bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite‐time output regulation by bounded linear time‐varying controls with applications to the satellite formation flying
Authors: Zhang Kai , Zhou Bin , Jiang Huaiyuan , Duan Guangren
Published: October 2021

This article studies the finite‐time output regulation problem for linear time‐invariant continuous‐time systems. By using the solution to a parametric Lyapunov equation (PLE) and regulator equations, three bounded linear time‐varying (LTV) state controllers composed of the LTV feedback gain and the LTV feedforward gain are designed, such that (prescribed) finite‐time output regulation is solved. As a further result, a linear LTV observer‐based controller is also designed. The most significant advantages of this article are that the system under consideration is more general and the output regulation problem is achieved within a user‐chosen regulation time. Finally, the developed LTV state controllers are utilized to the design of the satellite formation flying control system and simulation results verify the effectiveness of the proposed approaches.
Thiohydantoins as Potential Antioxidant Agents: In vitro and in silico evaluation
Authors: Camargo Priscila Goes , Fabris Marcieli , da Silva Talis Uelisson , Silva Lima Camilo Henrique , de Paula Machado Sérgio , Tonin Lilian Tatiani Dusman , de Lima Ferreira Bispo Marcelle , Macedo Fernando
Published: October 2021

Reactive oxygen species (ROS) cause oxidative damage to cellular membranes and macromolecules leading to diseases such as cancer. Antioxidants are chemical substances that scavenge free radicals and ROS and can be used as an alternative therapeutic approach to treat these diseases. In this work, we evaluate the in vitro antioxidant activity of a series of thiohydantoins, which five derivatives showed promising radical scavenging ability against stable DPPH (%I=90). The IC50 values ranged between 100 and 270 μM, and the best antioxidant potential was observed to thiohydantoin containing imidazole group in the side chain (IC50=40.0 μM). Kinetics analysis of the antioxidant activity indicated fast, intermediary, and slow behavior, while quantum calculations showed that the lowest IC50 is related to the best donating‐electron ability of the molecule. The molecular docking study for the best derivates against five relevant targets involved in the redox homeostasis: CP450, LOX, MPO, NOX, and XOX, suggest that the thiohydantoin ring acts as a pharmacophoric group in interactions with catalytic residues in the active site, demonstrating that thiohydantoin containing imidazole group in the side chain can be a promising compound as antioxidant agent.
Characterization of the bioactive compounds with efficacy against enteritis in Polygonum hydropiper L. by UHPLC‐Q‐Orbitrap HRMS combined with network pharmacological analysis**
Authors: Zhang Xiaorui , Ren Yuanyuan , Zeng Yijia , Li Tingna , Lv Hongyang , Li Xiaoqiu , Yao Renchuan , Huang Qinwan , Wang Chao
Published: October 2021

Polygonum hydropiper L. (PL) is widely used in treating enteritis in China. This study interpreted the active ingredient and mechanism of PL against enteritis through UHPLC‐Q‐Orbitrap HRMS, network pharmacology and molecular docking. UHPLC‐Q‐Orbitrap HRMS of PL manifested 68 compounds. In addition, the primary candidate genes and potential active components were identified by topological analysis of the single‐component disease gene interaction network. The interaction between the active ingredient, whose drug‐likeness properties were confirmed by Lipinski's rule, and the therapeutic gene was confirmed by molecular docking analysis. AutoDock Vina in AutoDock Tools was used to conduct molecular docking between significant components and critical genes. The advantage of this experiment is that the UHPLC‐Q‐Orbitrap HRMS method increases the total chemical composition of PL. Secondly, we obtained active compounds through network pharmacology and found that PL mainly acts on multiple inflammatory pathways in the treatment of enteritis. 61 potential genes of PL for the treatment of enteritis were obtained. The genes were mainly involved in biological processes such as response to oxidative stress, inhibition of inflammatory factors and inflammatory pathways, and role in treating enteritis by participating in AR, NOS2, MMP9, MMP2, SRC, and other signaling pathways.
Transparency in relational contracts
Authors: Fahn Matthias , Zanarone Giorgio
Published: October 2021

Research Summary

We model how an organization's transparency (toward employees or contractors) affects its ability to sustain relational governance. We show that transparency creates accountability: if the organization reneges on promises made to an agent, the other agents observe its defection and quit. Thus, transparency enables organizations with limited credibility to provide high‐powered incentives. However, transparency also triggers envious social comparisons that reduce profits and may erode its credibility benefit. In that case, the organization may find it optimal to appropriate a smaller share of a larger pie—that is, to elicit high effort from the envious agents by leaving them a rent. Social comparisons therefore create a tension between value creation and profitability, which may call for “sunshine laws” that force the organization to be transparent.

