bluuebunny/crossref_metadata_2025 huggingface dataset:
De novo design of membrane transport proteins
Authors: Zhou Chen , Lu Peilong
Published: March 2022

Membrane transport proteins, which include transporters and channels, are delicate protein machineries that mediate the exchange of a variety of substances across biomembranes. Accumulated structural and functional knowledge allows for the de novo design of transport proteins with new structures that do not exist in nature. Analysis based on these novel proteins provides new insights into the principles that govern protein assembly, conformational change, and substrate recognition. Here, we review the advances in the de novo design of transporters and channels over recent years and highlight the challenges and opportunities in this field.
Type‐II van der Waals Heterostructures Based on AsP and Transition Metal Dichalcogenides: Great Promise for Applications in Solar Cell
Authors: Zhao Huiyan , Han Lihong , Jia Baonan , Chen Yingjie , Guan Xiaoning , Wu Liyuan , Lu Pengfei
Published: March 2022

As an effective means to adjust the properties of 2D materials, type‐II van der Waals (vdW) heterostructures have been under extensive research due to their significantly reduced carrier recombination probability and extended carrier lifetime. Herein, stable vdW heterostructures based on arsenic phosphorus (AsP) and transition metal dichalcogenides are designed. The geometry, electronic, and optical properties for type‐II AsP/MX2 heterostructures (M = Mo, W; X = S, Se) by first‐principle calculations are systematically explored and their application in solar cell materials is predicted. AsP/MX2 heterostructures are indirect semiconductors with the quasiparticle bandgap ranging from 1.49 to 2.02 eV. They effectively widen the light absorption of AsP monolayers in visible and ultraviolet regions. It is worth noting that AsP/WSe2 heterostructure can form a built‐in electric field (0.832 eV Å−1) and have a minor exciton binding energy (0.22 eV), suggesting that it is a potential solar cell material. The power conversion efficiency is more than 15%. The results will provide a theoretical basis for sustainable energy applications of AsP‐based vdW heterostructures in the future.
Adaptive bipartite consensus of competitive linear multi‐agent systems with asynchronous intermittent communication
Authors: Xu Chengjie , Xu Haichuan , Su Housheng , Liu Chen
Published: March 2022

In this article, bipartite consensus is investigated for linear multi‐agent systems (MASs) via adaptive asynchronous intermittent control. Adaptive asynchronous intermittent bipartite consensus protocols are proposed for MASs with antagonistic links under both fixed and connected switching topologies. By using gauge transformation and stability theory, convergency analysis is given and some conditions of bipartite consensus are obtained. It is turned out that bipartite consensus can be realized if the communication rate is no less than a threshold under the assumption that the network is connected and structurally balanced. Finally, two simulation examples are provided to verify the effectiveness of the obtained results.
Supporting the Sustainable Development Goals: A context sensitive indicator for sustainable use of water at the facility level
Authors: Wang Xuantong , Hopeward James , Yi Ilcheong , McElroy Mark W. , Sutton Paul C.
Published: March 2022

This paper presents a low‐cost and scalable method for providing a sustainable water allocation for enterprises based on the hydrological, economic, and demographic contexts of their facilities. Context‐based performance indicators are vital for effectively monitoring and achieving the Sustainable Development Goals (SDGs). Currently, the SDGs consist of 17 goals that are associated with 169 targets and 232 indicators. Making valid and objective measurements of the 232 indicators represents a significant challenge for scientists and policy makers. Achieving the SDGs will likely involve significant efforts in developing and sustaining systems for monitoring status and progress, providing incentives, and conducting enforcement. Provision of low‐cost Sustainable Development Performance Indicators (SDPIs) of progress at high spatial and temporal resolution is essential for effective management by governments and businesses. The water allocations we produce are based on a facility's total and consumptive use of water, their contribution to gross domestic product (GDP), their number of full‐time employees, the population and GDP of several geographic contexts, and the annually specific hydrological balance (i.e., precipitation minus evapotranspiration) of those contexts. The allocations and related sustainability assessments are determined for a range of geographic contexts (circular regions centered on the facility with radii of 10, 50, 100, 200, and 300 km respectively). From the hydrological data we give priority to ‘Water for Nature’ and allocate a proportion of the remaining ‘Water for Economy’ to the facility based on their contribution to GDP and the number of full‐time employees they have. This allocation is compared to their actual water withdrawals to provide an indication of the sustainability of their economic activity.
The future sits in places: Electricity, value, and infrastructural triage in Tanzania
Authors: Phillips Kristin D.
Published: March 2022

This article explores the shifting landscapes of light, labor, and value produced by the politics of electrification in Tanzania. Through engaging the anthropologies of infrastructure and electricity, it asks, how do people understand the relationship between electricity and value in the landscapes that sustain them? A brief outline of the history of electrification in Tanzania highlights its role in the production of place, and analysis of fieldwork with residents, leaders, and energy advocates between 2017 and 2020 reveals contemporary understandings of the relationship between electricity, value, and place. The article then chronicles recent government efforts to dramatically expand access to electricity, outlines the processes of selective grid expansion, and describes how people experience and understand its effects. I construct a theory of infrastructural triage to conceptualize the process of assigning degrees of urgency, priority, and value for developing infrastructure in particular spaces and for particular people and highlight its role in newly configuring the landscapes and timescapes in which people live and experience their everyday lives. In the process of enhancing the productivity and labor of some people but not others, electricity facilitates, obstructs, and marks flows of value across landscapes.
Hydrodynamically Controlled Self‐Organization in Mixtures of Active and Passive Colloids
Authors: Madden Ian P. , Wang Linlin , Simmchen Juliane , Luijten Erik
Published: March 2022

