bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep learning-based monocular placental pose estimation: towards collaborative robotics in fetoscopy
Authors: Ahmad Mirza Awais , Ourak Mouloud , Gruijthuijsen Caspar , Deprest Jan , Vercauteren Tom , Vander Poorten Emmanuel
Published: April 2020

Purpose

Twin-to-twin transfusion syndrome (TTTS) is a placental defect occurring in monochorionic twin pregnancies. It is associated with high risks of fetal loss and perinatal death. Fetoscopic elective laser ablation (ELA) of placental anastomoses has been established as the most effective therapy for TTTS. Current tools and techniques face limitations in case of more complex ELA cases. Visualization of the entire placental surface and vascular equator; maintaining an adequate distance and a close to perpendicular angle between laser fiber and placental surface are central for the effectiveness of laser ablation and procedural success. Robot-assisted technology could address these challenges, offer enhanced dexterity and ultimately improve the safety and effectiveness of the therapeutic procedures.

Methods

This work proposes a ‘minimal’ robotic TTTS approach whereby rather than deploying a massive and expensive robotic system, a compact instrument is ‘robotised’ and endowed with ‘robotic’ skills so that operators can quickly and efficiently use it. The work reports on automatic placental pose estimation in fetoscopic images. This estimator forms a key building block of a proposed shared-control approach for semi-autonomous fetoscopy. A convolutional neural network (CNN) is trained to predict the relative orientation of the placental surface from a single monocular fetoscope camera image. To overcome the absence of real-life ground-truth placenta pose data, similar to other works in literature (Handa et al. in: Proceedings of the IEEE conference on computer vision and pattern recognition, 2016; Gaidon et al. in: Proceedings of the IEEE conference on computer vision and pattern recognition, 2016; Vercauteren et al. in: Proceedings of the IEEE, 2019) the network is trained with data generated in a simulated environment and an in-silico phantom model. A limited set of coarsely manually labeled samples from real interventions are added to the training dataset to improve domain adaptation.

Results

The trained network shows promising results on unseen samples from synthetic, phantom and in vivo patient data. The performance of the network for collaborative control purposes was evaluated in a virtual reality simulator in which the virtual flexible distal tip was autonomously controlled by the neural network.

Conclusion

Improved alignment was established compared to manual operation for this setting, demonstrating the feasibility to incorporate a CNN-based estimator in a real-time shared control scheme for fetoscopic applications.
Analytic roughness prediction by deep rolling
Authors: Denkena B. , Abrão A. , Krödel A. , Meyer K.
Published: April 2020

Deep rolling is a widely applied mechanical surface and subsurface treatment method. It is typically used after conventional machining to improve the roughness, increase the surface hardness and to induce compressive residual stresses. The main influence parameters on the surface topography are the applied deep rolling pressure, the ball diameter and the feed. In general, low feeds, larger ball diameters and higher pressures result in an even surface finish. However, an exact prediction of the roughness is not possible. Therefore, it is the aim of the presented research to find a generally applicable method for surface roughness prediction after deep rolling for a variety of steel and aluminum materials. It is shown that the surface topography can be predicted by an analytical model with high accuracy.
Dry Deep Drawing of Aluminum and the Influence of Sheet Metal Roughness
Authors: Flegler Felix , Groche Peter , Abraham Tim , Bräuer Günter
Published: April 2020

Dry forming processes are associated with major challenges, especially when it comes to aluminum as the workpiece material. Major losses in process quality and robustness occur when lubricants are spared. This is due to the high adhesion tendency of aluminum towards common tool materials. Nanoscopically smooth coatings based on amorphous hydrocarbons (a-C:H) can significantly reduce wear. Further preliminary investigations have shown that a reduction of the roughness of a mill-finished sheet results in a significant improvement with regard to the friction and wear behavior in the strip drawing test. These tests are now transferred to a real workpiece. First, the different zones of the deep drawing process are modeled in the strip drawing test and coefficients of friction are derived. Flawless deep drawing tests can be carried out with nanoscopically smooth a-C:H coatings. By polishing the sheets and using the a-C:H coated tools without further surface treatment, the dry friction and wear are reduced, but compared with experiments on smoothened a-C:H coatings, the necessary process forces are higher and may lead to rupture of the aluminum sheet.
Plasma and Nail Zinc Concentrations, But Not Hair Zinc, Respond Positively to Two Different Forms of Preventive Zinc Supplementation in Young Laotian Children: a Randomized Controlled Trial
Authors: Wessells K. Ryan , Brown Kenneth H. , Arnold Charles D. , Barffour Maxwell A. , Hinnouho Guy-Marino , Killilea David W. , Kounnavong Sengchanh , Hess Sonja Y.
Published: April 2020

