bluuebunny/crossref_metadata_2025 huggingface dataset:
Birth Outcomes for Medically High-Risk Pregnancies: Comparing Group to Individual Prenatal Care
Authors: Heberlein Emily C. , Smith Jessica C. , LaBoy Ana , Britt Jessica , Crockett Amy
Published: October 2021

Objectives Group prenatal care models were initially designed for women with medically low-risk pregnancies, and early outcome data focused on these patient populations. Pregnancy outcome data for women with medically high-risk pregnancies participating in group prenatal care is needed to guide clinical practice. This study compares rates of preterm birth, low birth weight, and neonatal intensive care unit admissions among women with medical risk for poor birth outcomes who receive group versus individual prenatal care.

Study Design This retrospective cohort study uses vital statistics data to compare pregnancy outcomes for women from 21 obstetric practices participating in a statewide expansion project of group prenatal care. The study population for this paper included women with pregestational or gestational hypertension, pregestational or gestational diabetes, and high body mass index (BMI > 45 kg/m2). Patients were matched using propensity scoring, and outcomes were compared using logistic regression. Two levels of treatment exposure based on group visit attendance were evaluated for women in group care: any exposure (one or more groups) or minimum threshold (five or more groups).

Results Participation in group prenatal care at either treatment exposure level was associated with a lower risk of neonatal intensive care unit (NICU) admissions (10.2 group vs. 13.8% individual care, odds ratio [OR] = 0.708, p < 0.001). Participating in the minimum threshold of groups (five or more sessions) was associated with reduced risk of preterm birth (11.4% group vs. 18.4% individual care, OR = 0.569, p < 0.001) and NICU admissions (8.4% group vs. 15.9% individual care, OR = 0.483, p < 0.001). No differences in birth weight were observed.

Conclusion This study provides preliminary evidence that women who have or develop common medical conditions during pregnancy are not at greater risk for preterm birth, low birth weight, or NICU admissions if they participate in group prenatal care. Practices who routinely exclude patients with these conditions from group participation should reconsider increasing inclusivity of their groups.

Key Points
Postpartum Pyelonephritis and Risk of Severe Maternal Morbidity
Authors: Addae-Konadu Kateena L. , Wein Lauren E. , Federspiel Jerome J. , Hughes Brenna L. , Dotters-Katz Sarah
Published: October 2021

Objective Pyelonephritis is the most common nonobstetric cause for hospitalization during pregnancy. The maternal and obstetric complications associated with antepartum pyelonephritis are well described. However, it is not clear whether these risks extend into the postpartum period. The primary objective of this study was to describe the morbidity associated with postpartum pyelonephritis, by comparing the morbidity associated with pyelonephritis in the postpartum period to morbidity seen during pregnancy or delivery.

Study Design A retrospective cohort study was performed using the Nationwide Readmissions Database (NRD), an all-payor sample of discharges from approximately 60% of U.S. hospitalizations. Discharges between October 2015 and December 2018 were included. Maternity-associated hospitalizations, diagnosis of pyelonephritis, comorbid conditions, and incidence of severe maternal morbidity were identified using International Classification of Disease-10th Revision (ICD-10) diagnosis and procedure codes. Bivariate statistics, weighted to account for the complex survey methods in the NRD, were used to evaluate the association between antepartum, delivery, and postpartum hospital stays associated with pyelonephritis and maternal morbidity. Weighted regression models were used to evaluate the association between admission timing and maternal outcomes.

Results A total of 32,850 pyelonephritis admissions were identified, corresponding to a national estimate of 61,837 admissions. Of these, 1,465 (2.4%) were postpartum, 55,056 (89.0%) were antepartum, and 5,317 (8.6%) involved a delivery stay. Rates of severe maternal morbidity were higher in the postpartum group than the antepartum or delivery hospitalization groups (59.5 vs. 12.9 and 15.8%, respectively, p < 0.001); when compared with antepartum hospitalizations, the adjusted relative risk for composite severe maternal morbidity for postpartum hospitalizations was 4.68 (95% confidence interval [CI]: 4.33, 5.05). Most of this difference was driven by rates of sepsis (53.2 vs. 11.0 vs. 10.9%).

Conclusion Though relatively uncommon, postpartum hospitalizations for pyelonephritis are associated with higher rates of severe maternal morbidity, driven by differential rates of sepsis, than are antepartum or delivery-associated hospitalizations.
Infecção após artroplastia total primária de joelho: estudo randomizado prospectivo controlado da adição de antibiótico ao cimento ósseo
Authors: Cobra Hugo Alexandre de Araujo Barros , Mozella Alan de Paula , Labronici Pedro José , Cavalcanti Amanda S. , Guimarães João Antonio Matheus
Published: October 2021

Objetivo O presente estudo prospectivo, randomizado e controlado foi realizado com 286 pacientes submetidos à artroplastia total primária do joelho (ATJ) com o objetivo de avaliar a eficácia da adição de antibiótico ao cimento ósseo como forma de prevenção da infecção pós-artroplastia (IPA).

Métodos Os pacientes foram randomizados em dois grupos: cimento ósseo sem antibiótico (Sem ATB, n = 158) ou cimento com antibiótico (Com ATB, n = 128), ao qual foram adicionados 2 g de Vancomicina para 40 g de cimento. Os pacientes foram acompanhados por 24 meses após a cirurgia.

