bluuebunny/crossref_metadata_2025 huggingface dataset:
A concurrent two‐scale coupling for wave propagation using direct solution schemes with explicit time integration
Authors: Grunwald Christoph , Durr Nathanaël , Sauer Martin , Riedel Werner , Hiermaier Stefan
Published: July 2021

This article proposes an efficient concurrent coupling of two different material scales—a macroscale and a microscale—in a direct solution scheme based on explicit time integration. Both scales may be discretized with different element sizes and the microdomain may exhibit a heterogeneous structure. A surface coupling is described, which imposes the macrovelocities at the interfaces on the microscale. Using an averaged stress state of several elements on the microscale within a bounded volume, forces are derived which transfer the micromaterial response back to the macroscale. Whereas established surface couplings based on Lagrange multipliers achieve an exact solution of the interface problem, the proposed coupling is based on a weak staggered scheme. The advantage is that no common global system of equations has to be solved and the approach preserves the efficiency of direct solution schemes almost completely. It is therefore well applicable to the simulation of wave propagation phenomena in heterogeneous materials with complex constitutive models and suitable for massive parallelization. Example simulations demonstrate the capabilities and current limitations.
A Godunov‐type discrete element model for elastic‐viscoplastic continuum impact problems
Authors: Liu Zhechao , Zhang Jun , He Yong , Zhao Wanhua
Published: July 2021

The discrete element model (DEM) has attractive advantages in expressing multiple cracks propagation problem in continuum, but the description of material plastic characteristics by current DEM is restricted by the connection model, which is the core procedure in DEM modeling process. A Godunov‐type continuum‐based DEM model is proposed to solve the dynamic response of materials under high‐speed impact, in which there is a state transition of material model from continuous to discontinuous. In this article, under the framework of DEM, the contact discontinuity between adjacent elements is analyzed with the Godunov method, and a connection model derived from the physical process is established. Firstly, the numerical solution of the Riemann problem, which is equivalent to the plane wave collision operator, is solved by an iterative method, and an explicit time‐marching integral format for the dynamic impact problem in elastic‐viscoplastic materials is derived. Then, the numerical model is validated by comparing the calculation results with theoretical results, using a wave propagation example in plate. In addition, the capacity of simulating material property discontinuity and multiple cracks are validated by cases of stress wave transmission and reflection at the materials interface and the cracks capture in Kalthoff dynamic shear test, respectively.
Late isolated central nervous system relapse in childhood B‐cell acute lymphoblastic leukemia treated with intensified systemic therapy and delayed reduced dose cranial radiation: A report from the Children's Oncology Group study AALL02P2
Authors: Hastings Caroline , Chen Yichen , Devidas Meenakshi , Ritchey A. Kim , Winick Naomi J. , Carroll William L. , Hunger Stephen P. , Wood Brent L. , Marcus Robert B. , Barredo Julio C.
Published: July 2021

Background

Patients with late, ≥18 months postdiagnosis, isolated central nervous relapse (iCNS‐R) of B‐acute lymphoblastic leukemia (ALL) have excellent outcomes with chemotherapy plus cranial radiotherapy, with 5‐year overall survival (OS) approaching 80% in POG 9412. Subsequent relapse and radiation‐related morbidity remain the causes of treatment failure and long‐term sequelae. COG AALL02P2 aimed to maintain outcomes in patients with late iCNS‐R using intensified chemotherapy and a decrease in cranial irradiation from 1800 to 1200 cGy.

Procedures

COG AALL02P2 enrolled 118 eligible patients with B‐cell ALL (B‐ALL) and late iCNS‐R who received intensified systemic therapy, triple intrathecal chemotherapy, and 1200 cGy cranial irradiation delivered at 12 months, with maintenance chemotherapy continuing until 104 weeks postdiagnosis.

Results

The 3‐year event‐free survival (EFS) and OS were 64.3% ± 4.5% and 79.6% ± 3.8%, with 46.1% (18/39) of second relapses including the CNS. Of the 112 patients who completed therapy, 78 received protocol‐specified radiation. Study enrollment was closed after interim monitoring analysis showed inferior EFS compared to POG 9412. Patients with initial NCI standard‐risk classification fared better than high‐risk patients.

Conclusions

COG AALL02P2 showed inferior EFS but similar OS compared to POG 9412. Limitations included a small sample size, more intensive prior therapies, and a significant number of patients (34/118, 29%) who did not receive protocol‐directed radiation due to early relapse prior to 1 year or did not otherwise follow the treatment plan. New approaches are needed to improve outcome for these patients and determine the optimal timing and dose of cranial radiation in the treatment of iCNS‐R.
Utility of fetal whole exome sequencing in the etiological evaluation and outcome of nonimmune hydrops fetalis
Authors: Correa Alec Reginald Errol , Naini Kamal , Mishra Pallavi , Dadhwal Vatsla , Agarwal Ramesh , Shukla Rashmi , Kabra Madhulika , Gupta Neerja
Published: July 2021

Introduction

Nonimmune hydrops fetalis (NIHF) has varied etiology. We assessed the etiological spectrum and evaluated the utility of fetal whole exome sequencing (fWES) for the diagnosis of NIHF.

