bluuebunny/crossref_metadata_2025 huggingface dataset:
Gradient Mineralized and Porous Double‐Network Hydrogel Effectively Induce the Differentiation of BMSCs into Osteochondral Tissue In Vitro for Potential Application in Cartilage Repair
Authors: Fan Zengjie , Chen Zizi , Zhang Hui , Nie Yingying , Xu Shumei
Published: December 2020

At present, it is a considerable challenge to mimic the complex architecture of osteochondral (OC) tissue. In this study, a porous and gradient mineralized double‐network hydrogel is synthesized and used to induce bone marrow mesenchymal stem cells (BMSCs) to differentiate into the desired OC tissue depending only on the material and mechanical properties. Physical and chemical characterizations show that hydroxyapatite nanoparticles grow and fill into the pores of the hydrogel, and their content presents a gradient change in different layers of hydrogel. The synthesized hydrogel has excellent mechanical properties and the compression strength with different mineralization degrees varies from 27 to 380 kPa, which fully meets the needs of increased mechanical strength of articular cartilage from the surface to the deep layer. Besides, the synthesized hydrogel has good biocompatibility that can promote the proliferation and growth of BMSCs. More importantly, the results of histochemistry, immunohistochemistry, and real time polymerase chain reaction show that gradient mineralized hydrogel can induce BMSCs to differentiate into the desired chondrocytes and osteoblasts in different layers of hydrogels, indicating that OC tissues can be successfully constructed through a simple induction differentiation of gradient mineralized hydrogel.
A new feeding topology with internal 180° phase reversal for wideband series‐fed slot array antennas
Authors: Hu Jiadong , Zhang Zhijun , Feng Zhenghe
Published: December 2020

This paper proposes a new feeding topology with internal 180° phase reversal for wideband series‐fed slot array antennas. As a demonstration, a serial fed, half‐wavelength separated, 7‐element array is designed at 5.8 GHz. Comparing with conventional series‐fed arrays, which require one‐wavelength separation, the phase difference between adjacent elements varies less with frequency. Thus, the proposed array has more stable beam pointing and wider 1 dB gain bandwidth. A prototype was fabricated and measured to validate the performance of the feeding topology. A wide operating bandwidth of 22.4% for S11 < −10 dB, a 1 dB gain bandwidth of 14% and bi‐directional peak gain of 10.01 dBi are achieved with the array length of 2.7λ0. The proposed feeding topology shows its potentials in realizing signal coverage on some special occasions, such as coal mines and tunnels.
A comprehensive electromagnetic evaluation of an MRI anthropomorphic head phantom
Authors: Wood Sossena , Santini Tales , Krishnamurthy Narayanan , Martins Tiago , Farhat Nadim , Ibrahim Tamer S.
Published: December 2020

Electromagnetic simulations are an important tool for the safety assessment of RF coils. They are a useful resource for MRI RF coil designers, especially when complemented with experimental measurements and testing using physical phantoms. Regular‐shaped (spherical/cylindrical) homogeneous phantoms are the MRI standard for RF testing but are somewhat inaccurate when compared with anthropomorphic anatomies, especially at high frequencies. In this work, using a recently developed anthropomorphic heterogeneous human head phantom, studies were performed to analyze the scattering parameters (S‐parameters) and the electric and magnetic field distributions using (1) the B1+ field mapping method on a 7 T human MRI scanner and (2) numerical full‐wave electromagnetic simulations. All studies used the following:

a recently developed six‐compartment refillable 3D‐printed anthropomorphic head phantom (developed from MRI scans obtained in vivo), where the phantom itself is filled in its entirety with either heterogeneous loading, or homogeneous brain or water loading,

in vivo imaging, and

a commercial homogeneous spherical water phantom.

Our results determined that the calculated S‐parameters for all the anthropomorphic head phantom models were comparable to the model that is based on the volunteer (within 17% difference of the reflection coefficient value) but differed for the commercial homogeneous spherical water phantom (within 45% difference). The experimentally measured B1+ field maps of the anthropomorphic heterogeneous and homogeneous brain head phantoms were most comparable to the in vivo measured values. The numerical simulations also show that both the anthropomorphic homogeneous water and brain phantom models were less accurate in terms of electric field intensities/distributions when compared with the segmented in‐vivo‐based head model and the anthropomorphic heterogeneous head phantom model. The presented data highlights the differences between the physical phantoms/phantom models, and the in vivo measurements/segmented in‐vivo‐based head model. The results demonstrate the usefulness of 3D‐printed anthropomorphic phantoms for RF coil evaluation and testing.
Scurvy: A Disease not to be Forgotten
Authors: Montalto Massimo , Porceddu Enrica , Pero Erika , Lupascu Andrea , Gallo Antonella , De Simone Clara , Nucera Eleonora , Aruanno Arianna , Giarretta Igor , Pola Roberto , Landolfi Raffaele
Published: December 2020