Active particles are known to exhibit collective behavior and induce structure in a variety of soft‐matter systems. However, many naturally occurring complex fluids are mixtures of active and passive components. The authors examine how activity induces organization in such multi‐component systems. Mixtures of passive colloids and colloidal micromotors are investigated and it is observed that even a small fraction of active particles induces reorganization of the passive components in an intriguing series of phenomena. Experimental observations are combined with large‐scale simulations that explicitly resolve the near‐ and far‐field effects of the hydrodynamic flow and simultaneously accurately treat the fluid–colloid interfaces. It is demonstrated that neither conventional molecular dynamics simulations nor the reduction of hydrodynamic effects to phoretic attractions can explain the observed phenomena, which originate from the flow field that is generated by the active colloids and subsequently modified by the aggregating passive units. These findings not only offer insight into the organization of biological or synthetic active–passive mixtures, but also open avenues to controlling the behavior of passive building blocks by means of small amounts of active particles.
Janus Hollow Nanofiber with Bifunctional Oxygen Electrocatalyst for Rechargeable Zn–Air Battery
Authors: Chen Xing , Pu Jie , Hu Xuhui , Yao Yuechao , Dou Yibo , Jiang Jianjun , Zhang Wenjing
Published: March 2022

Zn–air battery technologies have received increasing attention, while the application is hindered by the sluggish kinetics of the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). In order to explore an efficient method to fabricate a high‐performance electrocatalyst via modification of advanced nanostructure, a coaxial electrospinning method with in‐situ synthesis and subsequent carbonization to construct 3D flexible Janus‐like electrocatalysts is developed. The resulting Janus nanofibers have a unique core–shell hollow fiber structure, where NiFe alloy electrocatalysts supported by N‐doped carbon nanobelt are located on the inner wall of the carbon layer, and leaf‐like Co–N nanosheets are anchored on the outer wall of the carbon layer. As a result, the electrocatalyst exhibits excellent bifunctional catalytic performance for ORR and OER, demonstrating the small potential gap value of 0.73 V between the ORR half‐wave potential and the OER potential at 10 mA cm−2, which is even comparable to the mixed commercial noble catalyst with 20% Pt/C and RuO2. The rechargeable Zn–air battery is constructed and displays a large open‐circuit voltage of 1.44 V, high power density (130 mW cm−2) and energy density (874 Wh kg−1). This study provides a concept to synthesize and construct high performance bifunctional electrocatalysts.
7‐Dehydrocholesterol Encapsulated Polymeric Nanoparticles As a Radiation‐Responsive Sensitizer for Enhancing Radiation Therapy
Authors: Delahunty Ian , Li Jianwen , Jiang Wen , Lee Chaebin , Yang Xueyuan , Kumar Anil , Liu Zhi , Zhang Weizhong , Xie Jin
Published: March 2022

Therapeutics that can be activated by radiation in situ to enhance the efficacy of radiotherapy are highly desirable. Herein, 7‐Dehydrocholesterol (7‐DHC), a biosynthetic precursor of cholesterol, as a radiosensitizer, exploiting its ability to propagate the free radical chain reaction is explored. The studies show that 7‐DHC can react with radiation‐induced reactive oxygen species and in turn promote lipid peroxidation, double‐strand breaks, and mitochondrial damage in cancer cells. For efficient delivery, 7‐DHC is encapsulated into poly(lactic‐co‐glycolic acid) nanoparticles, forming 7‐DHC@PLGA NPs. When tested in CT26 tumor bearing mice, 7‐DHC@PLGA NPs significantly enhanced the efficacy of radiotherapy, causing complete tumor eradication in 30% of the treated animals. After treatment, 7‐DHC is converted to cholesterol, causing no detectable side effects or hypercalcemia. 7‐DHC@PLGA NPs represent a radiation‐responsive sensitizer with great potential in clinical translation.
Self‐Healing Polymer Electrolyte for Dendrite‐Free Li Metal Batteries with Ultra‐High‐Voltage Ni‐Rich Layered Cathodes
Authors: Li Zhuo , Fu Jialong , Zheng Sheng , Li Dinggen , Guo Xin
Published: March 2022

Practical applications of polymer electrolytes in lithium (Li) metal batteries with high‐voltage Ni‐rich cathodes have been hindered by the dendrite growth and poor oxidative stability of electrolytes. Herein, a self‐healing polymer electrolyte is developed by in situ copolymerization of 2‐(3‐(6‐methyl4‐oxo‐1,4‐dihydropyrimidin‐2‐yl)ureido)ethyl methacrylate (UPyMA) and ethylene glycol methyl ether acrylate (EGMEA) monomers. With the electrolyte, the dendrite growth is inhibited by spontaneously repairing dendrite‐induced defects, cracks, and voids at the Li/electrolyte interface; the suppressed dendrite growth and associated electro‐chemo behaviors are visualized by the kinetic Mont‐Carlo simulation. Benefitting from the high ionic conductivity, wide electrochemical window and good interfacial stability, the self‐healing polymer electrolyte enables stable cycling of the LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode under 4.7 V, achieving a high specific capacity of ≈228.8 mAh g−1 and capacity retention of 80.4% over 500 cycles. The new electrolyte is very promising for developing highly safe and dendrite‐free Li metal batteries with high energy density.
Hydrophobic Graphene Quantum Dots for Defect Passivation and Enhanced Moisture Stability of CH3NH3PbI3 Perovskite Solar Cells
Authors: Khorshidi Elahe , Rezaei Behzad , Blätte Dominic , Buyruk Ali , Reus Manuel A. , Hanisch Jonas , Böller Bernhard , Müller-Buschbaum Peter , Ameri Tayebeh
Published: March 2022

