bluuebunny/crossref_metadata_2025 huggingface dataset:
Model of stress-induced phase transformation and prediction of internal stresses of large steel workpieces during quenching
Authors: Shi W. , Zhang X. , Liu Z.
Published: July 2021

Because internal stresses in large steel workpieces are high during quenching, the coupling of stresses and phase transformations should be considered to predict the internal stresses. The influence of stresses on phase transformations was investigated by dilatometer experiments applied uniaxial loads, modified John-Mehl-Avrami equation and Koistinen-Marburger equation were suggested to model the stress-phase transformation coupling during quenching. The model suggested was used in an in-house FEM code NSHT developed by authors. The distribution of residual stresses of a hollow cylinder specimen was calculated to investigate the stress-induced phase transformation. The internal stresses of a generator rotor during different quenching processes and stresses at the groove bottom of a turbine rotor in quenching were analyzed.
Analysis of temporal and spatial temperature gradients at pronouncedly fluctuating cooling conditions
Authors: Galović A. , Andrassy M. , Mudrinić S.
Published: July 2021

Realised cooling velocities of a probe (cylinder) at discrete radius points during cooling at pronouncedly fluctuating cooling conditions are presented. Submerging the probe into an air-corundum (Al2O3) particles fluidised system of insufficient cooling capacity imposes the fluctuating cooling conditions. The particles have an average granulation of 95 m; the cylindrical probe diameter is 50 mm and its height 175 mm. The probe surface temperature and the temperature 1.5 mm beneath its surface are measured with built-in thermocouples. The thermocouples have a very high sensitivity, which enables temperature variation recording according to the cooling dynamics. The relevant cooling time is 125 seconds. The temperature changes in discrete points of the cylinder radius are determined by the control volume method. The calculation results indicate a shift of the maximum cooling velocity towards the interior of the cylinder.
Validation of a single component gas quenching model
Authors: Stratton P. F. , Richardson A.
Published: July 2021

An extensive CFD modelling study of cooling using nitrogen jets showed that an array of high velocity gas jets close to the part surface could produce cooling at a similar speed to oil. The optimum conditions were: an approximately uniform nozzle field with the jets four to eight times their own diameter apart at a distance from the part to be quenched of a quarter of the diameter of the jets; and a jet velocity of 100 m/s. When the optimised conditions were applied to an idealised gear form, the model suggested that it could be fully hardened if a nitrogen/hydrogen mixture was used. The use of the model had dramatically reduced the time to discover the optimum conditions but no validation experiments had been carried out. Before proceeding with any commercial applications, the model was validated using a physical test rig. It showed that the model was very close to reality and that the results of modelling could be used to predict the behaviour of production parts.
Description of short time phase transformations during the heating of steels based on high-rate experimental data
Authors: Mioković T. , Schwarzer J. , Schulze V. , Vöhringer O. , Löhe D.
Published: July 2021

During surface hardening of steels like laser hardening, rapid thermal changes are imposed to the material. The modelling of these hardening processes allows the determination of time-dependent temperature fields and phase transformations within the affected zones. While there are many investigations on the transformation behaviour during cooling, there is a lack of data concerning the transformation during heating at very high heating rates. Therefore, experiments simulating the fast temperature changes are necessary to implement the effects of short time phase transformation during hardening into simulation.
In this paper the effect of heating rates up to 10000 K/s on the austenitizing behaviour of the steel AISI 4140 (German grade 42CrMo4) are presented and described using an Avrami-function. The results obtained are summarized in time-temperature-transformation diagrams for continuous heating and isothermal time-temperature-transformation diagrams which may be used as input data for the simulation.
Experimental validation of an electro-thermo-metallurgical predictive model in resistance spot welding
Authors: Sibilia G. , Rogeon P. , Paillard P. , Saindrenan G. , Soigneux J. , Lemasson P. , Carron D.
Published: July 2021

In order to address spot welding numerical simulation of high strength steel, the validation of the model developed by the author in collaboration with PSA inc. using thermal kinetics measured within electrodes and sheets is described. The instrumentation techniques experimented here on either zinc coated or bare sheet assemblies aim at hindering interferences inevitably generated by the installation of intrusive sensors. Numerical and experimental results are compared for shape and size of welding spots, thermal kinetics and microstructures. All hypotheses and data sets considered to define interfacial conditions are then discussed.
Prediction of residual stresses in the heat affected zone
Authors: Taleb L. , Petit S. , Jullien J.-F.
Published: July 2021

In this paper the behavior of a disc made up of carbon manganese steel and subjected to an axisymmetric heating in its middle zone is considered. The applied thermal cycle generates localized metallurgical solid-solid phase transformations. Contrary to the study performed some years ago, the present work is concerned with relatively thick discs that lead to variable behavior according to axial direction. Experimentally, temperature and axial displacement of the face below have continuously been measured during tests. At the end of tests, the nature and the proportions of the final phases as well as residual stresses on both faces of the discs has also been assessed. These experimental results have been compared to numerical simulations using the finite element code ASTER, developed by Electricité de France (EDF), that enables to take into account the main mechanical consequences of phase transformations. From the obtained results it can be pointed out the significant importance to take into account the transformation induced plasticity (TRIP) phenomenon for better estimation of residual stresses.
Thermomechanical analysis applied to the laser beam welding simulation of aeronautical structures
Authors: Darcourt C. , Roelandt J. M. , Rachik M. , Deloison D. , Journet B.
Published: July 2021