Methods

In this prospective cohort study, we evaluated antenatally diagnosed fetuses with NIHF between July 2018 and December 2019 according to the routine diagnostic algorithm. Fetuses that remained undiagnosed after routine NIHF workup were subjected to fetal chromosomal microarray and/or WES. Pregnancies were followed up for clinical outcomes.

Results

Of the 45 fetuses, consanguinity and recurrent hydrops fetalis were observed in 13.3% (6/45) and 28.8% (13/45), respectively. Overall, an etiological diagnosis was possible in 75.5% (34/45) of fetuses, while the cause remained unknown in 24.4% (11/45). A genetic etiology was identified in 46.6% (21/45): aneuploidy and monogenic disorders in 28.8% (13/45) and 17.8% (8/45), respectively. fWES on 19 fetuses detected disease‐causing variants in 42.1% (8/19). Nine novel variants were detected in RAPSN, ASCC1, NEB, PKD1L1, GUSB, and PIEZO1. Only 8.8% (4/45) of the cohort survived without morbidity.

Conclusions

This study describes the etiological spectrum and the disease‐causing variants in an Indian cohort of hydropic fetuses.
Side‐chain amino‐acid‐based polymers: self‐assembly and bioapplications
Authors: Nayak Kasturee , Ghosh Pooja , Khan Md Ezaz Hasan , De Priyadarsi
Published: July 2021

The design and development of side‐chain amino‐acid‐based polymeric nanostructures have attracted a significant research interest as they bring a remarkable revolution in various territories of the biomedical field. The incorporation of amino acid moieties into the side chain of synthetic polymeric scaffolds exhibits several beneficial properties like aqueous solubility, chiral recognition, high biocompatibility, stimuli responsiveness, antifouling properties, as well as their capability to form higher ordered self‐assembled architectures. Considering the important features and widespread applications of side‐chain amino‐acid‐containing polymers, here we shed light on the self‐assembled characteristics of side‐chain amino‐acid‐containing polymers and their implications. The primary aim of this review article is to highlight the recent achievements of this bright area of research. We describe the numerous aspects of side‐chain amino‐acid‐containing polymers focusing mainly on self‐assembly properties and the biomedical applications, which include drug and gene delivery, antimicrobial activity, antifouling coating, wound healing, tissue engineering etc. © 2021 Society of Industrial Chemistry.
Study of crystal structure and properties of poly(vinylidene fluoride)/graphene composite fibers
Authors: Yan Jingjing , Xiao Changfa , Huang Yan , Zhang Tai
Published: July 2021

Poly(vinylidene fluoride) (PVDF) nascent composite fibers were prepared through the melt‐spinning method with different graphene (GE) contents, following which post‐stretched composite fibers were obtained using a post‐stretching process under thermal treatment condition. The effects of GE content and post‐stretching ratio on the crystal structure and properties of the fibers were investigated in order to obtain PVDF composite fibers with high β crystal content and high hydrophobicity and oleophilicity. The results indicated that the addition of GE led to some extent to an improvement in the content of β crystals and the orientation of crystals. Furthermore, the addition of GE obviously improved the mechanical properties, hydrophobicity and oleophilicity of nascent composite fibers. The post‐stretching ratio had a significant influence on the transition of the crystal phase from α to β and the orientation of crystals. In addition, the post‐stretching played a positive role in enhancement of mechanical properties and hydrophobicity. When 5 wt% GE was added and the post‐stretching ratio was 6, PVDF composite fibers with high β crystal content, super‐oleophilicity and high hydrophobicity could be obtained. The β crystal content of PVDF composite fibers could reach 62.8%, oil contact angle was 0° and water contact angle was 116.0°. © 2021 Society of Industrial Chemistry.
Effects of fadolmidine, an α2‐adrenoceptor agonist, as an adjuvant to spinal bupivacaine on antinociception and motor function in rats and dogs
Authors: Leino Tiina , Viitamaa Timo , Salonen Jarmo S. , Pesonen Ullamari , Haapalinna Antti
Published: July 2021

α2‐Adrenoceptor agonists such as clonidine and dexmedetomidine are used as adjuvants to local anesthetics in regional anesthesia. Fadolmidine is an α2‐adrenoceptor agonist developed especially as a spinal analgesic. The current studies investigate the effects of intrathecally administered fadolmidine with a local anesthetic, bupivacaine, on antinociception and motor block in conscious rats and dogs. The antinociceptive effects of intrathecal fadolmidine and bupivacaine alone or in combination were tested in the rat tail‐flick and the dog's skin twitch models. The durations of motor block in rats and in dogs were also assessed. In addition, the effects on sedation, mean arterial blood pressure, heart rate, respiratory rate and body temperature were evaluated in telemetrized dogs. Concentrations of fadolmidine in plasma and spinal cord were determined after intrathecal and intravenous administration in rats. Co‐administration of intrathecal fadolmidine with bupivacaine increased the magnitude and duration of the antinociceptive effects and prolonged motor block without hypotension. The interaction of the antinociceptive effect was synergistic in its nature in rats. Concentration of fadolmidine in plasma was very low after intrathecal dosing. Taken together, these studies show that fadolmidine as an adjuvant to intrathecal bupivacaine provides enhanced sensory‐motor block and enables a reduction of the doses of both drugs. The results indicate that co‐administration of fadolmidine with intrathecal bupivacaine was able to achieve an enhanced antinociceptive effect without hypotension and could thus represent a suitable combination for spinal anesthesia.
Binding interactions with sevelamer and polystyrene sulfonate in vitro
Authors: van Berlo‐van de Laar Inge R.F. , Prins‐Can Ilona , de Lange Aliesa A. , Taxis Katja , Jansman Frank G.A.
Published: July 2021

