bluuebunny/crossref_metadata_2025 huggingface dataset:
Conservation of Energy: Missing Features in Its Nature and Justification and Why They Matter
Authors: Pitts J. Brian
Published: April 2020

Misconceptions about energy conservation abound due to the gap between physics and secondary school chemistry. This paper surveys this difference and its relevance to the 1690s–2010s Leibnizian argument that mind-body interaction is impossible due to conservation laws. Justifications for energy conservation are partly empirical, such as Joule’s paddle wheel experiment, and partly theoretical, such as Lagrange’s statement in 1811 that energy is conserved if the potential energy does not depend on time. In 1918 Noether generalized results like Lagrange’s and proved a converse: symmetries imply conservation laws and vice versa. Conservation holds if and only if nature is uniform. The rise of field physics during the 1860s–1920s implied that energy is located in particular places and conservation is primordially local: energy cannot disappear in Cambridge and reappear in Lincoln instantaneously or later; neither can it simply disappear in Cambridge or simply appear in Lincoln. A global conservation law can be inferred in some circumstances. Einstein’s General Relativity, which stimulated Noether’s work, is another source of difficulty for conservation laws. As is too rarely realized, the theory admits conserved quantities due to symmetries of the Lagrangian, like other theories. Indeed General Relativity hasmoresymmetries and hence (at least formally)moreconserved energies. An argument akin to Leibniz’s finally gets some force. While the mathematics is too advanced for secondary school, the ideas that conservation is tied to uniformities of nature and that energy is in particular places, are accessible. Improved science teaching would serve the truth and enhance the social credibility of science.
Quantification of the endogenous growth hormone and prolactin lowering effects of a somatostatin-dopamine chimera using population PK/PD modeling
Authors: van Esdonk Michiel J. , Burggraaf Jacobus , Dehez Marion , van der Graaf Piet H. , Stevens Jasper
Published: April 2020

A phase 1 clinical trial in healthy male volunteers was conducted with a somatostatin-dopamine chimera (BIM23B065), from which information could be obtained on the concentration-effect relationship of the inhibition of pulsatile endogenous growth hormone and prolactin secretion. Endogenous growth hormone profiles were analyzed using a two-step deconvolution-analysis-informed population pharmacodynamic modeling approach, which was developed for the analyses of pulsatile profiles. Prolactin concentrations were modelled using a population pool model with a circadian component on the prolactin release. During treatment with BIM23B065, growth hormone secretion was significantly reduced (maximal effect [EMAX] = − 64.8%) with significant reductions in the pulse frequency in two out of three multiple ascending dose cohorts. A circadian component in prolactin secretion was identified, modelled using a combination of two cosine functions with 24 h and 12 h periods. Dosing of BIM23B065 strongly inhibited (EMAX = − 91%) the prolactin release and demonstrated further reduction of prolactin secretion after multiple days of dosing. This study quantified the concentration-effect relationship of BIM23B065 on the release of two pituitary hormones, providing proof of pharmacology of the chimeric actions of BIM23B065.
Pharmacological Characterization of a Betaine/GABA Transporter 1 (BGT1) Inhibitor Displaying an Unusual Biphasic Inhibition Profile and Anti-seizure Effects
Authors: Lie Maria E. K. , Kickinger Stefanie , Skovgaard-Petersen Jonas , Ecker Gerhard F. , Clausen Rasmus P. , Schousboe Arne , White H. Steve , Wellendorph Petrine
Published: April 2020

Focal epileptic seizures can in some patients be managed by inhibiting γ-aminobutyric acid (GABA) uptake via the GABA transporter 1 (GAT1) using tiagabine (Gabitril®). Synergistic anti-seizure effects achieved by inhibition of both GAT1 and the betaine/GABA transporter (BGT1) by tiagabine and EF1502, compared to tiagabine alone, suggest BGT1 as a target in epilepsy. Yet, selective BGT1 inhibitors are needed for validation of this hypothesis. In that search, a series of BGT1 inhibitors typified by (1R,2S)-2-((4,4-bis(3-methylthiophen-2-yl)but-3-en-yl)(methyl)amino)cyclohexanecarboxylic acid (SBV2-114) was developed. A thorough pharmacological characterization of SBV2-114 using a cell-based [3H]GABA uptake assay at heterologously expressed BGT1, revealed an elusive biphasic inhibition profile with two IC50 values (4.7 and 556 μM). The biphasic profile was common for this structural class of compounds, including EF1502, and was confirmed in the MDCK II cell line endogenously expressing BGT1. The possibility of two binding sites for SBV2-114 at BGT1 was assessed by computational docking studies and examined by mutational studies. These investigations confirmed that the conserved residue Q299 in BGT1 is involved in, but not solely responsible for the biphasic inhibition profile of SBV2-114. Animal studies revealed anti-seizure effects of SBV2-114 in two mouse models, supporting a function of BGT1 in epilepsy. However, as SBV2-114 is apparent to be rather non-selective for BGT1, the translational relevance of this observation is unknown. Nevertheless, SBV2-114 constitutes a valuable tool compound to study the molecular mechanism of an emerging biphasic profile of BGT1-mediated GABA transport and the putative involvement of two binding sites for this class of compounds.
Minimal important change in physical function in trauma patients: a study using the short musculoskeletal function assessment
Authors: de Graaf M. W. , Reininga I. H. F. , Heineman E. , El Moumni M.
Published: April 2020

Purpose

The Short Musculoskeletal Function Assessment (SMFA) questionnaire can be used to evaluate physical functioning in patients with traumatic injuries. It is not known what change in score reflects a meaningful change to patients. The aim was to determine minimal important change (MIC) values of the subscales (0–100) of the Dutch SMFA-NL in a sample of patients with a broad range of injuries.