The present work is being done in the framework of a national program about the lightening of aeronautical structures and describes a three-dimensional finite element simulation of the laser beam welding process. The targeted aeronautical structures are stiffened panels in aluminum alloys, which tend to replace riveted assemblies. Semi-coupled thermomechanical finite element analyses have been carried out to evaluate the magnitude and distribution of welding-induced residual stresses in order to take them into account for fatigue sizing. The finite element code MSC.Marc is used for the different calculations. Specific welding features have been added to the code through the implementation of a moving heat source or an elastoviscoplastic law. Experimental tests have been carried out in order to provide mechanical and thermal databases to the model. Monitored experimental welding have been made for comparisons with the simulation. In particular, results of thermocouple measurements have permitted to improve the thermal model.
Clinical attitude regarding denosumab drug-holiday for dental extraction in oncologic patients: a national survey
Authors: Lainé Claire , Desoutter Aline , Chaux Anne-Gaëlle
Published: July 2021

Introduction: Denosumab is indicated in oncology to reduce tumoral development. However, this medication may cause osteonecrosis of the jaw, especially after dental extractions. Drug holiday has been proposed to decrease the risk of osteonecrosis of the jaw. This survey aimed to assess the management of drug holidays for patients who needed both dental extraction and denosumab. Methods: A questionnaire was sent to a panel of healthcare professionals. Results: Of the 33 practitioners interviewed, 28 undertook or “were used to” dental extractions in patients on denosumab. 25% (7/28) of the practitioners questioned did not stop patients from taking denosumab before dental extraction and 75% (21/28) used a drug holiday. For those who stopped the treatment, 33% (7/21) waited 2 months before performing dental extraction and 38% (8/21) waited 2 months after the dental extraction before reintroducing the molecule; 2 months being the median duration in both cases. In addition, 89% (25/28) of practitioners, modified their surgical procedure for these patients. Conclusion: Despite a small number of responders, it seemed that a drug holiday of at least 2 months is mandatory before performing tooth extraction. The issue of the drug holiday should always be raised with the patient's oncologist.
Are microtargeted campaign messages more negative and diverse? An analysis of Facebook Ads in European election campaigns
Authors: López Ortega Alberto
Published: July 2021

Concerns about the use of online political microtargeting (OPM) by campaigners have arisen since the Cambridge Analytica scandal hit the international political arena. In addition to providing conceptual clarity on OPM and explore the use of such techniques in Europe, this paper seeks to empirically disentangle the differing behaviours of campaigners when they message citizens through microtargeted rather than non-targeted campaigning. More precisely, I hypothesise that campaigners use negative campaigning and are more diverse in terms of topics when they use OPM. To investigate whether these expectations hold true, I use text-as-data techniques to analyse an original dataset of 4,091 political Facebook Ads during the last national elections in Austria, Italy, Germany and Sweden. Results show that while microtargeted ads might indeed be more thematically diverse, there does not seem to be a significant difference to non-microtargeted ads in terms of negativity. In conclusion, I discuss the implications of these findings for microtargeted campaigns and how future research could be conducted.
Liquid photonic microcavity yields deformable soft microresonator that can be gradually tuned
Authors: Liebendorfer Adam
Published: July 2021

Computerized holographic tweezers provide one path forward for future 3D photonics circuits.
Demonstrating geometric phase acquisition in multi-path tunnel systems using a near-term quantum computer
Authors: Bhattacharyya Shaman , Bhattacharyya Somnath
Published: July 2021

Quantum computers have shown promise in simulating quantum many-body physics, even under the constraints that arise due to limitations in the number of qubits involved. Considering the effects of tunneling, backscattering and the accumulation of a geometric phase, we see the possibility of simulating weak anti-localization (WAL), in addition to the weak localization in a multi-path system. We show how a quantum simulator works through the construction of multiple scattering centers in closed paths and tunnel barriers yielding a large return probability (Pr) for electrons. A combination of inter- and intra-layer tunneling in a double-path circuit creates a phase reversal and subsequently the WAL effect. Incorporation of such arrangements of tunnel barriers can add a geometric phase and demonstrate Aharonov–Bohm-type Φ0 and Φ0/2 oscillations in a ring and a tube, respectively. Finally, the angle dependence of Pr shows a phase reversal in the two-path circuit caused by the inter-path resonance.
Surface acoustic wave induced modulation of tunneling magnetoresistance in magnetic tunnel junctions
Authors: Bhattacharya Dhritiman , Sheng Peng , Abeed Md Ahsanul , Zhao Zhengyang , Li Hongshi , Wang Jian-Ping , Bandyopadhyay Supriyo , Ma Bin , Atulasimha Jayasimha
Published: July 2021

