bluuebunny/crossref_metadata_2025 huggingface dataset:
Visible‐Light‐Induced Photochemical Hydrogen Evolution and Degradation of Crystal Violet Dye by Interwoven Layered MoS2/Wurtzite ZnS Heterostructure Photocatalyst
Authors: Rao Akshatha Sathyanarayana , Sreenivasa Swamy , Parashuram Lakshminarayana , Raghu Madihalli S. , Yogesh Kumar K. , Madhu Chakrapani Rao Tadimety
Published: June 2020

The photocatalytic properties of a material predominantly depend upon the material fabrication. In the last few years, sulfide based nanomaterials were used for their extraordinary efficiency due to their structural and morphological features. Present work is focused on the preparation of bimetallic layered molybdenum‐wurtzite zinc sulfide heterostructure by facile hydrothermal method. The prepared MoS2−ZnS was characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer‐Emmett‐Teller (BET) surface analysis and X‐ray photoelectron spectroscopy (XPS). MoS2−ZnS showed high photocatalytic hydrogen evolution reaction (HER) and dye degradation compared to pure ZnS and MoS2. The synergistic effect of layered MoS2 and wurtzite ZnS would have amplified the photocatalytic HER activity and degradation of crystal violet dye under visible light irradiation; the electron‐hole recombination was significantly reduced due to the heterostructured arrangement of MoS2‐ wurtzite ZnS
A user‐centered behavioral software development model
Authors: Güncan Damla , Onay Durdu Pınar
Published: June 2020

The concept of usability, which affects the quality and cost of the software projects, has become essential in recent years. There is a need to integrate usability testing activities and techniques into the development processes; however, integration is difficult. Therefore, this study proposes user‐centered behavioral (UCB) software development model, which aims to bridge the gap between human–computer interaction (HCI) and software engineering (SE) disciplines. A triangulation methodology of mixed methods is used to understand the current situation in software development companies in terms of usability and user‐centered software development by survey and interviews. Their results are then used to inform the development of the proposed model. The UCB software development model proposes a process in which several tools and techniques from SE and HCI are integrated to facilitate the production of highly usable software. In essence, the model proposes an iterative process that combines behavior‐driven development (BDD)—an agile approach that enables a better understanding and analysis of the requirements—with the style guides, usability tests, heuristic evaluation, and Wizard of Oz techniques of HCI. The model was evaluated in a pilot project and then is improved based on feedback gathered. Participants' feedback supported the effectiveness of the proposed model.
Multiphysics Model of the Hearth Lining State
Authors: Kaymak Yalçın , Bartusch Hauke , Hauck Thorsten , Mernitz Jörg , Rausch Harald , Lin Rongshan
Published: June 2020

The campaign life of the blast furnace is governed by the erosion of the hearth lining. Therefore, it is essential to keep track of the residual lining thickness not only for the better planning of the relining but also for the operational safety to avoid dangerous hearth breakthrough incidences. Modern blast furnaces are equipped with many thermocouples in the hearth refractory to monitor the temperature level. Higher temperatures indicate a lower residual wall thickness. However, the measured temperatures are also influenced by many other effects such as thermocouple defects, brittle layers in the refractory, hearth cooling system, production rate, temperature, and flow state of hot metal. Existing models lack comprehensive checks of the data plausibility or of possible effects unrelated to wear. The new multiphysics approach provides a flexible platform to include these influences as well as other physical aspects that are important for operational hearth monitoring. For instance, thermal stresses and the deformation of the hearth lining and steel shell can be analyzed. This enables the integration of strain‐gauge measurements into the model which were recently suggested for the monitoring of liquid levels. The numerical computations and visualization are performed using COMSOL Server with MATLAB for the 3D hearth geometry. This enables the use of a standard web browser to visualize the results interactively on any device connected to the internal network without any local software installation. The developed multiphysics model is calibrated and validated by comparing the estimated wear profile with the measured residual wall thickness during the blast furnace relinings in 2016 at Eisenhüttenstadt and Dillingen. Two instances of the multiphysics model are online and in use for monitoring the hearth lining state at these plants.
Tamoxifen and its metabolites induce mitochondrial membrane depolarization and caspase‐3 activation in equine neutrophils
Authors: Albornoz Alejandro , Morales Natalia , Uberti Benjamin , Henriquez Claudio , Burgos Rafael A. , Alarcon Pablo , Moran Gabriel
Published: June 2020