Managerial Summary

Organizational transparency (in pay and performance reviews) is often advocated but rarely used. Our paper provides a theoretical framework to evaluate the benefits and costs of transparency for organizations. Our model shows that transparent organizations are more accountable to their employees and partners, and hence more credible and trustworthy. At the same time, transparency triggers envious social comparisons among employees, which may reduce organizations' ability to capture value to the advantage of those employees. A managerial implication of our analysis, supported by preliminary evidence presented in the paper, is that organizations that aim to increase their employees' and contractors' trust benefit the most from transparency. A policy implication is that “sunshine laws” that impose transparency may enhance organizations' productivity, output, and value creation.
Power to the people: The benefits and limits of employee self‐selection in organizations
Authors: Ketkar Harsh , Workiewicz Maciej
Published: October 2021

Research Summary

One of the key features of boss‐less organizations is self‐selection, where each employee is allowed to both initiate and join projects freely. While this approach has been gaining in popularity within many big and small organizations, we have a limited understanding of its properties, limitations, and key mechanisms. In this article, we analyze the efficacy and boundary conditions of employee self‐selection with respect to project selection and employee allocation. Our results suggest that the relative balance between an organization's human capital and the number of opportunities it faces plays a critical role in determining the advantages of self‐selection, which performs better when human capital is scarce relative to opportunities. We also examine common policies that organizations use to further improve the efficacy of self‐selection.

Managerial Summary

Self‐selection or allowing employees to either launch their own or join existing projects freely, has been recently gaining in popularity. Companies across different industries have found this approach advantageous and have been pursuing it either across the entire organization, in selected units, or part time. In this article, we formally analyze the advantages and disadvantages of self‐selection and its different variants. We show that self‐selection is best pursued in organizations where the magnitude of opportunities outstrips available human resources. However, in environments where opportunities worth pursuing are in short supply relative to available employees, hierarchical arrangements tend to fare much better. We put forth a set of conditions that can help managers decide when self‐selection would be appropriate and when it may hurt performance.
Elucidating the Strain–Vacancy–Activity Relationship on Structurally Deformed Co@CoO Nanosheets for Aqueous Phase Reforming of Formaldehyde
Authors: Qian Kaicheng , Yan Yong , Xi Shibo , Wei Tong , Dai Yihu , Yan Xiaoqing , Kobayashi Hisayoshi , Wang Sheng , Liu Wen , Li Renhong
Published: October 2021

Lattice strain modulation and vacancy engineering are both effective approaches to control the catalytic properties of heterogeneous catalysts. Here, Co@CoO heterointerface catalysts are prepared via the controlled reduction of CoO nanosheets. The experimental quantifications of lattice strain and oxygen vacancy concentration on CoO, as well as the charge transfer across the Co–CoO interface are all linearly correlated to the catalytic activity toward the aqueous phase reforming of formaldehyde to produce hydrogen. Mechanistic investigations by spectroscopic measurements and density functional theory calculations elucidate the bifunctional nature of the oxygen‐vacancy‐rich Co–CoO interfaces, where the Co and the CoO sites are responsible for CH bond cleavage and OH activation, respectively. Optimal catalytic activity is achieved by the sample reduced at 350 °C, Co@CoO‐350 which exhibits the maximum concentration of Co–CoO interfaces, the maximum concentration of oxygen vacancies, a lattice strain of 5.2% in CoO, and the highest aqueous phase formaldehyde reforming turnover frequency of 50.4 h−1 at room temperature. This work provides not only new insights into the strain–vacancy–activity relationship at bifunctional catalytic interfaces, but also a facile synthetic approach to prepare heterostructures with highly tunable catalytic activities.
Design of a LiF‐Rich Solid Electrolyte Interphase Layer through Highly Concentrated LiFSI–THF Electrolyte for Stable Lithium Metal Batteries
Authors: Pham Thuy Duong , Bin Faheem Abdullah , Lee Kyung‐Koo
Published: October 2021

Lithium metal is a promising anode material for lithium metal batteries (LMBs). However, dendrite growth and limited Coulombic efficiency (CE) during cycling have prevented its practical application in rechargeable batteries. Herein, a highly concentrated electrolyte composed of an ether solvent and lithium bis(fluorosulfonyl)imide (LiFSI) salt is introduced, which enables the cycling of a lithium metal anode at a high CE (up to ≈99%) without dendrite growth, even at high current densities. Using 3.85 m LiFSI in tetrahydrofuran (THF) as the electrolyte, a Li||Li symmetric cell can be cycled at 1.0 mA cm−2 for more than 1000 h with stable polarization of ≈0.1 V, and Li||LFP cells can be cycled at 2 C (1 C = 170 mA g−1) for more than 1000 cycles with a capacity retention of 94.5%. These excellent performances are observed to be attributed to the increased cation–anion associated complexes, such as contact ion pairs and aggregate in the highly concentrated electrolyte; revealed by Raman spectroscopy and theoretical calculations. These results demonstrate the benefits of a high‐concentration LiFSI–THF electrolyte system, generating new possibilities for high‐energy‐density rechargeable LMBs.
Label‐Free Mycotoxin Raman Identification by High‐Performing Plasmonic Vertical Carbon Nanostructures
Authors: M. Santhosh Neelakandan , Shvalya Vasyl , Modic Martina , Hojnik Nataša , Zavašnik Janez , Olenik Jaka , Košiček Martin , Filipič Gregor , Abdulhalim Ibrahim , Cvelbar Uroš
Published: October 2021