We show that a surface acoustic wave (SAW) applied across the terminals of a magnetic tunnel junction (MTJ) decreases both the (time-averaged) parallel and antiparallel resistances of the MTJ, with the latter decreasing much more than the former. This results in a decrease in the tunneling magnetoresistance ratio. The coercivities of the free and fixed layers of the MTJ, however, are not affected significantly, suggesting that the SAW does not cause large-angle magnetization rotation in the magnetic layers through the inverse magnetostriction (Villari) effect at the power levels used. This study sheds light on the dynamical behavior of an MTJ under periodic compressive and tensile strain.
A particle-in-cell code comparison for ion acceleration: EPOCH, LSP, and WarpX
Authors: Smith Joseph R. , Orban Chris , Rahman Nashad , McHugh Brendan , Oropeza Ricky , Chowdhury Enam A.
Published: July 2021

There are now more Particle-in-Cell (PIC) codes than ever before that researchers use to simulate intense laser–plasma interactions. To date, there have been relatively few direct comparisons of these codes in the literature, especially for relativistic intensity lasers interacting with thin overdense targets. To address this, we perform a code comparison of three PIC codes: EPOCH, LSP, and WarpX for the problem of laser-driven ion acceleration in a 2D(3v) geometry for a 1020 W cm−2 intensity laser. We examine the plasma density, ion energy spectra, and laser–plasma coupling of the three codes and find strong agreement. We also run the same simulation 20 times with different random seeds to explore statistical fluctuations of the outputs. We then compare the execution times and memory usage of the codes (without “tuning” to improve performance) using between 1 and 48 processors on one node. We provide input files to encourage larger and more frequent code comparisons in this field.
Sheltering electroconvective instability in a weak electrolyte
Authors: Liu Wei , Zhou Yueting , Shi Pengpeng
Published: July 2021

Sheltering vortices by shear flow is a common method in plasma and neutral fluids and has recently been successfully applied to control ionic fluids. This work proposes a new chemical sheltering vortex method for electroconvective instability (ECI) based on the Onsager chemical effect. We reveal unique ECI behaviors in a weak electrolyte with the Onsager effect, including the vortex height selection, overlimiting transport, and vortex structure. Due to the strong electric field strength in the electric double layer, the Onsager effect in a weak electrolyte causes neutral molecules to generate additional free ions, which weakens the thickness of the extended space charge layer and causes the fluid to transition from a chaotic ECI to a steady ECI. Consequently, the Onsager effect shelters ECI without an oblique vortex, which is significantly different from the shear flow effect [Kwak et al., “Sheltering the perturbed vortical layer of electroconvection under shear flow,” J. Fluid Mech. 813, 799 (2017)]. We believe that the proposed chemical control strategy can be an alternative candidate for ionic fluids.
Teamwork in the viscous oceanic microscale
Authors: Kanso Eva A. , Lopes Rubens M. , Strickler J. Rudi , Dabiri John O. , Costello John H.
Published: July 2021

Significance

Nutrient acquisition is a challenge that often favors small individual phytoplanktors because they are superior competitors at low nutrient levels. An alternative to these individual solutions is the union of different species into consortia that rely upon division of labor for competitive advantage. Although planktonic epibionts are well documented, the advantages of consortia for the larger host cells have remained unclear. Here, we demonstrate that attached ciliates dramatically increase the flux of dissolved nutrients to host phytoplankton cells, providing the necessary conditions for large diatoms to thrive in oligotrophic ecosystems. This demonstrates that unions between different species can substantially increase rates of nutrient flow to host cells and provides an alternative to sinking for protists living in low-nutrient conditions.
Altered sense of self during seizures in the posteromedial cortex
Authors: Parvizi Josef , Braga Rodrigo M. , Kucyi Aaron , Veit Mike J. , Pinheiro-Chagas Pedro , Perry Claire , Sava-Segal Clara , Zeineh Michael , van Staalduinen Eric Klaas , Henderson Jaimie M. , Markert Matthew
Published: July 2021

Significance

In this manuscript, we report a rare case of a patient with localized seizures originating from the right anterior and dorsal posteromedial cortex (PMC). We mapped the electrophysiological and neuroimaging connectivity of the ictal onset site and replicated seizure auras by stimulating the homotopical PMC site in the left hemisphere. Our findings provide a causal link between PMC and the sense of self and provide unique clues about the pathophysiology of self-dissociation in neuropsychiatric conditions.
Previously unaccounted atmospheric mercury deposition in a midlatitude deciduous forest
Authors: Obrist Daniel , Roy Eric M. , Harrison Jamie L. , Kwong Charlotte F. , Munger J. William , Moosmüller Hans , Romero Christ D. , Sun Shiwei , Zhou Jun , Commane Róisín
Published: July 2021

