bluuebunny/crossref_metadata_2025 huggingface dataset:
Emergency hospitalizations for adverse drug events in China: Clinical pharmacists' approach to assessment and categorization
Authors: Zhang Yuyi , Jin Li , Zhang Xiaogang , Bai Rong , Chen Danxia , Ma Yabin , Zhai Xiaobo
Published: February 2021

Purpose

Little is known about emergency hospitalizations owing to adverse drug events (ADEs) in Chinese populations. The aim of this study was to identify the types and characteristics of ADEs as well as estimate the length of hospital stay and ADE‐related costs in a hospital emergency setting in China.

Methods

This prospective study was conducted in the emergency department of our hospital from April 1, 2017 to December 31, 2019. ADEs of patients admitted to the emergency department were collected by a clinical pharmacist during daily pharmacy rounds.

Results

Of 4020 cases admitted to the emergency department, 198 emergency ADE‐related hospitalizations (4.93%) were noted, which were classified into certain (n = 0, 0%), probable (n = 122, 61.6%), and possible (n = 76, 38.4%). The ADE was serious in 93.9% of the 198 cases. Ten cases were fatal, and two cases were life‐threatening. More than 80% of the emergency ADE‐related hospitalization cases were of patients over 60 years. The pharmacological agents implicated in the hospitalizations were oral antiplatelet agents (20.7%), oral hypoglycemic agents (16.7%), insulin (11.1%), and antihypertensive agents (9.1%). The average length of ADE‐related hospital stay was 10 (7.0–14.0) days. ADE‐related costs ranged from $1684.68 to $4531.35 for each hospitalization. The length of ADE‐related hospital stay and associated costs were statistically significant. Most ADEs (n = 146, 73.7%) were preventable.

Conclusions

Most emergency ADE‐related hospitalizations in older adults resulted from lack of medication monitoring or inappropriate medication. Improved management of medicines by clinical pharmacists has the potential to reduce ADE‐related hospitalizations in older adults in China.
The effect of annealing on tensile properties of injection molded biopolyesters based on 2,5‐furandicarboxylic acid
Authors: Zubkiewicz Agata , Paszkiewicz Sandra , Szymczyk Anna
Published: February 2021

In this study, we investigate four polyesters based on 2,5‐furandicarboxylic acid and different diols including 1,2‐ethylene glycol, 1,3‐propylene glycol, 1,4‐butylene glycol, and 1,6‐hexylene glycol. Poly(ethylene 2,5‐furanoate), poly(propylene 2,5‐furanoate), poly(butylene 2,5‐furanoate), and poly(hexylene 2,5‐furanoate) (PHF) were characterized by thermogravimetric analysis, X‐ray diffraction, differential scanning calorimeter, and tensile tests. In addition, the influence of annealing polyesters on their thermal and mechanical properties was investigated. For these reasons samples for the tensile test were prepared by injection molding. The tensile properties of injection molded samples were compared with samples that were additionally annealed after injection molding. All studied polyesters after heating treatment showed multiple melting behavior. The increase in the degree of crystallinity significantly influenced also the mechanical properties of the samples. It was found that the length of the aliphatic chain and degree of crystallinity plays a major role in the final properties of furan‐based polyesters.
Evidence of Carrier Localization in AlGaN/GaN‐Based UV Multiple Quantum Wells with Opposite Polarity Domains Provided by Nanoscale Imaging
Authors: Cui Mei , Guo Wei , Xu Houqiang , Jiang Jie'an , Chen Li , Mitra Somak , Roqan Iman S. , Jiang Haibo , Li Xiaohang , Ye Jichun
Published: February 2021

AlGaN‐based multiple quantum wells (MQWs) incorporating opposite polarity domains are grown by metal–organic chemical vapor deposition (MOCVD). A direct demonstration of the carrier localization effect is provided by a combination analysis of space‐resolved luminescence peak position and Ga/Al composition distribution. Furthermore, through Raman spectroscopy, it is found that compressive strain plays a key role in improving the optical properties of UV‐MQWs despite the inferior crystalline quality in the N‐polar domains. This suggests that incorporating sub‐micrometer‐scale polarity domains in the MQWs is promising for the development of efficient UV emitters.
Sedimentation calculations within an Eulerian framework using series of basis functions
Authors: Rodríguez Genó Camilo Fernando , Alfonso Léster
Published: February 2021