Plasma zinc concentrations (PZC) have been shown to significantly increase during zinc supplementation. This study investigated the effects of daily preventive zinc supplementation on hair and nail zinc concentrations compared with a control group. In a randomized controlled trial, 6- to 23-month-old children (n = 3407) in Lao PDR were randomly assigned to one of four groups and followed for ~ 36 weeks: daily preventive zinc dispersible tablet (7 mg/d; PZ), daily micronutrient powder (10 mg zinc/d; MNP), therapeutic zinc supplements for diarrhea treatment (20 mg/d for 10 days; TZ), or daily placebo powder (Control). Plasma, hair, and nail zinc concentrations were assessed in a sub-sample of participants (n = 457) at baseline and endline. At baseline, 75% of children had low PZC (< 65 μg/dL). At endline, geometric mean (95% CI) PZC were greater in the PZ and MNP groups compared with the TZ and control groups (P < 0.01), but hair zinc concentrations did not differ among groups (P = 0.99). Nail zinc concentrations were marginally higher in the PZ (115.8 (111.6, 119.9) μg/g) and the MNP (117.8 (113.3, 122.3) μg/g) groups than in the TZ group (110.4 (106.0, 114.8) μg/g;P = 0.055) at endline. This study does not support the use of hair zinc as a biomarker of zinc exposure in young children. However, it provides some evidence that zinc concentrations in nails may respond to supplemental zinc interventions and supports the need for collecting additional data on this emerging biomarker.
Fingolimod Affects Transcription of Genes Encoding Enzymes of Ceramide Metabolism in Animal Model of Alzheimer’s Disease
Authors: Jęśko Henryk , Wencel Przemysław L. , Wójtowicz Sylwia , Strosznajder Joanna , Lukiw Walter J. , Strosznajder Robert P.
Published: April 2020

The imbalance in sphingolipid signaling may be critically linked to the upstream events in the neurodegenerative cascade of Alzheimer’s disease (AD). We analyzed the influence of mutant (V717I) amyloid β precursor protein (AβPP) transgene on sphingolipid metabolism enzymes in mouse hippocampus. At 3 months of age AβPP/Aβ presence upregulated enzymes of ceramide turnover on the salvage pathway: ceramide synthases (CERS2, CERS4, CERS6) and also ceramidase ACER3. At 6 months, only CERS6 was elevated, and no ceramide synthase was increased at 12 months. However, sphingomyelin synthases, which utilize ceramide on the sphingomyelinase pathway, were reduced (SGMS1 at 12 and SGMS2 at 6 months). mRNAs for sphingomyelin synthases SGMS1 and SGMS2 were also significantly downregulated in human AD hippocampus and neocortex when compared with age-matched controls. Our findings suggest early-phase deregulation of sphingolipid homeostasis in favor of ceramide signaling. Fingolimod (FTY720), a modulator of sphingosine-1-phosphate receptors countered the AβPP-dependent upregulation of hippocampal ceramide synthase CERS2 at 3 months. Moreover, at 12 months, FTY720 increased enzymes of ceramide-sphingosine turnover: CERS4, ASAH1, and ACER3. We also observed influence of fingolimod on the expression of the sphingomyelinase pathway enzymes. FTY720 counteracted the AβPP-linked reduction of sphingomyelin synthases SGMS1/2 (at 12 and 6 months, respectively) and led to elevation of sphingomyelinase SMPD2 (at 6 and 12 months). Therefore, our results demonstrate potentially beneficial, age-specific effects of fingolimod on transcription of sphingolipid metabolism enzymes in an animal model of AD.
ECO-SEOM-SEEO safety recommendations guideline for cancer patients receiving intravenous therapy
Authors: Magallón-Pedrera I. , Pérez-Altozano J. , Virizuela Echaburu J. A. , Beato-Zambrano C. , Borrega-García P. , de la Torre-Montero J. C.
Published: April 2020

Purpose

Cancer patients require implantation of venous access devices to meet their personalized therapeutic needs, which are often complex due to the nature of the medication and the disease status. Therefore, it is essential to have standardized protocols that guarantee the best results in health and patient safety.

Methods

To learn about the availability of protocols and aspects related to safety in clinical practice and to detect possible opportunities for improvement, a survey has been conducted in various Spanish hospitals, in addition to a review of the evidence regarding the various devices available and complications associated with the administration of chemotherapy.

Results

As a result of both analyses, the Foundation for Excellence and Quality in Oncology (ECO), the Spanish Society of Medical Oncology (SEOM), and the Spanish Society of Oncology Nursing (SEEO) have developed a catheter selection algorithm based on patient characteristics and treatment to facilitate the clinical decision-making process, as well as some recommendations aimed at ensuring patient safety and rational use of available resources.

Conclusions

In conclusion, both the venous access catheter selection algorithm and the proposed recommendations aim to respond to the needs revealed in clinical practice and to become an integrable tool in electronic prescription systems to offer homogeneous criteria for action in cancer patients that require venous access, optimizing the use of available health resources with the highest safety and quality of life for the patient.
Die Ganztagskoordination und ihre Bedeutung für die multiprofessionelle Kooperation an Ganztagsschulen. Eine explorative Fallstudie
Authors: Reinert Martin
Published: April 2020