Mycotoxins are widespread chemical entities in the agriculture and food industries that can induce cancer growth and immune deficiency, posing a serious health threat for humankind. These hazardous compounds are produced naturally by various molds (fungi) that contaminate different food products and can be detected in cereals, nuts, spices, and other food products. However, their detection, especially at minimally harmful concentrations, remains a serious analytical challenge. This research shows that high‐performing plasmonic substrates (analytical enhancement factor = 5 × 107) based on plasma‐grown vertical hollow carbon nanotubes can be applied for immediate detection of the most toxic mycotoxins. Due to excellent sensitivity allowing operation at ppb concentrations, it is possible to collect vibrational fingerprints of aflatoxin B1, zearalenone, alternariol, and fumonisin B1, highlighting the key spectral differences between them using principal component analysis. Regarding time‐consuming conventional methods, including thin‐layer chromatography, gas chromatography, high‐performance liquid chromatography, and enzyme‐linked immunosorbent assay, the designed surface‐enhanced Raman spectroscopy substrates provide a clear roadmap to reducing the detection time‐scale of mycotoxins down to seconds.
Programmable and Site‐Specific Patterning on DNA Origami Templates with Heterogeneous Condensation of Silver and Silica
Authors: Zhao Yumeng , Zhang Chao , Yang Linlin , Xu Xuemei , Xu Rui , Ma Qian , Tang Qian , Yang Yang , Han Da
Published: October 2021

DNA origami has been widely used as a modular platform for condensation of functional molecules to assemble optical, electronic, and biological components. However, the heterogeneous condensation with greater diversities in chemical composition templated with DNA origami is still challenging. Herein, a programmable deposition method is developed to precisely condense silver–silica nanohybrids on DNA origami templates. First, the site‐specific metallization of Ag is achieved by thiol group‐initiated silver reduction at the designed areas of DNA origami. Next, cysteamine is used to selectively modify the condensed Ag surface with positively charged amino groups for creating an electronically different environment for site‐specific placement of silica by a modified Stöber method. Using these strategies, customized patterning of both silver and silica on tubular and rectangular DNA origami nanostructures is successfully achieved with nanoscale spatial resolution. These findings will greatly facilitate the development of DNA nanotechnology‐based bottom‐up nanofabrication.
Transcoding billions of Unicode characters per second with SIMD instructions
Authors: Lemire Daniel , Muła Wojciech
Published: October 2021

In software, text is often represented using Unicode formats (UTF‐8 and UTF‐16). We frequently have to convert text from one format to the other, a process called transcoding. Popular transcoding functions are slower than state‐of‐the‐art disks and networks. These transcoding functions make little use of the single‐instruction‐multiple‐data (SIMD) instructions available on commodity processors. By designing transcoding algorithms for SIMD instructions, we multiply the speed of transcoding on current systems (64 and ARM). To ensure reproducibility, we make our software freely available as an open source library.
Sequential pathway inference for multimodal neuroimaging analysis
Authors: Li Lexin , Shi Chengchun , Guo Tengfei , Jagust William J.
Published: October 2021

Motivated by a multimodal neuroimaging study for Alzheimer's disease, in this article, we study the inference problem, that is, hypothesis testing, of sequential mediation analysis. The existing sequential mediation solutions mostly focus on sparse estimation, while hypothesis testing is an utterly different and more challenging problem. Meanwhile, the few mediation testing solutions often ignore the potential dependency among the mediators or cannot be applied to the sequential problem directly. We propose a statistical inference procedure to test mediation pathways when there are sequentially ordered multiple data modalities and each modality involves multiple mediators. We allow the mediators to be conditionally dependent and the number of mediators within each modality to diverge with the sample size. We produce the explicit significance quantification and establish theoretical guarantees in terms of asymptotic size, power, and false discovery control. We demonstrate the efficacy of the method through both simulations and an application to a multimodal neuroimaging pathway analysis of Alzheimer's disease.
Clusia suborbicularis is not a synonym of Clusia flava: Molecular and metabolomic evidence
Authors: Herbert‐Doctor Luis Alfredo , Dzib Gabriel , Hammel Barry Edward , Chi‐Manzanero Bartolomé Humberto , Canto‐Canché Blondy Beatriz , García‐Sosa Karlina , Richomme Pascal , Derbré Séverine , Peña‐Rodríguez Luis Manuel
Published: October 2021

The genus Clusia (Clusiaceae) is notorious for its difficult taxonomy; most species are dioecious, with distantly related species having similar morphology, and closely related species having cryptic morphological differences. Because of this, Clusia spp. are often misidentified or, as in the case of C. suborbicularis and C. flava, considered to be the same species. Chemometric analyses of the HPLC metabolic profiles from bark extracts of C. suborbicularis and C. flava, combined with molecular evidence from ITS molecular markers were used to establish the metabolomic similarities and phylogenetic relationship between C. suborbicularis and C. flava, previously identified on the basis of their morphological characteristics. The principal component analyses of the HPLC metabolic profiles of bark extracts from individuals of C. suborbicularis and C. flava showed significant differences, suggesting they should be recognized as distinct species. This assumption was confirmed by phylogenetic reconstructions based on the molecular marker ITS. Furthermore, a theoretical geographical distribution analysis suggests C. suborbicularis could be considered a native species to the Yucatán Peninsula. The results from this investigation support C. suborbicularis as a distinct species, and not a synonym of C. flava. The identification of these two species represents a relevant contribution for the cataloguing, conservation and bioprospecting of Clusia spp. occurring in the Yucatán Peninsula.
Effects of extensional flow and nanofiller incorporation on dispersed phase size in the blending of high‐viscosity‐ratio immiscible vinyl polymers
Authors: Thompson Matthew S. , Agarwal Sushant , Gupta Rakesh K.
Published: October 2021

