

We conducted a meta-analysis using individual patient data (IPD) to investigate the average efficacy of nab-PTX-containing regimens as neoadjuvant chemotherapy for operable breast cancer. IPD were provided by principal investigators who agreed to participate. The primary endpoint was pathological complete response (pCR) rate of each breast cancer subtype.

Results

We analyzed the data of 16 studies involving 753 patients. The overall crude frequencies of pCR (ypT0 ypN0, ypT0/is ypN0, and ypT0/is ypNX) were 18.1, 26.0, and 28.6%, respectively. Specifically, the frequencies were 6.7, 10.2, and 13.4% for luminal (n = 343); 40.5, 63.5, and 68.9% for human epidermal growth factor receptor 2 (HER2)-rich, (n = 74); 21.9, 40.6, and 42.7% for luminal/HER2 (n = 96); and 26.3, 31.5, and 32.3% for triple-negative breast cancers (TNBC) (n = 232). The multivariate analyses indicated that HER2 positivity, TNBC, high Ki-67, high nuclear grade, and weekly nab-PTX administration were significantly associated with the pCR. The proportion of hematological toxicities (neutropenia (39.7%) and leukopenia (22.5%)), peripheral sensory neuropathy (9.7%), myalgia (5.7%), and arthralgia (4.7%) was higher than grade 3 adverse events, but most patients recovered.

Conclusions

Nab-PTX is a safe and acceptable chemotherapeutic agent in neoadjuvant settings, particularly for aggressive cancers. UMIN-CTR#: UMIN000028774
Laparoscopic versus open distal pancreatectomy: a single centre propensity score matching analysis
Authors: Casadei Riccardo , Ingaldi Carlo , Ricci Claudio , Alberici Laura , De Raffele Emilio , Vaccaro Maria Chiara , Minni Francesco
Published: April 2021

The laparoscopic approach is considered as standard practice in patients with body-tail pancreatic neoplasms. However, only a few randomized controlled trials (RCTs) and propensity score matching (PSM) studies have been performed. Thus, additional studies are needed to obtain more robust evidence. This is a single-centre propensity score-matched study including patients who underwent laparoscopic (LDP) and open distal pancreatectomy (ODP) with splenectomy for pancreatic neoplasms. Demographic, intra, postoperative and oncological data were collected. The primary endpoint was the length of hospital stay. The secondary endpoints included the assessment of the operative findings, postoperative outcomes, oncological outcomes (only in the subset of patients with pancreatic ductal adenocarcinoma-PDAC) and total costs. In total, 205 patients were analysed: 105 (51.2%) undergoing an open approach and 100 (48.8%) a laparoscopic approach. After PSM, two well-balanced groups of 75 patients were analysed and showed a shorter length of hospital stay (P = 0.001), a lower blood loss (P = 0.032), a reduced rate of postoperative morbidity (P < 0.001) and decreased total costs (P = 0.050) after LDP with respect to ODP. Regarding the subset of patients with PDAC, 22 patients were analysed: they showed a significant shorter length of hospital stay (P = 0.050) and a reduction in postoperative morbidity (P < 0.001) after LDP with respect to ODP. Oncological outcomes were similar. LDP showed lower hospital stay and postoperative morbidity rate than ODP both in the entire population and in patients affected by PDAC. Total costs were reduced only in the entire population. Oncological outcomes were comparable in PDAC patients.
Association of obstructive sleep apnea with non-alcoholic fatty liver disease in patients with obesity: an observational study
Authors: Bettini Silvia , Serra Roberto , Fabris Roberto , Dal Prà Chiara , Favaretto Francesca , Dassie Francesca , Duso Claudio , Vettor Roberto , Busetto Luca
Published: April 2021

Purpose

Obstructive Sleep Apnea (OSA) is associated with the presence and severity of Non-Alcoholic Fatty Liver Disease (NAFLD). We aimed to investigate the relationship between the severity of OSA and NAFLD and to recognize a polysomnographic parameter correlated with progression of fibrosis, determined by a non-invasive score of liver fibrosis, FIBrosis-4 index (FIB-4), in patients affected by severe obesity and OSA.

Methods

We enrolled 334 patients (Body Mass Index, BMI 44.78 ± 8.99 kg/m2), divided into classes according to severity of OSA evaluated with Apnea Hypopnea Index (AHI): OSAS 0 or absent (17%), mild OSA (26%), moderate OSA (20%), severe OSAS (37%). We studied anthropometric, polysomnographic, biochemical data and FIB-4. A multiple regression model was computed to identify a polysomnographic independent predictor of FIB-4 among those parameters previously simple correlated with FIB-4.