Resultados No que diz respeito aos dados demográficos pré-operatórios, a distribuição dos pacientes entre os grupos foi homogênea (p < 0,05). No período de 24 meses, a taxa global de infecção foi de 2,09% (6/286), não havendo diferença (odds ratio [OR] = 1,636; intervalo de confiança [IC] 95%: 0,294–9,080; p = 0,694) entre o grupo Com ATB (1,56%; 2/128) e Sem ATB (2,53%; 4/158). No grupo Sem ATB, a infecção foi causada por Staphylococcus aureus resistente à meticilina (MRSA, na sigla em inglês) (n = 2), S. aureus sensível à meticilina (MSSA, na sigla em inglês) (n = 1) e Eschirichia coli (n = 1). Proteus mirabilis e MSSA foram isolados dos pacientes do grupo Com ATB. Dentre as comorbidades, todos os pacientes com IPA eram hipertensos e não diabéticos. Dois pacientes com artrite reumatoide que desenvolveram IPA eram do grupo Com ATB.

Conclusão O uso de cimento com ATB reduziu o número absoluto de infecções; porém, sem diferença estatística entre os grupos. Desta forma, o uso rotineiro não deve ser encorajado.
Fixação interna de pseudoartrose de escafoide com deformidade angular associada utilizando enxerto de ilíaco e placa volar: Série de oito casos
Authors: Cagnolati Amanda Favaro , Andrade Fernanda Ruiz , Rezende Luis Guilherme Rosifini Alves , Mazzer Nilton , Sugano Raquel Metzker Mendes , Garcia Larissa Martins
Published: October 2021

Objetivos A finalidade do presente artigo é avaliar os resultados clínicos, radiográficos e funcionais de pseudoartroses de escafoide com deformidade angular utilizando enxerto de ilíaco e placa volar.

Métodos Foram seguidos prospectivamente 8 pacientes, todos do sexo masculino, com idade média de 39,6 anos, com pseudoartrose de cintura de escafoide, com tempo médio de 19 meses de trauma sem cirurgias prévias. Os pacientes foram tratados com enxerto retirado da crista ilíaca e placa volar para escafoide. Os pacientes foram submetidos a avaliações radiográficas e tomográficas no pré-operatório e em 1 mês, 3 meses, 6 meses e 1 ano de pós-operatório. A altura carpal e os ângulos escafossemilunares e intraescafoides foram medidos no pré-operatório e aos 3 meses e 1 ano do pós-operatório. A função foi avaliada no pré-operatório e repetida em 1 ano pós-operatório através do escores Disabilities of the Arm, Shoulder, and Hand (DASH, na sigla em inglês) e Patient-related Wrist Evaluation (PWRE, na sigla em inglês), assim como pela aferição de força de pinças e de amplitude de movimento do punho e do polegar.

Resultados Houve consolidação em todos os casos, com tempo médio de 3,38 meses. Foram observadas duas complicações: uma infecção de ferida operatória do ilíaco e um parafuso da placa colocado no espaço escafossemilunar. Houve melhora nos parâmetros de amplitude de movimento do punho e do polegar e de força de pinça em todas as avaliações funcionais, com significância estatística do PRWE e do ângulo escafossemilunar.

Conclusão Apesar da nossa amostra ter sido pequena, obtivemos consolidação em todos os casos operados, com complicações esperadas na literatura e melhoras tanto no padrão radiográfico quanto na avaliação funcional e na escala de dor dos nossos pacientes.
Tradução e adaptação cultural para o português do Brasil do Children's Physical Activity Questionnaire (C-PAQ)
Authors: Miranda Fernando Leite , Fernandes Carlos Henrique , Meirelles Lia Miyamoto , Faloppa Flavio , Ejnisman Benno , Cohen Moises
Published: October 2021

Objetivo Realizar a tradução e adaptação cultural para o português do Brasil do Children's Physical Activity Questionnaire.

Métodos O processo envolveu as etapas de tradução, síntese, retrotradução, e revisão pelo grupo de tradução. Foi então criada uma versão pré-final e, posteriormente, a versão final do questionário.

Resultados Devido ao estilo de vida da população, oito atividades descritas no questionário foram mudadas com o objetivo de adaptá-lo à cultura brasileira, sendo seis atividades esportivas e duas atividades de lazer. Oito pais/responsáveis responderam o questionário no pré-teste, com rapidez, sem inconsistências, e sem relatar dificuldades no entendimento quando realizada a entrevista final.

Conclusão A tradução e adaptação cultural do Children's Physical Activity Questionnaire para o português do Brasil resultou na versão C-PAQ.PT.
Corona splashing triggered by a loose monolayer of particles
Authors: Esmaili Ehsan , Chen Zih-Yin , Pandey Anupam , Kim Seungho , Lee Sungyon , Jung Sunghwan
Published: October 2021

In nature, high-speed raindrops often impact and spread on particulate surfaces (e.g., soil, plant leaves with spores or pollen). We study the dynamics of droplet impact on a loosely packed monolayer of particles by combining experimental and mathematical approaches. We find that the presence of mobile particles lowers the critical impact velocity at which the droplet exhibits corona splashing, as the particle area fraction is systematically increased. We rationalize this experimental observation by considering the jamming of frictional particles at the spreading rim. Elucidating the splashing transition of the drop on a particulate bed can lead to a better understanding of soil loss and erosion from falling raindrops.
Using extended MHD to explore lasers as a trigger for x-pinches
Authors: Young J. R. , Adams M. B. , Hasson H. , West-Abdallah I. , Evans M. , Gourdain P.-A.
Published: October 2021