Neutrophils participate in innate immunity as the first line of host defence against microorganisms. However, persistent neutrophil activity and delayed apoptosis can be harmful to surrounding tissues; this problem occurs in diverse inflammatory diseases, including asthma‐affected horses. Previous studies in horses with acute lung inflammation indicated that treatment with tamoxifen (TX), a selective oestrogen receptor modulator, produces a significant decrease in bronchoalveolar lavage fluid (BALF) neutrophil content. The aim of this study was to investigate the effect of tamoxifen and its metabolites (N‐desmethyltamoxifen and endoxifen) on the mitochondrial membrane potential assay by flow cytometry, and the activation of effector caspase‐3 through immunoblotting, in peripheral blood neutrophils obtained from healthy horses (n = 5). Results show that tamoxifen, N‐desmethyltamoxifen and endoxifen depolarize the mitochondrial membrane and activate caspase‐3 in healthy equine neutrophils in vitro. These findings suggest that tamoxifen and its metabolites may activate the intrinsic apoptotic pathway in equine neutrophils. However, more studies are necessary to further explore the signalling pathways of these drugs in the induction of apoptosis.
Use of grape racemes from Grillo cultivar to increase the acidity level of sparkling base wines produced with different Saccharomyces cerevisiae strains
Authors: Alfonzo Antonio , Francesca Nicola , Mercurio Vincenzo , Prestianni Rosario , Settanni Luca , Spanò Giacomo , Naselli Vincenzo , Moschetti Giancarlo
Published: June 2020

The most important oenological characteristics of high‐quality sparkling wines are aromatic aspect, taste persistence, perlage, high levels of acidity and low pH. Due to hot climate and reduced rainfall that characterize Sicily region, white grape varieties such as Grillo cultivar cultivated in this area are characterized by very low concentrations of malic and tartaric acids. Grillo cultivar is characterized by an intense production of raceme grapes with low pH and high content of tartaric and malic acids. These fruits possess the chemical properties useful to increase the amounts of acids in the final wines. With this in mind, the present research was carried out to test the ability of four Saccharomyces cerevisiae strains (CS182, GR1, MSE13 and MSE41) to ferment a raceme must with a pH of 2.9 at two concentrations (14° and 16° Babo degree) of total sugars. The inoculation of the strains was performed after a preadaptation at pH 2.5. The chemical parameters and kinetics of the fermentations were monitored. The experimental sparkling base wines were characterized by a very high total acidity with 16–17 g/L of tartaric acid and 9–10 g/L of malic acids. On the other hand, ethanol was detected at low values in the range 9–10% (v/v). The base wine obtained with GR1differed in their high acidity values, whereas trials inoculated with CS182 showed more intense odors and exotic fruit. Experimental wines produced in this study represent an innovative strategy for “blending wines” to produce sparkling wines in dry Mediterranean climate.
Neutrino and Z′ phenomenology in an anomaly-free U(1) extension: role of higher-dimensional operators
Authors: Choudhury Debajyoti , Deka Kuldeep , Mandal Tanumoy , Sadhukhan Soumya
Published: June 2020

Abstract

We consider an anomaly-free U(1) extension of the Standard Model with three right-handed neutrinos (RHNs) and two complex scalars, wherein the charge assignments preclude all tree-level mass terms for the neutrinos. Considering this setup, in turn, to be only a low-energy effective theory, we introduce higher-dimensional terms a la Froggatt-Nielsen to naturally generate tiny neutrino masses. One of the RHNs turns out to be very light, thereby constituting the main decay mode for the Z′ and hence relaxing the LHC dilepton resonance search constraints. The lightest RHN has a lifetime comparable to or bigger than the age of the Universe, and, hence, could account for a non-negligible fraction of the dark matter.
Conformal symmetry and composite operators in the O(N )3 tensor field theory
Authors: Benedetti Dario , Gurau Razvan , Suzuki Kenta
Published: June 2020

Abstract

We continue the study of the bosonic O(N )3 model with quartic interactions and long-range propagator. The symmetry group allows for three distinct invariant 𝜙
4 composite operators, known as tetrahedron, pillow and double-trace. As shown in [1, 2], the tetrahedron operator is exactly marginal in the large-N limit and for a purely imaginary tetrahedron coupling a line of real infrared fixed points (parametrized by the absolute value of the tetrahedron coupling) is found for the other two couplings. These fixed points have real critical exponents and a real spectrum of bilinear operators, satisfying unitarity constraints. This raises the question whether at large-N the model is unitary, despite the tetrahedron coupling being imaginary.

In this paper, we first rederive the above results by a different regularization and renormalization scheme. We then discuss the operator mixing for composite operators and we give a perturbative proof of conformal invariance of the model at the infrared fixed points by adapting a similar proof from the long-range Ising model. At last, we identify the scaling operators at the fixed point and compute the two- and three-point functions of 𝜙
4 and 𝜙
2 composite operators. The correlations have the expected conformal behavior and the OPE coefficients are all real, reinforcing the claim that the large-N CFT is unitary.
Using neural networks for efficient evaluation of high multiplicity scattering amplitudes
Authors: Badger Simon , Bullock Joseph
Published: June 2020

Abstract

Precision theoretical predictions for high multiplicity scattering rely on the evaluation of increasingly complicated scattering amplitudes which come with an extremely high CPU cost. For state-of-the-art processes this can cause technical bottlenecks in the production of fully differential distributions. In this article we explore the possibility of using neural networks to approximate multi-variable scattering amplitudes and provide efficient inputs for Monte Carlo integration. We focus on QCD corrections to e
+
e

−

→ jets up to one-loop and up to five jets. We demonstrate reliable interpolation when a series of networks are trained to amplitudes that have been divided into sectors defined by their infrared singularity structure. Complete simulations for one-loop distributions show speed improvements of at least an order of magnitude over a standard approach.
A Note on Integrability of the Norm of a Perturbed Semigroup
Authors: Bobrowski Adam
Published: June 2020