An 18‐year‐old man presented to our hospital with muscular pain, diffuse petechiae, spontaneous thigh ecchymosis, edema and pain of the right knee, bilateral pretibial subcutaneous nodules, and gingival hypertrophy and hemorrhage. His history was positive for a mixed anxiety‐depressive disorder and a restrictive diet caused by self‐diagnosed food allergies. Skin lesions appeared like hyperkeratotic papules with coiled hairs and perifollicular hemorrhages. A diagnosis of scurvy was made upon demonstration of low serum levels of ascorbic acid. An allergy evaluation found cross‐reactivity between pollens and food, related to the presence of panallergens. Moreover, we found that our patient was also affected by celiac disease. In conclusion, scurvy should be considered in the differential diagnosis of patients with petechiae and ecchymosis, especially when food restriction, malabsorption, or psychiatric disorders are present.
Tetrahydrothiophene‐Based Ionic Liquids: Synthesis and Thermodynamic Characterizations
Authors: Schmitz Alexa , Bülow Mark , Schmidt Dana , Zaitsau Dzmitry H. , Junglas Fabian , Knedel Tim‐Oliver , Verevkin Sergey P. , Held Christoph , Janiak Christoph
Published: December 2020

S‐alkyltetrahydrothiophenium, [CnTHT]+ bis(trifluorosulfonyl)imide, [NTf2]− room temperature ionic liquids (ILs) and tetraphenylborate, [BPh4]− salts with alkyl chain lengths from C4 to C10 have been prepared. The ILs and salts were characterized and their purity verified by 1H‐ and 13C‐nuclear magnetic resonance, elemental analysis, ion chromatography, Karl‐Fischer titration, single crystal X‐ray diffraction as well as thermogravimetric analysis. The experimentally determined density and viscosity decrease with increasing temperature. The experimental solubility of the [CnTHT][NTf2]‐ILs in water (75 to 2.2 mg/L for C4 to C10) was modelled with very good agreement by Perturbed Chain Statistical Associating Fluid Theory (PC‐SAFT), based on the extremely low vapor pressures for the [CnTHT][NTf2]‐ILs measured in this work (4.15 to 0.037 ⋅ 10−7×psat for C4 to C10). PC‐SAFT is able to predict and correlate different thermodynamic properties by estimating the Helmholtz residual energy.
Review of the past and recent developments in functionalization of graphene derivatives for reinforcement of polypropylene nanocomposites
Authors: Md Said Nur Hidayah , Liu Wei‐Wen , Khe Cheng‐Seong , Lai Chin‐Wei , Zulkepli Nik Noriman , Aziz Azizan
Published: December 2020

Graphene has become the promising reinforcing candidate for improvement of polymer composites. However, graphene easily stacks into piles due to the presence of van der Waals forces between graphene layers and make it tremendously hard to be dispersed homogeneously in different polar polymer matrix. For years, some dispersion methods, such as chemical functionalization, melt mixing, solution mixing, in situ polymerization, to enhance the dispersion of nanofillers in polymer matrix have been demonstrated. Therefore, several functionalization methods of graphene, synthesis of composites approaches, characterizations techniques of graphene‐polypropylene composites are highlighted in this comprehensive review. This review also reveals that the addition of very low amount of nanofiller able to enhance the mechanical properties of composites considerably. With this review, a clear direction is beneficial for the researchers to solve the dispersion issues and to enhance interfacial adhesion to produce better mechanical properties of composites. The application of nanocomposite, an outlook of the challenges and different approaches that can practically useful to tackle important issues are also presented.
Differentially expressed genes associated with disease severity in siblings with cystic fibrosis
Authors: Ekinci İlksen Berfin , Hızal Mina , Emiralioğlu Nagehan , Özçelik Uğur , Yalçın Ebru , Doğru Deniz , Kiper Nural , Dayangaç‐Erden Didem
Published: December 2020

Cystic fibrosis (CF) is an autosomal recessive disease caused by CFTR gene mutations. Despite having the same mutation, CF patients may demonstrate clinical variability in severity and prognosis of the disease. In this study, we aimed to determine differentially expressed genes between mild and severe siblings with same genotype. We performed targeted real‐time polymerase chain reaction based transcriptomic analysis of nasal epithelial cells obtained from two families with two siblings with Class II mutations (F508del/F508del) and (F508del/G85E), one family with three siblings with Class IV mutation (I1234V/I1234V). In severe siblings with Class II mutations, TNFRSF11A, KCNE1, STX1A, SLC9A3R2 were found to be up regulated. CXCL1, CFTR, CXCL2 were found to be down regulated. In the severe sibling with Class IV mutation; mainly genes responsible from complement and coagulation system were identified. Comparison of CF patients to non‐CF control; showed that ICAM1 was up regulated whereas EZR, TNFRSF1A, HSPA1A were down regulated in patients. As a result of this study, differentially expressed genes responsible for clinical severity among affected siblings carrying the same mutation were identified. The results will provide an opportunity for the development of novel target molecules for treatment of disease.
Descriptors for High‐Energy Nitro Compounds; Estimation of Thermodynamic, Physicochemical and Environmental Properties
Authors: Abraham Michael H. , Acree William E. , Liu Xiangli
Published: December 2020

We have used a variety of physicochemical systems, including water‐solvent partitions, solubility in non‐aqueous solvents, and HPLC and gas chromatographic retentions to obtain descriptors for nitro compounds and high energy compounds. These descriptors can then be used to predict a wide range of other physicochemical properties as well as thermodynamic and environmental properties. We illustrate the latter by predictions of the vapor pressure of sublimation, the enthalpy of sublimation and the heat capacity of sublimation at 298.15 K, and predictions of human skin permeability from water. With respect to the obtained descriptors, the most startling finding is that cyclic high energy compounds, with no ‘active’ hydrogen atom, have a substantial ‘hydrogen bond’ acidity. We suggest that this is due to electron‐deficient ring systems that act as Lewis acids.
A network model that combines latent factors and sparse graphs
Authors: Suh Namjoon , Huo Xiaoming , Heim Eric , Seversky Lee
Published: December 2020