Methods

Patients between 18 and 65 years of age completed the SMFA-NL and the Global Rating of Effect (GRE) questions at 6-week and 12-month post-injury. Anchor-based MIC values were calculated using univariable logistic regression analyses.

Results

A total of 225 patients were included (response rate 67%). The MIC value of the Upper Extremity Dysfunction (UED) subscale was 8 points, with a misclassification rate of 43%. The Lower Extremity Dysfunction subscale MIC value was 14 points, with a misclassification rate of 29%. The MIC value of the Problems with Daily Activities subscale was 25 points, with a misclassification rate of 33%. The MIC value of the Mental and Emotional Problems (MEP) subscale was 7 points, with a misclassification rate 37%.

Conclusion

MIC values of the SMFA-NL were determined. The MIC values aid interpreting whether a change in physical functioning can be considered clinically important. Due to the considerable rates of misclassification, the MIC values of the UED and MEP subscales should be used with caution.
Studying review articles in scientometrics and beyond: a research agenda
Authors: Blümel Clemens , Schniedermann Alexander
Published: April 2020

Review articles are an often neglected genre in scholarly communication. Though there was intense discussion about review articles in scientometrics in the 1970s and 1980s, we find less studies devoted to this genre within the last 20 years. Yet, recent discussions in other fields, such as linguistics, sociology or medicine imply that review articles are part of important debates about problems of research in academia, such as research quality or transparency. Against that background, the purpose of this paper is to review recent developments for the study of review articles in scientometrics and beyond, to discuss theoretical, conceptual and empirical accounts of how review articles can be defined, and to identify major methodological and conceptual challenges for studying review articles. Based on reviewing work and inputs received from of a workshop conducted at a Conference of the International Society of Informetrics in September 2019, we propose a research agenda for the study of review articles. We have identified six realms of study in this area: (1) the study of methodological caveats resulting from the usage of scholarly databases, (2) the study of field specific patterns of reception and usage of review articles, (3) the study of argumentative and textual structures of review articles, (4) the exploration of organizations and infrastructures for review articles, (5) the study of epistemic roles of review articles, and (6) the analysis of authorship patterns in review articles.
Thrombophilia screening revisited: an issue of personalized medicine
Authors: Colucci Giuseppe , Tsakiris Dimitrios A.
Published: April 2020

Clinical thrombophilia is the consequence of multiple gene and/or environment interactions. Thrombophilia screening requires a targeted patient with specific indication, in which a finding would have implications. Carrying out a thrombophilia examination in the physician’s practice is often a cause of uncertainty and concern. The concerns begin in choosing the right patient to be examined, are associated with the time of investigation, with the choice of analysis, the test-material and with the correct interpretation of the results. Difficulties, which can influence the results, can occur with both organization and blood sampling. As common for any analysis, pre-analytical, analytical and post-analytical factors should be considered, as well as the possibility of false positive or false negative results. Finally, recommendation of correct therapeutic and prophylactic measures for the patient and his relatives is an additional focus. In this article we want to provide—on the basis of the evidence and personal experience—the theory of thrombophilia-investigation, the indications for testing, as well as practical recommendations for treatment options.
The Impact of Elastic Deformations of the Extracellular Matrix on Cell Migration
Authors: Malik A. A. , Wennberg B. , Gerlee P.
Published: April 2020

The mechanical properties of the extracellular matrix, in particular its stiffness, are known to impact cell migration. In this paper, we develop a mathematical model of a single cell migrating on an elastic matrix, which accounts for the deformation of the matrix induced by forces exerted by the cell, and investigate how the stiffness impacts the direction and speed of migration. We model a cell in 1D as a nucleus connected to a number of adhesion sites through elastic springs. The cell migrates by randomly updating the position of its adhesion sites. We start by investigating the case where the cell springs are constant, and then go on to assuming that they depend on the matrix stiffness, on matrices of both uniform stiffness as well as those with a stiffness gradient. We find that the assumption that cell springs depend on the substrate stiffness is necessary and sufficient for an efficient durotactic response. We compare simulations to recent experimental observations of human cancer cells exhibiting durotaxis, which show good qualitative agreement.
Circular Tessera Codes in the Evolution of the Genetic Code
Authors: Fimmel Elena , Starman Martin , Strüngmann Lutz
Published: April 2020

The origin of the modern genetic code and the mechanisms that have contributed to its present form raise many questions. The main goal of this work is to test two hypotheses concerning the development of the genetic code for their compatibility and complementarity and see if they could benefit from each other. On the one hand, Gonzalez, Giannerini and Rosa developed a theory, based on four-based codons, which they called tesserae. This theory can explain the degeneracy of the modern vertebrate mitochondrial code. On the other hand, in the 1990s, so-called circular codes were discovered in nature, which seem to ensure the maintenance of a correct reading-frame during the translation process. It turns out that the two concepts not only do not contradict each other, but on the contrary complement and enrichen each other.
Selbstselektion beim Bezug des Betreuungsgelds? Eine Analyse bezahlter und unbezahlter Arbeit von Müttern
Authors: Höppner Julia
Published: April 2020