Results

The severity of OSA was associated with a decrease in High-Density Lipoprotein–cholesterol (HDL) and an increase in BMI, triglycerides, Homeostasis model assessment insulin-resistance index (HOMA), transaminases and FIB-4. FIB-4 correlated with sex, age, BMI, AHI, mean percentage oxyhaemoglobin (meanSaO2%), number of desaturations, platelets, transaminases, HDL, triglycerides and HOMA. The only variables independently related to FIB-4 were sex, BMI, triglycerides and meanSpO2 (r = 0.47, AdjRsqr = 0.197).

Conclusion

MeanSpO2% represented an independent determinant for the worsening of FIB-4 in patients with severe obesity and OSA. Hence, it could hypothesize a clinical role of meanSaO2% in recognizing patients with obesity and OSA and higher risk of developing advanced fibrosis and, thus, to undergo further investigation.

Level III

Evidence obtained from well-designed cohort analytic studies.
Evaluation of minimal fracture liaison service resource: costs and survival in secondary fracture prevention—a prospective one-year study in South-Finland
Authors: Lüthje P. , Nurmi-Lüthje I. , Tavast N. , Villikka A. , Kataja M.
Published: April 2021

Background

Fracture liaison service (FLS) is a secondary prevention model for identification of patients at risk for fragility fractures.

Aims

This study was conducted to evaluate the number and costs of secondary prevention of low-energy fractures in the city of Kouvola in Finland.

Methods

Women aged ≥ 45 years and men ≥ 60 years treated in the emergency department with a low-energy fracture were identified. Laboratory testing, BMI, and DXA scans were performed. Fracture Risk Assessment Tool was used. The direct FLS costs were calculated. Survival was analyzed using univariate and multivariate analysis and the life-table method.

Results

525 patients with 570 fractures were identified. The mean age of women was 73.8 years and of men 75.9 years. Most patients sustained wrist (31%), hip (21%) or proximal humerus (12%) fractures. 41.5% of the patients had osteoporosis according to DXA scans. 62% of patients used calcium and vitamin D daily and 38% started anti-osteoporotic medication. Protective factors for survival were: age < 80 years, female sex, and S-25OHD concentration of 50–119 nmol/L. Excess mortality was highest among patients with a fracture of the femur. The total annual direct costs of FLS were 1.3% of the costs of all fractures.

Discussion

Many low-energy fracture types were associated with excess mortality. The use of anti-osteoporotic medication was not optimal.

Conclusions

FLS increased the catchment of low-energy fracture patients and was inexpensive. However, identification, evaluation and post-fracture assessment of patients should be expedited. Rehabilitation of hip fracture patients needs to be improved.
Postoperative delirium after cardiac surgery of elderly patients as an independent risk factor for prolonged length of stay in intensive care unit and in hospital
Authors: Kirfel Andrea , Menzenbach Jan , Guttenthaler Vera , Feggeler Johanna , Mayr Andreas , Coburn Mark , Wittmann Maria
Published: April 2021

Background

Postoperative delirium (POD) is a relevant and underdiagnosed complication after cardiac surgery that is associated with increased intensive care unit (ICU) and hospital length of stay (LOS). The aim of this subgroup study was to compare the frequency of tested POD versus the coded International Statistical Classification of Diseases and Related Health Problems (ICD) diagnosis of POD and to evaluate the influence of POD on LOS in ICU and hospital.

Methods

254 elective cardiac surgery patients (mean age, 70.5 ± 6.4 years) at the University Hospital Bonn between September 2018 and October 2019 were evaluated. The endpoint tested POD was considered positive, if one of the tests Confusion Assessment Method for ICU (CAM-ICU) or Confusion Assessment Method (CAM), 4 'A's Test (4AT) or Delirium Observation Scale (DOS) was positive on one day.

Results

POD occurred in 127 patients (50.0%). LOS in ICU and hospital were significantly different based on presence (ICU 165.0 ± 362.7 h; Hospital 26.5 ± 26.1 days) or absence (ICU 64.5 ± 79.4 h; Hospital 14.6 ± 6.7 days) of POD (p < 0.001). The multiple linear regression showed POD as an independent predictor for a prolonged LOS in ICU (48%; 95%CI 31–67%) and in hospital (64%; 95%CI 27–110%) (p < 0.001). The frequency of POD in the study participants that was coded with the ICD F05.0 and F05.8 by hospital staff was considerably lower than tests revealed by the study personnel.