The influence of extensional strain and strain rate on dispersed phase size during blending of a dilute mixture of vinyl polymers, high‐density polyethylene in polystyrene, was examined; the viscosity ratio was substantially larger than four so that shearing was not expected to contribute to drop breakup. Coarse blends were formulated by employing an internal mixer, and these blends were processed through different converging dies attached to the outlet of a capillary viscometer. Variables included the die geometry and the volumetric flow rate. Average dispersed phase sizes were determined by analyzing scanning electron micrographs of sections of strands leaving the viscometer, and it was found that extensional flow was very effective in reducing the dispersed phase size. Coarse blends were also formulated by separately incorporating nanoparticles of hydrophobic fumed silica as well as hydrophilic fumed silica in the blends at a 4 wt% nanofiller level. This resulted in a significant reduction in drop size compared to the previous value; this was likely the result of lowered drop coalescence. These nanoparticle‐containing blends were also subjected to extensional flow, and this resulted in a further reduction in the average dispersed phase size. However, the final result was only slightly better than that obtained previously with the help of extensional flow alone. This suggests the use of nanoparticle incorporation along with employing extensional flow when the presence of nanoparticles provides multifunctionality to the resulting blend.
Multivariate temporal data analysis ‐ a review
Authors: Moskovitch Robert
Published: October 2021

The information technology revolution, especially with the adoption of the Internet of Things, longitudinal data in many domains become more available and accessible for secondary analysis. Such data provide meaningful opportunities to understand process in many domains along time, but also challenges. A main challenge is the heterogeneity of the temporal variables due to the different types of data, whether a measurement or an event, and type of samplings: fixed or irregular. Other variables can be also events that may or not have duration. In this review, we discuss the various types of temporal data, and the various relevant analysis methods. Starting with fixed frequency variables, with forecasting and time series methods, and proceeding with sequential data, and sequential patterns mining, and time intervals mining for events having various time duration. Also the use of various deep learning based architectures for temporal data is discussed. The challenge of heterogeneous multivariate temporal data analysis and discuss various options to deal with it, focusing on an increasingly used option of transforming the data into symbolic time intervals through temporal abstraction and the use of time intervals related patterns discovery for temporal knowledge discovery, clustering, classification prediction, and more. Finally, we discuss the overview of the field, and areas in which more studies and contributions are needed.

This article is categorized under:

Algorithmic Development > Spatial and Temporal Data Mining
Correction to: Gaining Insight into Determinants of Physical Activity Using Bayesian Network Learning
Authors: Tummers Simone C. M. W. , Hommersom Arjen , Lechner Lilian , Bolman Catherine , Bemelmans Roger
Published: October 2021

“Gaining Insight into Determinants of Physical Activity Using Bayesian Network Learning” was previously published non-open access. It has now been changed to open access under a CC BY 4.0 license and the copyright holder updated to ‘The Author(s)’. The book has also been updated with this change.
AAL als Geschäftsmodell – von Gewinnerzielungsabsichten, gesellschaftlicher Verantwortung, Systemrelevanz und den Zutaten für ein humanistisch geprägtes Älterwerden
Authors: Andelfinger Volker P.
Published: October 2021

Seit etwas mehr als 6 Jahren beschäftige ich mich mit AAL. Bei der Unternehmensberatung, bei der ich damals arbeitete, war es das übriggebliebene Thema, nachdem andere Kolleg*innen die Zukunftsfelder Mobilität, eHealth, Internet der Dinge bereits besetzt hatten. Ich war neu und bei Weitem der Älteste in der Firma, ein Mittfünfziger. Da war es ja auch quasi naheliegend, mich mit diesem „Älterwerdenthema“ zu betrauen. Tue was du liebst und liebe was du tust.
Towards a Higgs mass determination in asymptotically safe gravity with a dark portal
Authors: Eichhorn Astrid , Pauly Martin , Ray Shouryya
Published: October 2021

Abstract

There are indications that an asymptotically safe UV completion of the Standard Model with gravity could constrain the Higgs self-coupling, resulting in a prediction of the Higgs mass close to the vacuum stability bound in the Standard Model. The predicted value depends on the top quark mass and comes out somewhat higher than the experimental value if the current central value for the top quark mass is assumed. Beyond the Standard Model, the predicted value also depends on dark fields coupled through a Higgs portal. Here we study the Higgs self-coupling in a toy model of the Standard Model with quantum gravity that we extend by a dark scalar and fermion. Within the approximations used in [1], there is a single free parameter in the asymptotically safe dark sector, as a function of which the predicted (toy model) Higgs mass can be lowered due to mixing effects if the dark sector undergoes spontaneous symmetry breaking.
Critical 1- and 2-point spin correlations for the O(2) model in 3d bounded domains
Authors: Galvani Alessandro , Gori Giacomo , Trombettoni Andrea
Published: October 2021