Das 2013 eingeführte und bereits zwei Jahre später wieder abgeschaffte bundesweite Betreuungsgeld gehörte zu den kontroversesten Themen der jüngeren deutschen Familienpolitik. Von Seiten politischer Akteure, die das Betreuungsgeld ablehnten, aber auch aus der Forschung wurde die Befürchtung geäußert, dass sich die Leistung negativ auf die Erwerbsbeteiligung von Müttern auswirke und eine traditionelle Aufteilung von bezahlter und unbezahlter Arbeit zwischen Müttern und Vätern befördere. Tatsächlich gibt es eine Reihe von Studien, die eine solche Wirkung des Betreuungsgelds festgestellt haben. Allerdings ist bisher nicht geklärt, ob die gefundenen Effekte der Leistung kausaler Natur sind oder ob eine Selbstselektion der Bezieherinnen dafür ursächlich ist. Der Beitrag geht dieser Frage nach. Auf Basis der Erhebungswellen 2009 bis 2017 des Sozio-oekonomischen Panels werden Mütter untersucht, die ausgehend vom Alter ihrer Kinder die Leistung hätten beziehen können oder dies getan haben. Für die Arbeitszeit, Hausarbeitszeit und Dauer der mütterlichen Kinderbetreuung werden hybride Modelle geschätzt, um die Veränderungen dieser drei Variablen bei Müttern mit und ohne Betreuungsgeldbezug im Zeitverlauf zu analysieren. Die Ergebnisse zeigen, dass bereits vor der Geburt des Kindes signifikante Unterschiede zwischen den beiden Gruppen von Müttern bestehen, die auf eine Selbstselektion hinweisen.
High-Cycle Fatigue Behavior of a Self-tapping Timber Screw Under Axial Tensile Loading
Authors: Niebuhr P. , Sieder M.
Published: April 2020

The high-cycle fatigue behavior of a self-tapping timber screw is examined for axial tensile loading with R = 0.1. Based on 71 fatigue tests in the finite-life and long-life regime, Wöhler curves are derived for the failure modes thread area failure and head tear off. Comparisons with existing results of similar tests show equal behavior in the long-life regime and slight differences in the finite-life regime which cannot convincingly be attributed exclusively to either varying testing conditions or differences in the examined population. The fatigue verification according to EN 1993-1-9, detail category 50, is found to be highly conservative, whereas detail category 100 is shown to overestimate the observed fatigue behavior in the finite-life regime. Adding to existing observations on the fatigue behavior of a self-tapping screw, a first assessment of the decisiveness of geometrical and procedural differences in the screws can be made.
Nanotechnological Strategies for Osteoarthritis Diagnosis, Monitoring, Clinical Management, and Regenerative Medicine: Recent Advances and Future Opportunities
Authors: Mohammadinejad Reza , Ashrafizadeh Milad , Pardakhty Abbas , Uzieliene Ilona , Denkovskij Jaroslav , Bernotiene Eiva , Janssen Lauriane , Lorite Gabriela S. , Saarakkala Simo , Mobasheri Ali
Published: April 2020

Purpose of Review

In this review article, we discuss the potential for employing nanotechnological strategies for the diagnosis, monitoring, and clinical management of osteoarthritis (OA) and explore how nanotechnology is being integrated rapidly into regenerative medicine for OA and related osteoarticular disorders.

Recent Findings

We review recent advances in this rapidly emerging field and discuss future opportunities for innovations in enhanced diagnosis, prognosis, and treatment of OA and other osteoarticular disorders, the smart delivery of drugs and biological agents, and the development of biomimetic regenerative platforms to support cell and gene therapies for arresting OA and promoting cartilage and bone repair.

Nanotubes, magnetic nanoparticles, and other nanotechnology-based drug and gene delivery systems may be used for targeting molecular pathways and pathogenic mechanisms involved in OA development. Nanocomposites are also being explored as potential tools for promoting cartilage repair. Nanotechnology platforms may be combined with cell, gene, and biological therapies for the development of a new generation of future OA therapeutics.
Age-Related and Gender-Related Increases in Colorectal Cancer Mortality Rates in Brazil Between 1979 and 2015: Projections for Continuing Rises in Disease
Authors: Martin Francis L. , Morais Camilo L. M. , Sakita Juliana Yumi , Uyemura Sergio Akira , Kannen Vinicius
Published: April 2020

Purpose

Brazil is the largest country in South America. Although a developing nation, birth rates have been decreasing in the last few decades, while its overall population is undergoing lifestyle changes and ageing significantly. Moreover, Brazil has had increasingly high mortality rates related to colorectal cancer (CRC). Herein, we investigated whether the Brazilian population is exhibiting increasing mortality rates related to colon cancer (CC) or rectal cancer (RC) in recent years.

Methods

We examined data from the Brazilian Federal Government from 1979 to 2015 to determine whether CRC mortality and the population ageing process may be associated.