We propose a combined model, which integrates the latent factor model and a sparse graphical model, for network data. It is noticed that neither a latent factor model nor a sparse graphical model alone may be sufficient to capture the structure of the data. The proposed model has a latent (i.e., factor analysis) model to represent the main trends (a.k.a., factors), and a sparse graphical component that captures the remaining ad‐hoc dependence. Model selection and parameter estimation are carried out simultaneously via a penalized likelihood approach. The convexity of the objective function allows us to develop an efficient algorithm, while the penalty terms push towards low‐dimensional latent components and a sparse graphical structure. The effectiveness of our model is demonstrated via simulation studies, and the model is also applied to four real datasets: Zachary's Karate club data, Kreb's U.S. political book dataset (
http://www.orgnet.com), U.S. political blog dataset , and citation network of statisticians; showing meaningful performances in practical situations.
Cross‐Strand Interaction, Central Bending, and Sequence Pattern Act as Biomodulators of Simplified β‐Hairpin Antimicrobial Amphiphiles
Authors: Shao Changxuan , Zhu Yongjie , Jian Qiao , Lai Zhenheng , Tan Peng , Li Guoyu , Shan Anshan
Published: December 2020

Novel antimicrobial peptides (AMPs) have revolutionarily evolved into formidable candidates for antibiotic substitute materials against pathogenic infections. However, cost, lability, disorderly sequences, systemic toxicology, and biological profiles have plagued the perennial search. Here, a progressive β‐hairpin solution with the simplest formulation is implanted into an AMP‐based therapeutic strategy to systematically reveal the complex balance between function and toxicity of structural moieties, including cationicity, hydrophobicity, cross‐strand interactions, center bending, and sequence pattern. Comprehensive implementation of structural identification, ten microorganisms, eleven in vitro barriers, four mammalian cells, and a diversified membrane operation setup led to the emergence of β‐hairpin prototypes from a 24‐member library. Lead amphiphiles, WKF‐PG and WRF‐NG, can tackle bacterial infection through direct antimicrobial efficacy and potential inflammation‐limiting capabilities, such as an Escherichia coli challenge in a mouse peritonitis‐sepsis model, without observed toxicity after systemic administration. Their optimal states with dissimilar modulators and the unavailable drug resistance related to membrane lytic mechanisms, also provide an usher for renewed innovation among β‐sheet peptide‐based antimicrobial biomaterials.
Linker Defects Triggering Boosted Oxygen Reduction Activity of Co/Zn‐ZIF Nanosheet Arrays for Rechargeable Zn–Air batteries
Authors: Yang Fan , Xie Jinhao , Liu Xiaoqing , Wang Guizhen , Lu Xihong
Published: December 2020

The poor electronic conductivity and low intrinsically electrocatalytic activity of most metal–organic frameworks (MOFs) greatly limit their direct applications as oxygen reduction reaction (ORR) electrocatalysts. In this work, it is reported that introduction of linker defects can effectively trigger the ORR activity of leaf‐shaped zeolitic imidazolate framework (ZIF) by increasing the intrinsic activity of metal sites and electrical conductivity. Experimental results show that part of imidazole molecules is successfully removed from ZIF after a low‐temperature thermal treatment without destroying its structure integrity, resulting in the formation of unsaturated metal sites and faster electron transport rate. Consequently, the ZIF with imidazole molecules defects (D‐ZIF) exhibits a superior ORR activity than the pristine ZIF, possessing an onset potential of 0.86 V and higher half‐wave potential of 0.60 V. Furthermore, the home‐made Zn–air batteries with D‐ZIF as air cathode exhibit high open‐circuit voltage and well cycling stability. The developed linker‐deficient modulation strategy can provide a new prospect to enable MOF‐based electrocatalysts with efficient catalytic activity.
Montage als eigenständige Disziplin des Stahlgroßbrückenbaus (Teil 2)
Authors: Pelke Eberhard , Kurrer Karl‐Eugen
Published: December 2020

Mit den schweren Zug‐ und Lokomotivlasten der Eisenbahn und der Steigerung der Dienstlasten, den Zustandsverschlechterungen und den systemischen Defiziten, wird bereits vor der Wende zum 20. Jh. in Deutschland damit begonnen, die in die Jahre gekommenen Eisenbahnbrücken zu ersetzen. Das Austauschen der eisernen Überbauten unter Verkehr in kurzen Sperrpausen mechanisiert den Montageablauf und mündet in der Arbeitsteilung von Werkstatt und Montageabteilung. Montage und Montageingenieure emanzipieren sich von technischer Bearbeitung und Werkstatt und formen eine eigene Disziplin aus. Diese in der ersten Hälfte des vorigen Jahrhunderts erfolgende Disziplinbildung setzt leistungsfähige Hebezeuge und Kraftanlagen voraus, die durch deren Elektrifizierung nach 1900 beschleunigt wird.
Numerical study on the mechanical behavior of ultrahigh performance concrete using a three‐phase discrete element model
Authors: Rybczyński Sebastian , Dosta Maksym , Schaan Gunnar , Ritter Martin , Schmidt‐Döhl Frank
Published: December 2020