Abstract

We study the critical properties of the 3d O(2) universality class in bounded domains through Monte Carlo simulations of the clock model. We use an improved version of the latter, chosen to minimize finite-size corrections at criticality, with 8 orientations of the spins and in the presence of vacancies. The domain chosen for the simulations is the slab configuration with fixed spins at the boundaries. We obtain the universal critical magnetization profile and two-point correlations, which favorably compare with the predictions of the critical geometry approach based on the Yamabe equation. The main result is that the correlations, once the dimensionful contributions are factored out with the critical magnetization profile, are shown to depend only on the distance between the points computed using a metric found solving the corresponding fractional Yamabe equation. The quantitative comparison with the corresponding results for the Ising model at criticality is shown and discussed. Moreover, from the magnetization profiles the critical exponent η is extracted and found to be in reasonable agreement with up-to-date results.
Impact of systematic and amplitude model correlations within and between systems of combined input: a case study with ϕ2 (α)
Authors: Dalseno J.
Published: October 2021

Abstract

The pursuit of experimental precision in the CP-violating weak phase ϕ2 (α) is not without its challenges, in part due to the need to combine multiple physical observables from various related decay channels, and therein lies a fundamental issue. Similarities in analysis procedures give rise to systematic correlations between the measured inputs constraining ϕ2 that must be taken into account to avoid bias. Specifically, in the case of the irreducible model uncertainty accompanying analyses involving the ρ meson, it is demonstrated that ignoring correlations derived from its pole parameters, or indeed even treating correlations individually contained within each decay channel, can ultimately lead to a bias in ϕ2 of (1°). Correct treatment on the other hand, markedly reduces wandering of its central value as a function of the model uncertainty strength with the added dividend of a further improved overall uncertainty. Bias in the combination of B0 → (ρπ)0 and B → ρρ is also seen to depend on the statistical strength of the former in relation to that of the model uncertainty in the latter. This work can inspire other studies into the points at which systematic correlations beyond those determined in single measurements matter in combinations leading to other CP-violating weak phases such as ϕ1 (β), ϕ3 (γ) and ϕs.
Matching higher symmetries across Intriligator-Seiberg duality
Authors: Lee Yasunori , Ohmori Kantaro , Tachikawa Yuji
Published: October 2021

Abstract

We study higher symmetries and anomalies of 4d $$ \mathfrak{so} $$
so
(2nc) gauge theory with 2nf flavors. We find that they depend on the parity of nc and nf, the global form of the gauge group, and the discrete theta angle. The contribution from the fermions plays a central role in our analysis. Furthermore, our conclusion applies to $$ \mathcal{N} $$
N
= 1 supersymmetric cases as well, and we see that higher symmetries and anomalies match across the Intriligator-Seiberg duality between $$ \mathfrak{so} $$
so
(2nc) ↔$$ \mathfrak{so} $$
so
(2nf − 2nc + 4).
Charging up the functional bootstrap
Authors: Ghosh Kausik , Kaviraj Apratim , Paulos Miguel F.
Published: October 2021

Abstract

We revisit the problem of bootstrapping CFT correlators of charged fields. After discussing in detail how bounds for uncharged fields can be recycled to the charged case, we introduce two sets of analytic functional bases for correlators on the line. The first, which we call “simple”, is essentially a direct sum of analytic functionals for the uncharged case. We use it to establish very general bounds on the OPE density appearing in charged correlators. The second basis is dual to generalized free fields and we explain how it is related to a charged version of the Polyakov bootstrap. We apply these functionals to map out the space of correlators and obtain new improved bounds on the 3d Ising twist defect.
Janus solutions from dyonic ISO(7) maximal gauged supergravity
Authors: Karndumri Parinya , Maneerat Chawakorn
Published: October 2021

Abstract

We give a large class of new supersymmetric Janus solutions in dyonic ISO(7) maximal gauged supergravity encompassing all known solutions appearing recently. We consider SO(3) invariant sector in which the gauged supergravity admits four supersymmetric AdS4 vacua with N = 1, 1, 2, 3 unbroken supersymmetries and G2, SU(3), SU(3) × U(1) and SO(4) symmetries, respectively. We find Janus solutions preserving N = 1, 2, 3 supersymmetries and interpolating between AdS4 vacua and the N = 8 SYM phase. These solutions can be interpreted as conformal interfaces between SYM and various conformal phases of the dual field theory in three dimensions. The solutions can also be embedded in massive type IIA theory by a consistent truncation on S6. We also find a number of singular Janus solutions interpolating between N = 8 SYM or AdS4 vacua and singularities or between singular geometries. It turns out that, apart from the SYM phase on D2-branes, all the singularities arising in these solutions are unphysical in both four- and ten-dimensional frameworks.
Factorization of Polynomials Given by Arithmetic Branching Programs
Authors: Sinhababu Amit , Thierauf Thomas
Published: October 2021

Given a multivariate polynomial computed by an arithmetic branching
program (ABP) of size s, we show that all its factors can be
computed by arithmetic branching programs of size poly(s).
Kaltofen gave a similar result for polynomials computed by
arithmetic circuits. The previously known best upper bound for
ABP-factors was poly $$ (s^{ {\rm \log} s}) $$

(

s

log
s

)

.
Intrazerebrale Blutungen unter Plättchenaggregationshemmung und oraler Antikoagulation bei Patienten mit zerebraler Amyloidangiopathie
Authors: Haußmann R. , Homeyer P. , Haußmann M. , Brandt M. , Donix M. , Puetz V. , Linn J.
Published: October 2021