Results

Our mathematical modelling suggests that mortality rates related to CC and RC events in the Brazilian population may increase by 79% and 66% in the next 24 years, respectively. This finding led us to explore the mortality rates for both diseases in the country, and we observed that the highest levels were in the south and southeast regions from the year 2000 onwards. CC events appear to decrease life expectancy among people during their second decade of life in recent years, whereas RC events induced decreases in life expectancy in those aged >30 years. Additionally, both CC and RC events seem to promote significant mortality rates in the male population aged > 60 years and living in the southern states.

Conclusion

Our dataset suggests that both CC and RC events may lead to a significantly increasing number of deaths in the Brazilian male population in coming years.
Correction to: 1HN, 13C, and 15N resonance assignments of human calmodulin bound to a peptide derived from the STRA6 vitamin A transporter (CaMBP2)
Authors: Varney Kristen M. , Wilder Paul T. , Godoy-Ruiz Raquel , Mancia Filippo , Weber David J.
Published: April 2020

The article 1HN, 13C, and 15N resonance assignments of human calmodulin bound to a peptide derived from the STRA6 vitamin A transporter (CaMBP2), written by Kristen M. Varney, Paul T. Wilder, Raquel Godoy-Ruiz, Filippo Mancia and David J. Weber, was originally published Online First without Open Access. After publication in volume 13, issue 2, page [275–278] the author decided to opt for Open Choice and to make the article an Open Access publication.
Approaches to Teaching in Professional Training: a Qualitative Study
Authors: Bonnes Caroline , Hochholdinger Sabine
Published: April 2020

Teaching approaches have been shown to be an important aspect of teaching in school or higher education. Although differing approaches to teaching may play a role in the outcome of professional trainings, they have not yet been further studied in this context. It is first necessary to determine whether the existing approaches to teaching construct can be transferred to the context of professional training and how approaches to teaching can be operationalized for future studies. For a multi-perspective view, we conducted 45 interviews with trainers, human resource development practitioners and trainees. The interviews were analyzed by qualitative content analysis. Our results show that the construct can be transferred to professional training. However, to apply the approaches to teaching construct to professional training, some of the underlying categories must be modified. Furthermore, we discuss the need to include new aspects, such as the category of transfer. Implications for further research are presented, including the development of a measurement instrument based on the results.
Characterization of the retinal changes of the 3×Tg-AD mouse model of Alzheimer’s disease
Authors: Ferreira Hugo , Martins João , Nunes Ana , Moreira Paula I. , Castelo-Branco Miguel , Ambrósio António Francisco , Serranho Pedro , Bernardes Rui
Published: April 2020

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder whose diagnosis remains a notable challenge. The literature suggests that cerebral changes precede AD symptoms by over two decades, implying a significantly advanced stage of AD by the time it is usually diagnosed. In the study herein, texture analysis was applied to computed optical coherence tomography ocular fundus images to identify differences between a group of the transgenic mouse model of the Alzheimer’s disease (3×Tg-AD) and a group of wild-type mice, at the ages of one and two-months-old. A substantial difference between groups was found at both time-points across all neuroretina’s layers. Here, the inner nuclear layer stands out both in the level of statistically significant differences and on the extension of these differences which span through the imaged area. Also, the progression of AD is suggested to be spotted by texture analysis as demonstrated by the significant difference found in the inner plexiform and the outer nuclear layers from the age of one to the age of two-months-old. These findings demonstrate the potential of the use of the retina and texture analysis to the diagnosis of AD and monitor AD progression. Besides, the differences between groups found in this study suggest that the 3×Tg-AD model may be inappropriate to study early changes associated with the AD and other animal models should be tested following the same path and rationale. Moreover, these results also suggest that the human genes present in these transgenic mice may have an impact on the neurodevelopment of offspring which would justify the significant changes found at the age of one-month-old.
Correction to: Bio-economic analysis of super-intensive closed shrimp farming and improvement of management plans: a case study in Japan
Authors: Shinji Junpei , Nohara Setsuo , Yagi Nobuyuki , Wilder Marcy
Published: April 2020

The article "Bio-economic analysis of super-intensive closed shrimp farming and improvement of management plans: a case study in Japan", written by Junpei Shinji, Setsuo Nohara, Nobuyuki Yagi and Marcy Wilder was originally published electronically on the publisher's internet portal on 17 September 2019 without open access.
A highly complex variant of the plantaris tendon insertion and its potential clinical relevance
Authors: Kurtys K. , Gonera B. , Olewnik Ł. , Karauda P. , Polguj M.
Published: April 2020

The body is home to a number of unique and intriguing anatomical structures, plenty of which concern the muscles and their tendons. Of these, the plantaris muscle is reported to present a particularly high range of morphological variations. The muscle, passing distally throughout the length of the lower leg, consists of a small muscle belly and a long, thin tendon. It originates, traditionally, on the popliteal surface of the femur and the knee joint capsule, and then inserts to the calcaneal tuberosity. It has been suggested that mid-portion Achilles tendinopathy may be caused by certain plantaris tendon morphologies. This case report describes a new anomalous plantaris tendon insertion, closely related to the Achilles tendon. It comprise four distinct insertions and one direct merge with the calcaneal tendon. The current classification should be extended to accommodate such ‘rare cases’ to facilitate more successful Achilles tendinopathy treatment.
The acceptance of civil drones in Germany
Authors: Eißfeldt H. , Vogelpohl V. , Stolz M. , Papenfuß A. , Biella M. , Belz J. , Kügler D.
Published: April 2020