X-pinches have been shown to be a source of extremely intense x-ray emissions useful for diagnosing plasma dynamics and imaging biological objects. The most striking feature of an x-pinch is the hotspot, the point source from where all the x rays come from. Unfortunately, the exact timing and location of the hotspot are still unpredictable. Since an x-pinch hotspot forms from instabilities (like an m = 0 mode), we will computationally explore whether we can use a high-power laser to control the timing and location of these instabilities. Our goal is to reduce the temporal and spatial jitter associated with the x-ray burst. Using an extended MHD (XMHD) code, we explore the non-relativistic instability generation using a current profile of a 250 kA linear transformer driver system and laser characteristics of SLAC's Matter in Extreme Conditions laboratory. Our results include both laser-penetration results using a boundary-defined electromagnetic (EM) wave and instability results from a power-deposition method.
Terahertz emission from gradient InGaAs surfaces
Authors: Regalado-de-la-Rosa J. L. , Belio-Manzano A. , Mendez-Garcia V. H. , Castro-Camus E.
Published: October 2021

We present an experimental study of the terahertz emission from InxGa1−xAs epitaxial layers that were grown while varying the alloy fraction x. We observe the terahertz emission that is significantly different depending on the variation direction of the alloy fraction. We attribute the difference to the significant change of the band bending induced in the growth direction and to the position-dependent variation of the effective mass.
OrbNet Denali: A machine learning potential for biological and organic chemistry with semi-empirical cost and DFT accuracy
Authors: Christensen Anders S. , Sirumalla Sai Krishna , Qiao Zhuoran , O’Connor Michael B. , Smith Daniel G. A. , Ding Feizhi , Bygrave Peter J. , Anandkumar Animashree , Welborn Matthew , Manby Frederick R. , Miller Thomas F.
Published: October 2021

We present OrbNet Denali, a machine learning model for an electronic structure that is designed as a drop-in replacement for ground-state density functional theory (DFT) energy calculations. The model is a message-passing graph neural network that uses symmetry-adapted atomic orbital features from a low-cost quantum calculation to predict the energy of a molecule. OrbNet Denali is trained on a vast dataset of 2.3 × 106 DFT calculations on molecules and geometries. This dataset covers the most common elements in biochemistry and organic chemistry (H, Li, B, C, N, O, F, Na, Mg, Si, P, S, Cl, K, Ca, Br, and I) and charged molecules. OrbNet Denali is demonstrated on several well-established benchmark datasets, and we find that it provides accuracy that is on par with modern DFT methods while offering a speedup of up to three orders of magnitude. For the GMTKN55 benchmark set, OrbNet Denali achieves WTMAD-1 and WTMAD-2 scores of 7.19 and 9.84, on par with modern DFT functionals. For several GMTKN55 subsets, which contain chemical problems that are not present in the training set, OrbNet Denali produces a mean absolute error comparable to those of DFT methods. For the Hutchison conformer benchmark set, OrbNet Denali has a median correlation coefficient of R2 = 0.90 compared to the reference DLPNO-CCSD(T) calculation and R2 = 0.97 compared to the method used to generate the training data (ωB97X-D3/def2-TZVP), exceeding the performance of any other method with a similar cost. Similarly, the model reaches chemical accuracy for non-covalent interactions in the S66x10 dataset. For torsional profiles, OrbNet Denali reproduces the torsion profiles of ωB97X-D3/def2-TZVP with an average mean absolute error of 0.12 kcal/mol for the potential energy surfaces of the diverse fragments in the TorsionNet500 dataset.
The effect of entrance flow development on vortex formation and wall shear stress in a curved artery model
Authors: Cox Christopher , Plesniak Michael W.
Published: October 2021

We numerically investigate the effect of entrance condition on the spatial and temporal evolution of multiple three-dimensional vortex pairs and the wall shear stress distribution in a curved artery model. We perform this study using a Newtonian blood-analog fluid subjected to a pulsatile flow with two inflow conditions. The first flow condition is fully developed while the second condition is undeveloped (i.e., uniform). We discuss the connection along the axial direction between regions of organized vorticity observed at various cross sections of the model and compare results between the different entrance conditions. We model a human artery with a simple, rigid 180° curved pipe with a circular cross section and constant curvature, neglecting the effects of taper, torsion, and elasticity. Numerical results are computed from a discontinuous high-order spectral element flow solver. The flow rate used in this study is physiological. We observe differences in secondary flow patterns, especially during the deceleration phase of the physiological waveform where multiple vortical structures of both Dean-type and Lyne-type coexist. The results indicate that decreased axial velocities under an undeveloped condition produce smaller secondary flows that ultimately inhibit growth of any interior flow vortices. We highlight the effect of the entrance condition on the formation of these structures and subsequent appearance of abnormal inner wall shear stresses, which suggest there may be a lower prevalence of cardiovascular disease in curved arteries where the flow is rather undeveloped—a potentially physiologically significant result to help understand the influence of blood flow development on disease.
Atomic-scale characterization of structural and electronic properties of Hf doped β-Ga2O3
Authors: Chmielewski Adrian , Deng Ziling , Saleh Muad , Jesenovec Jani , Windl Wolfgang , Lynn Kelvin , McCloy John , Alem Nasim
Published: October 2021