Recently, Michael Gil’ has provided a condition for integrability of norms of semigroups generated by operators of the form $$A+B$$

A
+
B

where B is bounded, in terms of the norm of the commutator of A and B. We show that his argument, when slightly refined, leads to a bit more general result than the one presented in his paper. We also argue, by examining an example, that the size of the commutator may not be a good indicator of whether the perturbed semigroup has integrable norm or not.
Theoretical and Practical Approaches to the Denotational Semantics for MDESL based on UTP
Authors: Sheng Feng , Zhu Huibiao , He Jifeng , Yang Zongyuan , Bowen Jonathan P.
Published: June 2020

The hardware description language Verilog has been standardized and widely used in industry. Multithreaded Discrete Event Simulation Language (MDESL) is a Verilog-like language and it contains a rich variety of interesting features such as the event-driven computation and shared-variable concurrency as well as the realtime feature. In this paper, we present the denotational semantics for MDESL based on UTP. First a discrete time semantic model is proposed to describe the observation-oriented semantics for MDESL. The observations record the change of variables of atomic actions over time. Then the healthy formulae are defined to denote all different behaviors of programs and the semantics of programs is expressed in terms of healthy formulae. In addition, we demonstrate some interesting properties about the MDESL programs expressing as algebraic laws and their proofs are supported by our formalized denotational semantics. Our theoretical approach is complemented by a practical one, we use the theorem proof assistant Coq to formalize the UTP-based semantics for MDESL. The correctness of the algebraic laws is also verified via the mechanical approach in Coq. Our work provides a novel way to verify the correctness of UTP-based semantics forMDESL both in a theoretical approach and in a practical approach. It is also a new attempt for the application of Coq in the mechanized semantics.
New firm formation in the wake of mergers and acquisitions: An exploration of push and pull factors
Authors: Lougui Monia , Broström Anders
Published: June 2020

This study investigates the relationship between mergers and acquisitions (M&A) and entrepreneurial spawning in labour-intensive service sectors. We discuss two sets of theoretical mechanisms. First, M&As may push employees into entrepreneurship by lowering the average barriers of leaving the current employment (i.e. being associated with general deterioration of working conditions). Second, M&A activities may generate new entrepreneurial opportunities, which are first and foremost accessible by employees directly affected by M&As. Results on entrepreneurial spawning in 3,198 Swedish firms during the time period 2000–2009 confirm that the number of firms spawned from a specific incumbent increases following an M&A. Push-oriented factors are found to contribute to this effect, but a dominating part of the total effect remains in the presence of proxies for push-effects. This suggests that pull-oriented explanations of opportunity creation in the wake of M&As constitute an important avenue for further research on the antecedents of new firm formation.
Network formation with myopic and farsighted players
Authors: Luo Chenghong , Mauleon Ana , Vannetelbosch Vincent
Published: June 2020

We adopt the notion of myopic-farsighted stable set to study the stability of networks when myopic and farsighted individuals decide with whom they want to form a link, according to some utility function that weighs the costs and benefits of each connection. A myopic-farsighted stable set is the set of networks satisfying internal and external stability with respect to the notion of myopic-farsighted improving path. We first provide conditions on the utility function that guarantee the existence of a myopic-farsighted stable set and we show that, when the population becomes mixed, the myopic-farsighted stable set refines the set of pairwise stable networks by eliminating some Pareto-dominated networks. In the end, when all players are farsighted, the myopic-farsighted stable set only consists of all strongly efficient networks. We next show that, in the case of a distance-based utility function, a tension between stability and efficiency is likely to arise when the population is homogeneous (either all myopic or all farsighted). But, once the population is mixed, the tension vanishes if there are enough farsighted individuals. In the case of a degree-based utility function, myopic and farsighted individuals may end up segregated with myopic individuals being overconnected and farsighted ones getting the socially optimal payoff.
Analytical determination of the turn-to-turn capacitances for the prediction of voltage peaks in a PWM-fed motor winding
Authors: Stockbrügger Jan Ole , Ponick Bernd
Published: June 2020

The number of inverter-fed motors is increasing due to the good controllability of the motor and the meanwhile low acquisition costs. The steep voltage slopes of the converters lead to an uneven voltage distribution along the winding and thus to voltage peaks between the conductors, which stresses the insulation. The voltage distribution can be predicted by means of equivalent circuit diagrams, which take into account the capacitive coupling between the conductors. This paper presents a novel approach for an analytical determination of the turn-to-turn capacitances, which, in addition to the geometry and the placement of the conductors, considers the influence of materials with different permittivities.
The conductors are simulated by means of line charges discretely placed inside the electrodes and receptor points attached to the conductor surfaces. The capacitances are determined by means of the Maxwell capacitance matrix. The method is validated by means of FEM simulations for different geometries and materials.
Automated MRI-based volumetry of basal ganglia and thalamus at the chronic phase of cortical stroke
Authors: Baudat Cindy , Maréchal Bénédicte , Corredor-Jerez Ricardo , Kober Tobias , Meuli Reto , Hagmann Patric , Michel Patrik , Maeder Philippe , Dunet Vincent
Published: June 2020

Purpose

We aimed at assessing the potential of automated MR morphometry to assess individual basal ganglia and thalamus volumetric changes at the chronic phase after cortical stroke.