This study explored the binding of 28 drugs, which were selected based on frequency of concomitant use and chemical properties, to sevelamer and polystyrene sulfonate in vitro. The relative binding was determined by dissolving the investigated drugs alone (=control), together with 800 mg of sevelamer and 15 g of polystyrene sulfonate at different pH levels (1.5, 5.5, and 7.4), respectively. After incubation at 37℃ and shaking for 60 min, the solutions were diluted and centrifuged, and the drug concentrations were quantified with validated analytical assays. The binding assays were performed in threefold. The mean relative binding (MRB) at each pH level was calculated, with a MRB >20% for at least one pH level to be considered as relevant binding. Fourteen and 23 potentially new binding interactions were identified with sevelamer and polystyrene sulfonate, respectively. These potentially new binding interactions have to be studied in vivo to assess their clinical relevance.
Switching TNFα inhibitors: Patterns and determinants
Authors: Meijboom Rosanne W. , Gardarsdottir Helga , Becker Matthijs L. , de Groot Mark C. H. , Movig Kris L. L. , Kuijvenhoven Johan , Egberts Toine C. G. , Leufkens Hubert G. M. , Giezen Thijs J.
Published: July 2021

The aim of this study was to assess switching patterns and determinants for switching in patients initiating TNFα inhibitor (TNFα‐i) treatment. Patients were included who started TNFα‐i treatment between July 1, 2012 and December 31, 2017, from three Dutch hospitals, and were diagnosed with rheumatic diseases (RD), inflammatory bowel disease (IBD), or psoriasis. Outcomes were switching, defined as initiating another biological; switching patterns including multiple switches until the end of follow‐up; determinants for first switch, assessed using multivariate logistic regression. A total of 2228 patients were included (median age 43.3 years, 57% female), of which 52% (n = 1155) received TNFα‐i for RD, 43% (n = 967) for IBD, and 5% (n = 106) for psoriasis. About 16.6% of RD patients, 14.5% of IBD patients, and 16.0% of psoriasis patients switched at least once, mainly to another TNFα‐i. TNFα‐i dose escalation (OR 13.78, 95% CI 1.40–135.0) and high‐dose corticosteroids initiation (OR 3.62, 95% CI 1.10–12.15) were determinants for switching in RD patients. TNFα‐i dose escalation (OR 8.22, 95% CI 3.76–17.93), immunomodulator initiation/dose escalation (OR 2.13, 95% CI 1.04–4.34), high‐dose corticosteroids initiation (OR 6.91, 95% CI 2.81–17.01) and serum concentration measurement (OR 5.44, 95% CI 2.74–10.79) were determinants for switching in IBD patients. Switching biological treatment occurred in about one in six patients. RD patients with TNFα‐i dose escalation and/or high‐dose corticosteroids initiation were more likely to switch. IBD patients with TNFα‐i or immunomodulator initiation/dose escalation, high‐dose corticosteroids initiation or serum concentration measurement were more likely to switch. These findings might help clinicians anticipating switching in TNFα‐i treatment.
Population genomics of Digitaria insularis from soybean areas in Brazil
Authors: Gonçalves Netto Acácio , Cordeiro Erick MG , Nicolai Marcelo , de Carvalho Saul JP , Ovejero Ramiro Fernando Lopez , Brunharo Caio ACG , Zucchi Maria I , Christoffoleti Pedro J
Published: July 2021

BACKGROUND

Digitaria insularis is a weed species that has gained considerable importance in Brazil's soybean production areas that rely on glyphosate‐resistant cultivars. Herbicide‐resistant weed populations of this species have been reported in many regions in Brazil, first in the south, followed by later reports in the north. We hypothesized that the spread of herbicide‐resistant D. insularis is facilitated by movement of agricultural machinery from the southern regions of Brazil.

RESULTS

Population genomics revealed a weak or no genetic structure (FST = [0; 0.16]), moderate expected heterozygosity (HE = 0.15; 0.44) and low inbreeding (FIS = [−0.1; 0.1]) in D. insularis populations. Our data supported the hypothesis that herbicide resistance gene flow predominantly occurred in a south‐to‐north direction based on a migration analysis. We also found evidence of local adaptation of resistant populations in the northern soybean‐growing regions of Brazil.