Neben dem ‚Mehr an Zeit‘ ist die multiprofessionelle Kooperation zu einem wesentlichen Merkmal von Ganztagsschulen geworden. An die Zusammenarbeit zwischen unterschiedlich pädagogisch Tätigen werden Erwartungen gesetzt, da multiprofessionelle Teams gemeinsam erweiterte Bildungsinhalte und Lernerfahrungen für Schüler/innen ermöglichen sollen. Die Ganztagsschule expandiert so zu einem Ort mit erhöhtem Kooperationsbedarf und konfrontiert die schulischen Akteure mit zusätzlichen Anforderungen. Um den Herausforderungen der multiprofessionellen Kooperation nachzukommen, können Schulleiter/innen u. a. auf sog. Ganztagskoordinationen zurückgreifen. Aktuell lässt sich aufgrund des Mangels an einschlägigen Forschungsbefunden jedoch nur spekulieren, wodurch sich die Tätigkeiten von Ganztagskoordinator/innen tatsächlich auszeichnen. Zwar beschreiben einige Studien und Praxisempfehlungen die multiprofessionelle Kooperation als relevanten Ausschnitt des Aufgabenfeldes von Ganztagskoordinator/innen und weisen diesbezüglich auf erforderliche Kompetenzen hin, der konkrete Wirkungszusammenhang der Kooperation bleibt dabei aber unberührt. Ziel dieses Beitrags ist es daher, anhand einer Fallstudie grundlegend der Frage nach der Bedeutung der Ganztagskoordination für die multiprofessionelle Kooperation an Ganztagsschulen nachzugehen. Es zeigt sich, dass die Ganztagskoordination nicht nur eine strukturell wichtige Position in der Ganztagsschule einnimmt, sondern auch, dass sie gezielt für eine Aufrechterhaltung pädagogischer Zuständigkeitsbereiche genutzt wird.
Undergraduate learning in psychiatry: can we prepare our future medical graduates better?
Authors: Russell Vincent , O’Rourke Linda , Murphy Kieran C.
Published: April 2020

Irish medical schools attract an increasingly diverse student population and produce graduates who will practise in many parts of the world. There are particular implications in this for the planning and delivery of the undergraduate psychiatry curriculum. In all countries, mental health services struggle for equitable resourcing, and mental health care within general medical services remains relatively neglected. The traditional undergraduate psychiatry offering has been justifiably criticised for being excessively oriented towards secondary care when the vast majority of medical graduates will pursue careers in primary care or in specialties other than psychiatry. Recently published articles in the Irish Journal of Psychological Medicine address the current challenges and opportunities in providing an undergraduate experience that better prepares students for the mental health aspects of medical practice in a global context. We summarise and discuss these contributions and the recent Royal College of Psychiatrists publication Choose Psychiatry: Guidance for Medical Schools.
Long-time behavior of Lévy-driven Ornstein–Uhlenbeck processes with regime switching
Authors: Liao Zhongwei , Shao Jinghai
Published: May 2020

We investigate the long-time behavior of the Ornstein–Uhlenbeck process driven by Lévy noise with regime switching. We provide explicit criteria on the transience and recurrence of this process. Contrasted with the Ornstein–Uhlenbeck process driven simply by Brownian motion, whose stationary distribution must be light-tailed, both the jumps caused by the Lévy noise and the regime switching described by a Markov chain can derive the heavy-tailed property of the stationary distribution. The different role played by the Lévy measure and the regime-switching process is clearly characterized.
Associations between serum carotenoid levels and the risk of non-Hodgkin lymphoma: a case–control study
Authors: Li Shan , Zhu Xianglu , Zhu Lin , Hu Xin , Wen Shujuan
Published: April 2020

Limited studies have investigated the effects of serum carotenoids on the risk of non-Hodgkin lymphoma (NHL), and the findings have been inconclusive. This study aims to assess the association between serum total or specific carotenoid levels and NHL risk. This 1:1 matched, hospital-based case–control study enrolled 512 newly diagnosed (within 1 month) NHL patients and 512 healthy controls who were matched by age (±5 years) and sex in Urumqi, China. Serum carotenoid levels were measured by HPLC. Conditional logistic regression showed that higher serum total carotenoid levels and their subtypes (e.g.α-carotene,β-carotene,β-cryptoxanthin and lycopene) were dose-dependently associated with decreased NHL risk. The multivariable-adjusted OR and their 95 % CI for NHL risk for quartile 4 (v. quartile 1) were 0·31 (95 % CI 0·22, 0·48;Pfor trend< 0·001) for total carotenoids, 0·52 (95 % CI 0·33, 0·79;Pfor trend: 0·003) forα-carotene, 0·63 (95 % CI 0·42, 0·94;Pfor trend: 0·031) forβ-carotene, 0·73 (95 % CI 0·49, 1·05;Pfor trend: 0·034) forβ-cryptoxanthin and 0·51 (95 % CI 0·34, 0·75;Pfor trend: 0·001) for lycopene. A null association was observed between serum lutein + zeaxanthin and NHL risk (OR 0·89, 95 % CI 0·57, 1·38;Pfor trend: 0·556). Significant interactions were observed after stratifying according to smoking status, and inverse associations were more evident among current smokers than past or never smokers for total carotenoids,α-carotene and lycopene (Pfor heterogeneity: 0·047, 0·042 and 0·046). This study indicates that higher serum carotenoid levels might be inversely associated with NHL risk, especially among current smokers.
Renaissance Florence and the Origins of Capitalism: A Business History Perspective
Authors: Trivellato Francesca
Published: April 2020