Die Durchführung einer oralen Antikoagulation ist bei Patienten mit einer zerebralen Amyloidangiopathie eine therapeutische Herausforderung. Die Assoziation der zerebralen Amyloidangiopathie mit Lobärblutungen, eine hohe Mortalität intrazerebraler Blutungen insbesondere unter oraler Antikoagulation sowie das hohe Rezidivrisiko solcher Blutungen erfordern eine strenge und interdisziplinäre Risiko-Nutzen-Abwägung. Vitamin-K-Antagonisten erhöhen das Risiko für die mit intrazerebralen Blutungen vergesellschaftete Mortalität um 60 % und sollten daher möglichst vermieden bzw. speziellen klinischen Situationen (z. B. mechanischer Aortenklappenersatz) vorbehalten sein. Auch der Einsatz von neuen oralen Antikoagulanzien und Thrombozytenaggregationshemmern bedarf einer strengen Risiko-Nutzen-Abwägung, da auch diese Substanzen das zerebrale Blutungsrisiko erhöhen. Insbesondere bei Patienten mit einer absoluten Arrhyhtmie bei Vorhofflimmern ist der interventionelle Vorhofohrverschluss eine therapeutische Alternative. Darüber hinaus sind weitere klinische Implikationen bei Patienten mit zerebraler Amyloidangiopathie Gegenstand dieser Literaturübersicht, beispielsweise Besonderheiten nach akutem ischämischem Schlaganfall und erforderlicher Sekundärprophylaxe, bei vorherigen intrazerebralen Blutungen und bei Patienten mit kognitiven Defiziten.
Speeding up to keep up: exploring the use of AI in the research process
Authors: Chubb Jennifer , Cowling Peter , Reed Darren
Published: October 2021

There is a long history of the science of intelligent machines and its potential to provide scientific insights have been debated since the dawn of AI. In particular, there is renewed interest in the role of AI in research and research policy as an enabler of new methods, processes, management and evaluation which is still relatively under-explored. This empirical paper explores interviews with leading scholars on the potential impact of AI on research practice and culture through deductive, thematic analysis to show the issues affecting academics and universities today. Our interviewees identify positive and negative consequences for research and researchers with respect to collective and individual use. AI is perceived as helpful with respect to information gathering and other narrow tasks, and in support of impact and interdisciplinarity. However, using AI as a way of ‘speeding up—to keep up’ with bureaucratic and metricised processes, may proliferate negative aspects of academic culture in that the expansion of AI in research should assist and not replace human creativity. Research into the future role of AI in the research process needs to go further to address these challenges, and ask fundamental questions about how AI might assist in providing new tools able to question the values and principles driving institutions and research processes. We argue that to do this an explicit movement of meta-research on the role of AI in research should consider the effects for research and researcher creativity. Anticipatory approaches and engagement of diverse and critical voices at policy level and across disciplines should also be considered.
In silico evaluation of limited sampling strategies for individualized dosing of extended half-life factor IX concentrates in hemophilia B patients
Authors: Preijers T. , van Spengler M. W. F. , Meijer K. , Fijnvandraat K. , Fischer K. , Leebeek F. W. G. , Cnossen M. H. , Mathôt R. A. A.
Published: October 2021

Purpose

Hemophilia B is a bleeding disorder, caused by a factor IX (FIX) deficiency. Recently, FIX concentrates with extended half-life (EHL) have become available. Prophylactic dosing of EHL-FIX concentrates can be optimized by assessment of individual pharmacokinetic (PK) parameters. To determine these parameters, limited sampling strategies (LSSs) may be applied. The study aims to establish adequate LSSs for estimating individual PK parameters of EHL-FIX concentrates using in silico evaluation.

Methods

Monte Carlo simulations were performed to obtain FIX activity versus time profiles using published population PK models for N9-GP (Refixia), rFIXFc (Alprolix), and rIX-FP (Idelvion). Fourteen LSSs, containing three or four samples taken within 8 days after administration, were formulated. Bayesian analysis was applied to obtain estimates for clearance (CL), half-life (t1/2), time to 1% (Time1%), and calculated weekly dose (Dose1%). Bias and precision of these estimates were assessed to determine which LSS was adequate.

Results

For all PK parameters of N9-GP, rFIXFc and rIX-FP bias was generally acceptable (range: −5% to 5%). For N9-GP, precision of all parameters for all LSSs was acceptable (< 25%). For rFIXFc, precision was acceptable for CL and Time1%, except for t1/2 (range: 27.1% to 44.7%) and Dose1% (range: 12% to 29.4%). For rIX-FP, all LSSs showed acceptable bias and precision, except for Dose1% using LSS with the last sample taken on day 3 (LSS 6 and 10).

Conclusion

Best performing LSSs were LSS with samples taken at days 1, 5, 7, and 8 (N9-GP and rFIXFc) and at days 1, 4, 6, and 8 (rIX-FP), respectively.
Explainable AI to improve acceptance of convolutional neural networks for automatic classification of dopamine transporter SPECT in the diagnosis of clinically uncertain parkinsonian syndromes
Authors: Nazari Mahmood , Kluge Andreas , Apostolova Ivayla , Klutmann Susanne , Kimiaei Sharok , Schroeder Michael , Buchert Ralph
Published: October 2021

Purpose

Deep convolutional neural networks (CNN) provide high accuracy for automatic classification of dopamine transporter (DAT) SPECT images. However, CNN are inherently black-box in nature lacking any kind of explanation for their decisions. This limits their acceptance for clinical use. This study tested layer-wise relevance propagation (LRP) to explain CNN-based classification of DAT-SPECT in patients with clinically uncertain parkinsonian syndromes.