Significance

Direct measurements of atmospheric deposition of gaseous elemental mercury (GEM) over a temperate forest showed a pronounced annual deposition of 25.1 µg ⋅ m
−2
, which dominated as a source of mercury. GEM deposition was five times greater than wet deposition and three times greater than litterfall deposition, which has been used as a proxy for GEM deposition until now. Measured GEM deposition is driven by combined plant GEM uptake and underlying forest floor GEM uptake. Global forests may be a much larger global GEM sink than currently assumed, which may explain high mercury levels in soils across forests. Forest mercury mobilizes via watershed runoff and bioaccumulates in aquatic biota, ultimately leading to mercury exposures in wildlife and humans.
La traduction de titres de films
Authors: Ljepavić Danijela
Published: July 2021

Cet article part du constat que le processus de traduction des titres de films ne diffère pas beaucoup de ce que l’ont fait lors de la traduction des autres expressions de la langue, du moins en ce qui concerne les opérations mentales qui sont dans l’esprit du traducteur. Ce qui est différent, c’est l’approche même de la traduction, où un accent particulier est mis sur les aspects stylistiques et pragmatiques. Les simples équivalents lexicaux ne suffisent pas. Ici on parle de la culture, des associations de termes, souvent dans une visée persuasive. L’objectif de cet article est de montrer quelles sont les procédures et la finalité d’une traduction d’un titre de film.
Disarming as a tactic of resistance in Pink Dot
Authors: Mano Pavan
Published: July 2021

Pink Dot is an annual rally in support of LGBT (lesbian, gay, bisexual, and transgender) people in Singapore. In a country
where many prefer to avoid overt displays of dissent, Pink Dot has gained significant popular support. In this article, I explore how it has
done so. Through a close multimodal analysis focusing on the use of colour, layout, and typography in a Pink Dot 2017 flyer, I demonstrate
how these features work together in the Singaporean context to realize meanings of positivity, warmth, and inclusivity whilst simultaneously
de-emphasizing notions of claiming rights. I argue Pink Dot discursively attenuates the potentially discordant elements of its message and
marshals this apparent neutrality to gather support for its ostensibly depoliticized message – a process that I term disarming. It is an
assimilationist strategy deliberately made for Singapore’s particular sociopolitical context and it has proven effective in securing mass
popular support amongst Singaporeans.
A review of the Afrotropical sand tampan,
Ornithodoros savignyi
: a complex species
Authors: Charles Roxanne Albertha , Basu Asoke Kumar
Published: July 2021

The sand tampan,
Ornithodoros savignyi
(Audouin, 1827), is an economically important soft tick of the Afrotropics parasitising a wide range of livestock and humans. These ticks are known to inflict painful bites which may be fatal in susceptible hosts. Historically thought to be a single species,
Ornithodoros savignyi
is now considered to be a complex of four tick subspecies based on molecular and morphological studies. They include
Ornithodoros (Ornithodoros) kalahariensis, O. (O.) pavimentosus
,
O. (O.) noorsveldensis
and
O. (O.) savignyi
. As such there may be significant implications for previous biological studies conducted on this tick. Therefore, for the purposes of this review, sand tampan toxicosis and potentially useful biological molecules have been discussed for
O. (O.) savignyi
sensu lato since most reported work was based on ticks collected from the Kalahari and Lake Chad region. An overview of the host range and vector biology for the
O. (O.) savignyi
species complex will also be examined.
Tū Tahanga: A Qualitative Descriptive Study of a Culturally Adapted Violence Prevention Programme in a Forensic Mental Health Service
Authors: Florencio Francis , Healee David , Ratahi Te , Wiki Nick , McKenna Brian
Published: July 2021

There is growing evidence that culturally adapted, evidence-based, violence prevention programmes can have benefits for people in correctional and forensic mental health services. Adding to this evidence is crucial, given the over-representation of Indigenous people and ethnic minorities in such services. This qualitative descriptive study describes Tū Tahanga, which combines the ManAlive violence prevention programme, with Māori (Indigenous people of Aotearoa/New Zealand) cultural concepts. This was developed for Māori service users in a forensic mental health service. Content analysis was undertaken through interviews with participants in the group ( N = 11). Core aspects of ManAlive were maintained. These aspects coexist with cultural concepts of a specific healing space, a holistic Māori model of health, and the creation of family like supportive relationships reinforced by living in the same facility. This description lays a platform for future evaluative research to determine the impact of the programme on reducing violent offending.
CD16+CD163+ monocytes traffic to sites of inflammation during necrotizing enterocolitis in premature infants
Authors: Olaloye Oluwabunmi O. , Liu Peng , Toothaker Jessica M. , McCourt Blake T. , McCourt Collin C. , Xiao Jenny , Prochaska Erica , Shaffer Spenser , Werner Lael ,   UPMC NICU Faculty,   UPMC Pediatric Surgery Faculty, Gringauz Jordan , Good Misty , Goldsmith Jeffrey D. , An Xiaojing , Wang Fujing , Snapper Scott B. , Shouval Dror , Chen Kong , Tseng George , Konnikova Liza
Published: July 2021