This paper deals with numerical analysis on the mechanical behavior of ultrahigh performance concrete (UHPC) under uniaxial compression. For the modeling of the mechanical behavior of UHPC, the mesh‐free discrete element method was applied. To calibrate the model parameters and validate the numerical simulation results, a set of experimental investigations including mechanical tests, microscopy and tomography analysis, were performed. The scanning electron microscopy and polarized light microscopy were used to examine cross sections of UHPC as well as to characterize interfacial transition zone and aggregate in detail. X‐ray microtomography analysis was used to obtain information about the nonspherical shape of aggregate and to generate a realistic structural model. Simulation results have shown that the developed model predict stiffness reliably, strength, and breakage pattern of UHPC and shows good agreement with experimental results. Finally, the model has been applied to analyze the main crack initiation in static failure and to investigate the influence of different parameters such as aggregate content as well as aggregate and binder stiffness on the mechanical behavior of UHPC.
Recent Advances in Halogen Bonded Assemblies with Resorcin[4]arenes
Authors: Twum Kwaku , Rissanen Kari , Beyeh Ngong Kodiah
Published: December 2020

Resorcinarenes are cavity‐containing compounds when in the crown conformation, from the calixarene family of concave compounds. These easy to synthesize macrocycles can be decorated at the upper rim through the eight hydroxyl groups and/or the 2‐position of the aromatic ring. They are good synthons in supramolecular chemistry leading to appealing assemblies such as open‐inclusion complexes, capsules and tubes through multiple weak interactions with various guests. Halogen bonding (XB) is a highly directional non‐covalent interaction by an electron‐deficient halogen atom as a donor that interacts with a Lewis base, the XB acceptor. This tutorial review provides an overview of recent advances in halogen‐bonded assemblies based on resorcinarenes and their derivatives, specifically focusing on discrete and capsular assemblies.
Evaluation of absorption and depletion of florfenicol in European seabass Dicentrarchus labrax
Authors: Kogiannou Dimitra , Nikoloudaki Chrysanthi , Katharios Pantelis , Triga Adriana , Rigos George
Published: December 2020

The pharmacokinetic properties and residue elimination of florfenicol (FLO) and its amine were investigated in European seabass Dicentrarchus labrax at 24°C. The trial mainly included analysis of FLO in plasma after a single dose dietary administration of 10 mg/kg and in muscle plus skin following a multiple dosing (10 mg kg−1 day−1 for 7 days) to estimate pharmacokinetics and residue depletion, respectively. The maximum plasma concentration of FLO was measured to be 1.64 μg/ml, 4 hr post administration. The elimination half‐life (t1/2b) and the area under the concentration‐time curve extrapolated to infinity (AUC0‐∞) were calculated to be 13.0 hr and 34.7 μg h−1 ml−1, respectively. Withdrawal times of FLO and its amine were calculated to be 46.3 degree‐days, indicating a fast removal from the edible tissues of treated European seabass. Overall, FLO can be considered as a potentially efficient antibacterial agent for farmed European seabass provided that additional efforts will be devoted towards its in vitro and clinical efficacy.
Gravimetric Studies in the Sea of Japan
Authors: Valitov Maksim Georgievich , Kulinich Ruslan Grigoryevich , Proshkina Zoya Nikolaevna , Kolpashchikova Tatyana Nikolaevna
Published: December 2020

Marine gravimetric studies were carry out in the waters of the Sea of Japan and the Tatar Strait. Maps of the gravitational field of the earth were completed, structural density modeling was executed, the depth of the Mohorovičić discontinuity was determined.
Urban Flooding, Adaptation Strategies, and Resilience: Case Study of Accra, Ghana
Authors: Owusu Kwadwo , Obour Peter Bilson
Published: December 2020

Despite massive flood controlling investments, perennial flooding continues to be a major challenge in the Greater Accra Metropolitan Assembly in Ghana. Previous studies have mostly considered the vulnerability of Accra to flooding induced by urbanization and climate change. This chapter examined the impacts of and adaptation strategies to flooding in two flood-prone residential areas in Accra. A survey was conducted among 320 household heads to ascertain local impacts of floods and community adaptation strategies. To obtain a broader picture of government interventions and challenges, key stakeholders such as personnel from ministries, departments, and agencies who are involved in city planning, and private urban planning consultants were interviewed. The study found that a notable driver of floods in Accra is blocked waterways, and flawed and ad hoc engineering works. About three-quarters of the households interviewed have suffered flood-related losses over the past decade such as housing damage, income, and even a death of a relative. Key flood control interventions included dredging prior to start of rains and sporadic demolition of unauthorized buildings on or near waterways to allow free flow of water. However, these interventions only seem to be ephemeral due to the rapid rate of littering and re-siltation of the waterways after few rain events. The study highlights the need for more pragmatic and robust engineering solutions to build resilience of Accra to floods.
Twisted circle compactifications of 6d SCFTs
Authors: Bhardwaj Lakshya , Jefferson Patrick , Kim Hee-Cheol , Tarazi Houri-Christina , Vafa Cumrun
Published: December 2020