Methods

The study retrospectively included 1296 clinical DAT-SPECT with visual binary interpretation as “normal” or “reduced” by two experienced readers as standard-of-truth. A custom-made CNN was trained with 1008 randomly selected DAT-SPECT. The remaining 288 DAT-SPECT were used to assess classification performance of the CNN and to test LRP for explanation of the CNN-based classification.

Results

Overall accuracy, sensitivity, and specificity of the CNN were 95.8%, 92.8%, and 98.7%, respectively. LRP provided relevance maps that were easy to interpret in each individual DAT-SPECT. In particular, the putamen in the hemisphere most affected by nigrostriatal degeneration was the most relevant brain region for CNN-based classification in all reduced DAT-SPECT. Some misclassified DAT-SPECT showed an “inconsistent” relevance map more typical for the true class label.

Conclusion

LRP is useful to provide explanation of CNN-based decisions in individual DAT-SPECT and, therefore, can be recommended to support CNN-based classification of DAT-SPECT in clinical routine. Total computation time of 3 s is compatible with busy clinical workflow. The utility of “inconsistent” relevance maps to identify misclassified cases requires further investigation.
Entwicklung von Qualitätsstandards für die Versorgung von Patient*innen mit rheumatoider Arthritis zur Anwendung in Deutschland
Authors: Kiltz U. , Buschhorn-Milberger V. , Albrecht K. , Lakomek H.-J. , Lorenz H.-M. , Rudwaleit M. , Schneider M. , Schulze-Koops H. , Aringer M. , Hasenbring M. I. , Herzer P. , von Hinüber U. , Krüger K. , Lauterbach A. , Manger B. , Oltman R. , Schuch F. , Schmale-Grede R. , Späthling-Mestekemper S. , Zinke S. , Braun J.
Published: October 2021

Trotz einer qualitativ und strukturell guten Versorgung von Patient*innen mit rheumatoider Arthritis (RA) in Deutschland bestehen weiterhin potenziell behebbare Defizite in der Qualität der Versorgung. Aus diesem Grund hat die Deutsche Gesellschaft für Rheumatologie (DGRh) eine Expert*innengruppe, in der verschiedene Interessengruppen vertreten waren, beauftragt, nationale Qualitätsstandards (QS) mit dem Ziel zu entwickeln, die rheumatologische Versorgung von Patient*innen mit RA in Deutschland qualitativ zu verbessern. QS dienen der Festlegung und quantitativen Messung guter Versorgungsqualität unter dem Vorbehalt von Relevanz und Realisierbarkeit. Als Grundlage für die Entwicklung dienten die kürzlich publizierten Standards von NICE und ASAS und eine systematische Literatursuche. Insgesamt wurden 8 hiermit erstmals veröffentlichte QS konsentiert, die als Grundlage dienen können, die Versorgungsqualität von Patient*innen mit RA in Deutschland zu messen und weiter zu optimieren.
Advanced 3D Textile Applications for the Building Envelope
Authors: Lüling Claudia , Rucker-Gramm Petra , Weilandt Agnes , Beuscher Johanna , Nagel Dominik , Schneider Jens , Maier Andreas , Bauder Hans-Jürgen , Weimer Timo
Published: October 2021

Within the field of textile construction, textiles are traditionally used either as decorative elements in interior design or as flat textiles in tensile-stressed lightweight constructions (roofs, temporary buildings, etc.). Technical textiles made of glass or carbon fibers are now also used as steel substitutes in concrete construction. There, flat textiles are also used as lost formwork or shaping semi-finished products. Applications for 3D textiles and in particular spacer textiles have so far only been investigated as part of multilayer constructions in combination with other elements. Otherwise, there are no studies for their application potential in the roof and wall areas of buildings and as a starting structure for opaque and translucent components. The two research projects presented here, "ReFaTex" (adjustable spacer fabrics for solar shading devices) and "ge3TEX" (warp-knitted, woven and foamed spacer fabrics) illustrate for one thing the possibilities for using 3D textiles for the construction of movable and translucently variable solar protection elements in the building envelope. Otherwise they show how 3D textiles in combination with foamed materials can be transformed into opaque, lightweight, self-supporting and insulated wall and ceiling components in the building envelope. Both projects are designed experimentally and iteratively. The results are compared in a qualifying manner, the aim being not to quantify individual measured variables but to explore the development potential of textile construction for sustainable future components and to realize the first demonstrators. In the ReFaTex project, 1:1 demonstrators with different movement mechanisms for controlling the incidence of light were realized. In the ge3TEX project, 1:1 demonstrators made of three different textile and foam materials were added to form new single-origin composite components for ceiling elements. Both projects show the great application potential for 3D textiles in the construction industry.
How is price explosivity triggered in the cryptocurrency markets?
Authors: Cai Yuzhi , Chevapatrakul Thanaset , Mascia Danilo V.
Published: October 2021

We shed light on how the price explosivity characterising Bitcoin and other major cryptocurrencies is triggered, by employing the Quantile Self-Exciting Threshold Autoregressive (QSETAR) model. Our results for Bitcoin, Ripple, and Stellar reveal that the explosive behaviour originates from the extreme upper tails of the return distributions following a price increase in the preceding day. We do not find evidence of explositivity in the price of Litecoin.
Different Reality? Generations’ and Religious Groups’ Views of Spirituality Policies in the Workplace
Authors: Jolliffe Patricia , Foster Scott
Published: October 2021