From the 1940s to the 1970s, the commercial revolution of the Middle Ages was a historiographical concept with considerable traction. This article revisits the literature that brought about and engaged with that concept, with specific reference to Florence. In so doing, it draws attention to the place once held by business history in the study of Europe's takeoff. It also discusses the preliminary results of an ongoing project on limited partnerships in early modern Tuscany, which reaffirms the relevance of business history for understanding preindustrial economies but steers away from a teleological search for the origins of modern capitalism.
Triassic magmatism in the European Southern Alps as an early phase of Pangea break-up
Authors: De Min Angelo , Velicogna Matteo , Ziberna Luca , Chiaradia Massimo , Alberti Antonio , Marzoli Andrea
Published: April 2020

Magmatic rocks from the Dolomites, Carnic and Julian Alps, Italy, have been sampled to investigate the origin and geodynamic setting of Triassic magmatism in the Southern Alps. Basaltic, gabbroic and lamprophyric samples have been characterized for their petrography, mineral chemistry, whole-rock major and trace elements, and Sr, Nd and Pb isotopic compositions. Geothermobarometric estimates suggest that the basaltic magmas crystallized mostly at depths of 14–20 km. Isotopic data show variable degrees of crustal contamination decreasing westwards, probably reflecting a progressively more restitic nature of the crust, which has been variably affected by melting during the Permian period. Geochemical and isotopic data suggest that the mantle source was metasomatized by slab-derived fluids. In agreement with previous studies and based on geological evidence, we argue that this metasomatism was not contemporaneous with the Ladinian–Carnian magmatism but was related to previous subduction episodes. The lamprophyres, which likely originated some 20 Ma later by lower degrees of melting and at higher pressures with respect to the basaltic suite, suggest that the mantle source regions of Triassic magmatism in the Dolomites was both laterally and vertically heterogeneous. We conclude that the orogenic signatures of the magmas do not imply any coeval subduction in the surrounding of Adria. We rather suggest that this magmatism is related to the Triassic rifting episodes that affected the western Mediterranean region and that were ultimately connected to the rifting events that caused the break-up of Pangea during the Late Triassic – Early Jurassic period.
Feelings of obligation are valuations of signaling-mediated social payoffs
Authors: Rotella Amanda , Sparks Adam Maxwell , Barclay Pat
Published: April 2020

We extend Tomasello's framework by addressing the functional challenge of obligation. If the long-run social consequences of a decision are sufficiently costly, obligation motivates the actor to forgo potential immediate benefits in favor of long-term social interests. Thus, obligation psychology balances the downstream socially-mediated payoffs from a decision. This perspective can predict when and why obligation will be experienced.
Caregiving relationships as evolutionary and developmental bases of obligation
Authors: Reddy Rachna B. , Wellman Henry M.
Published: April 2020

Obligation as defined by Tomasello requires mutually capable parties, but one-sided caregiver relationships reveal its developmental and evolutionary precursors. Specifically, “coercive” emotions may prompt protective action by caregivers toward infant primates, and infants show distress toward caregivers when they appear to violate expectations in their relationships. We argue that these early social-relational expectations and emotions may form the base of obligation.
Differentiating between different forms of moral obligations
Authors: Anderson Rajen A. , Ruisch Benjamin C. , Pizarro David A.
Published: April 2020

We argue that Tomasello's account overlooks important psychological distinctions between how humans judge different types of moral obligations, such as prescriptive obligations (i.e., what oneshoulddo) and proscriptive obligations (i.e., what oneshould notdo). Specifically, evaluating these different types of obligations rests on different psychological inputs and has distinct downstream consequences for judgments of moral character.
Shared Intentionality, joint commitment, and directed obligation
Authors: Gilbert Margaret
Published: April 2020

Tomasello frequently refers to joint commitment, but does not fully characterize it. In earlier publications, I have offered a detailed account of joint commitment, tying it to a sense that the parties form a “we,” and arguing that it grounds directed obligations and rights. Here I outline my understanding of joint commitment and its normative impact.
The many faces of obligation
Authors: Tomasello Michael
Published: April 2020

My response to the commentaries focuses on four issues: (1) the diversity both within and between cultures of the many different faces of obligation; (2) the possible evolutionary roots of the sense of obligation, including possible sources that I did not consider; (3) the possible ontogenetic roots of the sense of obligation, including especially children's understanding of groups from a third-party perspective (rather than through participation, as in my account); and (4) the relation between philosophical accounts of normative phenomena in general – which are pitched as not totally empirical – and empirical accounts such as my own. I have tried to distinguish comments that argue for extensions of the theory from those that represent genuine disagreement.
Generational Discontinuities and the Memory of Traumatic Events: the Case of Eastern Europe with a Special Focus on Germany
Authors: Cavalli Alessandro
Published: May 2020

In certain contingencies, traumatic events intervene in breaking the continuity of the life of social communities or whole societies. Such events include natural catastrophes but also wars or revolutions. This article looks in particular at recollections of the Second World War.
Relationship between gestational acrylamide exposure and offspring’s growth: a systematic review and meta-analysis of cohort studies
Authors: Zhan Yongle , Xiao Ying , Guan Tianjia , Zhang Shuyang , Jiang Yu
Published: April 2020

Objective:

To estimate the current evidence regarding the association between gestational acrylamide (AA) exposure and offspring’s growth.

Design:

Systematic review and meta-analysis.