Methods

Ninety-six patients (mean age: 65 ± 18 years, male 55) with cortical stroke at the chronic phase were retrospectively included. Patients were scanned at 1.5 T or 3 T using a T1-MPRAGE sequence. Resulting 3D images were processed with the MorphoBox prototype software to automatically segment basal ganglia and thalamus structures, and to obtain Z scores considering the confounding effects of age and sex. Stroke volume was estimated by manual delineation on T2-SE imaging. Z scores were compared between ipsi- and contralateral stroke side and according to the vascular territory. Potential relationship between Z scores and stroke volume was assessed using the Spearman correlation coefficient.

Results

Basal ganglia and thalamus volume Z scores were lower ipsilaterally to MCA territory stroke (p values < 0.034) while they were not different between ipsi- and contralateral stroke sides in non-MCA territory stroke (p values > 0.37). In MCA territory stroke, ipsilateral caudate nucleus (rho = − 0.34, p = 0.007), putamen (rho = − 0.50, p < 0.001), pallidum (rho = − 0.44, p < 0.001), and thalamus (rho = − 0.48, p < 0.001) volume Z scores negatively correlated with the cortical stroke volume. This relation was not influenced by cardiovascular risk factors or time since stroke.

Conclusion

Automated MR morphometry demonstrated atrophy of ipsilateral basal ganglia and thalamus at the chronic phase after cortical stroke in the MCA territory. The atrophy was related to stroke volume. These results confirm the potential role for automated MRI morphometry to assess remote changes after stroke.
Successful reconstruction of the posterior cruciate ligament: assessment of posterior cruciate ligament footprints using an objective coordinate system
Authors: Vielgut Ines , Weiglein Andreas , Biber Stefan M. , Dreu Manuel , Leithner Andreas , Hohenberger Goria , Sadoghi Patrick
Published: June 2020

Introduction

Anatomic cruciate ligament reconstruction is known to be correlated with better clinical results. The aim of the study was to provide a simple method to enable anatomic results in the setting of PCL reconstruction. We, therefore, assessed the tibial and femoral insertion site of the posterior cruciate ligament (PCL) by the use of an objective coordinate system in an anatomical study. We also sought to show reproducibility of these measurements using intra- and inter-observer coefficients.

Materials and methods

We studied 64 knees, previously preserved according to Thiel’s technique. After proper preparation of the articular surfaces of both the tibiae and femora, photographs were taken according to a standardized protocol. PCL footprints were measured by the use of a coordinate system twice by two examiners. We evaluated these measurements by use of the Cohen’s kappa inter- and intra-observer coefficient for two observers.

Results

Tibial and femoral measurements of PCL footprints were generated with highly comparable inter- (k = 0.970) and intra-observer (k = 0.992) coefficients and may, therefore, be considered as highly reproducible.

Conclusion

Our findings confirmed the reproducibility of defining PCL footprints using a coordinate system and may contribute to planning intraoperative graft-placement to ensure optimal conditions in the upcoming techniques for PCL reconstruction.
Experimental investigation of flow field and string cavitation inside a transparent real-size GDI nozzle
Authors: Mamaikin Dmitrii , Knorsch Tobias , Rogler Philipp , Wensing Michael
Published: June 2020

Gasoline direct injection engines are highly dependent on the spray performance and associated combustion quality. The spray formation depends on many factors, namely internal flow characteristics, injection conditions, ambient conditions and fuel properties. There have been many studies performed to obtain a better understanding of these factors in recent years. In contrast to the others, studies on the internal flow characteristics are often performed numerically, as such, relevant experimental data is still lacking. Experimental investigations of the internal flow, such as flow turbulence, velocity distribution and cavitation are especially challenging under realistic conditions. Therefore, these conditions are generally simplified to diminish the demand for specialized experimental equipment and facilitate the measurements. In this regard, experimental data under relevant conditions are of high interest in the spray community. This work is focused on the internal flow study of multi-hole transparent nozzles under transient conditions at 1:1 geometrical scale. Injection pressure up to 100 bar is applied. The formation and development of string cavitation inside the nozzle hole are observed and presented in detail. For that, a novel ultra high-speed imaging technique at 5 MHz is applied. This technique in combination with the micro particle image velocimetry method, is then able to help to produce the velocity distribution of the internal flow. The velocity data is used further to reconstruct the pressure inside the nozzle by applying the Reynolds-averaged Navier–Stokes equations. Thus, the unique experimental data for the pressure distribution of the liquid fuel is obtained.