Passivating the defects and grain boundaries (GBs) of perovskite films at the interface by interface engineering is a promising route to achieve efficient and stable perovskite solar cells (PSCs). Herein, a new type of graphene, that is, hydrophobic graphene quantum dots (HGQDs) containing amide linkages, which consist of carbonyl and dodecyl amine groups, is successfully used as a bifunctional interface modifier to engineer the interface of the perovskite/hole transport layer. A comprehensive characterization including X‐ray photoelectron spectroscopy, Fourier‐transform photocurrent spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, and space‐charge‐limited current measurements is performed to identify the underlying passivation mechanisms. It can be demonstrated that the HGQDs, due to the bifunctional groups containing N and O atoms, effectively passivate the uncoordinated Pb2+ ions at the perovskite film surface and GBs and consequently induce a lower trap state density. Moreover, HGQDs enhance the quality of the perovskite film which reduces the charge recombination at the interface. Therefore, the power conversion efficiency of PSCs treated with HGQDs is significantly increased from 16.00% to 18.30%, mainly based on the improved open‐circuit voltage and fill factor. Importantly, the HGQDs featuring hydrophobicity due to alkyl chains significantly enhance moisture stability.
Significance of Nonmetallic Inclusions for the Clogging Phenomenon in Continuous Casting of Steel––A Review
Authors: Michelic Susanne K. , Bernhard Christian
Published: March 2022

Nonmetallic inclusions are well known to influence product quality and process stability in the production of steel. A process step that is very sensitive to the presence of nonmetallic inclusion (NMI) is continuous casting. Here, the so‐called clogging phenomenon can occur, resulting in a distinct disruption of the casting process and decreased steel quality. The presence of nonmetallic inclusions considerably contributes to the build‐up of deposits in the submerged entry nozzle provoking instabilities in the flow control system. Numerous research studies have been subject to different clogging mechanisms and related influencing parameters. Interfacial properties significantly influence the behavior of inclusions in the steel–refractory system. The present review demonstrates state of the art concerning the role of NMIs in the appearance of clogging. Particular focus is put on the wetting behavior between the different phases and their consequence for the deposition process. Industrial observations and laboratory methods are summarized and discussed; potential countermeasures are evaluated. A steel group that is especially prone to clogging are Ti‐ ultra low carbon (ULC) steels. An overview of the current understanding of their high clogging tendency and possible influences is presented, considering thermodynamic and interfacial aspects.
Expression profile analysis of sheep ovary after superovulation and estrus synchronisation treatment
Authors: Wang Huie , Feng Xinwei , Muhatai Gemingguli , Wang Lan
Published: March 2022

Superovulation is a widely used reproductive technique in livestock production, but the mechanism of sheep's superovulation is not yet clear. Here, a method of superovulation and estrus synchronisation was used to treat female Duolang sheep. After treatment, there were significant differences in serum FSH and LH levels and the number of dominant follicles between the two groups of sheep. We identified a total of 5021 differentially expressed genes (11, 13 and 15 days after treatment) and performed RT‐qPCR analysis to identify several mRNA expression levels. GO and KEGG enrichment analysis revealed that differentially expressed genes were involved in the regulation of signalling pathways of follicular development, cell cycle, material synthesis, energy metabolism, such as COL3A1, RPS8, ACTA2, RPL7 RPS6 and TNFAIP6 may play a key role in regulating the development of follicles. Our results show a comprehensive expression profile after superovulation and estrus synchronisation treatment. We provide the basis for further research on breeding techniques to improve the ovulation rate and birth rate of livestock.
Evaluation of a dog with inflammatory mammary carcinoma using 18F‐2‐deoxy‐2‐fluoro‐d‐glucose positron emission tomography/computed tomography
Authors: Koo Yoonhoi , Yun Taesik , Chae Yeon , Lee Dohee , Son Mingyun , Ku Dayoung , Kim Hakhyun , Yang Mhan‐Pyo , Kang Byeong‐Teck
Published: March 2022

Inflammatory mammary carcinoma is known to be aggressive, which makes thorough evaluation of the severity of tumour infiltration and metastasis important in determining a recommended treatment course. This case report describes the use of 18F‐2‐deoxy‐2‐fluoro‐d‐glucose positron emission tomography/computed tomography for evaluating the invasiveness and metastasis of inflammatory mammary carcinoma in a dog.
Quantification of tear glucose levels and their correlation with blood glucose levels in dogs
Authors: Lee Eunji , Kang Seonmi , Shim Jaeho , Jeong Dajeong , Jeong Youngseok , Ahn Junyeong , Seo Kangmoon
Published: March 2022

Background

No previous studies have quantified tear glucose (TG) levels in dogs or compared changes in TG and blood glucose (BG) concentrations.