CONCLUSION

Evidence in our work suggests that gene flow of glyphosate‐resistant D. insularis is associated with movement of agricultural machinery, although local selection pressure seems to play an important role in the evolution of herbicide resistance throughout the country. Our results suggest preventive practices such as equipment sanitation should be implemented to limit the spread of herbicide resistant D. insularis. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Confidence intervals of prediction accuracy measures for multivariable prediction models based on the bootstrap‐based optimism correction methods
Authors: Noma Hisashi , Shinozaki Tomohiro , Iba Katsuhiro , Teramukai Satoshi , Furukawa Toshi A.
Published: July 2021

In assessing prediction accuracy of multivariable prediction models, optimism corrections are essential for preventing biased results. However, in most published papers of clinical prediction models, the point estimates of the prediction accuracy measures are corrected by adequate bootstrap‐based correction methods, but their confidence intervals are not corrected, for example, the DeLong's confidence interval is usually used for assessing theC‐statistic. These naïve methods do not adjust for the optimism bias and do not account for statistical variability in the estimation of parameters in the prediction models. Therefore, their coverage probabilities of the true value of the prediction accuracy measure can be seriously below the nominal level (eg, 95%). In this article, we provide two generic bootstrap methods, namely, (1) location‐shifted bootstrap confidence intervals and (2) two‐stage bootstrap confidence intervals, that can be generally applied to the bootstrap‐based optimism correction methods, that is, the Harrell's bias correction, 0.632, and 0.632+ methods. In addition, they can be widely applied to various methods for prediction model development involving modern shrinkage methods such as the ridge and lasso regressions. Through numerical evaluations by simulations, the proposed confidence intervals showed favorable coverage performances. Besides, the current standard practices based on the optimism‐uncorrected methods showed serious undercoverage properties. To avoid erroneous results, the optimism‐uncorrected confidence intervals should not be used in practice, and the adjusted methods are recommended instead. We also developed the R packagepredbootfor implementing these methods (https://github.com/nomahi/predboot). The effectiveness of the proposed methods are illustrated via applications to the GUSTO‐I clinical trial.
Controlling Movement at Nanoscale: Curvature Driven Mechanotaxis
Authors: Machado Leonardo D. , Bizao Rafael A. , Pugno Nicola M. , Galvão Douglas S.
Published: July 2021

Locating and manipulating nano‐sized objects to drive motion is a time and effort consuming task. Recent advances show that it is possible to generate motion without direct intervention, by embedding the source of motion in the system configuration. In this work, an alternative manner to controllably displace nano‐objects without external manipulation is demonstrated, by employing spiral‐shaped carbon nanotube (CNT) and graphene nanoribbon structures (GNR). The spiral shape contains smooth gradients of curvature, which lead to smooth gradients of bending energy. It is shown that these gradients as well as surface energy gradients can drive nano‐oscillators. An energy analysis is also carried out by approximating the carbon nanotube to a thin rod and how torsional gradients can be used to drive motion is discussed. For the nanoribbons, the role of layer orientation is also analyzed. The results show that motion is not sustainable for commensurate orientations, in which AB stacking occurs. For incommensurate orientations, friction almost vanishes, and in this instance, the motion can continue even if the driving forces are not very high. This suggests that mild curvature gradients, which can already be found in existing nanostructures, could provide mechanical stimuli to direct motion.
Wood‐Derived, Conductivity and Hierarchical Pore Integrated Thick Electrode Enabling High Areal/Volumetric Energy Density for Hybrid Capacitors
Authors: Wang Feng , Liu Xiaolin , Duan Gaigai , Yang Haoqi , Cheong Jun Young , Lee Jiyoung , Ahn Jaewan , Zhang Qian , He Shuijian , Han Jingquan , Zhao Yan , Kim Il‐Doo , Jiang Shaohua
Published: July 2021

For the proliferation of the supercapacitor technology, it is essential to attain superior areal and volumetric performance. Nevertheless, maintaining stable areal/volumetric capacitance and rate capability, especially for thick electrodes, remains a fundamental challenge. Here, for the first time, a rationally designed porous monolithic electrode is reported with high thickness of 800 µm (46.74 mg cm−2, with high areal mass loading of NiCo2S4 6.9 mg cm−2) in which redox‐active Ag nanoparticles and NiCo2S4 nanosheets are sequentially decorated on highly conductive wood‐derived carbon (WC) substrates. The hierarchically assembled WC@Ag@NiCo2S4 electrode exhibits outstanding areal capacitance of 6.09 F cm−2 and long‐term stability of 84.5% up to 10 000 cycles, as well as exceptional rate capability at 50 mA cm−2. The asymmetric cell with an anode of WC@Ag and a cathode of WC@Ag@NiCo2S4 delivers areal/volumetric energy density of 0.59 mWh cm−2/3.93 mWh cm−3, which is much‐improved performance compared to those of most reported thick electrodes at the same scale. Theoretical calculations verify that the enhanced performance could be attributed to the decreased adsorption energy of OH− and the down‐shifted d‐band of Ag atoms, which can accelerate the electron transport and ion transfer.
The Longer Route can be Better: Electrosynthesis in Extended Path Flow Cells
Authors: Brown Richard C. D.
Published: July 2021

This personal account provides an overview of work conducted in my research group, and through collaborations with other chemists and engineers, to develop flow electrolysis cells and apply these cells in organic electrosynthesis. First, a brief summary of my training and background in organic synthesis is provided, leading in to the start of flow electrosynthesis in my lab in collaboration with Derek Pletcher. Our work on the development of extended path electrolysis flow reactors is described from a synthetic organic chemist's perspective, including laboratory scale‐up to give several moles of an anodic methoxylation product in one day. The importance of cell design is emphasised with regards to achieving good performance in laboratory electrosynthesis with productivities from hundreds of mg h−1to many g h−1, at high conversion in a selective fashion. A simple design of recycle flow cell that can be readily constructed in a small University workshop is also discussed, including simple modifications to improve cell performance. Some examples of flow electrosyntheses are provided, including Shono‐type oxidation, anodic cleavage of protecting groups, Hofer‐Moest reaction of cubane carboxylic acids, oxidative esterification and amidation of aldehydes, and reduction of aryl halides.
Toward learning‐centered education in colleges and universities
Authors: Fink L. Dee
Published: July 2021