In this Letter, we investigate the atomic and electronic structure of a Hf-doped beta-gallium oxide (β-Ga2O3) single crystal using high resolution scanning transmission electron microscopy imaging and electron energy loss spectroscopy. Ultraviolet-visible (UV-Vis)-near-infrared absorption measurements and density functional theory calculations are performed to further connect the nanoscale observation to the macroscale properties arising from the atomic structure. The Hf-doped sample was grown from the melt with a nominal Hf concentration of 0.5 at. %. We show that the Hf dopants prefer to occupy octahedral over tetrahedral sites by 0.68 eV and have some resistance to form precipitates due to a repulsive interaction of 0.17 eV between Hf atoms on neighboring sites. Also, the presence of Hf atoms on either tetrahedral or octahedral sites do not significantly affect the crystal structure of β-Ga2O3. Finally, the bandgap values of the Hf doped β-Ga2O3 obtained by electron energy loss spectroscopy and UV-Vis-spectroscopy were Eg = 4.83 ± 0.1 and 4.75 ± 0.02 eV, respectively, similar to the values reported for unintentionally doped β-Ga2O3 crystals. All these results make Hf an excellent dopant candidate for β-Ga2O3.
Tunable microwave plasma coaxial resonator
Authors: Lee Jimo , Yun Gunsu S.
Published: October 2021

We report the design, performance, and characterization of a tunable microwave plasma resonator based on a coaxial transmission line structure operated at atmospheric pressure. The adjustable tuners of the compact device enable over 20 dB enhancement of reflection coefficient by counterbalancing the impedance mismatch. The in situ tuning capability can also neutralize the sudden change in impedance upon plasma discharge, elongating the microwave driven plasma plume. It is observed that the fine adjustment of two small bolts can maintain a high device efficiency up to 96% with plasma load impedance, and a wide operation range can be covered by a single device.
Distinguishing bulk and surface recombination in CdTe thin films and solar cells using time-resolved terahertz and photoluminescence spectroscopies
Authors: Taheri Mohammad M. , Truong Triet M. , Li Siming , Shafarman William N. , McCandless Brian E. , Baxter Jason B.
Published: October 2021

Understanding the nature of recombination and its dependence on defects and interfaces is essential for engineering materials and contacts for a higher open-circuit voltage (Voc) and power conversion efficiency in photovoltaic (PV) devices. Time-resolved photoluminescence (TRPL) has conventionally been used to evaluate recombination, but carrier redistribution often dominates the response at short times. Here, we report on the quantification of carrier dynamics and recombination mechanisms by complementary use of both time-resolved terahertz spectroscopy and TRPL combined with numerical modeling of the continuity equations and Poisson's equation. We have demonstrated this approach using CdTe thin films. A thin-film stack with CdTe fabricated by vapor transport deposition and treated with CdCl2 exhibited a bulk lifetime of 1.7 ± 0.1 ns, a negligible CdTe/CdS interface recombination velocity, and a back surface recombination velocity of 6.3 ± 1.3 × 104 cm/s. In contrast, a film stack without CdCl2 treatment had a bulk lifetime of only 68 ± 12 ps and a higher interface recombination velocity of 4 ± 2 × 108 cm/s. By determining the locus and mechanisms of performance-limiting recombination, we can accelerate the development of thin-film PVs with higher Voc and efficiency. While the method has been demonstrated here using CdTe, it is also applicable to perovskites, Cu(InGa)Se2, Cu2ZnSn(S,Se)4, and emerging technologies.
Bayesian estimation of the hydroxyl radical diffusion coefficient at low temperature and high pressure from atomistic molecular dynamics
Authors: Butts Carter T. , Martin Rachel W.
Published: October 2021

The hydroxyl radical is the primary reactive oxygen species produced by the radiolysis of water and is a significant source of radiation damage to living organisms. Mobility of the hydroxyl radical at low temperatures and/or high pressures is hence a potentially important factor in determining the challenges facing psychrophilic and/or barophilic organisms in high-radiation environments (e.g., ice-interface or undersea environments in which radiative heating is a potential heat and energy source). Here, we estimate the diffusion coefficient for the hydroxyl radical in aqueous solution using a hierarchical Bayesian model based on atomistic molecular dynamics trajectories in TIP4P/2005 water over a range of temperatures and pressures.
Quantum computing without quantum computers: Database search and data processing using classical wave superposition
Authors: Balynsky Mykhaylo , Chiang Howard , Gutierrez David , Kozhevnikov Alexander , Filimonov Yuri , Khitun Alexander
Published: October 2021

Quantum computers are proven to be more efficient at solving a specific class of problems compared to traditional digital computers. Superposition of states and quantum entanglement are the two key ingredients that make quantum computing so powerful. However, not all quantum algorithms require quantum entanglement (e.g., search through an unsorted database). Is it possible to utilize classical wave superposition to speed up database searching as much as by using quantum computers? There were several attempts to mimic quantum computers using classical waves. It was concluded that the use of classical wave superposition comes with the cost of an exponential increase in resources. In this work, we consider the feasibility of building classical wave-based devices able to provide fundamental speedup over digital counterparts without the exponential overhead. We present experimental data on database searching through a magnetic database using spin wave superposition. The results demonstrate the same speedup as expected for quantum computers. Also, we present examples of numerical modeling demonstrating classical wave interference for period finding. This approach may not compete with quantum computers with efficiency but outperform classical digital computers. We argue that classical wave-based devices can perform some of the quantum algorithms with the same efficiency as quantum computers as long as quantum entanglement is not required.
Low-energy quasilocalized excitations in structural glasses
Authors: Lerner Edan , Bouchbinder Eran
Published: October 2021