Objective

To quantify TG concentration and evaluate its correlation with BG level in dogs.

Methods

Twenty repetitive tests were performed in alternate eyes of four dogs, with a minimum washout period of 1 week. Tears and blood were collected at 30‐min intervals with successive glucose injections (1 g/kg) every 30 min. Cross‐correlations of BG and TG levels were assessed. The delay and association between TG and corresponding BG levels were analysed for each dog; samples were collected at 5‐min intervals. The tears were collected using microcapillary tubes. Collected tears and blood were analysed for glucose concentration using a colorimetric assay and commercially available glucometer, respectively.

Results

The average baseline BG and TG levels were 4.76 ± 0.58 and 0.39 ± 0.04 mmol/L, respectively. Even with highly fluctuating BG levels, a significant cross‐correlation coefficient (r = 0.86, p < 0.05) was observed between changes of BG and TG levels. The delay time between BG and TG levels was 10 min. On average, BG levels were 16.34 times higher than TG levels. There was strong correlation between BG and TG levels (rs = 0.80, p < 0.01). Significant differences in TG concentrations between normoglycaemia, mild hyperglycaemia, and severe hyperglycaemia were found (p < 0.05).

Conclusions

Canine TG concentrations have not been quantified previously. Our findings suggest preliminary data for future research on TG levels in dogs and show TG measurement could be used to screen for diabetes mellitus in dogs.
Catalyst design within asymmetric organocatalysis
Authors: Iribarren Iñigo , Garcia Marianne Rica , Trujillo Cristina
Published: March 2022

The field of organocatalysis, more specifically asymmetric organocatalysis, is continuously expanding having grown significantly over the recent years. However, despite this exponential expansion, the ability to determine with any degree of certainty the reaction mechanisms of these types of reactions fails to keep within pace. Due to increasing calculation capacity and methods accuracy, computational methodologies have been established as an essential approach in both a predictive and supportive role to aid the synthetic design of novel catalysts by enabling the prediction of catalytic behaviour. This review is focused on the computationally‐led catalyst design within asymmetric organocatalysis, discussing the different theoretical approaches most commonly utilised.

This article is categorized under:

Structure and Mechanism > Reaction Mechanisms and Catalysis

Software > Quantum Chemistry

Quantum Computing > Algorithms
Fine corrections in the effective string describing SU(2) Yang-Mills theory in three dimensions
Authors: Caristo F. , Caselle M. , Magnoli N. , Nada A. , Panero M. , Smecca A.
Published: March 2022

Abstract

We present a study of the effective string that describes the infrared dynamics of SU(2) Yang-Mills theory in three dimensions. By combining high-precision lattice simulation results for Polyakov-loop correlators at finite temperatures close to (and less than) the deconfinement one with the analytical constraints from renormalization-group arguments, from the exact integrability of the two-dimensional Ising model that describes the universality class of the critical point of the theory, from conformal perturbation theory, and from Lorentz invariance, we derive tight quantitative bounds on the corrections to the effective string action beyond the Nambu-Gotō approximation. We show that these corrections are compatible with the predictions derived from a bootstrap analysis of the effective string theory, and have a value which does not allow to prove the Axionic String Ansatz for this model.
Lepton-pair production at hadron colliders at N3LO in QCD
Authors: Duhr Claude , Mistlberger Bernhard
Published: March 2022

Abstract

We compute for the first time the complete corrections at N3LO in the strong coupling constant to the inclusive neutral-current Drell-Yan process including contributions from both photon and Z-boson exchange. Our main result is the computation of the QCD corrections to the inclusive production cross section of an axial-vector boson to third order in the strong coupling in a variant of QCD with five massless quark flavours. Since the axial anomaly does not cancel for an odd number of flavours, we also consistently include non-decoupling effects in the top-quark mass through three loops. We perform a phenomenological study of our results, and we present for the first time predictions for the inclusive Drell-Yan process at the LHC at this order in QCD perturbation theory.
Moduli stabilization in asymptotic flux compactifications
Authors: Grimm Thomas W. , Plauschinn Erik , van de Heisteeg Damian
Published: March 2022

Abstract

We present a novel strategy to systematically study complex-structure moduli stabilization in Type IIB and F-theory flux compactifications. In particular, we determine vacua in any asymptotic regime of the complex-structure moduli space by exploiting powerful tools of asymptotic Hodge theory. In a leading approximation the moduli dependence of the vacuum conditions are shown to be polynomial with a dependence given by sl(2)-weights of the fluxes. This simple algebraic dependence can be extracted in any asymptotic regime, even though in nearly all asymptotic regimes essential exponential corrections have to be present for consistency. We give a pedagogical introduction to the sl(2)-approximation as well as a detailed step-by-step procedure for constructing the corresponding Hodge star operator. To exemplify the construction, we present a detailed analysis of several Calabi-Yau three- and fourfold examples. For these examples we illustrate that the vacua in the sl(2)-approximation match the vacua obtained with all polynomial and essential exponential corrections rather well, and we determine the behaviour of the tadpole contribution of the fluxes. Finally, we discuss the structure of vacuum loci and their relations to several swampland conjectures. In particular, we comment on the realization of the so-called linear scenario in view of the tadpole conjecture.
Global symmetries and partial confinement
Authors: Hanada Masanori , Holden Jack , Knaggs Matthew , O’Bannon Andy
Published: March 2022