A gravitational sedimentation parametrization is presented, which sets the dynamic framework for the parametrization philosophy of linear combination of basis functions. The entire drop spectrum is represented as a linear combination of log‐normal distributions as part of an Eulerian simulation framework, in which all parameters of the distributions are calculated based on a prescribed set of three prognostic moments, thus eliminating the need of fixing any parameter to close the system of equations. The parametrization presents the advantage of avoiding the classification of water substance in artificial categories such as cloud water or rain water. Several experiments were performed, with an increasing number of distribution functions up to three, and with different sets of moments to establish which set performed the best. The comparison against the solution of an explicit sedimentation model shows that this parametrized approach is accurate enough to consider its inclusion in multi‐dimensional cloud models, achieving a better representation of the spectra with the use of a three‐member linear combination of basis functions.
An approach to characterizing spatial aspects of image system blur
Authors: Adams Jesse , Pillow Jessica , Joyce Kevin , Brennan Michael , Español Malena I. , Morzfeld Matthias , Breckling Sean , Champion Daniel , Clarkson Eric , Coffee Ryan , Gehring Amanda , Lund Margaret , Smalley Duane , Williams Ajanae , Zier Jacob , Frayer Daniel , Howard Marylesa , Machorro Eric
Published: February 2021

Quantitative X‐ray radiographic imaging systems that utilize a charged couple device (CCD) camera connected to a thick, monolithic scintillator can exhibit blur that varies spatially across the field of view, especially for thick scintillators used in pulse‐power radiography of dynamically compressed objects. A three‐point approach to estimating and accounting for this effect is demonstrated by (a) using a local estimation technique to measure the effect of blurring a calibration object at key locations across the field of view, (b) combining each of the local estimates into a spatially varying blurring function via partitions of unity interpolation, and (c) resolving the effects of that blur on the image by solving an ill‐posed inverse problem using a spatially varying regularization term. The technique is demonstrated on synthetic examples and actual radiographs collected at the Naval Research Laboratory's (NRL) Mercury pulsed power facility.
A fault detection framework using recurrent neural networks for condition monitoring of wind turbines
Authors: Cui Yue , Bangalore Pramod , Bertling Tjernberg Lina
Published: February 2021

This paper proposes a fault detection framework for the condition monitoring of wind turbines. The framework models and analyzes the data in supervisory control and data acquisition systems. For log information, each event is mapped to an assembly based on the Reliawind taxonomy. For operation data, recurrent neural networks are applied to model normal behaviors, which can learn the long‐time temporal dependencies between various time series. Based on the estimation results, a two‐stage threshold method is proposed to determine the current operation status. The method evaluates the shift values deviating from the estimated behaviors and their duration time to attenuate the effect of minor fluctuations. The generated results from the framework can help to understand when the turbine deviates from normal operations. The framework is validated with the data from an onshore wind park. The numerical results show that the framework can detect operational risks and reduce false alarms.
Charged complexity and the thermofield double state
Authors: Chapman Shira , Chen Hong Zhe (Vincent)
Published: February 2021

Abstract

We establish a systematic framework for studying quantum computational complexity of Gaussian states of charged systems based on Nielsen’s geometric approach. We use this framework to examine the effect of a chemical potential on the dynamics of complexity. As an example, we consider the complexity of a charged thermofield double state constructed from two free massive complex scalar fields in the presence of a chemical potential. We show that this state factorizes between positively and negatively charged modes and demonstrate that this fact can be used to relate it, for each momentum mode separately, to two uncharged thermofield double states with shifted temperatures and times. We evaluate the complexity of formation for the charged thermofield double state, both numerically and in certain analytic expansions. We further present numerical results for the time dependence of complexity. We compare various aspects of these results to those obtained in holography for charged black holes.
Nonrelativistic near-BPS corners of $$ \mathcal{N} $$ = 4 super-Yang-Mills with SU(1, 1) symmetry
Authors: Baiguera Stefano , Harmark Troels , Wintergerst Nico
Published: February 2021