Conclusion

Approximately 50% of elderly patients who underwent cardiac surgery developed POD, which is associated with an increased ICU and hospital LOS. Furthermore, POD is highly underdiagnosed in clinical routine.
Fuzzy dynamic-prioritization agent-based system for forecasting job cycle time in a wafer fabrication plant
Authors: Chen Tin-Chih Toly , Wang Yu-Cheng
Published: April 2021

A fuzzy dynamic-prioritization agent-based system was developed in this study to improve the forecasting of the cycle time of a job in a wafer fabrication plant (wafer fab). In this system, multiple fuzzy agents forecast the cycle time of a job from various viewpoints, after which the aggregation and evaluation agent aggregates these fuzzy cycle time forecasts using an innovative operator (i.e., the fuzzy weighted intersection) into a single representative value. Subsequently, the optimization agent varies the authority levels of the fuzzy cycle time forecasting agents to optimize the forecasting performance. A practical example was used to evaluate the effectiveness of the fuzzy dynamic-prioritization agent-based system. The experiment results indicated that the fuzzy dynamic-prioritization agent-based system outperformed three rival methods in improving forecasting accuracy. In addition, the forecasting performance could be enhanced by discriminating the authority levels of the fuzzy cycle time forecasting agents.
Adaptive feature extraction and fault diagnosis for three-phase inverter based on hybrid-CNN models under variable operating conditions
Authors: Sun Quan , Yu Xianghai , Li Hongsheng , Fan Jisheng
Published: April 2021

The increasing reliability and availability requirements of power electronic systems have drawn great concern in many industrial applications. Aiming at the difficulty in fault characteristics extraction and fault modes classification of the three-phase full-bridge inverter (TFI) that used as the drive module of brushless DC motor (BLDCM). A hybrid convolutional neural network (HCNN) model consists of one-dimensional CNN (1D-CNN) and two-dimensional CNN (2D-CNN) is proposed in this paper, which can tap more effective spatial feature for TFI fault diagnosis. The frequency spectrum from the three-phase current signal preprocess are applied as the input for 1D-CNN and 2D-CNN to conduct feature extraction, respectively. Then, the feature layers information are combined in the fully connected layer of HCNN. Finally, the performance status of TFI could be identified by the softmax classifier with Adam optimizer. Several groups of experiments have been studied when the BLDCM under different operating conditions. The results show that the fusion features can get a higher degree of discrimination so as to the presented network model also obtains better classification accuracy, which verify the feasibility and superiority to the other networks.
On Sufficient Conditions for Chaotic Behavior of Multidimensional Discrete Time Dynamical System
Authors: Kamarudin Nor Syahmina , Dzul-Kifli Syahida Che
Published: April 2021

In this work, we look at the extension of classical discrete dynamical system to multidimensional discrete-time dynamical system by characterizing chaos notions on $${\mathbb {Z}}^d$$

Z

d

-action. The $${\mathbb {Z}}^d$$

Z

d

-action on a space X has been defined in a very general manner, and therefore we introduce a $${\mathbb {Z}}^d$$

Z

d

-action on X which is induced by a continuous map, $$f:{\mathbb {Z}}\times X \rightarrow X$$

f
:
Z
×
X
→
X

and denotes it as $$T_f:{\mathbb {Z}}^d \times X \rightarrow X$$

T
f

:

Z

d

×
X
→
X

. Basically, we wish to relate the behavior of origin discrete dynamical systems (X, f) and its induced multidimensional discrete-time $$(X,T_f)$$

(
X
,

T
f

)

. The chaotic behaviors that we emphasized are the transitivity and dense periodicity property. Analogues to these chaos notions, we consider k-type transitivity and k-type dense periodicity property in the multidimensional discrete-time dynamical system. In the process, we obtain some conditions on $$(X,T_f)$$

(
X
,

T
f

)

under which the chaotic behavior of $$(X,T_f)$$

(
X
,

T
f

)

is inherited from the original dynamical system (X, f). The conditions varies whenever f is open, totally transitive or mixing. Some examples are given to illustrate these conditions.
A Proactive Approach to Evaluating Intersection Safety Using Hard-Braking Data
Authors: Hunter Margaret , Saldivar-Carranza Enrique , Desai Jairaj , Mathew Jijo K. , Li Howell , Bullock Darcy M.
Published: April 2021

Typical safety improvements at signalized intersections are identified and prioritized using crash data over 3–5 years. Enhanced probe data that provides date, time, heading, and location of hard-braking events has recently become available to agencies. In a typical month, over six million hard-braking events are logged in the state of Indiana. This study compared rear-end crash data over a period of 4.5 years at 8 signalized intersections with weekday hard-braking data from July 2019. Using Spearman’s rank-order correlation, results indicated a strong correlation between hard-braking events and rear-end crashes occurring more than 400 ft upstream of an intersection. The paper concludes that using a month or two of hard-braking events occurring upstream from the stop bar may be a useful tool to screen potential locations with elevated rear-end crashes. Using these techniques described in this paper, new commercially available hard-braking data sources will provide an opportunity for agencies to follow up with mitigation measures addressing emerging problems much quicker than typical practices that rely on 3–5 years of crash data.
Research on the viscosity of stabilized emulsions in different pipe diameters using pressure drop and phase inversion
Authors: Plasencia Jose , Inkson Nathanael , Nydal Ole Jørgen
Published: April 2021