Glassy solids exhibit a wide variety of generic thermomechanical properties, ranging from universal anomalous specific heat at cryogenic temperatures to nonlinear plastic yielding and failure under external driving forces, which qualitatively differ from their crystalline counterparts. For a long time, it has been believed that many of these properties are intimately related to nonphononic, low-energy quasilocalized excitations (QLEs) in glasses. Indeed, recent computer simulations have conclusively revealed that the self-organization of glasses during vitrification upon cooling from a melt leads to the emergence of such QLEs. In this Perspective, we review developments over the past three decades toward understanding the emergence of QLEs in structural glasses and the degree of universality in their statistical and structural properties. We discuss the challenges and difficulties that hindered progress in achieving these goals and review the frameworks put forward to overcome them. We conclude with an outlook on future research directions and open questions.
Variational embedding of protein folding simulations using Gaussian mixture variational autoencoders
Authors: Ghorbani Mahdi , Prasad Samarjeet , Klauda Jeffery B. , Brooks Bernard R.
Published: October 2021

Conformational sampling of biomolecules using molecular dynamics simulations often produces a large amount of high dimensional data that makes it difficult to interpret using conventional analysis techniques. Dimensionality reduction methods are thus required to extract useful and relevant information. Here, we devise a machine learning method, Gaussian mixture variational autoencoder (GMVAE), that can simultaneously perform dimensionality reduction and clustering of biomolecular conformations in an unsupervised way. We show that GMVAE can learn a reduced representation of the free energy landscape of protein folding with highly separated clusters that correspond to the metastable states during folding. Since GMVAE uses a mixture of Gaussians as its prior, it can directly acknowledge the multi-basin nature of the protein folding free energy landscape. To make the model end-to-end differentiable, we use a Gumbel-softmax distribution. We test the model on three long-timescale protein folding trajectories and show that GMVAE embedding resembles the folding funnel with folded states down the funnel and unfolded states outside the funnel path. Additionally, we show that the latent space of GMVAE can be used for kinetic analysis and Markov state models built on this embedding produce folding and unfolding timescales that are in close agreement with other rigorous dynamical embeddings such as time independent component analysis.
“Breakdown” of stratified electrical explosion products: Plasma development and its mechanical effect
Authors: Han Ruoyu , Li Chen , Wang Kun , Yuan Wei , Wang Yanan , Ding Weidong , Ouyang Jiting
Published: October 2021

The physical image of breakdown dynamics inside striations is depicted. High-speed photography along with electrophysical and spectral diagnostics reveals three modes for plasma development in Cu wire explosion: current cutoff, initial breakdown (with quenching), and main breakdown (with re-strike). The growth of spatial heterogeneity by electrothermal instability (ETI) provides a stratified structure before the initial breakdown. The characteristic wavelength of the strata is <100 μm for thinner wires (d = 90/130 μm) but in mm level for thicker ones (d = 240/290 μm). By increasing the stored energy from 200 to 220 J, the 290-μm-diameter Cu wire experiences a transition from current cutoff to initial breakdown, with a deposited energy of 2.64 and 3.10 eV/atom. Although the energy is not sufficient to vaporize the wire, axial micro-plasma-channels develop among bright layers (higher temperature but lower density), forming a crossed low-conductive “plasma-network” connecting two electrodes. If the residual energy is enough, the scenario (main breakdown) would be similar to “streamer-spark transition” and enhance the expansion of discharge channel. Two paralleled wires are exploded simultaneously but only one establishes main breakdown; therein, three stronger shock waves are detected, namely, two for vaporization and one for breakdown.
Burstlike first-order transformation studied by semi-adiabatic relaxation calorimetry
Authors: Hardy V. , Hamane R. , Larose X. , Risser M. , Guillou F.
Published: October 2021

This article reports on a mode of analysis of semi-adiabatic relaxation data allowing to account for exotic phenomena sometimes observed in first-order transitions. The principal interest is to get a detailed characterization of latent heat while using the same experimental configuration as that employed for accurate heat capacity measurements outside the transition. Special attention is paid to the recalescence/antirecalescence effects and to the existence of spikes in the time-dependent exchange of latent heat. The present approach—based on the notion of “power of latent heat”—is shown to be consistent with differential scanning calorimetry, magnetization measurements, and the usual analysis in terms of heat capacity. The study is carried out on a LaFe10.77Si1.23Co0.28 compound that belongs to one of the most promising families of giant magnetocaloric materials.
Multifaceted local action for the conservation of the transboundary Prespa lakes Ramsar sites in the Balkans
Authors: Catsadorakis Giorgos , Roumeliotou Vivi , Koutseri Irene , Malakou Myrsini
Published: October 2021