In recent years, civil drones have become more and more visible in everyday life. There are numerous reports in the media covering a variety of drone aspects and technical developments. In addition, everyone is used to bird’s-eye views as common features in television, movies and photography. However, little is known about how the public perceives this development. This article reports the results of a representative national study on the acceptance of civilian drones. Overall, a balanced but slightly positive attitude towards civil drones was revealed. Factors analyzed include age, gender, place of residence or interest in technical matters, as well as the individual level of knowledge about the topic. Free verbal associations with the general term drone are described as well as concerns about the usage of civil drones. Concerning different applications of civil drones, results indicate clear approval in Germany for the use of drones in civil protection, rescue missions and research work. However, flights for advertising, leisure and parcel delivery purposes are disagreed with by at least half of those questioned. In the presentation of the results, this article describes social acceptance of civilian drones and thus helps to better understand the perception of civil unmanned aerial vehicles.
A Brief Introduction to Manifold Optimization
Authors: Hu Jiang , Liu Xin , Wen Zai-Wen , Yuan Ya-Xiang
Published: April 2020

Manifold optimization is ubiquitous in computational and applied mathematics, statistics, engineering, machine learning, physics, chemistry, etc. One of the main challenges usually is the non-convexity of the manifold constraints. By utilizing the geometry of manifold, a large class of constrained optimization problems can be viewed as unconstrained optimization problems on manifold. From this perspective, intrinsic structures, optimality conditions and numerical algorithms for manifold optimization are investigated. Some recent progress on the theoretical results of manifold optimization is also presented.
Barometric formulas: various derivations and comparisons to environmentally relevant observations
Authors: Lente Gábor , Ősz Katalin
Published: April 2020

Three different lines of thinking (mechanical, mixed thermodynamical-mechanical, statistical thermodynamic) are presented to derive the noted barometric formula, which gives the altitude dependence of the pressure of a gas in a gravity field. It is shown that the first two methods can be extended to non-isothermal cases, whereas statistical thermodynamics relies on the concept of thermal equilibrium and its usefulness is limited to the isothermal barometric formula. The temperature changes in the gravity field are taken into account by two different methods: simple conservation of energy, and a more refined line of thought based on the adiabatic expansion of an ideal gas. The changes in gravitational acceleration are also considered in further refinements. Overall, six different formulas are derived and their usefulness is tested on the atmosphere of the Earth. It is found that none of the formulas is particularly useful above an altitude of 20 km because radiation effects make the temperature changes in the atmosphere difficult to predict by simple theories. Finally, the different components of air are also considered separately in the context of the barometric formula, and it is shown that the known composition changes of the atmosphere are primarily caused by photochemical processes and not by the gravity field.

Graphical abstract
Lost in Translation? Multiple Discursive Strategies and the Interpretation of Sustainability in the Norwegian Salmon Farming Industry
Authors: Aarset Bernt , Carson Siri Granum , Wiig Heidi , Måren Inger Elisabeth , Marks Jessica
Published: April 2020

The term ‘sustainability’ is vague and open to interpretation. In this paper we analyze how firms use the term in an effort to make the concept their own, and how it becomes a premise for further decisions, by applying a bottom-up approach focusing on the interpretation of ‘sustainability’ in the Norwegian salmon-farming industry. The study is based on a strategic selection of informants from the industry and the study design rests on: 1) identification of the main drivers of sustainability, and 2) the application of five different discursive strategies to analyze how the firms maneuver to legitimize ‘sustainability’ in their conduct. We employ the Critical Discourse Analysis framework, which emphasizes how discourses provide different concepts of meaning. The sustainability concept is assessed based on how sustainability is brought into action by social actors in a legitimate way, and how this action results in sustainable practices. The empirical case of the study is the verbal justification of sustainability practices among representatives of the Norwegian salmon-farming industry. We aim to find out how these representatives translate the rather vague directives of the sustainability concept into legitimate choices that resonate with the firms’ contextual environment, hence, how the salmon farmers perceive, explore, interpret, explain, enact, and defend the diverse landscape of sustainability when implementing professional decisions. We found a trend of passive adaptation to external requirements, such as public regulations and regulative requirements from certification bodies. At the same time, there are progressive forces that attempt to improve the sustainability of the farming practices by involvement in research and innovation projects or cooperation with other firms, e.g. the contribution from offshore engineers in developing high seas farms. The strategies outlined and discussed cannot be seen as a typology to categorize the firms. More than one discursive strategy may be involved in one firm’s choice, and the strategies may work on different levels.
Anisotropy-Related Machining Characteristics in Ultra-Precision Diamond Cutting of Crystalline Copper
Authors: Wang Zhanfeng , Zhang Junjie , Li Guo , Xu Zongwei , Zhang Haijun , Zhang Jianguo , Hartmaier Alexander , Fang Fengzhou , Yan Yongda , Sun Tao
Published: April 2020