Graphic abstract
Topological atlas of the hypothalamus in adult rhesus monkey
Authors: Wells Anne Marie , García-Cabezas Miguel Ángel , Barbas Helen
Published: June 2020

The prosomeric model explains the embryological development of the central nervous system (CNS) shared by all vertebrates as a Bauplan. As a primary event, the early neural plate is patterned by intersecting longitudinal plates and transverse segments, forming a mosaic of progenitor units. The hypothalamus is specified by three prosomeres (hp1, hp2, and the acroterminal domain) of the secondary prosencephalon with corresponding alar and basal plate parts, which develop apart from the diencephalon. Mounting evidence suggests that progenitor units within alar and basal plate parts of hp1 and hp2 give rise to distinct hypothalamic nuclei, which preserve their relative invariant positioning (topology) in the adult brain. Nonetheless, the principles of the prosomeric model have not been applied so far to the hypothalamus of adult primates. We parcellated hypothalamic nuclei in adult rhesus monkeys (Macaca mulatta) using various stains to view architectonic boundaries. We then analyzed the topological relations of hypothalamic nuclei and adjacent hypothalamic landmarks with homology across rodent and primate species to trace the origin of adult hypothalamic nuclei to the alar or basal plate components of hp1 and hp2. We generated a novel atlas of the hypothalamus of the adult rhesus monkey with developmental ontologies for each hypothalamic nucleus. The result is a systematic reinterpretation of the adult hypothalamus whose prosomeric ontology can be used to study relationships between the hypothalamus and other regions of the CNS. Further, our atlas may serve as a tool to predict causal patterns in physiological and pathological pathways involving the hypothalamus.
Regulation of TrkB cell surface expression—a mechanism for modulation of neuronal responsiveness to brain-derived neurotrophic factor
Authors: Andreska Thomas , Lüningschrör Patrick , Sendtner Michael
Published: June 2020

Neurotrophin signaling via receptor tyrosine kinases is essential for the development and function of the nervous system in vertebrates. TrkB activation and signaling show substantial differences to other receptor tyrosine kinases of the Trk family that mediate the responses to nerve growth factor and neurotrophin-3. Growing evidence suggests that TrkB cell surface expression is highly regulated and determines the sensitivity of neurons to brain-derived neurotrophic factor (BDNF). This translocation of TrkB depends on co-factors and modulators of cAMP levels, N-glycosylation, and receptor transactivation. This process can occur in very short time periods and the resulting rapid modulation of target cell sensitivity to BDNF could represent a mechanism for fine-tuning of synaptic plasticity and communication in complex neuronal networks. This review focuses on those modulatory mechanisms in neurons that regulate responsiveness to BDNF via control of TrkB surface expression.
Variation in Vegetation and Ecosystem Carbon Stock Due to the Conversion of Disturbed Forest to Oil Palm Plantation in Peruvian Amazonia
Authors: Málaga Natalia , Hergoualc’h Kristell , Kapp Gerald , Martius Christopher
Published: June 2020

Peruvian national and regional plans promoting oil palm have prompted a rapid expansion of the crop in the Amazonian region. This expansion has taken place primarily at the expense of forest, both undisturbed and disturbed. Assessments of carbon emissions from forest-to-oil palm conversion have essentially been confined to Southeast Asia, and research on Peruvian Amazonian forests has mainly targeted undisturbed sites. This study characterizes the vegetation structure and composition of disturbed forests and smallholder oil palm plantations and evaluates the change in ecosystem (that is, phytomass and soil) carbon stocks associated with forest-to-oil palm conversion. Inventories were conducted in four degraded forest sites neighboring six oil palm plantation sites in Ucayali. Time-averaged carbon stocks over the 30-year oil palm rotation were computed from models developed upon the sampled chronosequence (1 to 28 years old). Disturbed forests harbored species typical of primary forests, pioneer species and gaps opportunistic species. Their tree basal area (18.7 ± 1.4 m2 ha−1) and above-ground C stock (71.3 ± 4.2 Mg C ha−1) were, respectively, 50 and 60% of the values of undisturbed forests from the literature. The growth curve for oil palm above-ground biomass was consistently below models developed for plantations in Indonesia. Thirty-year time-averaged ecosystem C stock (Mg C ha−1) in oil palm plantations (78.2 ± 2.0) represented 55% of the stock in disturbed forest (140.9 ± 5.8), resulting in a 62.7 ± 6.1 loss from such conversion. These results reinforce recommendations to redirect oil palm expansion toward low-carbon degraded lands, sparing disturbed and undisturbed forests.
Effects of Impactor Geometry on the Low-Velocity Impact Behaviour of Fibre-Reinforced Composites: An Experimental and Theoretical Investigation
Authors: Liu Haibao , Liu Jun , Ding Yuzhe , Zhou Jin , Kong Xiangshao , Blackman Bamber R.K. , Kinloch Anthony J. , Falzon Brian G. , Dear John P.
Published: June 2020

Carbon-fibre/epoxy-matrix composites used in aerospace and vehicle applications are often susceptible to critical loading conditions and one example is impact loading. The present paper describes a detailed experimental and numerical investigation on the relatively low-velocity (i.e. <10 m/s) impact behaviour of such composite laminates. In particular, the effects of the geometry of the impactor have been studied and two types of impactor were investigated: (a) a steel impactor with a hemispherical head and (b) a flat-ended steel impactor. They were employed to strike the composite specimens with an impact energy level of 15 J. After the impact experiments, all the composite laminates were inspected using ultrasonic C-scan tests to assess the damage that was induced by the two different types of impactor. A three-dimensional finite-element (FE) model, incorporating a newly developed elastic-plastic damage model which was implemented as a VUMAT subroutine, was employed to simulate the impact event and to investigate the effects of the geometry of the impactor. The numerical predictions, including those for the loading response and the damage maps, gave good agreement with the experimental results.
From demonstrations to task-space specifications. Using causal analysis to extract rule parameterization from demonstrations
Authors: Angelov Daniel , Hristov Yordan , Ramamoorthy Subramanian
Published: June 2020