We provide a short overview of the bottom-up, non-governmental organisation (NGO)-driven conservation efforts that go a long way towards implementing the Ramsar Convention on the ground in the Prespa basin in the Balkans. Encompassing two lakes, the transboundary Prespa basin is covered by three Ramsar sites. The lakes host significant endemism and internationally important breeding and wintering waterbirds. For over 30 years, the Society for the Protection of Prespa (SPP), a locally based NGO representing an international constituency, has successfully used the obligations, goals and objectives laid out by the Ramsar Convention. The SPP has led broader alliances, implementing and coordinating conservation action, initially on the Greek side and later at basin level, through an integrated ecosystem approach, multiparticipatory decision-making processes and transboundary collaboration. It has achieved substantial benefits for waterbird populations, especially pelicans, engaged in community-based resource management approaches and drawn support, mainly from international donors, to achieve progress in the wise use of the wetland. The established decision-making mechanisms in Greek Prespa, the long-term monitoring data on the wetland ecosystem and the operation of transboundary collaboration networks are also expected to contribute towards addressing ongoing challenges, such as eutrophication and adaptation to climate change.
Empirical audit and review and an assessment of evidentiary value in research on the psychological consequences of scarcity
Authors: O’Donnell Michael , Dev Amelia S. , Antonoplis Stephen , Baum Stephen M. , Benedetti Arianna H. , Brown N. Derek , Carrillo Belinda , Choi Andrew L. , Connor Paul , Donnelly Kristin , Ellwood-Lowe Monica E. , Foushee Ruthe , Jansen Rachel , Jarvis Shoshana N. , Lundell-Creagh Ryan , Ocampo Joseph M. , Okafor Gold N. , Azad Zahra Rahmani , Rosenblum Michael , Schatz Derek , Stein Daniel H. , Wang Yilu , Moore Don A. , Nelson Leif D.
Published: October 2021

Empirical audit and review is an approach to assessing the evidentiary value of a research area. It involves identifying a topic and selecting a cross-section of studies for replication. We apply the method to research on the psychological consequences of scarcity. Starting with the papers citing a seminal publication in the field, we conducted replications of 20 studies that evaluate the role of scarcity priming in pain sensitivity, resource allocation, materialism, and many other domains. There was considerable variability in the replicability, with some strong successes and other undeniable failures. Empirical audit and review does not attempt to assign an overall replication rate for a heterogeneous field, but rather facilitates researchers seeking to incorporate strength of evidence as they refine theories and plan new investigations in the research area. This method allows for an integration of qualitative and quantitative approaches to review and enables the growth of a cumulative science.
First-order antiferromagnetic transitions of SrMn
2
P
2
and CaMn
2
P
2
single crystals containing corrugated-honeycomb Mn sublattices
Authors: Sangeetha N. S. , Pakhira Santanu , Ding Qing-Ping , Krause Lennard , Lee Hyung-Cheol , Smetana Volodymyr , Mudring Anja-Verena , Iversen Bo Brummerstedt , Furukawa Yuji , Johnston David C.
Published: October 2021

Significance

With rare exceptions, an antiferromagnetic (AFM) transition in zero magnetic field is thermodynamically of second order where the thermal-average magnetic moments of the magnetic atoms (ordered moments) vary continuously on cooling through the AFM ordering temperature

T
N

with no latent heat at the transition. Such materials include the AFM pnictides CaMn
2
As
2
, SrMn
2
As
2
, CaMn
2
Sb
2
, SrMn
2
Sb
2
, and CaMn
2
Bi
2
. Here we demonstrate that the closely related SrMn
2
P
2
and CaMn
2
P
2
insulators instead exhibit first-order AFM transitions at

T
N

=
53

and 70 K, respectively, where the heat capacity exhibits a latent heat at

T
N

. The mechanism causing these first-order transitions remains to be explained, but its understanding may lead to the development of novel magnetic materials of technological interest.
Gas tungsten arc weldability of stainless steel 304 using CoCrFeMnNi filler metals for cryogenic applications
Authors: Nam Hyunbin , Moon Byungrok , Park Sangwon , Kim Namkyu , Song Sangwoo , Park Nokeun , Na Youngsang , Kang Namhyun
Published: October 2021

This study investigates the gas tungsten arc (GTA) weldability of austenitic stainless steel (STS) 304 using STS 308L and high-entropy alloy (HEA) fillers and its applicability in cryogenic environments. Because the grain sizes of both weld metals (WMs) were coarser than those of base metal (BM), and all WMs have a few phase transformations, the tensile properties of all WMs were worse than that of the BM. However, the tensile strength and elongation of HEA weld at 77 K increased simultaneously than those at 298 K, whereas the elongation of STS 308L weld decreased at 77 K than that at 298 K. All WMs exhibited excellent tensile strengths at 77 K, attributable to martensite transformations and deformation twins, respectively.
The ratio of heart rate to heart rate variability reflects sympathetic activity during incremental cycling exercise
Authors: Tanoue Yukiya , Komatsu Tomohiro , Nakashima Shihoko , Matsuda Takuro , Michishita Ryoma , Higaki Yasuki , Uehara Yoshinari
Published: October 2021

A low‐frequency to a high‐frequency component ratio (LF/HF) in heart rate variability (HRV) may not accurately reflect sympathetic nervous activity during exercise. Thus, a valid HRV‐based index of sympathetic nervous activity is needed. Therefore, the heart rate to LF ratio (Heart rate/LF) was evaluated as sympathetic nervous activity index which is reflected by catecholamine levels during incremental exercise. In this study, 15 healthy adults performed an incremental exercise test using a cycle ergometer. HRV was derived from electrocardiography and HRV components related to the autonomic nervous system were obtained using frequency analysis. Heart rate/LF was calculated using the heart rate and LF component produced by HRV analysis. Catecholamine, blood lactate levels and respiratory gas were also measured throughout the exercise test. While LF/HF did not increase with increasing exercise intensity, Heart rate/LF non‐linearly increased during the incremental exercise test, as did noradrenaline and blood lactate. Interestingly, Heart rate/LF values were positively correlated with noradrenaline (ρ = 0.788, p < 0.05) and blood lactate (ρ = 0.802, p < 0.05) levels and carbon dioxide production (ρ = 0.903, p < 0.05) from at rest through the exercise stages. Heart rate/LF reflects sympathetic nervous activity and metabolic responses during incremental cycling exercise and has potential as an HRV index of sympathetic nervous activity during exercise.