Setting:

A systematic literature search for relevant publications was conducted using PubMed, Medline, Embase, Web of Science databases from inception to 26 April 2019. The standardised mean difference (SMD) or OR with 95 % CI was selected as the effect sizes and was calculated using a random effects model.

Results:

Five cohort studies including 54 728 participants were identified. Offspring’s birth weight was significantly lower in high AA exposure group than in low AA exposure group (SMD –0·05, 95 % CI –0·09, –0·02, P = 0·005). There was also an association between maternal AA exposure and small for gestational age (OR 1·14, 95 % CI 1·06, 1·23, P < 0·001). In addition, pooled ORs suggested that children had a high risk of developing overweight/obesity in the future in maternal high AA exposure group (OR 1·14, 95 % CI 1·08, 1·21, P < 0·001 at age 3; OR 1·13, 95 % CI 1·07, 1·19, P < 0·001 at age 5; OR 1·09, 95 % CI 1·02, 1·16, P = 0·020 at age 8).

Conclusions:

These findings have important implications for conducting health education, providing guidance on maternal diet and developing an appropriate dietary strategy for pregnant women to reduce dietary AA exposure.
Meal deals, combos and bundling: the impact on the nutrition composition of children’s meals in restaurants
Authors: Reeves Sue
Published: April 2020

Increased consumption of food outside the home means that the nutritional content of meals served in restaurants now makes a significant contribution to overall diet. Children’s menus in restaurants, usually aimed at those aged 10 years and younger, are frequently high in energy, fat, salt, sugar and lack variety. The food and drink on children’s menus are often bundled together as a combo or meal deal that may be convenient to order and sometimes, but not always, cheaper. Bundling has the potential to add additional foods that may not have been selected individually thus increasing the amount ordered and consumed. Substituting some meal deal items for healthier options has the potential to make it easier to eat well when eating outside the home and improve dietary intakes. However, the impact of such measures on child health has yet to be fully explored.
Freedom in the External Relation of All Human Beings: On Kant’s Cosmopolitanism
Authors: Rostbøll Christian F.
Published: April 2020

An influential interpretation of Kant’s Doctrine of Right suggests that the relationship between public right and freedom is constitutive rather than instrumental. The focus has been on domestic right and members’ relations to their own state. This has resulted in a statist bias which has not adequately dealt with the fact that Kant regards public right as a system composed of three levels – domestic, international and cosmopolitan right. This article suggests that the constitutive relationship is between all levels of right, on the one hand, and ‘freedom in the external relation’ of all human beings, on the other hand.
Determination of Mass Attenuation Coefficients of Th, U, Np, and Pu for Oxygen KαX-Rays Using an Electron Microprobe
Authors: Pöml Philipp , Llovet Xavier
Published: April 2020

Mass attenuation coefficients (MACs) of Th, U, Np, and Pu for oxygen X-rays have been experimentally determined using an electron microprobe. The MACs were obtained by measuring relative X-ray intensities emitted from ThO2, UO2, NpO2, and PuO2targets, for incident electron energies from 5 to 30 keV, and processing them with the help of the computer program XMAC. The accuracy of the measured MACs is estimated to be better than 5%. Results are compared with MAC tabulations commonly used in electron probe microanalysis as well as with theoretical photoionization calculations. It is concluded that the MACs implemented in the Monte Carlo simulation program PENELOPE which are based on the photoionization cross-section calculations of Sabbatucci & Salvat [(2016). Theory and calculation of the atomic photoeffect.Rad Phys Chem121, 122–140], provide the best agreement with our measurements. The use of different MAC schemes for the analysis of mixed actinide oxide materials is discussed.
Legal pedagogy and its discontents
Authors: Abel Richard
Published: May 2020

I taught torts and legal profession at six US law schools over the course of forty years (1969–2008). This paper describes my efforts to incorporate socio-legal studies and critical legal studies into my teaching and my reflections on how successful this was.
Delayed severe median nerve palsy due to undiagnosed brachial pseudoaneurysm
Authors: Trihan Jean-Eudes , Lebuhotel Iris , Desvergnes Mathieu , Schneider Fabrice
Published: May 2020

Summary. Post-catheterization pseudoaneurysms are a well-known complication of many endovascular procedures at the site of arterial puncture. However, long-term neurological complications due to undiagnosed compression are rare. A 60-year-old man presented to our unit for round, non-pulsatile, painless swelling in the inner side of his upper arm. Clinical examination showed finger paralysis, associated with amyotrophy of the forearm. Large brachial pseudoaneurysm with median nerve compression was diagnosed. The patient underwent autologous vein bypass, with poor 6-month neurological recovery. Early diagnosis of pseudoaneurysms is paramount because, when associated with nerve compression, the longer the diagnostic delay, the poorer the neurological prognosis.
The Brittle‐Plastic Transition, Earthquakes, Temperatures, and Strain Rates
Authors: Molnar Peter
Published: April 2020