Deformation behavior at grain levels greatly affects the machining characteristics of crystalline materials. In the present work, we investigate the influence of material anisotropy on ultra-precision diamond cutting of single crystalline and polycrystalline copper by experiments and crystal plasticity finite element simulations. Specifically,
diamond turning and in situ SEM orthogonal cutting experiments are carried out to provide direct experimental evidence of the material anisotropy-dependent cutting results in terms of machined surface morphology and chip profile. Corresponding numerical simulations with the analysis of built stress further validate experimental results and reveal the mechanisms governing the material anisotropy influence.
The above findings provide insight into the fabrication of ultra-smooth surfaces of polycrystalline metals by ultra-precision diamond turning.
An Efficient Solution for Semantic Segmentation of Three Ground‐based Cloud Datasets
Authors: Song Qianqian , Cui Zhihui , Liu Pu
Published: April 2020

The machine learning approach has shown its state‐of‐the‐art ability to handle segmentation and detection tasks. It is increasingly employed to extract patterns and spatiotemporal features from the ever‐increasing stream of Earth system data. However, there is still a significant challenge, which is the generalization capability of the model on cloud images in different types and weather conditions. After studying several popular methods, we propose a semantic segmentation neural network for cloud segmentation. It extracts features learned by source and target domains in an end‐to‐end behavior, which can address the problem of significant lack of labels in the observed cloud image data. It is further evaluated on the Singapore Whole Sky Image Segmentation (SWIMSEG) dataset by using Mean Intersection‐over‐Union, recall, F‐score, and accuracy matrices. The scores of these matrices are 86%, 97%, 92%, and 96%, which prove that it has excellent efficiency and robustness. Most importantly, a new benchmark based on the SWIMSEG dataset for the task of cloud segmentation is introduced. The others, BENCHMARK, Cirrus Cumulus Stratus Nimbus are evaluated through the model trained from the SWIMSEG dataset by way of visualization.
Eddy‐Modified Iron, Light, and Phytoplankton Cell Division Rates in the Simulated Southern Ocean
Authors: Rohr Tyler , Harrison Cheryl , Long Matthew C. , Gaube Peter , Doney Scott C.
Published: April 2020

We examine the effects of Southern Ocean eddies on phytoplankton cell division rates in a global, multiyear, eddy‐resolving, 3‐D ocean simulation of the Community Earth System Model. We first identify and track eddies in the simulation and validate their distribution and demographics against observed eddy trajectory characteristics. Next, we examine how simulated cyclones and anticyclones differentially modify iron, light, and ultimately population‐specific cell division rates. We use an eddy‐centric, depth‐averaged framework to explicitly examine the dynamics of the phytoplankton population across the entire water column within an eddy. We find that population‐averaged iron availability is elevated in anticyclones throughout the year. The dominant mechanism responsible for vertically transporting iron from depth in anticyclones is eddy‐induced Ekman upwelling. During winter, in regions with deep climatological mixed layer depths, anticyclones also induce anomalously deep mixed layer depths, which further supply new iron from depth via an increased upward mixing flux. However, this additional contribution comes at the price of deteriorating light availability as biomass is distributed deeper in the water column. Therefore, even though population‐averaged specific division rates are elevated in Southern Ocean anticyclones throughout most of the year, in the winter, severe light stress can dominate relieved iron stress and lead to depressed division rates in some anticyclones, particularly in the deep mixing South Pacific Antarctic Circumpolar Current. The opposite is true in cyclones, which exhibit a consistently symmetric physical and biogeochemical response relative to anticyclones.
The Simulated Biological Response to Southern Ocean Eddies via Biological Rate Modification and Physical Transport
Authors: Rohr Tyler , Harrison Cheryl , Long Matthew C. , Gaube Peter , Doney Scott C.
Published: April 2020

We examine the structure and drivers of anomalous phytoplankton biomass in Southern Ocean eddies tracked in a global, multiyear, eddy‐resolving, 3‐D ocean simulation of the Community Earth System Model. We examine how simulated anticyclones and cyclones differentially modify phytoplankton biomass concentrations, growth rates, and physical transport. On average, cyclones induce negative division rate anomalies that drive negative net population growth rate anomalies, reduce dilution across shallower mixed layers, and advect biomass anomalously downward via eddy‐induced Ekman pumping. The opposite is true in anticyclones. Lateral transport is dominated by eddy stirring rather than eddy trapping. The net effect on anomalous biomass can exceed 10–20% of background levels at the regional scale, consistent with observations. Moreover, we find a strong seasonality in the sign and magnitude of regional anomalies and the processes that drive them. The most dramatic seasonal cycle is found in the South Pacific Antarctic Circumpolar Current, where physical and biological processes dominate at different times, modifying biomass in different directions throughout the year. Here, in cyclones, during winter, anomalously shallow mixed layer depths first drive positive surface biomass anomalies via reduced dilution, and later drive positive depth‐integrated biomass anomalies via reduced light limitation. During spring, reduced iron availability and elevated grazing rates suppress net population growth rates and drive the largest annual negative surface and depth‐integrated biomass anomalies. During summer and fall, lateral stirring and eddy‐induced Ekman pumping create small negative surface anomalies but positive depth‐integrated anomalies. The same mechanisms drive biomass anomalies in the opposite direction in anticyclones.
Middle to Late Pleistocene Evolution of the Bengal Fan: Integrating Core and Seismic Observations for Chronostratigraphic Modeling of the IODP Expedition 354 8° North Transect
Authors: Reilly Brendan T. , Bergmann Fenna , Weber Michael E. , Stoner Joseph S. , Selkin Peter , Meynadier Laure , Schwenk Tilmann , Spiess Volkhard , France‐Lanord Christian
Published: April 2020