Abstract

In gauge theories, spontaneous breaking of the centre symmetry provides a precise definition of deconfinement. In large-N gauge theories, evidence has emerged recently that between confined and deconfined phases a partially-deconfined phase can appear, in which only a subset of colours deconfine. In the partially-deconfined phase, the centre symmetry is spontaneously broken, raising the question of whether an order parameter exists that can distinguish completely- and partially-deconfined phases. We present two examples in gauge theories of global symmetries that are spontaneously broken in the confined phase and preserved in the deconfined phase, and we show that this symmetry is spontaneously broken in the partially-deconfined phase. As a result, in these theories the transition from complete to partial deconfinement is accompanied by the spontaneous breaking of a global symmetry. The two examples are CP symmetry in $$ \mathcal{N} $$
N
= 1 super-Yang-Mills with a massive gluino and theta-angle θ = π, and chiral symmetry in a strongly-coupled lattice gauge theory. For $$ \mathcal{N} $$
N
= 1 SYM we also present numerical evidence that the same phenomenon occurs at finite N ≥ 30. We thus conjecture that global symmetries may provide order parameters to distinguish completely and partially deconfined phases generically, including at finite N.
Graded Hilbert spaces, quantum distillation and connecting SQCD to QCD
Authors: Ünsal Mithat
Published: March 2022

Abstract

The dimension of the Hilbert space of QFT scales exponentially with the volume of the space in which the theory lives, yet in supersymmetric theories, one can define a graded dimension (such as the supersymmetric index) that counts just the number of bosonic minus fermionic ground states. Can we make this observation useful in non-supersymmetric QFTs in four dimensions? In this work, we construct symmetry graded state sums for a variety of non-supersymmetric theories. Among the theories we consider is one that is remarkably close to QCD: Yang-Mills theory with Nf = Nc fundamental Dirac fermions and one adjoint Weyl fermion, QCD(F/adj). This theory can be obtained from SQCD by decoupling scalars and carry exactly the same anomalies. Despite the existence of fundamental fermions, the theory possess an exact 0-form color-flavor center (CFC) symmetry for a particular grading/twist under which Polyakov loop is a genuine order parameters. By a two-loop analysis, we prove that CFC-symmetry remains unbroken at small β due to grading. Chiral symmetry is spontaneously broken within the domain of validity of semi-classics on ℝ3 × S1 in a pattern identical to Nf = Nc SQCD on ℝ4 and the two regimes are adiabatically connected. The vacuum structures of the theory on ℝ4 and ℝ3 × S1 are controlled by the same mixed ’t Hooft anomaly condition, implying a remarkable persistent order.
Adjoint maps between implicative semilattices and continuity of localic maps
Authors: Erné Marcel , Picado Jorge , Pultr Aleš
Published: March 2022

We study residuated homomorphisms (r-morphisms) and their adjoints, the so-called localizations (or l-morphisms), between implicative semilattices, because these objects may be characterized as semilattices whose unary meet operations have adjoints. Since left resp. right adjoint maps are the residuated resp. residual maps (having the property that preimages of principal downsets resp. upsets are again such), one may not only regard the l-morphisms as abstract continuous maps in a pointfree framework (as familiar in the complete case), but also characterize them by concrete closure-theoretical continuity properties. These concepts apply to locales (frames, complete Heyting lattices) and provide generalizations of continuous and open maps between spaces to an algebraic (not necessarily complete) pointfree setting.
On a Solution of the Multidimensional Truncated Matrix-Valued Moment Problem
Authors: Kimsey David P. , Trachana Matina
Published: March 2022

We will consider the multidimensional truncated $$p \times p$$

p
×
p

Hermitian matrix-valued moment problem. We will prove a characterisation of truncated $$p \times p$$

p
×
p

Hermitian matrix-valued multisequence with a minimal positive semidefinite matrix-valued representing measure via the existence of a flat extension, i.e., a rank preserving extension of a multivariate Hankel matrix (built from the given truncated matrix-valued multisequence). Moreover, the support of the representing measure can be computed via the intersecting zeros of the determinants of matrix-valued polynomials which describe the flat extension. We will also use a matricial generalisation of Tchakaloff’s theorem due to the first author together with the above result to prove a characterisation of truncated matrix-valued multisequences which have a representing measure. When $$p = 1$$

p
=
1

, our result recovers the celebrated flat extension theorem of Curto and Fialkow. The bivariate quadratic matrix-valued problem and the bivariate cubic matrix-valued problem are explored in detail.
Lagrangian Fibrations
Authors: Huybrechts D. , Mauri M.
Published: March 2022

We review the theory of Lagrangian fibrations of hyperkähler manifolds as initiated by Matsushita. We also discuss more recent work of Shen–Yin and Harder–Li–Shen–Yin. Occasionally, we give alternative arguments and complement the discussion by additional observations.
On video lectures during remote teaching and beyond
Authors: Schwarz Gunnar , Bleiner Davide , Günther Detlef
Published: March 2022

Graphical abstract
Does the COVID-19 personal protective equipment impair the surgeon’s performance?
Authors: Kolb Jan P. , Hättich Annika , Strahl André , Rolvien Tim , Hennigs Jan K. , Barg Alexej , Frosch Karl-Heinz , Hartel Maximilian J. , Schlickewei Carsten
Published: March 2022

Introduction

Despite increasing vaccination rates, new viral variants of SARS-CoV-2 (severe acute respiratory syndrome coronavirus type 2) are advancing the COVID 19 (coronavirus disease 2019) pandemic and continue to challenge the entire world. Surgical care of SARS-CoV-2 positive patients requires special protective measures. We hypothesized that "COVID-19" personal protective equipment (PPE) during surgery of SARS-CoV-2 positive or potentially positive patients would negatively affect the surgeon and thus the surgical outcome.