This paper reports experimental research on the flow behavior of oil-water surfactant stabilized emulsions in different pipe diameters along with theoretical and computational fluid dynamics (CFD) modeling of the relative viscosity and inversion properties. The pipe flow of emulsions was studied in turbulent and laminar conditions in four pipe diameters (16, 32, 60, and 90 mm) at different mixture velocities and increasing water fractions. Salt water (3.5% NaCl w/v, pH = 7.3) and a mineral oil premixed with a lipophilic surfactant (Exxsol D80 + 0.25% v/v of Span 80) were used as the test fluids. The formation of water-in-oil emulsions was observed from low water fractions up to the inversion point. After inversion, unstable water-in-oil in water multiple emulsions were observed under different flow regimes. These regimes depend on the mixture velocity and the local water fraction of the water-in-oil emulsion. The eddy turbulent viscosity calculated using an elliptic-blending k-ε model and the relative viscosity in combination act to explain the enhanced pressure drop observed in the experiments. The inversion process occurred at a constant water fraction (90%) and was triggered by an increase of mixture velocity. No drag reduction effect was detected for the water-in-oil emulsions obtained before inversion.
IASI‐Derived Sea Surface Temperature Data Set for Climate Studies
Authors: Parracho Ana C. , Safieddine Sarah , Lezeaux Olivier , Clarisse Lieven , Whitburn Simon , George Maya , Prunet Pascal , Clerbaux Cathy
Published: April 2021

Sea surface temperature (SST) is an essential climate variable, that is directly used in climate monitoring. Although satellite measurements can offer continuous global coverage, obtaining a long‐term homogeneous satellite‐derived SST data set suitable for climate studies based on a single instrument is still a challenge. In this work, we assess a homogeneous SST data set derived from reprocessed Infrared Atmospheric Sounding Interferometer (IASI) level‐1 (L1C) radiance data. The SST is computed using Planck's Law and simple atmospheric corrections. We assess the data set using the ERA5 reanalysis and the EUMETSAT‐released IASI level‐2 SST product. Over the entire period, the reprocessed IASI SST shows a mean global difference with ERA5 close to zero, a mean absolute bias under 0.5°C, with a SD of difference around 0.3°C and a correlation coefficient over 0.99. In addition, the reprocessed data set shows a stable bias and SD, which is an advantage for climate studies. The interannual variability and trends were compared with other SST data sets: ERA5, Hadley Centre's SST (HadISST), and NOAA's Optimal Interpolation SST Analysis (OISSTv2). We found that the reprocessed SST data set is able to capture the patterns of interannual variability well, showing the same areas of high interannual variability (>1.5°C), including over the tropical Pacific in January corresponding to the El Niño Southern Oscillation. Although the period studied is relatively short, we demonstrate that the IASI data set reproduces the same trend patterns found in the other data sets (i.e., cooling trend in the North Atlantic, warming trend over the Mediterranean).
The TEC Enhancement Before Seismic Events Is an Artifact
Authors: Eisenbeis J. , Occhipinti G.
Published: April 2021

Since 2011 there has been an ongoing debate about the possibility of short‐term earthquake prediction using total electron content (TEC) ionospheric monitoring by the Global Navigation Satellite System (GNSS). Heki (2011), https://doi.org/10.1029/2011gl047908 initiated this debate when he published results for the 2011 Tohoku event reporting a TEC enhancement 40 min before the earthquake; several later papers by Heki and coworkers have made similar claims for other earthquakes. If correct, Heki's methods might contribute to short‐term earthquake prediction. However, Heki's claims have been strongly criticized as being due to a decrease in the background TEC after earthquakes–the so called ionospheric hole–rather than an enhancement before. Depending on the choice of reference curve to be subtracted from the raw data to infer the “anomaly,” the data analysis can produce either a hole or an enhancement. We show that the choice of reference curve ‐calculated by Heki with a polynomial fit‐is strongly affected by the degree of the polynomial, as well as by the selection of the time window. We also show using synthetic examples that even if there is actually no signal before the event, Heki's methods can lead to spurious precursory signals (i.e., signals with non‐zero amplitude before the event) after the reference curve is subtracted. It thus appears likely that the reported TEC enhancements are artifacts.
A Comparison of Fabry–Perot Interferometer and Meteor Radar Wind Measurements Near the Polar Mesopause Region
Authors: Lee Changsup , Jee Geonhwa , Kam Hosik , Wu Qian , Ham Young‐Bae , Kim Yong Ha , Kim Jeong‐Han
Published: April 2021