We investigate chronology and age uncertainty for the middle to upper Pleistocene lower Bengal Fan using a novel age‐depth modeling approach that factors lithostratigraphic, magnetostratigraphic, biostratigraphic, cyclostratigraphic, and seismic stratigraphic constraints, based on results from the International Ocean Discovery Program Expedition 354 Bengal Fan and analysis of the GeoB97‐020/027 seismic line. The initial chronostratigraphic framework is established using regionally extensive hemipelagic sediment units, and only age‐depth models of fan deposits that respect the superposition of channel‐levee systems between sites are accepted. In doing so, we reconstruct signals of regional sediment accumulation rate and lithogenic sediment input through the perspective of a two‐dimensional ~320 km transect at 8°N that are consistent with more distal and more ambiguous regional records. This chronology allows us to discuss the depositional history of the middle to upper Pleistocene lower Bengal Fan within the context of sea level, climate, and tectonic controls. We hypothesize, based on the timing of accumulation rate changes, that progradation and intensification of the Bengal Fan's channel‐levee system at 8°N was largely driven by increases in sea level amplitude during this time. However, it is also possible this progradation was influenced by changes in Pleistocene climate and increased Himalayan erosion rates, driving greater sediment flux to the fan.
Neural Network Repair of Lossy Compression Artifacts in the September 2015 to March 2016 Duration of the MMS/FPI Data Set
Authors: da Silva Daniel , Barrie A. , Gershman D. , Elkington S. , Dorelli J. , Giles B. , Patterson W.
Published: April 2020

During the September 2015 to March 2016 duration (sometimes referred to as Phase 1A) of the Magnetospheric Multiscale Mission, the Dual Electron Spectrometers (DES) were configured to generously utilize lossy compression. While this maximized the number of velocity distribution functions downlinked, it came at the expense of lost information content for a fraction of the frames. Following this period of lossy compression, the DES was reconfigured in a way that allowed for 95% of the frames to arrive to the ground without loss. Using this high‐quality set of frames from on‐orbit observations, we compressed and decompressed the frames on the ground to create a side‐by‐side record of the compression effect. This record was used to drive an optimization method that (a) derived basis functions capable of approximating the lossless sample space and with nonnegative coefficients and (b) fitted a function which maps the lossy frames to basis weights that recreate the frame without compression artifacts. This method is introduced and evaluated in this paper. Data users should expect a higher level of confidence in the absolute scale of density/temperature measurements and notice less sinusoidal bias in the velocity X and Y components (GSE)
Altitude of Two‐Stream Irregularities in Equatorial E Region Using Sounding Rocket Experiments From Thumba
Authors: Pandey Kuldeep , Gupta S. P.
Published: April 2020

Amplitudes of two‐stream irregularities and equatorial electrojet (EEJ) current are known to peak around the same altitude. Sounding rocket‐borne magnetometer experiments have consistently shown that the EEJ current density maximizes around 105‐km altitude whereas the theoretical models predict the EEJ peak around 100 km. One of the propositions to bridge this difference in the altitude has been based on the inclusion of small‐scale turbulence (wavelength of <100 m) with the large‐scale dynamics (kilometer size). This proposition is examined based on in situ measurements of E region electron density and plasma irregularities (two‐stream and gradient‐drift irregularities) obtained at different times of the day and night. These measurements were obtained based on sounding rocket flight experiments conducted from Thumba Equatorial Rocket Launching Station (8.54° N, 76.86° E), a facility in the vicinity of the dip equator. Whenever two‐stream irregularities are present, the minimum electrojet current density is estimated based on the threshold velocity required for generation of these plasma irregularities. This method provides estimates of nighttime E region current also, which is difficult to measure. It is found that amplitudes of both two‐stream irregularities and the estimated EEJ current peak around 105‐km altitude irrespective of the presence or absence of the gradient‐drift irregularities at the base of electrojet (95‐ to 100‐km altitude).
Do Statistical Models Capture the Dynamics of the Magnetopause During Sudden Magnetospheric Compressions?
Authors: Staples F. A. , Rae I. J. , Forsyth C. , Smith A. R. A. , Murphy K. R. , Raymer K. M. , Plaschke F. , Case N. A. , Rodger C. J. , Wild J. A. , Milan S. E. , Imber S. M.
Published: April 2020