Over the past 20 years, there has been considerable expansion, particularly spirituality theory in the workplace. Simultaneously, there has been a growth of research, most especially in practitioner publication into generational differences. The study's context is human resource (HR) policy and procedures in the workplace. Through this prism, generational perspectives and religious theory are compared and scrutinised within the United Kingdom. Two major religious groups (Muslim and Christian) and three-generational categories (Millennials, Generation X, and Baby Boomers) were selected to explore different attitudes, with participants identifying as belonging to religious groups outside of these two major religions, categorised as 'Other.' This study adopts a quantitative approach, with questionnaires gathering employees' perceptions of spirituality policy within their place of work. Although the study found differences in expectations between the religious groups and between the three generations, there is greater homogeneity than a difference in that the results provide limited support for workplace spirituality. Indeed, the study raises more questions than answers. The study uncovered areas ripe for informed debate around personal values, generations, and spirituality in the workplace. This is a relatively new research area, and our findings are in line with others that suggest that employee spiritual well-being is both underresearched and underexplored by organisations. Changing the current intransigence around the place of spirituality is overdue.
Inequalities in Access and Utilization of Maternal, Newborn and Child Health Services in sub-Saharan Africa: A Special Focus on Urban Settings
Authors: Sidze E. M. , Wekesah F. M. , Kisia L. , Abajobir A.
Published: October 2021

Objectives

The aim of this paper is to share the results of a systematic review on the state of inequalities in access to and utilization of maternal, newborn and child health (MNCH) services in the sub-Saharan African region. The focus of the review was on urban settings where growing needs and challenges have been registered over the past few years due to rapid increase in urban populations and urban slums.

Methods

The review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Studies published in English between 2000 and 2019 were included. A narrative synthesis of both qualitative and quantitative data was undertaken. The record for registration in PROSPERO was CRD42019122066.

Results

The review highlights a great variation in MNCH services utilization across urban sub-Saharan Africa (SSA). The main aspects of vulnerability to unequal and poor MNCH services utilization in urban settings of the region include poverty, low level of education, unemployment, lower socioeconomic status and poor livelihoods, younger maternal age, low social integration and social support, socio-cultural taboos, residing in slums, and being displaced, refugee, or migrant. At the health system level, persistent inequalities are associated with distance to health facility, availability of quality services and discriminating attitudes from health care personnel.

Conclusion

Context-specific intervention programs that aim at resolving the identified barriers to access and use MNCH services, particularly for the most vulnerable segments of urban populations, are essential to improve the overall health of the region and universal health coverage (UHC) targets.
Bayesian Mixture Model of Extended Redundancy Analysis
Authors: Kyung Minjung , Park Ju-Hyun , Choi Ji Yeh
Published: October 2021

Extended redundancy analysis (ERA), a generalized version of redundancy analysis (RA), has been proposed as a useful method for examining interrelationships among multiple sets of variables in multivariate linear regression models. As a limitation of the extant RA or ERA analyses, however, parameters are estimated by aggregating data across all observations even in a case where the study population could consist of several heterogeneous subpopulations. In this paper, we propose a Bayesian mixture extension of ERA to obtain both probabilistic classification of observations into a number of subpopulations and estimation of ERA models within each subpopulation. It specifically estimates the posterior probabilities of observations belonging to different subpopulations, subpopulation-specific residual covariance structures, component weights and regression coefficients in a unified manner. We conduct a simulation study to demonstrate the performance of the proposed method in terms of recovering parameters correctly. We also apply the approach to real data to demonstrate its empirical usefulness.
Pollution indices and biotests as useful tools for the evaluation of the degree of soil contamination by trace elements
Authors: Wieczorek Jerzy , Baran Agnieszka
Published: October 2021

Purpose

The aim of the study was the calculation of geochemical, ecological, and ecotoxicological indices for the assessment of risk resulting from the presence of trace metals in soil.

Methods

Around 320 soil points were determined for the tests by the regular square-grid method with a square side equal to 7.5 km. A total of 11 indices were used, including 6 geochemical indices, 1 index assessing potential ecological risk, and 4 indices assessing soil ecotoxicity.

Results

Two groups of elements were distinguished. The first one included Ni, Cr, and Cu. The calculated geochemical indices generally indicated their natural content and low degree of soil contamination with them and that the elements’ sources were connected with natural processes. The second group included Cd, Pb, and Zn. These elements occur in high concentrations in the studied area, which is influenced by both natural and anthropogenic factors. However, contamination with these elements is heterogeneous in the Małopolska and generally observed in its northwestern part. PCA showed that Cd and Pb had the greatest effect on the degree of soil contamination and pose the greatest potential threat to the soil environment. Heterocypris incongruens proved to be a more sensitive indicator of soil ecotoxicity compared to plant tests. The potential ecological risk index and biotests indicated that most of the soil samples had low potential ecological risk and low ecotoxicity.

Conclusion

The key to the effective assessment of soil contamination with trace elements is the combined use of geochemical, ecological, and ecotoxicological indices, which allows comprehensive monitoring of soil quality.