Maximum depths of earthquakes in different settings are commonly thought to lie within a transition, many kilometers in width, from brittle deformation at shallow depths to plastic deformation by high‐temperature creep at greater depth. A review of temperatures and strain rates, both of which are low in intraplate settings, shows faster deformation in warmer tectonically active regions and highest strain rates in regions where the movement of magma affects strain rates and temperatures are especially high. Although intraplate earthquakes appear to occur in oceanic lithosphere only where colder than ~600°C, in tectonically active regions, where strain rates are several orders of magnitude higher than intraplate settings, earthquakes occur where temperatures exceed 600°C and perhaps 800°C. The temperature cutoff increases by ~100°C as strain rates increase by ~2 to 2.5 orders of magnitude. Nowhere, however, do any two of average strain rates, background stresses, and temperatures seem to be determined well enough that, when combined with laboratory‐based flow laws for high‐temperature creep, they can place a tight constraint on the third of these quantities. At the same time, the pattern of higher temperatures at higher strain rates follows the general forms of power law and Peierls creep that are appropriate for lithospheric conditions.
Constraints on the Abundances of Carbon and Silicon in Mercury's Core From Experiments in the Fe‐Si‐C System
Authors: Vander Kaaden Kathleen E. , McCubbin Francis M. , Turner Amber A. , Ross D. Kent
Published: April 2020

The composition of a planet's core has important implications for the thermal and magmatic evolution of that planet. Here, we conducted carbon (C) solubility experiments on iron‐silicon (Fe‐Si) metal mixtures (up to 35 wt% [~52 atom%] Si) at 1 GPa and 800–1800°C to determine the carbon concentration at graphite saturation (CCGS) in metallic melt and crystalline metal with varying proportions of Fe and Si to constrain the C content of Mercury's core. Our results, combined with those in the literature, show that composition is the major controlling factor for carbon solubility in Fe‐rich metal with minimal effects from temperature and pressure. Moreover, there is a strong anticorrelation between the abundances of carbon and silicon in iron‐rich metallic systems. Based on the previous estimates of <1–25 wt% Si in Mercury's core, our results indicate that a carbon‐saturated Mercurian core has 0.5–6.4 wt% C, with 6.4 wt% C corresponding to an Si‐free, Fe core and 0.5 wt% C corresponding to an Fe‐rich core with 25 wt% Si. The upper end of estimated FeO abundances in the mantle (up to 2.2 wt%) are consistent with a core that has <1 wt% Si and up to 6.4 wt% C, which would imply that bulk Mercury has a superchondritic Fe/Si ratio. However, the lower end of estimated FeO (≤0.05 wt%) supports CB chondrite‐like bulk compositions of Mercury with core Si abundances in the range of 5–18.5 wt% and C abundances in the range of 0.8–4.0 wt%.
Modeling the Formation of Topographic Asymmetry by Aspect‐Dependent Erosional Processes and Lateral Channel Migration
Authors: Richardson P. W. , Perron J. T. , Miller S. R. , Kirchner J. W.
Published: April 2020

Some landscapes exhibit the intriguing characteristic that the steepness of hillslopes varies systematically with the direction they face, even where there is no bias introduced by bedrock structure. This topographic asymmetry has inspired numerous explanations. In the simplest scenario, insolation‐driven microclimatic differences lead to different erosion rates on opposing slopes and topographic asymmetry develops. Alternatively, lateral channel migration and the corresponding steepening of undercut slopes have also been suggested as a dominant cause of topographic asymmetry. To examine these proposed origins of asymmetric topography, we adapted a numerical landscape evolution model to include lateral channel migration as well as aspect‐induced variations in soil creep, regolith strength, and runoff. We compared the resulting topography and erosional response produced by each mechanism and found that the model with lateral channel migration produces unique signatures in erosion rates and the ridgetop Laplacian of elevation. To further investigate lateral channel migration, we developed a model of hillslope profile evolution in which sediment fluxes from opposing slopes control lateral channel migration rate and direction. We find that topographic asymmetry in this system can be self‐sustaining. All else being equal, we find that the aspect‐dependent models with variable regolith strength or runoff predict that less topographic asymmetry should develop as slope length decreases. These two models also predict that weaker asymmetry should develop as rock strength increases, whereas the lateral channel migration model predicts that greater rock strength should lead to weaker asymmetry only if lateral channel migration efficiency increases faster than fluvial incision efficiency.
Enhanced Poleward Flux of Atmospheric Moisture to the Weddell Sea Region (ODP Site 690) During the Paleocene‐Eocene Thermal Maximum
Authors: Kozdon Reinhard , Penman Donald E. , Kelly D. C. , Zachos J. C. , Fournelle John H. , Valley J. W.
Published: April 2020

Earth's hydrological cycle was profoundly perturbed by massive carbon emissions during an ancient (56 Ma) global warming event referred to as the Paleocene‐Eocene thermal maximum (PETM). One approach to gaining valuable insight into the response of the hydrological cycle is to construct sea‐surface salinity (SSS) records that can be used to gauge changes in the rates of evaporation and precipitation during the PETM in such climatically sensitive areas as the circum‐Antarctic region. Here, we pair oxygen isotope (δ18O) and magnesium‐calcium (Mg/Ca) measurements to reconstruct PETM sea‐surface temperatures (SSTs) and δ18O composition of seawater (δ18Osw) at austral Site 690 (Weddell Sea). Several discrepancies emerge between the δ18O‐ and Mg/Ca‐based SST records, with the latter indicating that the earliest PETM was punctuated by a short‐lived ~4°C increase in local SSTs. Conversion of the δ18Osw values to SSS reveals a ~4 ppt decrease ~50 ka after peak PETM warming at Site 690. This negative SSS (δ18Osw) anomaly coincides with a prominent minimum in the planktic foraminifer δ18O record published for the Site 690 PETM section. Thus, our revised interpretation posits that this δ18O minimum signals a decrease in surface‐ocean δ18Osw fostered by a transient increase in mean annual precipitation in the Weddell Sea region. The results of this study corroborate the view that the poleward flux of atmospheric moisture temporarily increased during a distinctive stage of the PETM.
Effects of Spatial Variability in the Groundwater Isotopic Composition on Hydrograph Separation Results for a Pre‐Alpine Headwater Catchment
Authors: Kiewiet Leonie , van Meerveld Ilja , Seibert Jan
Published: May 2020