Necrotizing enterocolitis (NEC) is a severe gastrointestinal complication of prematurity. Using suspension and imaging mass cytometry coupled with single-cell RNA sequencing, we demonstrate severe inflammation in patients with NEC. NEC mucosa could be subtyped by an influx of three distinct neutrophil phenotypes (immature, newly emigrated, and aged). Furthermore, CD16+CD163+ monocytes/Mϕ, correlated with newly emigrated neutrophils, were specifically enriched in NEC mucosa, found adjacent to the blood vessels, and increased in circulation of infants with surgical NEC, suggesting trafficking from the periphery to areas of inflammation. NEC-specific monocytes/Mϕ transcribed inflammatory genes, including TREM1, IL1A, IL1B, and calprotectin, and neutrophil recruitment genes IL8, CXCL1, CXCL2, CXCL5 and had enrichment of gene sets in pathways involved in chemotaxis, migration, phagocytosis, and reactive oxygen species generation. In summary, we identify a novel subtype of inflammatory monocytes/Mϕ associated with NEC that should be further evaluated as a potential biomarker of surgical NEC and a target for the development of NEC-specific therapeutics.
Galilean relativity for Brownian dynamics and energetics
Authors: Li Minghao , Sentissi Oussama , Azzini Stefano , Genet Cyriaque
Published: July 2021

We study experimentally the impact of inertial reference frame changes on overdamped Brownian motion. The reference frame changes are implemented by inducing, with a laser, laminar convection flows in a column of fluid where Brownian microspheres are dispersed. The convection flow plays the role of the relative velocity between the laboratory and the fluid comoving frames, and enables us to analyse the consequences of Galilean transformations on Brownian diffusion. We verify in particular how the Brownian dynamics remains ‘weakly’ Galilean invariant, in agreement with recent discussions Cairoli et
al (2018 Proc. Natl Acad. Sci. USA
115 5714). We also carefully look at the consequences of Galilean relativity on the Brownian energetics. This leads us to derive a Galilean invariant expression of the stochastic thermodynamic first law, consistent with existing theoretical results Speck et
al (2008 Phys. Rev. Lett.
100 178302). We finally discuss a potential ambiguity of the Galilean relativistic features of diffusive systems that has obvious practical implications in the context of force measurements in external flows.
Explaining excess dipole in NVSS data using superhorizon perturbation
Authors: Das Kaustav K. , Sankharva Kishan , Jain Pankaj
Published: July 2021

Many observations in recent times have shown evidence against the standard assumption of isotropy in the Big Bang model. Introducing a superhorizon scalar metric perturbation has been able to explain some of these anomalies. In this work, we probe the net velocity arising due to the perturbation. We find that this extra component does not contribute to the CMB dipole amplitude while it does contribute to the dipole in large scale structures. Thus, within this model's framework, our velocity with respect to the large scale structure is not the same as that extracted from the CMB dipole, assuming it to be of purely kinematic origin. Taking this extra velocity component into account, we study the superhorizon mode's implications for the excess dipole observed in the NRAO VLA Sky Survey (NVSS). We find that the mode can consistently explain both the CMB and NVSS observations. We also find that the model leads to small contributions to the local bulk flow and the dipole in Hubble parameter, which are consistent with observations. The model leads to several predictions which can be tested in future surveys. In particular, it implies that the observed dipole in large scale structure should be redshift dependent and should show an increase in amplitude with redshift. We also find that the Hubble parameter should show a dipole anisotropy whose amplitude must increase with redshift in the CMB frame. Similar anisotropic behaviour is expected for the observed redshift as a function of the luminosity distance.
Charged black-bounce spacetimes
Authors: Franzin Edgardo , Liberati Stefano , Mazza Jacopo , Simpson Alex , Visser Matt
Published: July 2021

Given the recent development of rotating black-bounce-Kerr spacetimes,
for both theoretical and observational purposes it becomes interesting to see whether it might be possible to construct black-bounce variants of the entire Kerr-Newman family.
Specifically, herein we shall consider black-bounce-Reissner-Nordström and black-bounce-Kerr-Newman spacetimes as particularly simple and clean everywhere-regular black hole “mimickers” that deviate from the Kerr-Newman family in a precisely controlled and minimal manner, and smoothly interpolate between regular black holes and traversable wormholes.
While observationally the electric charges on astrophysical black holes are likely to be extremely low, |Q|/m ≪ 1, introducing any non-zero electric charge has a significant theoretical impact. In particular, we verify the existence of a Killing tensor (and associated Carter-like constant) but without the full Killing tower of principal tensor and Killing-Yano tensor, also we discuss how, assuming general relativity, the black-bounce-Kerr-Newman solution requires an interesting, non-trivial matter/energy content.
An experimental apparatus for in-situ neutron diffraction studies of hydrogen ingress, dissolution and precipitation at controlled temperature and applied tensile stresses
Authors: Lang J. , Gharghouri M. , Fritzsche H.
Published: July 2021

This manuscript presents the design and utilisation of a unique environmental chamber allowing specimens to be heated and cooled, under tensile load and controlled atmosphere, while in a neutron beam, offering a unique opportunity for in-situ neutron diffraction experiments. The chamber was built to gain insight into the impact of parameters such as tensile stress, temperature and exposed atmosphere on the hydrogen solubility of materials and on the mechanisms relating to delayed hydride cracking, hydrogen embrittlement and hydrogen ingress.