This preface to the chapters that follow contextualizes the historical context within which Essential Learning Outcomes are discussed. A conceptual framework for the discussion of the context within which these projects occur is described in this preface.
Within our reach: Essential learning outcomes, engaged pedagogy, and assessment for quality learning
Authors: Rhodes Terrel
Published: July 2021

This article describes the alignment between a liberal arts education and essential learning outcomes that prepare individuals with a breadth of skills and knowledge in preparation for work and life. Association of American Colleges and Universities' (AAC&U) efforts prompt institutions to adopt essential learning outcomes and assess students’ proficiency throughout their college education.
Integrating essential learning outcomes and electronic portfolios: Recommendations for assessment of student growth, course objectives, program outcomes, and accreditation standards
Authors: Sowers Kerri L. , Meyers Shelly
Published: July 2021

Stockton University is a mid‐size liberal arts institution in Southern New Jersey. Degree seekers must complete required course work in both liberal studies and core, specialized areas, such as business, health sciences, hospitality, education, social and behavioral sciences, or organizational leadership. Stockton emphasizes Essential Learning Outcomes (ELOs) in undergraduate programs, aligning them to course goals and program outcomes. Faculty implement ELOs in many courses, across disciplines, providing students with opportunities to generalize ELOs in different contexts, in meaningful and relevant ways. Electronic portfolios (ePortfolios) are used to give students opportunities to develop their own personal profiles and expand their goal setting practices, by choosing artifacts that most represent who they are as learners and who they will be as future employees. Students enrolled in the courses included in this case study were encouraged to maintain an electronic portfolio that facilitates skill acquisition of reflective thought, self‐assessment, authentic learning, self‐determination, critical thinking and problem solving in preparation to successfully participate in a 21st century global world. Together with ELOs, ePortfolios give students a means of promoting their value to a future employer. This paper explores multiple case studies through courses that have integrated ELOs and ePortfolios for the purpose of assessing student growth, course objectives, program outcomes, or accreditation assessment. The case studies highlight the use of ELOs merged with ePortfolios for: first‐year students and their involvement in campus and course activities to assess personal and academic growth; first‐year students and the development of their research and information literacy skills to assess academic growth and course objectives; upper level undergraduate students and reflective assessment of student growth and course outcomes; and graduate students and reflective assessment of student growth and evidence for documenting accreditation standards. Examples of how ELOs and ePortfolios can be merged for different disciplines, and different student levels, are explored in detail. Suggestions for additional opportunities to embed ELOs into ePortfolios are discussed and provided for faculty who are interested in the utilization of these merged concepts for the assessment of student growth, course objectives, program outcomes and accreditation standards.
Building preservice teacher's essential skill competencies through a situated learning approach
Authors: Cydis Susan , Haria Priti , Meyers Shelly
Published: July 2021

This study reports on the value of teaching preservice teachers in an authentic setting. Outcomes suggest that the situated learning setting was more effective to the acquisition of content and pedagogy and increasing essential skill competence than when courses are offered in a more traditional format of lecture and discussion.
Supercharged AdS3 Holography
Authors: Rawash Sami , Turton David
Published: July 2021

Abstract

Given an asymptotically Anti-de Sitter supergravity solution, one can obtain a microscopic interpretation by identifying the corresponding state in the holographically dual conformal field theory. This is of particular importance for heavy pure states that are candidate black hole microstates. Expectation values of light operators in such heavy CFT states are encoded in the asymptotic expansion of the dual bulk configuration. In the D1-D5 system, large families of heavy pure CFT states have been proposed to be holographically dual to smooth horizonless supergravity solutions. We derive the precision holographic dictionary in a new sector of light operators that are superdescendants of scalar chiral primaries of dimension (1,1). These operators involve the action of the supercharges of the chiral algebra, and they play a central role in the proposed holographic description of recently-constructed supergravity solutions known as “supercharged superstrata”. We resolve the mixing of single-trace and multi-trace operators in the CFT to identify the combinations that are dual to single-particle states in the bulk. We identify the corresponding gauge-invariant combinations of supergravity fields. We use this expanded dictionary to probe the proposed holographic description of supercharged superstrata, finding precise agreement between gravity and CFT.
Twisted 6d (2, 0) SCFTs on a circle
Authors: Duan Zhihao , Lee Kimyeong , Nahmgoong June , Wang Xin
Published: July 2021

Abstract

We study twisted circle compactification of 6d (2, 0) SCFTs to 5d $$ \mathcal{N} $$
N
= 2 supersymmetric gauge theories with non-simply-laced gauge groups. We provide two complementary approaches towards the BPS partition functions, reflecting the 5d and 6d point of view respectively. The first is based on the blowup equations for the instanton partition function, from which in particular we determine explicitly the one-instanton contribution for all simple Lie groups. The second is based on the modular bootstrap program, and we propose a novel modular ansatz for the twisted elliptic genera that transform under the congruence subgroups Γ0(N) of SL(2, ℤ). We conjecture a vanishing bound for the refined Gopakumar-Vafa invariants of the genus one fibered Calabi-Yau threefolds, upon which one can determine the twisted elliptic genera recursively. We use our results to obtain the 6d Cardy formulas and find universal behaviour for all simple Lie groups. In addition, the Cardy formulas remain invariant under the twist once the normalization of the compact circle is taken into account.
Corners of gravity: the case of gravity as a constrained BF theory
Authors: Durka Remigiusz , Kowalski-Glikman Jerzy
Published: July 2021