Materials and methods

Ten experienced trauma surgeons participated in the study. Each surgeon performed two simulated surgeries of a distal tibial fracture on a Sawbone® under standardized conditions either wearing regular PPE or special COVID-19 PPE. Baseline values at rest were acquired for heart rate, blood pressure, saturation of peripheral oxygen (SpO2), respiratory rate and capillary blood gas (CBG) analysis including capillary partial pressure of oxygen (pO2) and carbon dioxide (pCO2), followed by four different standardized tests of attentional performance (TAP). Subsequently, the surgeon performed the first surgery according to a randomly determined order, with regular or COVID-19 PPE conditions in an operation theatre. After each surgery vital signs were acquired and CBG and TAP were performed again.

Results

In our simulated surgical procedure heart rate, respiratory rate, systolic and diastolic blood pressure did not show relevant differences. Percutaneously measured SpO2 decreased with additional layers of PPE, while CBG parameters were not affected. TAP tests showed a significant impairment of attention if PPEs were compared to the baseline, but both PPEs had similar results and no meaningful differences could be measured.

Conclusions

According to our results, for surgical procedures additional PPE required during COVID-19 pandemic does not relevant affect the surgeon’s mental and physical performance. Surgeries under COVID-19 PPE conditions appear safe and do not increase patient risk.

Level of evidence

Level I.
BMI as a risk factor for the development of chronic rhinosinusitis: a prospective population-based study
Authors: Clarhed Ulrika K. E. , Schiöler Linus , Torén Kjell , Fell Anne Kristin M. , Hellgren Johan
Published: March 2022

Purpose

Obesity is a growing, global health problem and previous cross-sectional studies have demonstrated an association between obesity and chronic rhinosinusitis (CRS). There is, however, a lack of prospective studies regarding the impact of obesity on developing (new-onset) CRS.

Methods

Questionnaire-based data (n = 5769) relating to new-onset CRS and Body Mass Index (BMI) were collected in 2013 and 2018 from the Telemark population study in Telemark, Norway. Odds ratios for the risk of new-onset CRS in 2018 in relation to BMI in 2013 were calculated, adjusted for smoking habits, asthma, gender and age.

Results

When comparing the group with normal weight (18.5 ≤ BMI < 25) with the obese group (BMI ≥ 30), the odds of new-onset CRS was 53% higher [OR 1.53 (1.11, 2.10)] in the obese group.

Conclusion

CRS is a multifactorial disease with different phenotypes and it is important to consider obesity when assessing patients with CRS in a clinical setting.
Survey highlighting the lack of consensus on diagnosis and treatment of patent ductus arteriosus in prematurity
Authors: Hundscheid Tim , El-Khuffash Afif , McNamara Patrick J. , de Boode Willem P.
Published: March 2022

To gain insight in the availability of guidelines, diagnostic criteria, and treatment strategies and whether clinical equipoise regarding optimal treatment for patent ductus arteriosus (PDA) in prematurity is present. We hypothesized that (co-)authors of PDA-related papers were more likely to screen for a PDA and would treat earlier and more aggressively. An international internet-based survey between September 2019 and March 2020 in which we collected (1) baseline characteristics; (2) availability of guidelines; (3) screening strategy for PDA; (4) diagnostic criteria for hemodynamic significance; (5) treatment strategy; and (6) metrics of treatment efficacy. Finally, ten clinical equipoise statements were posed on a Likert scale. In total, 144 surveys were sent, of which 71/144 (49%) surveys could be analyzed with 56/71 (79%) fully completed surveys. The respondents, mainly neonatologists in a level III neonatal intensive care unit, of whom 36/71 (51%) had (co-)authored a publication on the PDA, highlighted a lack of national guidelines, heterogeneous approach to screening strategies, and marked variability in diagnostic criteria to assess hemodynamic significance, treatment strategies and effect measurement. No major significant differences were observed between respondents who did or did not (co-)author a publication on the PDA. Respondents who screened for PDA scored significantly higher on the need for screening, early and aggressive treatment. Remarkably, the scores of all statements regarding clinical equipoise varied widely.

   Conclusions: Our survey highlights the lack of guidelines and enormous heterogeneity in current practice. Current evidence is not robust enough to harmonize current treatment strategies into (inter)national guidelines.

What is Known:• Patent ductus arteriosus (PDA) incidence is inversely related to gestational age.• Although early pharmacological treatment induces PDA closure, optimal treatment is debated due to the lack of beneficial effects on outcome.