Trial registration: UMIN Japan identifier: UMIN000039639.
HVEM structures and mutants reveal distinct functions of binding to LIGHT and BTLA/CD160
Authors: Liu Weifeng , Chou Ting-Fang , Garrett-Thomson Sarah C. , Seo Goo-Young , Fedorov Elena , Ramagopal Udupi A. , Bonanno Jeffrey B. , Wang Qingyang , Kim Kenneth , Garforth Scott J. , Kakugawa Kiyokazu , Cheroutre Hilde , Kronenberg Mitchell , Almo Steven C.
Published: October 2021

HVEM is a TNF (tumor necrosis factor) receptor contributing to a broad range of immune functions involving diverse cell types. It interacts with a TNF ligand, LIGHT, and immunoglobulin (Ig) superfamily members BTLA and CD160. Assessing the functional impact of HVEM binding to specific ligands in different settings has been complicated by the multiple interactions of HVEM and HVEM binding partners. To dissect the molecular basis for multiple functions, we determined crystal structures that reveal the distinct HVEM surfaces that engage LIGHT or BTLA/CD160, including the human HVEM–LIGHT–CD160 ternary complex, with HVEM interacting simultaneously with both binding partners. Based on these structures, we generated mouse HVEM mutants that selectively recognized either the TNF or Ig ligands in vitro. Knockin mice expressing these muteins maintain expression of all the proteins in the HVEM network, yet they demonstrate selective functions for LIGHT in the clearance of bacteria in the intestine and for the Ig ligands in the amelioration of liver inflammation.
NRPyCritCol & SFcollapse1D: an open-source, user-friendly toolkit to study critical phenomena
Authors: Werneck Leonardo R , Etienne Zachariah B , Abdalla Elcio , Cuadros-Melgar Bertha , Pellicer CE
Published: October 2021

We present a new open-source, user-friendly toolkit of two codes—SFcollapse1D and NRPyCritCol—to study critical phenomena in the context of gravitational collapse. SFcollapse1D is a C/C++ tool designed to solve the problem of gravitational collapse of massless, spherically symmetric scalar fields with the ADM formalism in spherical-like coordinates. NRPyCritCol is a collection of Python modules that leverage the NRPy+ infrastructure to generate a highly optimized C-code for evolving massless scalar fields within a covariant BSSN formalism. The toolkit was developed with user-friendliness and code efficiency in mind, enabling the exploration of critical phenomena with consumer-grade computers. We present a study of critical phenomena from the collapse of massless scalar fields in spherical symmetry, using only these two codes and a laptop computer.
Carroll limit of four-dimensional gravity theories in the first order formalism
Authors: Guerrieri Amanda , Sobreiro Rodrigo F
Published: October 2021

We explore the ultra-relativistic (UR) limit of a class of four dimensional gravity theories, known as Lovelock–Cartan (LC) gravities, in the first order formalism. First, we review the well known limit of the Einstein–Hilbert (EH) action. A very useful scale symmetry involving the vierbeins and the boost connection is presented. Moreover, we explore the field equations in order to find formal solutions. Some remarkable results are obtained: Riemann and Weitzenböck like manifolds are discussed; Birkhoff’s theorem is verified for the torsionless case; an explicit solution with non-trivial geometry is discussed; a quite general solution in the presence of matter is obtained. Latter, we consider the UR limit of the more general LC gravity. The previously scale symmetry is also discussed. The field equations are studied in vacuum and in the presence of matter. In comparison with the EH case, a few relevant results are found: Birkhoff’s theorem is also verified for the torsionless case; a quite general solution in the presence of matter is obtained. This solution generalizes the previous case; Riemann and Weitzenböck like manifolds are derived in the same lines of the EH case.
Electromotive force (emf) for the confused
Authors: Ho Timothy , Toh Dylan , Ricardo Bernard
Published: October 2021

The electromotive force (emf) is a topic that is introduced in high school and undergraduate physics courses, but the numerous expressions for this quantity in different scenarios often lead to confusion among students. In addition, emf and potential difference are often treated as the same concept when being taught to students, and several misconceptions may arise from not distinguishing between the two. This paper aims to demonstrate the difference between the two quantities from their definitions and through the use of several examples, including the conceptual challenges when it comes to voltmeter measurements. This is expected to be of great interest to educators and students alike, as proper teaching of the topic will allow students to have a more thorough understanding of the effects of electromagnetic fields.
Approximation error method for imaging the human head by electrical impedance tomography*
Authors: Candiani V , Hyvönen N , Kaipio J P , Kolehmainen V
Published: October 2021

This work considers electrical impedance tomography imaging of the human head, with the ultimate goal of locating and classifying a stroke in emergency care. One of the main difficulties in the envisioned application is that the electrode locations and the shape of the head are not precisely known, leading to significant imaging artifacts due to impedance tomography being sensitive to modeling errors. In this study, the natural variations in the geometry of the head and skull are modeled based on a library of head anatomies. The effect of these variations, as well as that of misplaced electrodes, on (absolute) impedance tomography measurements is in turn modeled by the approximation error method. This enables reliably reconstructing the conductivity perturbation caused by the stroke in an average head model, instead of the actual head, relative to its average conductivity levels. The functionality of a certain edge-preferring reconstruction algorithm for locating the stroke is demonstrated via numerical experiments based on simulated three-dimensional data.
Ultra-low power signal conditioning system for effective biopotential signal recording
Authors: Thakur Diksha , Sharma Kulbhushan , Kapila Sonal , Sharma Rajnish
Published: October 2021