The neutral winds in the Mesosphere and Lower Thermosphere (MLT) region have been observed at King Sejong Station, Antarctica using a meteor radar (MR) and a Fabry–Perot interferometer (FPI) simultaneously. These two independent MLT wind measurements are compared to each other to identify the characteristics of FPI measurement. Instead of using a fixed emission height for FPI winds, for the first time, we consider the temporal variations of airglow emission layer in association with corresponding meteor height distributions for more accurate comparison between the FPI and MR winds. The temporal variations of the airglow emission layers are examined from the inverse relationship between the height integrated emission rate and the peak emission height derived from the TIMED/SABER observations. It is found that FPI winds are consistently smaller than MR winds and the discrepancy becomes larger for OI emission at higher altitude, which may be related to large wind shear in the MLT region and variabilities of the emission layers. Finally, we found that the FPI can provide reliable height‐averaged winds in the MLT region where existing a strong wind shear from this simultaneous MR wind measurements.
Electrostatic Waves and Electron Heating Observed Over Lunar Crustal Magnetic Anomalies
Authors: Chu F. , Halekas J. S. , Cao X. , McFadden J. P. , Bonnell J. W. , Glassmeier K.‐H.
Published: April 2021

Above lunar crustal magnetic anomalies, large fractions of solar wind electrons and ions can be scattered and stream back toward the solar wind flow, leading to a number of interesting effects such as electrostatic instabilities and waves. These electrostatic structures can also interact with the background plasma, resulting in electron heating and scattering. We study the electrostatic waves and electron heating observed over the lunar magnetic anomalies by analyzing data from the Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) spacecraft. Based on the analysis of two lunar flybys in 2011 and 2013, we find that the electron two‐stream instability (ETSI) and electron cyclotron drift instability (ECDI) may play an important role in driving the electrostatic waves. We also find that ECDI, along with the modified two‐stream instability (MTSI), may provide the mechanisms responsible for substantial isotropic electron heating over the lunar magnetic anomalies.
Quiet Night Arctic Ionospheric D Region Characteristics
Authors: Thomson Neil R. , Clilverd Mark A. , Brundell James B. , Rodger Craig J.
Published: April 2021

VLF radio propagation recordings are used to determine the characteristics of the nighttime polar lower D region of the ionosphere. Recordings of both VLF phase and amplitude in the Arctic on days within ∼1–2 weeks of the equinoxes enable their day‐to‐night changes to be determined. These changes are then combined with previously measured daytime polar D region characteristics to find the nighttime characteristics. The previously determined daytime characteristics were measured in the Arctic summer; the NRLMSISE atmosphere model is used to help determine the height change from daytime summer to daytime equinox (∼5 km lower). The principal path used was from the 16.4 kHz Norwegian transmitter JXN (67°N, 14°E) 1,334 km northwards across the Arctic Ocean to Ny‐Ålesund (79°N, 12°E), Svalbard. Also used were the 2,014‐km path from NRK (37.5 kHz, Grindavik, 64°N, Iceland) to Ny‐Ålesund, the 1,655‐km path from JXN to Reykjavik (64°N, Iceland), and the 5,302‐km path from JXN across the Arctic Ocean to Fairbanks (65°N) in Alaska. The night values of (the Wait parameters) H′ and β were found to average from ∼79 km at equinox down to 77 km near winter solstice (lower than the 85 km at low and midlatitudes by ∼7 km) and 0.6 km−1, respectively. This lower height and its variability are shown to be consistent with the principal source of ionization being energetic electron precipitation.
Sustained Oxygen Spectral Gaps and Their Dynamic Evolution in the Inner Magnetosphere
Authors: Yue Chao , Zhou Xu‐Zhi , Bortnik Jacob , Zong Qiu‐Gang , Li Yuxuan , Ren Jie , Reeves Geoffrey D. , Spence Harlan E.
Published: April 2021

Van Allen Probes observations of ion spectra often show a sustained gap within a very narrow energy range throughout the full orbit. To understand their formation mechanism, we statistically investigate the characteristics of the narrow gaps for oxygen ions and find that they are most frequently observed near the noon sector with a peak occurrence rate of over 30%. The magnetic moment (μ) of the oxygen ions in the gap shows a strong dependence on magnetic local time (MLT), with higher and lower μ values in the morning and afternoon sectors, respectively. Moreover, we find through superposed epoch analysis that the gap formation also depends on geomagnetic conditions. Those gaps formed at lower magnetic moments (μ < 3,000 keV/G) are associated with stable convection electric fields, which enable magnetospheric ions to follow a steady drift pattern that facilitates the gap formation by corotational drift resonance. On the other hand, gaps with higher μ values are statistically preceded by a gradual increase of geomagnetic activity. We suggest that ions within the gap were originally located inside the Alfven layer following closed drift paths, before they were transitioned into open drift paths as the convection electric field was enhanced. The sunward drift of these ions, with very low fluxes, forms a drainage void in the dayside magnetosphere manifested as the sustained gap in the oxygen spectrum. This scenario is supported by particle‐tracing simulations, which reproduce most of the observed characteristics and therefore provide new insights into inner magnetospheric dynamics.
Thermal Weakening Friction During Seismic Slip: Experiments and Models With Heat Sources and Sinks
Authors: Nielsen S. , Spagnuolo E. , Violay M. , Di Toro G.
Published: April 2021