What is New:• In the absence of (inter)national guidelines, diagnostic and treatment strategies are heterogeneous and contradictory, even in a selected hemodynamically- interested group.• Different PDA screening strategies did, while PDA publication status did not, show significant differences in treatment strategy and responses to equipoise statements.
Three methods to generalize Pawlak approximations via simply open concepts with economic applications
Authors: El-Bably Mostafa K. , El-Sayed Mohammad
Published: March 2022

The generalizations of rough sets based on topological structures have become the hot topic of rough set theory. In the present article, based on the notion of $$j$$
j
-neighborhood space and the related concept of $$j$$
j
-simply open sets, three new methods for generalizing Pawlak rough sets are proposed and their properties are studied. These methods are compared with some of the previous methods. Moreover, we prove that the suggested approaches are more accurate than the other methods and then these approaches may be useful in real-life applications. Finally, an economic application in decision-making is introduced as a simple practical example to demonstrate the ideas proposed. It is providing a comparison between the proposed methods with already existing in the literature.
Successful treatment of acquired von Willebrand syndrome associated with monoclonal gammopathy
Authors: Jeryczynski Georg , Agis Hermine , Eichinger-Hasenauer Sabine , Krauth Maria Theresa
Published: March 2022

Acquired von Willebrand syndrome is exceedingly rare and accounts for only 1–3% of von Willebrand disease cases. In this short report, we present our own cases of acquired von Willebrand syndrome associated with monoclonal gammopathy. Both cases went into complete and sustained remission after intensive antimyeloma treatment. The first patient was not deemed fit for autologous stem cell transplantation and was managed with an extensive multidrug combination including daratumumab, carfilzomib, lenalidomide, cyclophosphamide and dexamethasone. After at least VGPR was achieved the coagulation studies rapidly normalized and remained normal after treatment de-escalation to lenalidomide/dexamethasone maintenance. The second patient successfully underwent ASCT after 5 cycles of induction with daratumumab, bortezomib, cyclophosphamide and dexamethasone and has remained in full hematologic and hemostaseologic remission ever since.

The two cases highlight the efficacy of aggressive antimyeloma treatment in monoclonal gammopathy-associated acquired von Willebrand syndrome to achieve normalization of coagulation study, providing a possible way to manage these patients.
An exploration of wellbeing in men diagnosed with prostate cancer undergoing active surveillance: a qualitative study
Authors: Eymech Omar , Brunckhorst Oliver , Fox Louis , Jawaid Anam , Van Hemelrijck Mieke , Stewart Robert , Dasgupta Prokar , Ahmed Kamran
Published: March 2022

Purpose

There is a growing emphasis on improving quality of life of people with prostate cancer. However, those undergoing active surveillance remain underrepresented in the literature with less known about their unique challenges. Therefore, we aimed to explore their lived experiences post diagnosis and its effect on their mental, social, and physical wellbeing.

Methods

Qualitative semi-structured interviews were conducted with 13 men undergoing active surveillance for low-risk disease. Thematic analysis was used to inductively co-construct themes through the lens of the biopsychosocial model.

Results

Mental wellbeing was strongly affected in our participants due to the overwhelming emotional impact of their diagnosis resulting in an ‘Emotional Diagnostic Disequilibrium’. Informational awareness and education about prostate cancer helped patients with ‘Recognition of the Impact’. Patients experienced an ‘Unsettling Monitoring Cycle’ due to the increased fear and anxiety around PSA monitoring appointments, with some men ignoring their mental wellbeing needs as their disease is ‘A Future Problem’. ‘Concealment of Diagnosis’ left many feeling isolated and highlighted an important coping mechanisms in the ‘Importance of a Social Support Network’ theme. Finally, physical health mostly changed through alterations in health behaviour, leading to ‘A Healthier Lifestyle’ with increasing attribution of physical symptoms to age through ‘Symptomatic Overshadowing’.

Conclusion

The greatest disease impact on men’s wellbeing was at the time of diagnosis, with a subsequent cyclical anxiety and fear of disease progression prominent around monitoring appointments. Future research should explore ways to better support patients with these issues and at these times, improving their quality of life.
Model-driven management of BPMN-based business process families
Authors: Delgado Andrea , Calegari Daniel , García Félix , Weber Barbara
Published: March 2022

Business processes can have variants depending on specific business requirements, which lead to the definition of a so-called business process family. Since conventional business process modeling languages, e.g., the Business Process Model and Notation (BPMN), do not explicitly support variants’ specification, several proposals have emerged to deal with it. However, they mainly focus on languages’ definition, while less emphasis is made on providing complete variability management. This article presents a Model-Driven Engineering approach for managing BPMN-based business process families composed of a metamodel for conceptualizing process families, a high-level process for managing them (involving model transformations for the configuration of variants), and tool support for the complete approach. We validated the proposal using a real-world example from a university and an empirical study with real users. Users rated the support tool’s principal functional suitability and usability features as very good. Many improvement opportunities were detected, e.g., version control, collaborative work, and error reporting. We also provide a literature review and thorough evaluation of BPMN-based business process families’ proposals using the VIVACE framework.
Georg Friedrich Knapp und die Modern Monetary Theory
Authors: Greitens Jan
Published: March 2022

Aus Anlass der Wiederveröffentlichung des Sonderhefts „Georg Friedrich Knapp — ein literarisches Bildnis“ im Wirtschaftsdienst zum 80. Geburtstag von Knapp vor genau 100 Jahren wird der Versuch unternommen, Person und Werk des Wissenschaftlers aus heutiger Sicht zu würdigen und die aktuelle Kontroverse um ihn zu beleuchten, denn die Modern Monetary Theory sieht in Knapp ihren Ursprung.
2-Arachidonoylglycerol Attenuates Myocardial Fibrosis in Diabetic Mice Via the TGF-β1/Smad Pathway
Authors: Chen Zhengjie , Zheng Liangyu , Chen Gang
Published: March 2022

Purpose

Diabetic cardiomyopathy (DM) is the cause of late cardiac dysfunction in diabetic patients. Myocardial fibrosis is the main pathological mechanism, and it is associated with transforming growth factor-β1(TGF-β1) expression up-regulation. 2-Arachidonoylglycerol (2-AG) is an endogenous cannabinoid that can effectively improve myocardial cell energy metabolism and cardiac function. Here, we evaluated the protective effect of 2-AG on diabetic cardiomyopathy.