The investigation presented in this work shows the chamber's performance up to 450°C and 275 MPa applied tensile stress. The effect of tensile stresses and temperature on hydrogen solubility in Zr-2.5Nb is presented for samples nominally charged to hydrogen concentration equivalents of 200 and 500 wppm (mg/kg). Due to kinetic factors, no significant effect of tensile stress on the hydrogen solubility of our samples was found for temperatures up to 300°C and at tensile stresses up to 275 MPa.
The future of bone regeneration: integrating AI into tissue engineering
Authors: Mackay Benita S , Marshall Karen , Grant-Jacob James A , Kanczler Janos , Eason Robert W , Oreffo Richard O C , Mills Ben
Published: July 2021

Tissue engineering is a branch of regenerative medicine that harnesses biomaterial and stem cell research to utilise the body’s natural healing responses to regenerate tissue and organs. There remain many unanswered questions in tissue engineering, with optimal biomaterial designs still to be developed and a lack of adequate stem cell knowledge limiting successful application. Advances in artificial intelligence (AI), and deep learning specifically, offer the potential to improve both scientific understanding and clinical outcomes in regenerative medicine. With enhanced perception of how to integrate artificial intelligence into current research and clinical practice, AI offers an invaluable tool to improve patient outcome.
Core opportunities for future optical fibers
Authors: Ballato John , Gibson Ursula J
Published: July 2021

Hair-thin strands of glass, intrinsically transparent and strong, of which many millions of kilometers are made annually, connect the world in ways unimaginable 50 years ago. What could another 50 years bring? That question is the theme of this Perspective. The first optical fibers were passive low-loss conduits for light, empowered by sophisticated sources and signal processing; a second advance was the addition of dopants utilizing atomic energy levels to promote amplification, and a third major initiative was physical structuring of the core-clad combinations, using the baseline silica material. Recent results suggest that the next major expansions in fiber performance and devices are likely to utilize different materials in the core, inhomogeneous structures on different length scales, or some combination of these. In particular, fibers with crystalline cores offer an extended transparency range with strong optical nonlinearities and open the door to hybrid opto-electronic devices. Opportunities for future optical fiber that derive from micro- and macro-structuring of the core phase offer some unique possibilities in ‘scattering by design’.
Attitudes of German high school students toward different varieties of English
Authors: Meer Philipp , Hartmann Johanna , Rumlich Dominik
Published: July 2021

In line with international developments in applied linguistics, school curricula in Germany have begun to demand that Global Englishes be included in English Language Teaching. However, the perspectives of German school students, the main addressees of such a shift, are little explored. This article investigates the attitudes to and familiarity with different Englishes among 160 German high school students, using a mix of direct and indirect attitude elicitation methods and a nationality identification task. Informants rated (speakers of) Standard Southern British (StSBrE), Standard American (StAmE), Indian (IndE), German (GerE), and African/Kenyan English (AfrE/KenE). Multivariate analyses revealed that informants are most familiar with StSBrE and StAmE. StSBrE and, to a smaller degree, StAmE are perceived as reference norms, while English as a Second Language (ESL) varieties, especially IndE are rated negatively for competence, professionalism, and intelligibility. Familiarity with specific English as a First/Native Language varieties is linked to more positive attitudes. The observed congruence of directly and indirectly elicited attitudes suggests that changes put forth in language curricula have not influenced language attitudes (yet).
Local ancestry inference in heterogeneous populations—Are recent recombination events more relevant?
Authors: van Eeden Gerald , Uren Caitlin , van der Spuy Gian , Tromp Gerard , Möller Marlo
Published: July 2021

To date, numerous software tools have been developed to infer recombination maps. Many of these software tools infer the recombination rate from linkage disequilibrium, and therefore they infer recombination many generations into the past. Other recently developed methods rely on the inference of recent recombination events to determine the recombination rate, such as identity by descent- and local ancestry inference (LAI)-based tools. Methods that mainly use recent recombination events to infer the recombination rate might be more relevant for certain analyses like LAI. We therefore describe a protocol for creating high-resolution, population-specific recombination maps using methods that mainly use recent recombination events and a method that uses recent and distant recombination events for recombination rate inference. Subsequently, we compared the effect of using maps inferred by these two paradigms on LAI accuracy.
A comparative benchmark of classic DNA motif discovery tools on synthetic data
Authors: Castellana Stefano , Biagini Tommaso , Parca Luca , Petrizzelli Francesco , Bianco Salvatore Daniele , Vescovi Angelo Luigi , Carella Massimo , Mazza Tommaso
Published: July 2021

Hundreds of human proteins were found to establish transient interactions with rather degenerated consensus DNA sequences or motifs. Identifying these motifs and the genomic sites where interactions occur represent one of the most challenging research goals in modern molecular biology and bioinformatics. The last twenty years witnessed an explosion of computational tools designed to perform this task, whose performance has been last compared fifteen years ago. Here, we survey sixteen of them, benchmark their ability to identify known motifs nested in twenty-nine simulated sequence datasets, and finally report their strengths, weaknesses, and complementarity.
DNA methylome perturbations: an epigenetic basis for the emergingly heritable neurodevelopmental abnormalities associated with maternal smoking and maternal nicotine exposure
Authors: Buck Jordan M , Yu Li , Knopik Valerie S , Stitzel Jerry A
Published: July 2021