Design of Low-power signal conditioning system comprising of biopotential amplifier (BPA) and low pass Filter (LPF) remains one of the most critical block of system on chips (SoCs) targeted for wearable non-invasive and semi-invasive biomedical applications like electroencephalography and electrocorticography. Design of the same is a challenging task owing to noise-power trade-off in BPA and dependency of process voltage and temperature variations on the filter circuit. We report the design of a signal conditioning system comprising of a capacitively coupled capacitive feedback (CC-CF) BPA and composite p-channel metal oxide semiconductor (PMOS) based complementary source-follower LPF. The results obtained in Cadence with standard 0.18 µm technology and BSIM3V3 MOS models for the proposed signal conditioning system provide a DC-gain value of 36.76 dB, bandwidth of 280 mHz–174 Hz, power consumption of 24.54 µW, supply current of 24.54 µA, area consumption of 0.212826 mm2 from

±

0.5 V supply voltage. Robustness of this signal conditioning system has been checked by performing 200 runs of monte carlo simulations. The statistical results obtained for gain of (CC-CF) BPA, complementary source follower (CSF-C) LPF and signal conditioning system show mean (µ) values of 39.93 dB, −3.92 dB and 35.96 dB as well as standard deviation (

σ

) of 135.433 mdB, 1.90 dB, and 2.00 dB respectively. The CC-CF BPA architecture, CSF-C LPF and complete signal conditioning system are expected to be used in SoCs targeted for various low-power biomedical applications.
Oblique drive tolerance of elliptical skyrmions moving in perpendicularly magnetized nanowire
Authors: Kaiya Yuki , Nishiyama Shota , Honda Syuta , Itoh Hiroyoshi , Ohsawa Tomokatsu
Published: October 2021

A magnetic skyrmion is stabilized via the Dzyaloshinskii–Moriya interaction in a perpendicularly magnetized thin nanowire. When the skyrmion is driven by a spin-transfer torque due to spin currents flowing through the wire, the skyrmion approaches the wire edge owing to the skyrmion Hall effect. In other words, the skyrmion moves obliquely along the longitudinal direction of the wire. The skyrmion often breaks or disappears because of this oblique motion. In this study, we propose an elliptical skyrmion to prevent this disappearance. We simulated the current-induced motion of an elliptical skyrmion produced in a wire through a micromagnetic approach. The elliptical skyrmion was also moved obliquely to the longitudinal direction of the wire. When a small current flowed through the wire, the skyrmion moved in the longitudinal direction of the wire after it approached the wire edge. When a larger current flowed through the wire, the skyrmion disappeared after it approached the wire edge. The elliptical skyrmion can be driven over a long distance with a larger current compared to a circular skyrmion. The motion of the skyrmion approaching the wire edge was analyzed using Thiele’s equation, with an external force. We estimated the external force from the simulation results of the skyrmion motion. The external force was proportional to the distance between the skyrmion edge and the wire edge. The results of this study indicate that using the elliptical skyrmion as a binary digit in a magnetic memory, such as a skyrmion-based racetrack memory, can be advantageous in term of the stability of the binary digit.
Construction and application of knotted acoustic fields with intensity maxima
Authors: Liu Ya , Zhang Weixuan , Zhang Xiangdong
Published: October 2021

Knots have always played an important role in the life sciences because of their complex topology. Some previous investigations have shown that an optical field can be modulated into knot structures, and a knotted trap formed by light beams has also been demonstrated. Very recently, it has also been demonstrated that an acoustic vortex field with phase singularities can be tied into a knotted structure. However, for knotted tweezers, we need to use the relative maximum points of the amplitude distribution to construct the knotted field (although it is still not known how to create such a knotted line acoustic field) which is beneficial for particle trapping into knotted shapes. In this work we propose a method to generate acoustic fields with knotted intensity maxima in three dimensions. Based on the finite element method and angular spectrum theory, we prove that both Hopf link and trefoil knot lines in acoustic fields can be generated by the designed holograms. Furthermore, under particle tracking simulation in the time domain, we demonstrate that the knotted line acoustic fields can be used to capture particles into different topologies in three dimensions.
Constraining the density dependence of the symmetry energy: the isospin transport ratio revisited
Authors: Mallik S , Gulminelli F , Gruyer D
Published: October 2021

The isospin diffusion of the quasi-projectile formed in the

Ni

64
,
58

on

Ni

64
,
58

reactions in the Fermi energy domain is investigated in the framework of the Boltzmann–Uehling–Uhlenbeck transport model. The well known isospin transport ratio observable is revisited, with the aim of insuring an optimal comparison between experimental data and theoretical calculations and reducing the present uncertainties in the extraction of empirical equation of state parameters. We show that isospin transport ratios are sensitive to all the low order isovector parameters (E
sym, L
sym and K
sym, but the quantitative results depend on the choice of the isospin sensitive observable. We demonstrate that realistic models of the equation of state, covering the uncertainty that presently affects the theoretical description of neutron stars static observables, can be effectively discriminated by isospin diffusion experiments, provided the neutron to proton ratio of the projectile remnant is precisely measured as a function of centrality.