Methods

Male C57BL/6 mice were injected with 2-AG intraperitoneally for 4 weeks (10 micro g/kg/day) after 12 weeks of diabetic modeling. After 4 weeks, heart function was evaluated by echocardiography. Heart structure was assessed by hematoxylin and eosin staining. Cardiac fibrosis was analyzed using immunohistochemistry, Sirius red stain, and western blot.

Results

After modeling in diabetic mice, cardiac ultrasonography showed decreased cardiac function and pathological findings showed myocardial fibrosis. 2-AG could effectively inhibit the up-regulation of TGF-β1 and Smad2/3, reduce myocardial fibrosis, and ultimately improve cardiac function in diabetic mice.

Conclusion

2-AG reduces cardiac fibrosis via the TGF-β1/Smad2/3 pathway and is a potential pathway for the treatment of cardiac dysfunction in diabetic mice.
Effects of Nature (Greenspace) on Cognitive Functioning in School Children and Adolescents: a Systematic Review
Authors: Vella-Brodrick Dianne A. , Gilowska Krystyna
Published: March 2022

There is growing interest in understanding the extent to which natural environments can influence learning particularly in school contexts. Nature has the potential to relieve cognitive overload, reduce stress and increase wellbeing—all factors that are conducive to learning. This paper provides a PRISMA-guided systematic review of the literature examining the effects of nature interventions on the cognitive functioning of young people aged 5 to 18 years. Examples of nature interventions include outdoor learning, green playgrounds, walks in nature, plants in classrooms and nature views from classroom windows. These can vary in duration and level of interaction (passive or active). Experimental and quasi-experimental studies with comparison groups that employed standardized cognitive measures were selected, yielding 12 studies from 11 papers. Included studies were rated as being of high (n = 10) or moderate quality (n = 2) and most involved short-term nature interventions. Results provide substantial support for cognitive benefits of nature interventions regarding selective attention, sustained attention and working memory. Underlying mechanisms for the benefits were also explored, including enhanced wellbeing, cognitive restoration and stress reduction—all likely to be contributors to the nature-cognition relationship. The cognitive effects of nature interventions were also examined according to age and school level with some differences evident. Findings from this systematic review show promise that providing young people with opportunities to connect with nature, particularly in educational settings, can be conducive to enhanced cognitive functioning. Schools are well placed to provide much needed ‘green’ educational settings and experiences to assist with relieving cognitive overload and stress and to optimize wellbeing and learning.
Will you come back to contribute? Investigating the inactivity of OSS core developers in GitHub
Authors: Calefato Fabio , Gerosa Marco Aurélio , Iaffaldano Giuseppe , Lanubile Filippo , Steinmacher Igor
Published: March 2022

Several Open-Source Software (OSS) projects depend on the continuity of their development communities to remain sustainable. Understanding how developers become inactive or why they take breaks can help communities prevent abandonment and incentivize developers to come back. In this paper, we propose a novel method to identify developers’ inactive periods by analyzing the individual rhythm of contributions to the projects. Using this method, we quantitatively analyze the inactivity of core developers in 18 OSS organizations hosted on GitHub. We also survey core developers to receive their feedback about the identified breaks and transitions. Our results show that our method was effective for identifying developers’ breaks. About 94% of the surveyed core developers agreed with our state model of inactivity; 71% and 79% of them acknowledged their breaks and state transition, respectively. We also show that all core developers take breaks (at least once) and about a half of them (~45%) have completely disengaged from a project for at least one year. We also analyzed the probability of transitions to/from inactivity and found that developers who pause their activity have a ~35 to ~55% chance to return to an active state; yet, if the break lasts for a year or longer, then the probability of resuming activities drops to ~21–26%, with a ~54% chance of complete disengagement. These results may support the creation of policies and mechanisms to make OSS community managers aware of breaks and potential project abandonment.
In the Shadow of Rawls: Egalitarianism Today
Authors: Stone Peter
Published: March 2022

Two recent collections of papers—Social Equality: On What It Means to Be Equals, edited by Carina Fourie, Fabian Schuppert, and Ivo Wallimann-Helmer (Fourie et al. 2015) and The Equal Society: Essays on Equality in Theory and Practice, edited by George Hull (Hull 2015)—demonstrate well the wide diversity of perspectives on egalitarianism within political theory today. But there are unifying themes amidst all this diversity. In particular, these collections make plain the extent to which contemporary egalitarianism in all forms is indebted to Rawls. This debt is reflected, for example, in the luck egalitarianism/social egalitarian debate which plays a central role in both books. It is also reflected in the concern so many contemporary egalitarians have for respect and its social basis. But while egalitarianism today owes much to Rawls, this does not mean that Rawls has nothing left to contribute to the conversation. This essay will argue that a return to Rawls can help contemporary egalitarians avoid taking their debates in certain unproductive directions.