Under periods of strong solar wind driving, the magnetopause can become compressed, playing a significant role in draining electrons from the outer radiation belt. Also termed “magnetopause shadowing,” this loss process has traditionally been attributed to a combination of magnetospheric compression and outward radial diffusion of electrons. However, the drift paths of relativistic electrons and the location of the magnetopause are usually calculated from statistical models and, as such, may not represent the time‐varying nature of this highly dynamic process. In this study, we construct a database ∼20,000 spacecraft crossings of the dayside magnetopause to quantify the accuracy of the commonly used Shue et al. (1998, https://doi.org/10.1029/98JA01103) model. We find that, for the majority of events (74%), the magnetopause model can be used to estimate magnetopause location to within ±1 RE. However, if the magnetopause is compressed below 8 RE, the observed magnetopause is greater than 1 RE inside of the model location on average. The observed magnetopause is also significantly displaced from the model location during storm sudden commencements, when measurements are on average 6% closer to the radiation belts, with a maximum of 42%. We find that the magnetopause is rarely close enough to the outer radiation belt to cause direct magnetopause shadowing, and hence rapid outward radial transport of electrons is also required. We conclude that statistical magnetopause parameterizations may not be appropriate during dynamic compressions. We suggest that statistical models should only be used during quiescent solar wind conditions and supplemented by magnetopause observations wherever possible.
Implications for Magnetosphere‐Ionosphere Coupling From Jupiter's System IV Quasi‐Period
Authors: Coffin Drew , Delamere Peter , Damiano Peter
Published: April 2020

The Io plasma torus exhibits a fundamental rotational periodicity distinct from the rotation of the magnetic field that is easily observed in physical components such as ultraviolet emission or ionic mixing ratios, yet this distinct periodicity has no widely accepted explanation. To seek the origins of this additional periodicity, called System IV, a two‐dimensional (radial and azimuthal) physical chemistry model (Copper et al., 2016), is used to investigate the torus response to a prescribed System III hot electron modulation following Steffl et al. (2008) and an additional hot electron modulation that we relate to various transport and mass loading parameters. The model thus self‐consistently generates a radially independent periodicity consistent with that of System IV. We argue that the origin of this periodicity is the interplay between chemical and transport time scales working to prevent an azimuthal shearing of the hot electron modulation due to the physical subcorotation profile. We also examine recent observations (Tsuchiya et al., 2019,) that volcanic eruptions return the System IV periodicity toward rigid corotation with System III, counter to previous magnetosphere‐ionosphere(MI) coupling models that examined mass loading (Pontius & Hill, 1982, ). Instead, the return to corotation implies improved MI coupling, possibly due to a transport‐related increase in hot electrons following the eruption. Thus, we argue that the System IV periodicity is a diagnostic of MI coupling efficiency at Jupiter and the ultimate result of energy dissipation associated with Alfvénic coupling to the planet.
Electron Acceleration and Thermalization at Magnetotail Separatrices
Authors: Norgren C. , Hesse M. , Graham D. B. , Khotyaintsev Yu. V. , Tenfjord P. , Vaivads A. , Steinvall K. , Xu Y. , Gershman D. J. , Lindqvist P.‐A. , Plaschke F. , Burch J. L.
Published: April 2020

In this study we use the Magnetospheric Multiscale mission to investigate the electron acceleration and thermalization occurring along the magnetic reconnection separatrices in the magnetotail. We find that initially cold electron lobe populations are accelerated toward the X line forming beams with energies up to a few kiloelectron volts, corresponding to a substantial fraction of the electron thermal energy inside the exhaust. The accelerated electron populations are unstable to the formation of electrostatic waves which develop into nonlinear electrostatic solitary waves. The waves' amplitudes are large enough to interact efficiently with a large part of the electron population, including the electron beam. The wave‐particle interaction gradually thermalizes the beam, transforming directed drift energy to thermal energy.
Extreme Magnetosphere‐Ionosphere‐Thermosphere Responses to the 5 April 2010 Supersubstorm
Authors: Nishimura Y. , Lyons L. R. , Gabrielse C. , Sivadas N. , Donovan E. F. , Varney R. H. , Angelopoulos V. , Weygand J. M. , Conde M. G. , Zhang S. R.
Published: April 2020

The extreme substorm event on 5 April 2010 (THEMIS AL = −2,700 nT, called supersubstorm) was investigated to examine its driving processes, the aurora current system responsible for the supersubstorm, and the magnetosphere‐ionosphere‐thermosphere (M‐I‐T) responses. An interplanetary shock created shock aurora, but the shock was not a direct driver of the supersubstorm onset. Instead, the shock with a large southward IMF strengthened the growth phase with substantially larger ionosphere currents, more rapid equatorward motion of the auroral oval, larger ionosphere conductance, and more elevated magnetotail pressure than those for the growth phase of classical substorms. The auroral brightening at the supersubstorm onset was small, but the expansion phase had multistep enhancements of unusually large auroral brightenings and electrojets. The largest activity was an extremely large poleward boundary intensification (PBI) and subsequent auroral streamer, which started ~20 min after the substorm auroral onset during a steady southward IMF Bz and elevated dynamic pressure. Those were associated with a substorm current wedge (SCW), plasma sheet flow, relativistic particle injection and precipitation down to the D‐region, total electron content (TEC), conductance, and neutral wind in the thermosphere, all of which were unusually large compared to classical substorms. The SCW did not extend over the entire nightside auroral activity but was localized azimuthally to a few 100 km in the ionosphere around the PBI and streamer. These results reveal the importance of localized magnetotail reconnection for releasing large energy accumulation that can affect geosynchronous satellites and produce the extreme M‐I‐T responses.