Abstract

We study 6d superconformal field theories (SCFTs) compactified on a circle with arbitrary twists. The theories obtained after compactification, often referred to as 5d Kaluza-Klein (KK) theories, can be viewed as starting points for RG flows to 5d SCFTs. According to a conjecture, all 5d SCFTs can be obtained in this fashion. We compute the Coulomb branch prepotential for all 5d KK theories obtainable in this manner and associate to these theories a smooth local genus one fibered Calabi-Yau threefold in which is encoded information about all possible RG flows to 5d SCFTs. These Calabi-Yau threefolds provide hitherto unknown M-theory duals of F-theory configurations compactified on a circle with twists. For certain exceptional KK theories that do not admit a standard geometric description we propose an algebraic description that appears to retain the properties of the local Calabi-Yau threefolds necessary to determine RG flows to 5d SCFTs, along with other relevant physical data.
Krylov Solvability of Unbounded Inverse Linear Problems
Authors: Caruso Noè Angelo , Michelangeli Alessandro
Published: December 2020

The abstract issue of ‘Krylov solvability’ is extensively discussed for the inverse problem$$Af=g$$Af=gwhereAis a (possibly unbounded) linear operator on an infinite-dimensional Hilbert space, andgis a datum in the range ofA. The question consists of whether the solutionfcan be approximated in the Hilbert norm by finite linear combinations of$$g,Ag,A^2g,\dots $$g,Ag,A2g,⋯, and whether solutions of this sort exist and are unique. After revisiting the known picture whenAis bounded, we study the general case of a densely defined and closedA. Intrinsic operator-theoretic mechanisms are identified that guarantee or prevent Krylov solvability, with new features arising due to the unboundedness. Such mechanisms are checked in the self-adjoint case, where Krylov solvability is also proved by conjugate-gradient-based techniques.
On Efficiently Solvable Cases of Quantum k-SAT
Authors: Aldi Marco , de Beaudrap Niel , Gharibian Sevag , Saeedi Seyran
Published: December 2020

Estimating ground state energies of local Hamiltonian models is a central problem in quantum physics. The question of whether a given local Hamiltonian is frustration-free, meaning the ground state is the simultaneous ground state of all local interaction terms, is known as the Quantum k-SAT (k-QSAT) problem. In analogy to its classical Boolean constraint satisfaction counterpart, the NP-complete problem k-SAT, Quantum k-SAT is $$\hbox {QMA}_1$$

QMA
1

-complete (for $$k\ge 3$$

k
≥
3

, and where $$\hbox {QMA}_1$$

QMA
1

is a quantum generalization of NP with one-sided error), and thus likely intractable. But whereas k-SAT has been well-studied for special tractable cases, as well as from a “parameterized complexity” perspective, much less is known in similar settings for k-QSAT. Here, we study the open problem of computing satisfying assignments to k-QSAT instances which have a “dimer covering” or “matching”; such systems are known to be frustration-free, but it remains open whether one can efficiently compute a ground state. Our results fall into three directions, all of which relate to the “dimer covering” setting: (1) We give a polynomial-time classical algorithm for k-QSAT when all qubits occur in at most two interaction terms or clauses. (2) We give a “parameterized algorithm” for k-QSAT instances from a certain non-trivial class, which allows us to obtain exponential speedups over brute force methods in some cases. This is achieved by reducing the problem to solving for a single root of a single univariate polynomial. An explicit family of hypergraphs, denoted Crash, for which such a speedup is obtained is introduced. (3) We conduct a structural graph theoretic study of 3-QSAT interaction graphs which have a “dimer covering”. We remark that the results of (2), in particular, introduce a number of new tools to the study of Quantum SAT, including graph theoretic concepts such as transfer filtrations and blow-ups from algebraic geometry.
Cylindric Hecke Characters and Gromov–Witten Invariants via the Asymmetric Six-Vertex Model
Authors: Korff Christian
Published: December 2020

We construct a family of infinite-dimensional positive sub-coalgebras within the Grothendieck ring of Hecke algebras, when viewed as a Hopf algebra with respect to the induction and restriction functor. These sub-coalgebras have as structure constants the 3-point genus zero Gromov–Witten invariants of Grassmannians and are spanned by what we call cylindric Hecke characters, a particular set of virtual characters for whose computation we give several explicit combinatorial formulae. One of these expressions is a generalisation of Ram’s formula for irreducible Hecke characters and uses cylindric broken rim hook tableaux. We show that the latter are in bijection with so-called ‘ice configurations’ on a cylindrical square lattice, which define the asymmetric six-vertex model in statistical mechanics. A key ingredient of our construction is an extension of the boson-fermion correspondence to Hecke algebras and employing the latter we find new expressions for Jing’s vertex operators of Hall–Littlewood functions in terms of the six-vertex transfer matrices on the infinite planar lattice.
A $$C^1$$-continuous Trace-Finite-Cell-Method for linear thin shell analysis on implicitly defined surfaces
Authors: Gfrerer Michael H.
Published: December 2020

A Trace-Finite-Cell-Method for the numerical analysis of thin shells is presented combining concepts of the TraceFEM and the Finite-Cell-Method. As an underlying shell model we use the Koiter model, which we re-derive in strong form based on first principles of continuum mechanics by recasting well-known relations formulated in local coordinates to a formulation independent of a parametrization. The field approximation is constructed by restricting shape functions defined on a structured background grid on the shell surface. As shape functions we use on a background grid the tensor product of cubic splines. This yields $$C^1$$