Maternal smoking during pregnancy is associated with an ensemble of neurodevelopmental consequences in children and therefore constitutes a pressing public health concern. Adding to this burden, contemporary epidemiological and especially animal model research suggests that grandmaternal smoking is similarly associated with neurodevelopmental abnormalities in grandchildren, indicative of intergenerational transmission of the neurodevelopmental impacts of maternal smoking. Probing the mechanistic bases of neurodevelopmental anomalies in the children of maternal smokers and the intergenerational transmission thereof, emerging research intimates that epigenetic changes, namely DNA methylome perturbations, are key factors. Altogether, these findings warrant future research to fully elucidate the etiology of neurodevelopmental impairments in the children and grandchildren of maternal smokers and underscore the clear potential thereof to benefit public health by informing the development and implementation of preventative measures, prophylactics, and treatments. To this end, the present review aims to encapsulate the burgeoning evidence linking maternal smoking to intergenerational epigenetic inheritance of neurodevelopmental abnormalities, to identify the strengths and weaknesses thereof, and to highlight areas of emphasis for future human and animal model research therein.
Building from the Ashes: Towards a Three-Dimensional Approach for Social Work Intervention Facing Social Conflicts in Vulnerable Neighbourhoods
Authors: Barciela Fernández Sergio , Lorenzo Gilsanz Francisco , Martínez Herrero María Inés
Published: July 2021

About 56 percent of the world’s population lives in urban environments. In more economically developed countries, this percentage is considerably higher. Increasingly, cities’ more vulnerable and culturally diverse neighbourhoods are the context of violent conflicts linked to interconnected socio-economic (inequality), ethnocultural (discrimination) and public-institutional (delegitimation) causal factors. Social outbursts such as London (2011) or Husby’s (Stockholm, 2013) riots are amongst the most notorious recent examples of these. Both the frequency and intensity of these conflicts are only expected to worsen as the economic impact of the coronavirus disease 2019 (COVID-19) pandemic takes hold. This article introduces the ‘Theory of Rupture Frames (TRF)’, which offers a new three-dimensional explanatory model of violent conflicts in vulnerable neighbourhoods with high socio-cultural diversity. The ‘TRF’, it is argued, offers a novel and suitable framework for founding and guiding social work’s preventative and healing-oriented interventions facing these. This is in relation to the TRF’s dual potential for (i) contributing to the theoretical understanding in the social work profession of this type of conflict and for (ii) offering a tool for guiding the assessment of needs and strategic planning of social work-led actions in the context of the neighbourhoods affected by the conflicts or at risk of their outburst.
Masters and Slaves: A Matching Model of Forced Labor with Heterogeneous Workers
Authors: Willert Bianca
Published: July 2021

At present, most countries have officially ratified the ILO Convention concerning forced or compulsory labor; however, serfdom is still present in the 21st century. This article addresses how oppressors recruit their victims and how certain mechanisms affect the extent of modern slavery. We use a matching model to analyze this recruitment process, incorporating involuntariness, which is the distinctive factor of employment relationships in modern slavery. In contrast to the standard matching model, not the workers exert effort to find jobs but the employers exert effort to find and hire slaves. Workers are heterogeneous regarding their vulnerability to enslavement, which is ex-ante unknown to the potential employers. The employer’s decision whether and to what extent to engage in forced labor depends on governmental labor protection and on the probability of detection. The model includes the possibility of bribery such that an employer can avoid sanctions if illicit behavior is detected. Solving the model yields that a high probability of detection and strict labor protection decrease slavery. We show that a high share of slaveholders increases the probability of enslavement and thus, the number of slaves. Surprisingly, strict labor protection increases the slaveholder’s effort, but also decreases their profit. (JEL codes: J23, J47, and J71)
Tackling Biopiracy in International Investment Arbitration: Consideration of the Perspective(s) of Developing Countries
Authors: Kim Jinyup
Published: July 2021

Biopiracy, defined as misappropriation of biological resources and associated knowledge, has been criticized by developing countries for exploiting their resources and knowledge without their consent. To tackle biopiracy, debates have been ongoing in various international regimes. This article focuses on the international investment regime. In most of the biopiracy cases, multinational corporations (MNCs) obtain and market intellectual property rights, which fall within the category of investment in most of the investment agreements. This enables MNCs to claim the protection of their rights based on resources and knowledge in the investment arbitration if developing countries take action to tackle biopiracy, although it is not always feasible. Therefore, this article aims to discuss how developing countries could protect their rights to resources and knowledge against MNCs in (potential) investment arbitrations.
Novel atrioventricular sequential pacing approach using a transvenous atrial pacemaker and a leadless pacemaker: a case report
Authors: Guella Elhosseyn , Devereux Frances , Ahmed Fozia Zahir , Scott Peter , Cunnington Colin , Zaidi Amir
Published: July 2021

Background

The use of transvenous pacing leads is associated with the risk of developing tricuspid valve (TV) dysfunction. This develops through several mechanisms including the failure of leaflet coaptation or direct damage to the TV or to its sub-valvular apparatus and can result in significant tricuspid regurgitation (TR). Multiple approaches to pacemaker implantation after transvenous lead extraction (TLE) or surgical TV repair have been described. Placement of pacing leads across the TV is generally avoided in such circumstances.