Abstract

Following recent works on corner charges we investigate the boundary structure in the case of the theory of gravity formulated as a constrained BF theory. This allows us not only to introduce the cosmological constant, but also explore the influence of the topological terms present in the action of this theory. Established formulas for charges resemble previously obtained ones, but we show that they are affected by the presence of the cosmological constant and topological terms. As an example we discuss the charges in the case of the AdS-Schwarzschild solution and we find that the charges give correct values.
Rotating multi-charge spindles and their microstates
Authors: Hosseini Seyed Morteza , Hristov Kiril , Zaffaroni Alberto
Published: July 2021

Abstract

Some AdS3 × M7 type IIB vacua have been recently proposed to arise from D3-branes wrapped on a spindle, a sphere with conical singularities at the poles. We explicitly construct a generalization of these solutions corresponding to a class of electrically charged and rotating supersymmetric black strings in AdS5 × S5 with general magnetic fluxes on the spindle. We then perform a counting of their microstates using the charged Cardy formula. To this purpose, we derive the general form of the anomaly polynomial of the dual $$ \mathcal{N} $$
N
= (0, 2) CFT in two dimensions and we show that it can be obtained via a simple gluing procedure.
Chiral separation effect for spin 3/2 fermions
Authors: Khaidukov Z. V. , Abramchuk R. A.
Published: July 2021

Abstract

Chiral Separation Effect (CSE) for systems that feature spin 3/2 fermions was considered. For the self-consistent Adler’s model with relativistic massless Rarita-Schwinger fermions (RSA model), we found that the CSE conductivity is five times larger than for massless Dirac fermions. For a model of four-fold band crossing in Rarita-Schwinger-Weyl semimetals, in which massless fermions with quasispin 3/2 exist, we calculated that the CSE conductivity is four times larger than for Weyl fermions. We show that CSE conductivity for any multi-degenerate Fermi point in topological semimetals is proportional to its Chern number and is topologically protected. Along the calculations, we proved an index theorem that relates Chern number of a Fermi-point and spectral asymmetry of the corresponding Landau band structure. The assumption that CSE for any system of chiral fermions is dictated by the corresponding Chern number is found to be correct for RSA model (and for the Dirac fermions).
Exact results in a $$ \mathcal{N} $$ = 2 superconformal gauge theory at strong coupling
Authors: Beccaria M. , Billò M. , Frau M. , Lerda A. , Pini A.
Published: July 2021

Abstract

We consider the $$ \mathcal{N} $$
N
= 2 SYM theory with gauge group SU(N) and a matter content consisting of one multiplet in the symmetric and one in the anti-symmetric representation. This conformal theory admits a large-N ’t Hooft expansion and is dual to a particular orientifold of AdS5 × S5. We analyze this gauge theory relying on the matrix model provided by localization à la Pestun. Even though this matrix model has very non-trivial interactions, by exploiting the full Lie algebra approach to the matrix integration, we show that a large class of observables can be expressed in a closed form in terms of an infinite matrix depending on the ’t Hooft coupling λ. These exact expressions can be used to generate the perturbative expansions at high orders in a very efficient way, and also to study analytically the leading behavior at strong coupling. We successfully compare these predictions to a direct Monte Carlo numerical evaluation of the matrix integral and to the Padé resummations derived from very long perturbative series, that turn out to be extremely stable beyond the convergence disk |λ| < π2 of the latter.
Loops in AdS: from the spectral representation to position space. Part II
Authors: Carmi Dean
Published: July 2021

Abstract

We continue the study of AdS loop amplitudes in the spectral representation and in position space. We compute the finite coupling 4-point function in position space for the large-N conformal Gross Neveu model on AdS3. The resummation of loop bubble diagrams gives a result proportional to a tree-level contact diagram. We show that certain families of fermionic Witten diagrams can be easily computed from their companion scalar diagrams. Thus, many of the results and identities of [1] are extended to the case of external fermions. We derive a spectral representation for ladder diagrams in AdS. Finally, we compute various bulk 2-point correlators, extending the results of [1].
A new Wilson line-based action for gluodynamics
Authors: Kakkad Hiren , Kotko Piotr , Stasto Anna
Published: July 2021

Abstract

We perform a canonical transformation of fields that brings the Yang-Mills action in the light-cone gauge to a new classical action, which does not involve any triple-gluon vertices. The lowest order vertex is the four-point MHV vertex. Higher point vertices include the MHV and $$ \overline{\mathrm{MHV}} $$