Isotope hydrograph separation is a powerful tool to investigate catchment functioning. In most hydrograph separation studies, a pre‐event baseflow sample is used to represent the pre‐event water, and thus, baseflow is assumed to be a mixture of all the water that is stored in the catchment. However, baseflow may not be representative of all water stored in the catchment because some sources may not contribute to baseflow. This is problematic when the isotopic composition of the sources is highly variable. We quantified the effects of spatial variability in the shallow groundwater isotopic composition on pre‐event water characterization and hydrograph separation results. We compared the composition of groundwater sampled at 38 wells in a 0.2 km2 pre‐alpine catchment with stream water sampled before, during, and after three rainfall events. We estimated the number of groundwater samples needed to characterize the average groundwater composition in the catchment and its spatial variability and compared the results of two‐component hydrograph separations for different ways to characterize the pre‐event water. We found that differences in the calculated pre‐event water fractions and uncertainties were large and depended on which and how many samples were used to characterize the pre‐event water composition. Analyses based on a limited number of groundwater samples likely underestimate the real uncertainty and can give a false impression of accuracy. Our results highlight the importance of representing the variability in the pre‐event water composition when applying hydrograph separation analyses. We therefore recommend sampling pre‐event water at multiple locations or estimating the variability based on literature values.
Solid fuel use and early child development disparities in Ghana: analyses by gender and urbanicity
Authors: Nazif-Muñoz José Ignacio , Spengler John D. , Arku Raphael E. , Oulhote Youssef
Published: May 2020

In Ghana, more than 77% of the population depends on biomass fuels for cooking. Previous studies show that solid fuel use (SFU) has adverse effects on pregnancy and child health outcomes. Yet, no previous study considered potential effects on early child development indicators (ECDI), nor how SFU effects may vary by gender, and rural and urban areas. We investigated the associations of SFU with ECDI measures, and whether these associations exhibited sex and urban/rural differences. We used the 2011–2012 Ghana’s Multiple Indicator Cluster Surveys–UNICEF (N = 3326 children; 3–4 years). We derived a binary ECDI measure reflecting whether the child is developmentally on track or not from a caregiver-report of ten yes/no/do not know questions designed specifically to assess four domains of early child development: learning-cognition, literacy-numeracy, socio-emotional, and physical. We used multilevel Poisson regressions adjusting for neighborhood, household, mother, and child’s characteristics to estimate covariate-adjusted prevalence ratios (PRs) of the associations between SFU and ECDI and its four dimensions. We run stratified analyses and used z-score tests of differences to evaluate effect modification by sex and urbanicity. Overall, 85% of children were exposed to SFU and 28% of children were not developmentally on track. After adjustment for confounders, children exposed to SFU were more likely to be not developmentally on track in comparison with nonexposed children (PR = 1.16; 95% confidence interval, [95% CI]: 1.10,1.22). These associations were stronger in girls (PR = 1.36; 95% CI: 1.03,1.79) in comparison with boys (PR = 0.87; 95% CI: 0.73,1.04). No difference in associations was observed between urban and rural children. Overall, these associations were mainly driven by the literacy-numeracy dimension. In this study, we show that SFU was associated with developmental delays in Ghanaian girls. Policy efforts which tackle SFU should be mindful of gender disparities in susceptibility to indoor pollution.
A systematic analysis of apple root resistance traits to Pythium ultimum infection and the underpinned molecular regulations of defense activation
Authors: Zhu Yanmin , Saltzgiver Melody
Published: April 2020

Apple replant disease (ARD), caused by a pathogen complex, significantly impacts apple orchard establishment. The molecular regulation on ARD resistance has not been investigated until recently. A systematic phenotyping effort and a series of transcriptomic analyses were performed to uncover the underpinned molecular mechanism of apple root resistance to P. ultimum, a representative member in ARD pathogen complex. Genotype-specific plant survival rates and biomass reduction corresponded with microscopic features of necrosis progression patterns along the infected root. The presence of defined boundaries separating healthy and necrotic sections likely caused delayed necrosis expansion in roots of resistant genotypes compared with swift necrosis progression and profuse hyphae growth along infected roots of susceptible genotypes. Comprehensive datasets from a series of transcriptome analyses generated the first panoramic view of genome-wide transcriptional networks of defense activation between resistant and susceptible apple roots. Earlier and stronger molecular defense activation, such as pathogen perception and hormone signaling, may differentiate resistance from susceptibility in apple root. Delayed and interrupted activation of multiple defense pathways could have led to an inadequate resistance response. Using the panel of apple rootstock germplasm with defined resistant and susceptible phenotypes, selected candidate genes are being investigated by transgenic manipulation including CRISPR/Cas9 tools for their specific roles during apple root defense toward P. ultimum infection. Individual apple genes with validated functions regulating root resistance responses can be exploited for developing molecular tools for accurate and efficient incorporation of resistance traits into new apple rootstocks.
Integrative transcriptome, proteome, and microRNA analysis reveals the effects of nitrogen sufficiency and deficiency conditions on theanine metabolism in the tea plant (Camellia sinensis)
Authors: Liu Zhi-Wei , Li Hui , Liu Jie-Xia , Wang Yu , Zhuang Jing
Published: April 2020