C
1

-continuous approximation spaces, which are required by the governing equations of fourth order. The parametrization-free formulation allows a natural implementation of the proposed method and manufactured solutions on arbitrary geometries for code verification. Thus, the implementation is verified by a convergence analysis where the error is computed with an exact manufactured solution. Furthermore, benchmark tests are investigated.
Evaluation of contact force distribution along a curve, based on measured electric potentials
Authors: Magyar Bálint , Wohlfart Richárd , Zana Roland , Hénap Gábor , Csernák Gábor , Stepan Gabor
Published: December 2020

The paper presents the first results of an exploratory research work, aiming the experimental evaluation of the mechanical contact between conforming surfaces of metallic bodies. The proposed procedure—that is based on the measurement of electric potentials—is able to determine the actual contact pattern and estimate the force distribution on the opposing surfaces. In the present paper, the contact properties along a curve are evaluated, but the basic principles supporting the solution of the more general surface contact problem are also laid down. The goal of this research work is to provide a reliable basis for the investigation of contact-related effects on the modal properties of structures and machines. The distribution of electric contact resistivity can also be assessed using this method, opening the way to the refined characterization of electric switches and connectors. During the application of the method, measured electric voltage values are processed by a neural network trained on a data set generated by finite element software. The resulting electric contact conductivity distribution is used to determine the contact force distribution, taking into account the equilibrium of forces and moments. The results are also checked by available alternative experimental methods.
The cognitive ability and working memory framework: Interpreting cognitive reflection test results in the domain of the cognitive experiential theory
Authors: Engin Ayşegül
Published: December 2020

The cognitive reflection test (hereafter, CRT) is a widely used tool in studies that deal with human decision-making and problem-solving. However, the interpretation of the results of the test remains an open discussion in extant literature. Despite the high predictive power, the characteristics of a decision-maker measured by the CRT remain unclear. This article suggests a novel and inclusive framework that relates the CRT to the cognitive experiential theory (hereafter, CET), which is a well-established dual-process theory. The framework explains the observed phenomena (e.g., individual decision-maker differences) using data from five laboratory experiments. The framework is inclusive because it provides possible explanations for the results in the published literature. The overall results support the argument that the CRT measures the efficiency of the resources of an individual’s working memory. In contrast, the rationality experientiality inventory (hereafter, REI) (a measurement tool of the cognitive experiential theory) captures an individual’s cognitive ability. The efficient use of the working memory leads to the full potential of decision-makers’ cognitive abilities in analytical tasks, thereby indicating thatcognitive ability and working memoryform a viable framework for studies in the disciplines behavioral operational research (hereafter, OR) and decision sciences.
Incentivizing by example and money
Authors: Bauer Thomas , Wirl Franz
Published: December 2020

Leaders are role models that affect their employees’ efforts. The effect depends on how much an employee identifies with the “boss”. Since this degree of identification is private information of the employee, additional financial incentives must be provided. Therefore, we study a principal-agent problem in which the principal affects the agent’s effort by her own effort and by financial incentives. The resulting principal-agent problem has a few non-standard specifics such as: (i) bilateral externalities as the principal’s effort affects the agent and vice versa and (ii) endogenous reservation utility of the agent. Combined, this leads to non-trivial and interesting contracts.
An analysis of capability meta-models for expressing dynamic business transformation
Authors: Koutsopoulos Georgios , Henkel Martin , Stirna Janis
Published: December 2020

Environmental dynamism is gaining ground as a driving force for enterprise transformation. To address the changes, the capabilities of digital enterprises need to adapt. Capability modeling can facilitate this process of transformation. However, a plethora of approaches for capability modeling exist. This study explores how concepts relevant to change have been implemented in the meta-models of these approaches, aiming to visualize relationships among change-related concepts, and identify ways to improve capability modeling toward a more efficient depiction of capability change. The concepts are visualized in concept maps, and a framework is developed to assist the classification of concepts relevant to change functions. Similarities and differences among the existing models are discussed, leading to suggestions toward improvements of capability modeling for capability adaptation.
Evolvement of Peer Support Workers’ Roles in Psychiatric Hospitals: A Longitudinal Qualitative Observation Study
Authors: Nossek Alexa , Werning Anna , Otte Ina , Vollmann Jochen , Juckel Georg , Gather Jakov
Published: December 2020

Peer support workers (PSWs) use their experiential knowledge and specific skills to support patients in their recovery process. The aim of our study was to examine the integration and role-finding process of PSWs in adult psychiatric hospitals in Germany. We conducted open nonparticipant observations of 25 multiprofessional team meetings and 5 transregional peer support worker meetings over a period of six months. The data were analyzed using qualitative content analysis. Regarding the integration of PSWs into multiprofessional teams, we identified three subcategories: “Features of success,” “challenges” and “positioning between team and patients.” Concerning the PSWs’ roles, we developed two subcategories: “Offers” and “self-perception.” The PSWs’ specific roles within a multiprofessional mental healthcare team evolve in a process over a longer period of time. This role-finding process should be supported by a framework role description which leaves sufficient freedom for individual development. Regular opportunities for mutual exchange among PSWs can help to address specific support needs at different points in time.
AnnuityRIR: an R-package to approximate the value of an annuity according to the non-central moments of the capitalization factor
Authors: Rambaud Salvador Cruz , Maturo Fabrizio , Pérez Ana Maria Sánchez , Squillante Massimo
Published: December 2020