MHV
¯

vertices, that reduce to the corresponding amplitudes in the on-shell limit. In general, any n-leg vertex has 2 ≤ m ≤ n − 2 negative helicity legs. The canonical transformation of fields can be compactly expressed in terms of path-ordered exponentials of fields and their functional derivative. We apply the new action to compute several tree-level amplitudes, up to 8-point NNMHV amplitude, and find agreement with the standard methods. The absence of triple-gluon vertices results in fewer diagrams required to compute amplitudes, when compared to the CSW method and, obviously, considerably fewer than in the standard Yang-Mills action.
Identification of the source of a Listeria monocytogenes outbreak by investigational tracing
Authors: Becker Natalie , Schewe Thomas , Setzer Frauke K. , Schröder Mandy , Reckzeh Claudia , Vossenkuhl Birgit , Luber Petra
Published: July 2021

The number of identified listeriosis outbreaks has increased since the sequence typing of Listeria monocytogenes isolates was established in Germany. Due to the nature of the disease, listeriosis outbreaks are difficult to solve. We present investigational tracing as a simple and rapid method to conduct outbreak investigations. The method was applied in 2019 to stop a prolonged listeriosis outbreak in Germany. The starting point for the investigational tracing was nine health care facilities (HCF). Single cases developed listeriosis while they were staying at the nine facilities. Data were collected from companies that delivered foods to HCF and from ready-to-eat (RTE) foods that were consumed there. Following a step-wise approach, data analysis identified similarities in the food supply of the HCF. Food data were heterogeneous and needed to be standardised. Own brands and changing article numbers were challenging aspects during the identification of manufacturers. The analysis of the delivering companies revealed no similarities. Detailed information about the consumed risk foods for Listeria contamination became available for six HCF. All facilities served a wide variety of cold cut meat products to their in-patients. Investigational tracing revealed that only meat products from one out of 29 food business operators had been consumed in all six HCF. Further activities of the authorities enabled the identification of the outbreak strain on food products and in the processing environment of this company. A product recall and the measures taken stopped the listeriosis outbreak. Thus, investigational tracing can be crucial for the clarification of listeriosis outbreaks.
Hyperrigidity of C*-Correspondences
Authors: Kim Se-Jin
Published: July 2021

We show that hyperrigidity for a C*-correspondence (A, X) is equivalent to non-degeneracy of the left action of the Katsura ideal$$\mathcal {J}_X$$JXonX. This extends the work of Kakariadis (Bull Lond Math Soc 45(6):1119–1130, 2013, Theorem 3.3) and Dor-On and Salomon (J Lond Math Soc 98(2):416–438, 2018, Theorem 3.5) who establish this equivalence for discrete graphs as well as the work of Katsoulis and Ramsey (The non-selfadjoint approach to the Hao–Ng isomorphism, arXiv preprintarXiv:1807.11425, 2018, Theorem 3.1), who establish one direction of this equivalence.
AI management beyond the hype: exploring the co-constitution of AI and organizational context
Authors: Holmström Jonny , Hällgren Markus
Published: July 2021

AI technologies hold great promise for addressing existing problems in organizational contexts, but the potential benefits must not obscure the potential perils associated with AI. In this article, we conceptually explore these promises and perils by examining AI use in organizational contexts. The exploration complements and extends extant literature on AI management by providing a typology describing four types of AI use, based on the idea of co-constitution of AI technologies and organizational context. Building on this typology, we propose three recommendations for informed use of AI in contemporary organizations. First, explicitly define the purpose of organizational AI use. Second, define the appropriate level of transparency and algorithmic management for organizational AI use. Third, be aware of AI’s context-dependent nature.
Imaging sensor data modelling and evaluation based on optical composite characteristics
Authors: Meister Sebastian , Grundhöfer Lars , Stüve Jan , Groves Roger M.
Published: July 2021

Automated Fibre Placement is a common manufacturing technique for composite parts in the aero-space industry. Therefore, a visual part inspection is required which often covers up to 50% of the actual production time. Moreover, the inspection quality of this manual step fluctuates significantly. A camera-based automated inline inspection is capable of increasing the inspection efficiency and accuracy. However, the interpretability of the acquired data strongly depends on the sensor configuration and the inspected material. Thus, this paper introduces methods for modelling and assessing an imaging sensor on the example of a composite material reflecting a spot laser to a camera sensor. In this context, the reflection properties of the material are incorporated into a simulation and validated in comparison to real camera images from the experimental setup. The EMVA 1288 sensor model in combination with the Cramér–Rao lower bound indicates a feasible estimability of the beam propagation, but shows limitations in the predictability of the number of incident photons. The laser spot analysis indicated that the laser spot can deviate from an exact oval shape but its peak value is suitable for robust spot identification in an image. The outlined methodology is also adaptable to other imaging sensors, illumination sources and materials. Thus, the findings can be useful for other fields and manufacturing processes.
A novel multiscale material plasticity simulation model for high-performance cutting AISI 4140 steel
Authors: Bai Jinxuan , Tong Zhen
Published: July 2021