Experiments that systematically explore rock friction under crustal earthquake conditions reveal that faults undergo abrupt dynamic weakening. Processes related to heating and weakening of fault surfaces have been invoked to explain pronounced velocity weakening. Both contact asperity temperature Ta and background temperature T of the slip zone evolve significantly during high‐velocity slip due to heat sources (frictional work), heat sinks (e.g., latent heat of decomposition processes), and diffusion. Using carefully calibrated High‐Velocity Rotary Friction experiments, we test the compatibility of thermal weakening models: (1) a model of friction based only on T in an extremely simplified, Arrhenius‐like thermal dependence; (2) a flash heating model which accounts for the evolution of both V and T; (3) same but including heat sinks in the thermal balance; and (4) same but including the thermal dependence of diffusivity and heat capacity. All models reflect the experimental results but model (1) results in unrealistically low temperatures and model (2) reproduces the restrengthening phase only by modifying the parameters for each experimental condition. The presence of dissipative heat sinks in stage (3) significantly affects T and reflects on the friction, allowing a better joint fit of the initial weakening and final strength recovery across a range of experiments. Temperature is significantly altered by thermal dependence of (4). However, similar results can be obtained by (3) and (4) by adjusting the energy sinks. To compute temperature in this type of problem, we compare the efficiency of three different numerical approximations (finite difference, wavenumber summation, and discrete integral).
Cross‐Scale Seismic Anisotropy Analysis in Metamorphic Rocks From the COSC‐1 Borehole in the Scandinavian Caledonides
Authors: Kästner Felix , Pierdominici Simona , Zappone Alba , Morales Luiz F. G. , Schleicher Anja M. , Wilke Franziska D. H. , Berndt Christian
Published: April 2021

Metamorphic and deformed rocks in thrust zones show particularly high seismic anisotropy causing challenges for seismic imaging and interpretation. A good example is the Seve Nappe Complex in central Sweden, an old exhumed orogenic thrust zone that is characterized by a strong but incoherent seismic reflectivity and considerable seismic anisotropy. However, only little is known about their origin in relation to composition and structural influences on measurements at different seismic scales. Here, we present a new integrative study of cross‐scale seismic anisotropy analyses combining mineralogical composition, microstructural analyses, and seismic laboratory experiments from the COSC‐1 borehole, which sampled a 2.5‐km‐deep section of metamorphic rocks deformed in an orogenic root now preserved in the Lower Seve Nappe. While there is strong crystallographic preferred orientation in most samples in general, variations in anisotropy depend mostly on bulk mineral composition and dominant core lithology as shown by a strong correlation between these. This relationship enables to identify three distinct seismic anisotropy facies providing a continuous anisotropy profile along the borehole. Moreover, comparison of laboratory seismic measurements and electron‐backscatter diffraction data reveals a strong scale dependence, which is more pronounced in the highly deformed, heterogeneous samples. This highlights the need for comprehensive cross‐validation of microscale anisotropy analyses with additional lithological data when integrating seismic anisotropy over seismic scales.
Nearshore Monitoring With X‐Band Radar: Maximizing Utility in Dynamic and Complex Environments
Authors: Atkinson J. , Esteves L. S. , Williams J. J. , Bell P. S. , McCann D. L.
Published: April 2021

Coastal management and engineering applications require data that quantify the nature and magnitude of changes in nearshore bathymetry. However, bathymetric surveys are usually infrequent due to high costs and complex logistics. This study demonstrates that ground‐based X‐band radar offers a cost‐effective means to monitor nearshore changes at relatively high frequency and over large areas. A new data quality and processing framework was developed to reduce uncertainties in the estimates of radar‐derived bathymetry and tested using data from an 18‐months installation at Thorpeness (UK). In addition to data calibration and validation, two new elements are integrated to reduce the influence of data scatter and outliers: (a) an automated selection of periods of “good data” and (b) the application of a depth‐memory stabilization. For conditions when the wave height is >1 m, the accuracy of the radar‐derived depths is shown to be ±0.5 m (95% confidence interval) at 40 × 40‐m spatial resolution. At Thorpeness, radar‐derived bathymetry changes exceeding this error were observed at time scales ranging from 3 weeks to 6 months. These data enabled quantification of changes in nearshore sediment volume at frequencies and spatial cover that would be difficult and/or expensive to obtain by other methods. It is shown that the volume of nearshore sediment movement occurring at time scale as short as few weeks are comparable with the annual longshore transport rates reported in this area. The use of radar can provide an early warning of changes in offshore bathymetry likely to impact vulnerable coastal locations.
Wave Effects on Sediment Transport and Entrapment in a Channel‐Shoal Estuary: The Pearl River Estuary in the Dry Winter Season
Authors: Zhang Guang , Chen Yuren , Cheng Weicong , Zhang Heng , Gong Wenping
Published: April 2021