The aim of this paper is to design the package of the R statistical software called “Annuity Random Interest Rate”, referred hereinafter as , in order to calculate the value of ann-annuity with payments of one unit each when the interest rate is random. To do this, we have employed different approaches; the two main methodologies treated in this study consider that all non-central moments of the capitalization factor are known, or contrarily some of them are unknown. Consequently, five different approaches have been developed and the practical application of the proposed methods is reflected in this paper by pricing an annuity with a random risk-free interest rate during the last ten years. The version is available from CRAN:https://cran.r-project.org/web/packages/AnnuityRIR/index.html.
Dynamics of N-P-K demand and uptake in cassava
Authors: Adiele Joy Geraldine , Schut Antonius G. T. , Ezui Kodjovi S. , Pypers Pieter , Giller Ken E.
Published: December 2020

Fertilizers are required to improve productivity of cassava and meet the increasing demand for cassava as food, feed, or raw material for processing industries. Our objective was to develop nutrition indices for N, P, and K to provide quantitative insight in the dynamics of nutrient demand and uptake of cassava. On-farm experiments were conducted at six locations in Nigeria from 2016 to 2018, across the major cassava growing agro-ecologies of West Africa. Nitrogen, P, and K were applied at different rates. Uptake of nutrients was measured in leaves, stems, and storage roots at 4, 8, and 12 or 14 months after planting (MAP) and used to construct NPK dilution curves and nutrition indices. About 67, 61, and 52% of total N, P, and K were taken up at 4 MAP, with a maximum uptake rate of 0.21, 0.03, and 0.12 g/m2/d for N, P, and K, respectively. Nutrient concentrations in stems and storage roots declined gradually, in contrast to concentrations in the leaves that fluctuated within narrow ranges. Dilution curves and nutrition indices for N, P, and K were established for the first time in cassava. Dilution curves of N, P, and K in the crop for the highest NPK application treatment were described as Nc = 82DM−0.61, Pc = 7.4DM−0.54, and Kc = 43DM−0.54, when total biomass was between 5 and 57 t/ha dry matter (DM). The nutrition indices were linearly related to relative crop biomass. Insight into the nutrient uptake and dilution patterns during the growth cycle can help to understand the temporal nutrient demands of cassava and identify sustainable management practices. Initial ample supply of N and P and moderate K, with extra K top-dress during the second growth phase, will benefit cassava growth and yield. Furthermore, such information provides a basis to develop a dynamic model to simulate nutrient-limited growth of cassava.
Productive integration, economic recession and employment in Europe: an assessment based on vertically integrated sectors
Authors: Villani Davide , Fana Marta
Published: December 2020

The Covid-19 crisis has revamped the discussion about the redefinition of GVC. This paper contributes to the debate, analysing the productive relationships between European countries in four key manufacturing activities. In particular, the paper addresses two objectives. First, it maps the degree of productive integration in Europe, focusing on the generation of employment in the production of exported intermediate inputs and final goods. Second, it provides a preliminary assessment of the potential impact on employment that the current economic crisis will have on some manufacturing activities across Europe. The analysis is realised employing the concept of vertically integrated labour (Pasinetti 1973) which allows to account for the employment directly and indirectly involved in the production of final goods. The estimations are derived from Multi-Regional Input–Output tables to map the supply chain and to differentiate between the employment involved in the production of exported intermediate inputs and final goods. The results show that most of the employment involved in the production of final output of the activities studied in the paper is linked to international trade. Although Europe shows a high degree of productive links, there are important differences in the modality of insertion in the productive structure of European countries. Moreover, the impact on the level of employment due to the current economic crisis can be significant, affecting more than 1.3 million of people in Europe. These results are relevant to policy makers, who should consider carefully the high degree of linkages of the European economies when designing industrial policies and measure of support to the economy.
scLM: Automatic Detection of Consensus Gene Clusters Across Multiple Single-Cell Datasets
Authors: Song Qianqian , Su Jing , Miller Lance D. , Zhang Wei
Published: December 2020

In gene expression profiling studies, including single-cell RNAsequencing (scRNA-seq) analyses, the identification and characterization of co-expressed genes provides critical information on cell identity and function. Gene co-expression clustering in scRNA-seq data presents certain challenges. We show that commonly used methods for single-cell data are not capable of identifying co-expressed genes accurately, and produce results that substantially limit biological expectations of co-expressed genes. Herein, we present single-cell Latent-variable Model (scLM), a gene co-clustering algorithm tailored to single-cell data that performs well at detecting gene clusters with significant biologic context. Importantly, scLM can simultaneously cluster multiple single-cell datasets, i.e., consensus clustering, enabling users to leverage single-cell data from multiple sources for novel comparative analysis. scLM takes raw count data as input and preserves biological variation without being influenced by batch effects from multiple datasets. Results from both simulation data and experimental data demonstrate that scLM outperforms the existing methods with considerably improved accuracy. To illustrate the biological insights of scLM, we apply it to our in-house and public experimental scRNA-seq datasets. scLM identifies novel functional gene modules and refines cell states, which facilitates mechanism discovery and understanding of complex biosystems such as cancers. A user-friendly R package with all the key features of the scLM method is available at https://github.com/QSong-github/scLM.
Determining Gravity Wave Sources and Propagation in the Southern Hemisphere by Ray‐Tracing AIRS Measurements
Authors: Perrett Jon A. , Wright Corwin J. , Hindley Neil P. , Hoffmann Lars , Mitchell Nicholas J. , Preusse Peter , Strube Cornelia , Eckermann Stephen D.
Published: December 2020