The achievable machined surface quality relies significantly on the material behavior during the high-performance cutting process. In this paper, a multiscale material plasticity simulation framework is developed to predict the deformation behaviors of AISI 4140 steel under various high-performance cutting conditions. The framework was built by coupling a three-dimensional discrete dislocation dynamic (3D-DDD) model with a finite element method (FEM) through the optimization of a dislocation density-based (DDB) constitutive equation (compiled as a user-defined subroutine in ABAQUS). The movement of edge and screw dislocations such as generation, propagation, siding, and their interactions, was performed by 3D-DDD, and the statistical features of dislocations were used to optimize the critical constants of the DDB constitutive equation. For validation, a classic FEM cutting model (Johnson-Cook constitutive equation) was employed as a reference. The simulation results indicated that the proposed multiscale model not only can precisely predict the stress, strain, cutting force, and temperature as those predicted by the classic FEM simulations, but also capture the microstructure characteristics such as grain size and dislocation density distributions under the tested cutting conditions. Severe dynamic recrystallization phenomena were found at the core shear zones. The recrystallization process reached a dynamic equilibrium at the machined surfaces when the cutting speed is larger than 280 m/min or the external-assisted temperature is between 200 and 350°, indicating an optimal range of machining parameters for improved surface integrity.
The action of the mapping class group on metrics of positive scalar curvature
Authors: Frenck Georg
Published: July 2021

We present a rigidity theorem for the action of the mapping class group $$\pi _0({\mathrm{Diff}}(M))$$

π
0

(
Diff

(
M
)

)

on the space $$\mathcal {R}^+(M)$$

R

+

(
M
)

of metrics of positive scalar curvature for high dimensional manifolds M. This result is applicable to a great number of cases, for example to simply connected 6-manifolds and high dimensional spheres. Our proof is fairly direct, using results from parametrised Morse theory, the 2-index theorem and computations on certain metrics on the sphere. We also give a non-triviality criterion and a classification of the action for simply connected 7-dimensional $${\mathrm{Spin}}$$
Spin
-manifolds.
Serendipitous observations from animal-borne video loggers reveal synchronous diving and equivalent simultaneous prey capture rates in chinstrap penguins
Authors: Hinke Jefferson T. , Russell Tamara M. , Hermanson Victoria R. , Brazier Laura , Walden Stephanie L.
Published: July 2021

Seabirds often engage in coordinated, cooperative foraging to improve detection and capture of prey. An extreme example of such coordinated behavior is synchronicity, whereby the movements of individuals are aligned temporally and spatially. Synchronous diving among penguins has been reported, but simultaneous observations of predation by synchronously diving individuals have not. We instrumented chinstrap penguins (Pygoscelis antarcticus) during their incubation period in December 2019 from Cape Shirreff, Livingston Island, Antarctica (60.79°W, 62.46°S) with video and depth recorders to monitor predator foraging behavior and prey consumption rates. Serendipitously, two instrumented individuals, accompanied by a third, banded individual, engaged in synchronous foraging activities on Antarctic krill (Euphausia superba) for 9.25 h. This group formed ashore, transited together to their foraging area, remained in close visual contact after dives, synchronously timed diving behavior, and foraged at similar depths. Prey capture rates were positively correlated across dives and total consumption estimates were equivalent for the two instrumented birds during the video observation period. Video loggers confirmed that synchronous diving and foraging behavior are among the behavioral repertoire of chinstrap penguins and demonstrated equivalent prey capture rates by synchronously foraging predators. The results further suggest that group formation while ashore and group cohesion during a foraging trip may facilitate shared foraging success among group members.
A Stochastic Maximum Principle for Control Problems Constrained by the Stochastic Navier–Stokes Equations
Authors: Benner Peter , Trautwein Christoph
Published: July 2021

We analyze the control problem of the stochastic Navier–Stokes equations in multi-dimensional domains considered in Benner and Trautwein (Math Nachr 292(7):1444–1461, 2019) restricted to noise terms defined by a Q-Wiener process. The cost functional related to this control problem is nonconvex. Using a stochastic maximum principle, we derive a necessary optimality condition to obtain explicit formulas the optimal controls have to satisfy. Moreover, we show that the optimal controls satisfy a sufficient optimality condition. As a consequence, we are able to solve uniquely control problems constrained by the stochastic Navier–Stokes equations especially for two-dimensional as well as for three-dimensional domains.
The impact of bZIP Atf1ortholog global regulators in fungi
Authors: Leiter Éva , Emri Tamás , Pákozdi Klaudia , Hornok László , Pócsi István
Published: July 2021

Regulation of signal transduction pathways is crucial for the maintenance of cellular homeostasis and organismal development in fungi. Transcription factors are key elements of this regulatory network. The basic-region leucine zipper (bZIP) domain of the bZIP-type transcription factors is responsible for DNA binding while their leucine zipper structural motifs are suitable for dimerization with each other facilitiating the formation of homodimeric or heterodimeric bZIP proteins. This review highlights recent knowledge on the function of fungal orthologs of the Schizosaccharomyces pombe Atf1, Aspergillus nidulans AtfA, and Fusarium verticillioides FvAtfA, bZIP-type transcription factors with a special focus on pathogenic species. We demonstrate that fungal Atf1-AtfA-FvAtfA orthologs play an important role in vegetative growth, sexual and asexual development, stress response, secondary metabolite production, and virulence both in human pathogens, including Aspergillus fumigatus, Mucor circinelloides, Penicillium marneffei, and Cryptococcus neoformans and plant pathogens, like Fusarium ssp., Magnaporthe oryzae, Claviceps purpurea, Botrytis cinerea, and Verticillium dahliae.

Key points

• Atf1 orthologs play crucial role in the growth and development of fungi.

• Atf1 orthologs orchestrate environmental stress response of fungi.

• Secondary metabolite production and virulence are coordinated by Atf1 orthologs.