Nitrogen (N) is associated with amino acid metabolism in higher plants. Theanine is an important amino acid in tea plants. To explore the relationship between theanine metabolism and N conditions, we examined the differentially expressed genes (DEGs), proteins (DEPs), and microRNAs (DEMs) involved in theanine metabolism in tea plant shoots and roots under N sufficiency and deficiency conditions. Transcriptome, proteome, and microRNA analyses were performed on tea plant shoots and roots under N sufficiency and deficiency conditions. The contents of theanine, expression levels of genes involved in theanine metabolism, contents of proteinogenic amino acids, and activity of enzymes were analyzed. The DEP–DEG correlation pairs and negative DEM–DEG interactions related to theanine metabolism were identified based on correlation analyses. The expression profiles of DEGs and negative DEM–DEG pairs related to theanine biosynthesis were consistent with the sequencing results. Our results suggest that the molecular and physiological mechanism of theanine accumulation is significantly affected by N sufficiency and deficiency conditions. The DEGs, DEPs, and DEMs and the activity of the enzymes involved in theanine biosynthesis might play vital roles in theanine accumulation under N sufficiency and deficiency conditions in the shoots and roots of tea plants.
Joint Iterative Fast Projection Matching for Fully Automatic Marker-free Alignment of Nano-tomography Reconstructions
Authors: Wang Chun-Chieh
Published: April 2020

Highly accurate, fully automatic marker-free image alignment plays an important role in nano-tomographic reconstruction, particularly in cases where the spatial resolution of the tomographic system is on the nanometer scale. However, highly accurate marker-free methods such as the projection matching method are computationally complex and time-consuming. Achieving alignment accuracy with reduced computational complexity remains a challenging problem. In this study, we propose an efficient method to achieve marker-free fully automatic alignment. Our method implements three main alignment procedures. First, the frequency-domain common line alignment method is used to correct the in-plane rotational errors of each projection. Second, real-space common line alignment method is used to correct the vertical errors of the projections. Finally, a single layer joint-iterative reconstruction and re-projection method is used to correct the horizontal projection errors. This combined alignment approach significantly reduces the computational complexity of the classical projection matching method, and increases the rate of convergence towards determining the accurate alignment. The total processing time can be reduced by up to 4 orders of magnitude as compared to the classical projection matching method. This suggests that the algorithm can be used to process image alignment of nano-tomographic reconstructions on a conventional personal computer in a reasonable time-frame.
A Posteriori Reconstruction of the Temperature Distribution in Surface Hardened Tempering Steel
Authors: Mevec Daniel G. , Raninger Peter , Prevedel Petri , Jászfi Vince
Published: May 2020

Process control in surface hardening depends greatly on the repeatability of the results. Induction heating facilities stand out in this aspect but challenges arise when it comes to the verification of the expected temperatures. In-situ temperature measurement of a workpiece may be made impossible due to it moving through an enclosed, automated induction facility that lacks built-in sensors. This paper uses transition patterns in the microstructure of the hardened region to reconstruct isothermal contour lines of the temperature field during austenitisation. It does so based on a continuous cooling transformation phase diagram and a time-temperature-austenitisation diagram of the considered steel. The presented method serves as a practical approach to validate simulations of the inductive austenitising process and supports simulations of the heat treatment of the work piece. Once these simulations have been iterated upon and validated thoroughly, they may then yield a reconstruction of the entire temperature field during the heat treatment process.
Simple capacitor-switch model of excitatory and inhibitory neuron with all parts biologically explained allows input fire pattern dependent chaotic oscillations
Authors: Cejnar Pavel , Vyšata Oldřich , Kukal Jaromír , Beránek Martin , Vališ Martin , Procházka Aleš
Published: April 2020

Due to known information processing capabilities of the brain, neurons are modeled at many different levels. Circuit theory is also often used to describe the function of neurons, especially in complex multi-compartment models, but when used for simple models, there is no subsequent biological justification of used parts. We propose a new single-compartment model of excitatory and inhibitory neuron, the capacitor-switch model of excitatory and inhibitory neuron, as an extension of the existing integrate-and-fire model, preserving the signal properties of more complex multi-compartment models. The correspondence to existing structures in the neuronal cell is then discussed for each part of the model. We demonstrate that a few such inter-connected model units are capable of acting as a chaotic oscillator dependent on fire patterns of the input signal providing a complex deterministic and specific response through the output signal. The well-known necessary conditions for constructing a chaotic oscillator are met for our presented model. The capacitor-switch model provides a biologically-plausible concept of chaotic oscillator based on neuronal cells.