Sediment dynamics have great effects on the morphology of estuaries and deltas. As riverine sediment input has decreased in many estuaries in recent years, the removal and dispersion of sediments by currents and waves inside estuaries has assumed a more dominant role; however, the overall effects of waves are less well understood. In this study, we used the Coupled Ocean Atmosphere Wave Sediment Transport system to model the effects of waves on sediment transport in China's Pearl River Estuary. The results indicate that the presence of waves increased the landward current and sediment transport at the bottom of the channel and the seaward fluxes of water and sediment at the West Shoal, which is the main shallow area that accepts riverine sediment. Relative to the case without waves, the effects of waves increased the estuary's total sediment export by 45% to 9.14 megatons in one typical year, which even exceeded the annual riverine load in the year. The dry winter season shows the highest wave effects on sediment budget, and the sediment export was increased by 86% to 2.59 megatons with waves when compared with that without waves. This increase export was mainly concentrated at the surface near the western shore. Moreover, the waves increased lateral sediment entrapment in the Southwest Shoal, which explains the local geomorphologic evolution in recent decades. This study is of implication for the study on sediment exchange between shoal and channel in estuaries and on the fates of riverine sediment from source to sink.
Estimate of the D/H Ratio in the Martian Upper Atmosphere from the Low Spectral Resolution Mode of MAVEN/IUVS
Authors: Chaufray J‐Y. , Mayyasi M. , Chaffin M. , Deighan J. , Bhattacharyya D. , Clarke J. , Jain S. , Schneider N. , Jakosky B.
Published: April 2021

Recent Mars Atmosphere and Volatile EvolutioN (MAVEN) observations have shown unexpectedly large deuterium Lyman‐α emissions near the Martian southern summer solstice. The deuterium Lyman‐α brightness can reach ∼10% of the hydrogen Lyman‐α brightness below 200 km. In this study, we propose a method to estimate the D/H ratio in the Martian upper atmosphere through analysis of the Lyman‐α vertical profiles without the ability to spectrally separate the two atomic emission lines. Lyman‐α vertical profiles measured by MAVEN/IUVS at four periods are analyzed. During southern summer, the derived D/H ratios at 200 km are larger than the HDO/H2O ratio measured in the lower atmosphere, yet the extrapolated D/H ratio from 200 to 80 km agrees with the HDO/H2O ratio. This larger D/H ratio at higher altitude is attributed to the more efficient escape of hydrogen atoms compared to deuterium atoms. The method we describe accounts for uncertainties related to constraining the temperature and density profiles of H and D in the lower thermosphere. Because spectrally resolved D and H Lyman‐α measurements are not always available, this method provides a way to estimate D/H variations in their absence. This method will be useful for analysis of relevant data sets from past and future Mars missions.
An Urban Scheme for the ECMWF Integrated Forecasting System: Single‐Column and Global Offline Application
Authors: McNorton J. R. , Arduini G. , Bousserez N. , Agustí‐Panareda A. , Balsamo G. , Boussetta S. , Choulga M. , Hadade I. , Hogan R. J.
Published: April 2021

The societal benefits of numerical weather prediction (NWP) forecasts are most evident in populated areas. An urban representation within NWP models should provide improved forecast accuracy. Here, we present the preliminary implementation of an urban scheme within the Integrated Forecasting System (IFS) using a simplified single‐layer urban canopy model. The scheme makes assumptions of canyon geometry and considers fluxes from roads, walls, and roofs. Temperature observations were used to optimize single‐column model (SCM) parameters using the Gauss‐Newton method. Observation comparisons over six European cities, show a 2‐m temperature root‐mean‐squared error reduction from 1.85  to 1.75 K with the urban scheme. Optimized parameters were used globally at kilometric scale in a land surface model. A sensitivity experiment assuming a 100% urban world showed spatially averaged northern hemisphere 2‐m temperatures increased by 0.54 K (January) and 0.42 K (July) at night caused by changes in the albedo, emissivity, roughness, and thermal and hydrological properties. Global ∼1‐km resolution simulations using ancillary urban mapping information produce an urban heat island effect over major and minor conurbations. Only major conurbations were well represented at ∼9‐km resolution. Results from SCM simulations show a heightening of the planetary boundary layer over city sites, with the largest enhancements occurring at night in July (84 ± 48 m) caused by an increased sensible heat flux. These initial developments show the importance of a high‐resolution urban representation within NWP models. Improved parameterization and mapping will enable an online representation of energy, water, and trace gas fluxes over residential areas.
The Determination of Satellite Orbital Decay From POD Data During Geomagnetic Storms
Authors: Li Ruoxi , Lei Jiuhou
Published: April 2021