Case summary

A 66-year-old woman presented with a year-long history of exertional dyspnoea, peripheral oedema, and postural neck pulsations. Her medical history included a dual-chamber pacemaker implantation for sinus node dysfunction 14 years ago. Echocardiography revealed severe lead-related TR. Her case was discussed in our multi-disciplinary team meeting. A decision was made to perform a TLE and implant a leadless pacemaker in an attempt to avoid open-heart surgery if possible. This was reserved as an option in the event of persistent severe TR. Transvenous extraction of the right ventricular lead was performed. The atrial lead was preserved and connected to and AAI device. A Micra AV was implanted allowing for atrioventricular (AV) synchronous pacing.

Discussion

We present the first case of successful implementation of AV sequential pacing using a dual-pacemaker approach involving the use of an AAI pacemaker and a Micra AV device. This was performed after TLE for severe lead-related TR.
Rate of device-related infections using an antibacterial envelope in patients undergoing cardiac resynchronization therapy reoperations
Authors: Frausing Maria Hee Jung Park , Nielsen Jens Cosedis , Johansen Jens Brock , Jørgensen Ole Dan , Gerdes Christian , Olsen Thomas , Kronborg Mads Brix
Published: July 2021

Aims 

Cardiac resynchronization therapy (CRT) reoperations are associated with a particularly high risk of device-related infection (DRI). An antibacterial envelope reduces the occurrence of DRIs in a broad population of moderate-tohigh-risk patients. To investigate the efficacy of an antibacterial envelope in a very high-risk population of patients undergoing CRT reoperation.

Methods and results

In this Danish two-centre, observational cohort study, we included consecutive patients who underwent a CRT pacemaker- or defibrillator reoperation procedure between January 2008 and November 2019. We obtained data from the Danish Pacemaker and ICD Register and through systematic medical chart review. Follow-up was restricted to 2 years. A total of 1943 patients were included in the study of which 736 (38%) received an envelope. Envelope patients had more independent risk factors for infection than non-envelope patients. Sixty-seven (3.4%) patients met the primary endpoint of DRI requiring device system extraction; 50 in the non-envelope group and 17 in the envelope group [4.1% vs. 2.3%, adjusted hazard ratio (HR) 0.52, 95% confidence interval (CI) 0.30–0.90; P = 0.021]. This difference persisted in propensity score analysis (HR 0.51, 95% CI 0.29–0.90; P = 0.019).

Conclusion 

Use of an antibacterial envelope was associated with a clinically and statistically significant reduction in DRIs in patients undergoing CRT reoperations. Our results were comparable to those recently reported from a large randomized controlled trial, which is suggestive of a proportional effect of the envelope even in very high-risk patients.
Geographic barriers to achieving universal health coverage: evidence from rural Madagascar
Authors: Garchitorena Andres , Ihantamalala Felana A , Révillion Christophe , Cordier Laura F , Randriamihaja Mauricianot , Razafinjato Benedicte , Rafenoarivamalala Feno H , Finnegan Karen E , Andrianirinarison Jean Claude , Rakotonirina Julio , Herbreteau Vincent , Bonds Matthew H
Published: July 2021

Poor geographic access can persist even when affordable and well-functioning health systems are in place, limiting efforts for universal health coverage (UHC). It is unclear how to balance support for health facilities and community health workers in UHC national strategies. The goal of this study was to evaluate how a health system strengthening (HSS) intervention aimed towards UHC affected the geographic access to primary care in a rural district of Madagascar. For this, we collected the fokontany of residence (lowest administrative unit) from nearly 300 000 outpatient consultations occurring in facilities of Ifanadiana district in 2014–2017 and in the subset of community sites supported by the HSS intervention. Distance from patients to facilities was accurately estimated following a full mapping of the district’s footpaths and residential areas. We modelled per capita utilization for each fokontany through interrupted time-series analyses with control groups, accounting for non-linear relationships with distance and travel time among other factors, and we predicted facility utilization across the district under a scenario with and without HSS. Finally, we compared geographic trends in primary care when combining utilization at health facilities and community sites. We find that facility-based interventions similar to those in UHC strategies achieved high utilization rates of 1–3 consultations per person year only among populations living in close proximity to facilities. We predict that scaling only facility-based HSS programmes would result in large gaps in access, with over 75% of the population unable to reach one consultation per person year. Community health delivery, available only for children under 5 years, provided major improvements in service utilization regardless of their distance from facilities, contributing to 90% of primary care consultations in remote populations. Our results reveal the geographic limits of current UHC strategies and highlight the need to invest on professionalized community health programmes with larger scopes of service.