Gravity waves (GWs) are key drivers of atmospheric circulation. Understanding their sources and propagation is essential to improving weather and climate models. We apply a 3D Stockwell Transform to 1 month of stratospheric temperature data from NASA's Atmospheric InfraRed Sounder to obtain 3D GW measurements and parameters. We use ray‐tracing methods to determine the sources and propagation characteristics of these GWs over the entire Southern Ocean. We trace 1.28 million GW measurements per day for the month of June 2010. Our analysis suggests that ground‐based sources around the Andes, Antarctic Peninsula, and Kerguelen play major roles, and that the GWs generated by these and other sources travel large zonal distances. We show evidence that GWs propagate into the 60°S belt, a possible source of “missing momentum flux” in GCMs at this latitude. These results emphasize the need for models to incorporate the possibility that GWs can exhibit large horizontal propagation.
Inherited State of Stress as a Key Factor Controlling Slip and Slip Mode: Inference From the Study of a Slow Slip Event in the Longitudinal Valley, Taiwan
Authors: Canitano Alexandre , Godano Maxime , Thomas Marion Y.
Published: December 2020

Using borehole strainmeters, we detected a 13‐day long slow slip event in 2011 with Mw = 5.45 on the Longitudinal Valley Fault, Taiwan. It has been likely promoted by the significant Coulomb stress changes (∼0.5–1 MPa) imparted by a combination of coseismic and postseismic slip of the 2003 Chengkung earthquake. Using kinematic slip models, we infer that the slow event has accommodated about 15%–35% of the slip deficit accumulated from 1997 to 2011 in its source region. Further, we find that inherited state of stress may have controlled the slow event southward propagation. We also highlight a spatiotemporal correlation between the slow event and a cluster of repeating microearthquakes, suggesting a complex interplay between seismic and aseismic processes on the fault, where transient aseismic regions are adjacent to highly coupled zones.
Implications of Electron Detachment in Associative Collisions of Atomic Oxygen Anion with Molecular Nitrogen for Modeling of Transient Luminous Events
Authors: Janalizadeh Reza , Pasko Victor P.
Published: December 2020

Electron detachment from O− is important for understanding of lightning‐induced upper atmospheric discharges. Contrary to previous studies, Rayment and Moruzzi (1978) (RM78) argue that the associative detachment reaction of O− with N2 proceeds with N2 in its ground state. Here, we analyze the experimental setup in RM78 and demonstrate that vibrationally excited N2 may have in fact contaminated the results, the theoretical approach in RM78 requires corrections, and the rate calculations provided in RM78 are inconsistent. As the vibrational temperature of N2 remains relatively low in the initial stages of gas discharges in air, i.e., streamer formation, we conclude that if in fact vibrationally excited N2 is required for the O− + N2 → N2O + e reaction to proceed, the process will happen only in later stages of the discharge, e.g., during streamer to leader transition. Controlled experiments are required to reconcile the literature on the reaction of O− with ground state N2.
Comprehensive Study of the Climatology of the Quasi‐6‐Day Wave in the MLT Region Based on Aura/MLS Observations and SD‐WACCM‐X Simulations
Authors: Qin Yusong , Gu Sheng‐Yang , Teng Chen‐Ke‐Min , Dou Xian‐Kang , Yu You , Li Na
Published: December 2020

The westward quasi‐6‐day wave (Q6DW) with zonal wavenumber 1 is a prominent and recurrent phenomenon in the mesosphere and lower thermosphere (MLT) and has a significant impact on day‐to‐day ionospheric variability. Geopotential height measurements from Aura Microwave Limb Sounder and Specified Dynamics Whole Atmosphere Community Climate Model eXtended Version simulations during 2005–2019 are utilized to study the climatological variations of Q6DW. The spectral analysis clearly indicates that four typical Q6DW events occur in the MLT region before and after the two equinoxes in 1 year. The wave amplitudes in the summer hemisphere are considerably larger than the amplitudes in the winter hemisphere. The Eliassen‐Palm flux diagnostics show that the wave source of the post‐September equinox event is located in both hemispheres, while the sources of the other three Q6DW events are in the winter hemisphere. The diagnostic analysis results show that the climatological features of Q6DW are primarily due to the seasonal variations of the mean flow, which can determine the Q6DW critical layers, baroclinic/barotropic instability, and waveguides. Specifically, the Q6DW can be amplified in the summer hemisphere mesosphere at high latitudes during pre‐ and postequinox periods when the critical layers penetrate the unstable region. At the two equinoxes, the Q6DW can also propagate into the MLT region with similar amplitudes in both hemispheres due to the weak zonal mean flow but without additional amplification. At the two solstices, the Q6DW is suppressed because the critical layers envelop the whole unstable region, which prevents its amplification through wave‐mean flow interaction.