Learning models of user behaviour is an important problem that is broadly applicable across many application domains requiring human–robot interaction. In this work, we show that it is possible to learn generative models for distinct user behavioural types, extracted from human demonstrations, by enforcing clustering of preferred task solutions within the latent space. We use these models to differentiate between user types and to find cases with overlapping solutions. Moreover, we can alter an initially guessed solution to satisfy the preferences that constitute a particular user type by backpropagating through the learned differentiable models. An advantage of structuring generative models in this way is that we can extract causal relationships between symbols that might form part of the user’s specification of the task, as manifested in the demonstrations. We further parameterize these specifications through constraint optimization in order to find a safety envelope under which motion planning can be performed. We show that the proposed method is capable of correctly distinguishing between three user types, who differ in degrees of cautiousness in their motion, while performing the task of moving objects with a kinesthetically driven robot in a tabletop environment. Our method successfully identifies the correct type, within the specified time, in 99% [97.8–99.8] of the cases, which outperforms an IRL baseline. We also show that our proposed method correctly changes a default trajectory to one satisfying a particular user specification even with unseen objects. The resulting trajectory is shown to be directly implementable on a PR2 humanoid robot completing the same task.
Influence of Concentration on Sedimentation of a Dense Suspension in a Viscous Fluid
Authors: Shajahan Tariq , Breugem Wim-Paul
Published: June 2020

Macroscopic properties of sedimenting suspensions have been studied extensively and can be characterized using the Galileo number (Ga), solid-to-fluid density ratio ($$\pi _p$$

π
p

) and mean solid volume concentration ($${\bar{\phi }}$$

ϕ

¯

). However, the particle–particle and particle–fluid interactions that dictate these macroscopic trends have been challenging to study. We examine the effect of concentration on the structure and dynamics of sedimenting suspensions by performing direct numerical simulation based on an Immersed Boundary Method of monodisperse sedimenting suspensions of spherical particles at fixed $$Ga=144$$

G
a
=
144

, $$\pi _p=1.5$$

π
p

=
1.5

, and concentrations ranging from $${\bar{\phi }}=0.5$$

ϕ

¯

=
0.5

to $${\bar{\phi }}=30\%$$

ϕ

¯

=
30
%

. The corresponding particle terminal Reynolds number for a single settling particle is $$Re_T = 186$$

R

e
T

=
186

. Our simulations reproduce the macroscopic trends observed in experiments and are in good agreement with semi-empirical correlations in literature. From our studies, we observe, first, a change in trend in the mean settling velocities, the dispersive time scales and the structural arrangement of particles in the sedimenting suspension at different concentrations, indicating a gradual transition from a dilute regime ($${\bar{\phi }} \lesssim 2\%$$

ϕ

¯

≲
2
%

) to a dense regime ($${\bar{\phi }} \gtrsim 10\%$$

ϕ

¯

≳
10
%

). Second, we observe the vertical propagation of kinematic waves as fluctuations in the local horizontally-averaged concentration of the sedimenting suspension in the dense regime.
Loan to Value Caps and Government-Backed Mortgage Insurance: Loan-Level Evidence from Dutch Residential Mortgages
Authors: de Haan Leo , Mastrogiacomo Mauro
Published: June 2020

Using loan level data on mortgage loans originated by Dutch banks during 1996 to 2015, we analyse the determinants of the incidence of non-performance. We find that both the originating loan-to-value ratio (OLTV) and the debt-service-to-income ratio are significantly positively associated with the probability of non-performance. The results suggest that mortgages with government-loan-guarantees perform better. Moreover, several mortgage loan and borrower characteristics, such as the (interest-only) loan type and the underwater status of the borrower, increase credit risk. Our model predictions suggest a novel policy implication: in order to avoid acceleration of non-performance probabilities, the OLTV-limit should be set to about 70–80% for uninsured mortgages, and to about 90% for those with mortgage insurance.
Sticky and slippery destinations for academic mobility: the case of Singapore
Authors: Chou Meng-Hsuan
Published: June 2020

This article seeks to contribute to the existing scholarship on academic mobility in two ways. First, it brings together insights on academic mobility (aspirations, desperations) and higher education internationalisation to show how we may analytically organise these insights to shed light on the shifting global higher education landscape from an experiential perspective. Second, it provides fresh data on the ‘lived experiences’ of mobile faculty members based in an attractive academic destination outside of the traditional knowledge cores—Singapore. As a city state without any natural resources, Singapore has successfully transformed its economy into one that is knowledge-intensive based on combined efforts from grooming locals to recruiting foreign talents to shore up skilled manpower needs. These efforts are reflected in the university sector where Singapore’s comprehensive universities have consistently ranked high across many global university rankings. Using survey and interview data, I show how the mobility and immobility experiences of faculty based in Singapore have contributed to its making as a ‘sticky’ and ‘slippery’ academic destination. My contributions point to the need to integrate individual-level factors underpinning academic mobility decisions with systemic developments to better understand the changing global higher education landscape today.
Right ventricular phenotype, function, and failure: a journey from evolution to clinics
Authors: Taverne Yannick J. H. J. , Sadeghi Amir , Bartelds Beatrijs , Bogers Ad J. J. C. , Merkus Daphne
Published: June 2020