In our previous study (Li et al., 2017, https://doi.org/10.1007/s11430-016-9052-1), we derived the satellite energy‐decay with a 20‐min resolution based on the Precise Orbit Determination (POD) data, using a proximate analytic approach to represent the time variation gravitational potential. In this follow‐up study, we improved the previous approach and calculated the POD‐based energy‐decays by using a numerical integration approach. Based on the precise energy‐decays, the orbital decays and decay rates with higher accuracy and resolution were further derived. The relative deviations of the orbital decays are generally less than 10% with respect to the accelerometer‐reference. The satellite orbital decays and decay rates derived from this approach were used to study the effects of geomagnetic activities and background density on the orbital changes. Our results show that, during the severe November 2003 storm, the storm‐induced orbital decay rate increased by a factor of 8 with respect to the quiet‐time reference. This POD‐based integration approach was also applied to study the orbital changes of multiple satellites at different altitudes during the September 2017 moderate storm. It is found that the storm‐induced orbital decay rates of Swarm‐B, Swarm‐A, and Gravity Recovery and Climate Experiment satellites increased by 100%–150% depending on their altitudes. Overall, the results suggest that our integration approach has better performance than the previous approach in deriving the orbital decay rate at solar minimum or at high altitude when the atmospheric density is relatively low.
ASHLEY: A New Empirical Model for the High‐Latitude Electron Precipitation and Electric Field
Authors: Zhu Qingyu , Deng Yue , Maute Astrid , Kilcommons Liam M. , Knipp Delores J. , Hairston Marc
Published: April 2021

In this study, a new high‐latitude empirical model is introduced, named for Auroral energy Spectrum and High‐Latitude Electric field variabilitY (ASHLEY). This model improves specifications of soft electron precipitations and electric field variability that are not well represented in existing high‐latitude empirical models. ASHLEY consists of three components, ASHLEY‐A, ASHLEY‐E, and ASHLEY‐Evar, which are developed based on the electron precipitation and bulk ion drift measurements from the Defense Meteorological Satellite Program (DMSP) satellites during the most recent solar cycle. On the one hand, unlike most existing high‐latitude electron precipitation models, which have assumptions about the energy spectrum of incident electrons, the electron precipitation component of ASHLEY, ASHLEY‐A, provides the differential energy fluxes in the 19 DMSP energy channels under different geophysical conditions without making any assumptions about the energy spectrum. It has been found that the relaxation of spectral assumptions significantly improves soft electron precipitation specifications with respect to a Maxwellian spectrum (up to several orders of magnitude). On the other hand, ASHLEY provides consistent mean electric field and electric field variability under different geophysical conditions by ASHLEY‐E and ASHLEY‐Evar components, respectively. This is different from most existing electric field models which only focus on the large‐scale mean electric field and ignore the electric field variability. Furthermore, the consistency between the electric field and electron precipitation is better taken into account in ASHLEY.
Massive Deposition of Carbonate Nodules in the Hyperarid Northwest Qaidam Basin of the Northern Tibetan Plateau
Authors: Sun Yu , Li Yiliang , Li Kan , Li Long , He Hongping
Published: April 2021

Concretionary nodule formation is a subaerial process common to both Earth and Mars. The resulting nodules contain information about particular paleoclimatic cycles. However, their genesis and the mineralogical and geochemical effects of climate change on nodule formation have not well constrained so far, limiting their applications to paleoclimatic reconstruction. Since the late Pleistocene, the Qaidam Basin in the northern Tibetan Plateau has been subjected to extreme drought, resulting in a vast area of playas with a diverse eolian morphology that resembles the surface of Mars. Recently, a massive carbonate nodule field was discovered on an ancient diluvial platform in the northwest Qaidam Basin. Detailed analyses revealed that an early period of aragonite precipitation (251 kyr before present) provided seeding material for the later growth of nodule bodies during a period of ∼100 kyr. The highly unstable hydrologic and geochemical conditions during this period led to the growth of high‐Mg calcite zones with varied elemental contents (e.g., Mn), crystal patterns, and porosity levels within the nodule bodies. The δ13C and δ18O values increased by 3‰ and 6‰, respectively, from the cores to the rims of the measured nodules. Rayleigh distillation model suggested that 50% of the H2O and 25% of the dissolved CO2 had been removed during nodule growth in response to the drought. These results show that nodules formed in hyperarid environments can record important hydrologic information, which may provide insights for paleo‐environment studies on Mars by examining the formation of nodules in Gale Crater.