The right ventricle has long been perceived as the “low pressure bystander” of the left ventricle. Although the structure consists of, at first glance, the same cardiomyocytes as the left ventricle, it is in fact derived from a different set of precursor cells and has a complex three-dimensional anatomy and a very distinct contraction pattern. Mechanisms of right ventricular failure, its detection and follow-up, and more specific different responses to pressure versus volume overload are still incompletely understood. In order to fully comprehend right ventricular form and function, evolutionary biological entities that have led to the specifics of right ventricular physiology and morphology need to be addressed. Processes responsible for cardiac formation are based on very ancient cardiac lineages and within the first few weeks of fetal life, the human heart seems to repeat cardiac evolution. Furthermore, it appears that most cardiogenic signal pathways (if not all) act in combination with tissue-specific transcriptional cofactors to exert inductive responses reflecting an important expansion of ancestral regulatory genes throughout evolution and eventually cardiac complexity. Such molecular entities result in specific biomechanics of the RV that differs from that of the left ventricle. It is clear that sole descriptions of right ventricular contraction patterns (and LV contraction patterns for that matter) are futile and need to be addressed into a bigger multilayer three-dimensional picture. Therefore, we aim to present a complete picture from evolution, formation, and clinical presentation of right ventricular (mal)adaptation and failure on a molecular, cellular, biomechanical, and (patho)anatomical basis.
Illness Perceptions in Pediatric Spinal Muscular Atrophy: Agreement between Children and their Parents, and its Association with Quality of Life
Authors: Fischer M. J. , Ketelaar M. , van der Veere P. J. , Verhoef M. , Wadman R. I. , Visser-Meily J. M. A. , van der Pol W. L. , Schröder C. D.
Published: June 2020

In adults with neuromuscular conditions illness perceptions show a strong relation with QoL. For young patients, illness perceptions are shaped through interaction with their parents. A shared perception between child and parent may benefit the child’s QoL. This study investigated agreement in illness perceptions of children with Spinal Muscular Atrophy (SMA) and their parents, the association between the child’s illness perceptions and QoL, and the relation between child-parent agreement in illness perceptions and the child’s QoL. Twenty-six children and their parents completed the Brief Illness Perception Questionnaire (BIPQ) and the Kidscreen-52 QoL questionnaire (children only). Correspondence between children’s and parents’ illness perceptions was low. Generally, parents held more negative illness perceptions about SMA. Whereas children’s illness perceptions were related to QoL, no clear association was found between agreement in illness perceptions and children’s QoL. Therefore, to understand and improve QoL, healthcare professionals should discuss children’s own illness perceptions during consultations.
Expressive voting, graded interests and participation
Authors: Klein Dominik
Published: June 2020

I assume that voters mark ballots exclusively to express their true preferences among parties, leaving aside any considerations about an election’s possible outcome. The paper then analyzes the resulting voting behavior.
In particular, it studies how effective different voting systems such as plurality rule, approval voting, and range voting are in fostering high turnout rates of such expressive voters.
Complexity and potentials of clinical feedback in mental health: an in-depth study of patient processes
Authors: Solstad Stig Magne , Kleiven Gøril Solberg , Moltu Christian
Published: June 2020

Purpose

Routine outcome monitoring (ROM) and clinical feedback systems (CFS) are becoming increasingly prevalent in mental health services. Their overall efficacy is unclear, but quantitative evidence suggests they can be useful tools for preventing treatment failure and enhancing therapeutic outcomes, especially for patients who are not progressing in therapy. The body of qualitative material, however, is smaller and less refined. We need to know more about how ROM/CFS is used in psychotherapy, and why it is helpful for some patients, but not others.

Methods

We recorded therapy sessions of 12 patients who were using a CFS as part of their therapies at an outpatient clinic in Norway. We then conducted video-assisted interviews and follow-up interviews with patients. Data were analyzed with systematic text condensation.

Results

Analysis revealed three themes: (1) triggering reflections, emotions, and self-awareness, (2) Ambivalent and ambiguous self-presentation, and (3) potential for feeling understood and talking about what matters.

Conclusion

Answering questions in a CFS is an interpretative and intentional process of self-presentation and the results from ROM/CFS must be interpreted and explored in conversation to be clinically useful. When they are, they have potential for enhancing the therapeutic process by stimulating self-awareness, reflexivity, and allowing access to new therapeutic topics. Further research should explore this how-to aspect of ROM/CFS with different CFS and different types of patients. Integrating clinical feedback in therapeutic practice can be conceptualized as a clinical skill, which should be a part of training programs for therapists.
Benchmarking stateless NAT64 implementations with a standard tester
Authors: Lencse G.
Published: June 2020

RFC 5180, the IPv6 update of RFC 2544, declared IPv6 transition technologies out of its scope. RFC 8219 defined a benchmarking methodology for IPv6 transition technologies including stateless NAT64 (more properly called SIIT) in the category of single translation solutions. Whereas several research papers have dealt with the performance of different stateful NAT64 implementations, none of them used RFC 8219 compliant measurements or addressed stateless NAT64 implementations. In this paper, we show, how stateless NAT64 implementations can be benchmarked carrying out the most important tests recommended by RFC 8219 without a special purpose NAT64 Tester, using simply an RFC 2544/RFC 5180 compliant legacy Tester. We carry out benchmarking measurements to examine the performance of three free software NAT64 implementations, namely: Jool, TAYGA and map646. All the details of our measurements are disclosed and their results are presented in the paper.
What is it going to cost? Empirical evidence from a systematic literature review of audit fee determinants
Authors: Widmann Markus , Follert Florian , Wolz Matthias
Published: June 2020

The audit market is subject to ongoing regulation to ensure or improve the quality of audit services. For this reason, international research on the audit market is highly popular. As part of this discussion, pricing is considered one of the most relevant aspects of audits. However, a remarkable heterogeneity of the control variables used in empirical studies can be observed. Prior meta-analyses on audit fees already summarized and categorized them for audit fee studies covering financial periods until fiscal year 2007. We contribute to the international literature with an up-to date and systematic review approach on audit fee studies published in international relevant scientific journals (JQ3 A + , A, B). In addition to prior reviews and meta-analyses, we finally suggest a standard model for the most important fee drivers that can be used for future audit fee studies. Our unique approach is based on an EBSCO keyword search with a sample of 385 papers published in international relevant scientific journals (JQ3 A + , A, B) and is using a scoring model to assess significance of audit fee control variables. On the one hand, we enrich the literature by a new state of the art paper on pricing within audit firms. On the other hand, we contribute to the international literature on audit markets from a theoretical point of view by deriving a new testable model of audit fee determinants. Therefore, our empirical results provide several fundamental insights that can be used for further empirical and theoretical research on the pricing of audit services. Thus, the results are meaningful not only for researchers within the field of auditing but also for experts in management, pricing or European legislature.
Characterizing the heterogeneous correlations between the landscape patterns and seasonal variations of total nitrogen and total phosphorus in a peri-urban watershed
Authors: Li Chongwei , Zhang Haiyan , Hao Yonghong , Zhang Ming
Published: June 2020

Landscape patterns in a watershed potentially have significant influence on the occurrence, migration, and transformation of pollutants, such as nitrogen (N) and phosphorus (P) in rivers. Human activities can accelerate the pollution and complicate the problem especially in a peri-urban watershed with different types of land use. To characterize the heterogeneous correlations between landscape patterns and seasonal variations of N and P in a peri-urban watershed located upstream of Tianjin metropolis, China, observations of total nitrogen (TN) and total phosphorus (TP) at 33 locations were performed in the wet and dry seasons from 2013 to 2016. The data from individual locations were averaged for the wet and dry seasons and analyzed with geographical detector to identify influential landscape indices on seasonal water quality variations. The geographically weighted regression method, capable of analyzing heterogeneous correlations, was used to evaluate the integrated effects from different landscape indices. The results demonstrated that the location-weighted landscape contrast index (LWLI), the ratio of urban areas, and the ratio of forest areas were major influential indicators that affected TN and TP in river water. These indices also had integrated effects on variations of TN and TP together with other indices such as Shannon diversity index, landscape shape index, largest patch index, and contagion index. The integrated effects were different in the wet and dry seasons because of different effects of flushing and dilution by rainwater and the heterogeneity in landscape patterns. The LWLI had a positive relationship to water quality in the areas with high ratio of urban areas, indicating that domestic wastewater can be a major source of N and P pollution. The approaches and findings of this study may provide a reference for characterizing the major factors and integrated effects that control nonpoint source pollution in a watershed.
Distance to landfill and human activities affects the debris incorporation into the white stork nests in urbanized landscape in central Spain
Authors: Jagiello Zuzanna , López-García Alejandro , Aguirre José I. , Dylewski Łukasz
Published: June 2020

Human’s activities dominates many aspects of the Earth’s environment; thus animals are forced to adapt and respond to the resulting changes in habitat structure and functioning due to anthropogenic pressure. Along with the growing human population and the associated amount of waste produced, the amount of different type of physical contamination component in environment is increasing. Incorporation of debris in nests may be a mounting avian response to anthropogenic pollution. In this research, we quantified the constituent pieces and total mass of human-derived materials incorporated in white stork nests. The study was conducted on four locations in central Spain where white storks nest along a urbanization gradient. In total, we examined 49 nests. This study demonstrates that the incorporation of debris by white storks into their nests is related to human activity, measured by the Human Footprint Index (HFI). Moreover, the distance between these nests and landfills predicts the occurrence of debris incorporated into nests. Our study shows that birds nest building behaviour is impacted by human activities and pollution in environment.