Abstract

We consider limits of $$ \mathcal{N} $$
N
= 4 super Yang-Mills (SYM) theory that approach BPS bounds and for which an SU(1,1) structure is preserved. The resulting near-BPS theories become non-relativistic, with a U(1) symmetry emerging in the limit that implies the conservation of particle number. They are obtained by reducing $$ \mathcal{N} $$
N
= 4 SYM on a three-sphere and subsequently integrating out fields that become non-dynamical as the bounds are approached. Upon quantization, and taking into account normal-ordering, they are consistent with taking the appropriate limits of the dilatation operator directly, thereby corresponding to Spin Matrix theories, found previously in the literature. In the particular case of the SU(1,1—1) near-BPS/Spin Matrix theory, we find a superfield formulation that applies to the full interacting theory. Moreover, for all the theories we find tantalizingly simple semi-local formulations as theories living on a circle. Finally, we find positive-definite expressions for the interactions in the classical limit for all the theories, which can be used to explore their strong coupling limits. This paper will have a companion paper in which we explore BPS bounds for which a SU(2,1) structure is preserved.
Recursive construction of the operator product expansion in curved space
Authors: Fröb Markus B.
Published: February 2021

Abstract

I derive a formula for the coupling-constant derivative of the coefficients of the operator product expansion (Wilson OPE coefficients) in an arbitrary curved space, as the natural extension of the quantum action principle. Expanding the coefficients themselves in powers of the coupling constants, this formula allows to compute them recursively to arbitrary order. As input, only the OPE coefficients in the free theory are needed, which are easily obtained using Wick’s theorem. I illustrate the method by computing the OPE of two scalars ϕ in hyperbolic space (Euclidean Anti-de Sitter space) up to terms vanishing faster than the square of their separation to first order in the quartic interaction gϕ4, as well as the OPE coefficient "Image missing" at second order in g.
Closed string disk amplitudes in the pure spinor formalism
Authors: Bischof Andreas , Haack Michael
Published: February 2021

Abstract

We evaluate closed string disk amplitudes in the pure spinor formalism. We focus on low point functions (two- and one-point functions) but our analysis is also relevant for higher n-point functions. Amongst others we discuss issues arising due to the gauge fixing of the conformal Killing group of the disk and due to the zero mode prescription in the pure spinor formalism. As expected, in the end we find agreement with the known results from the RNS formalism.
Pole skipping away from maximal chaos
Authors: Choi Changha , Mezei Márk , Sárosi Gábor
Published: February 2021

Abstract

Pole skipping is a recently discovered subtle effect in the thermal energy density retarded two point function at a special point in the complex (ω, p) planes. We propose that pole skipping is determined by the stress tensor contribution to many-body chaos, and the special point is at (ω, p)p.s.=$$ i{\lambda}^{(T)}\left(1,1/{u}_B^{(T)}\right) $$iλT11/uBT, whereλ(T)= 2π/βand$$ {u}_B^{(T)} $$uBTare the stress tensor contributions to the Lyapunov exponent and the butterfly velocity respectively. While this proposal is consistent with previous studies conducted for maximally chaotic theories, where the stress tensor dominates chaos, it clarifies that one cannot use pole skipping to extract the Lyapunov exponent of a theory, which obeysλ≤λ(T). On the other hand, in a large class of strongly coupled but non-maximally chaotic theories$$ {u}_B^{(T)} $$uBTis the true butterfly velocity and we conjecture thatuB≤$$ {u}_B^{(T)} $$uBTis a universal bound. While it remains a challenge to explain pole skipping in a general framework, we provide a stringent test of our proposal in the large-qlimit of the SYK chain, where we determineλ, uB, and the energy density two point function in closed form for all values of the coupling, interpolating between the free and maximally chaotic limits. Since such an explicit expression for a thermal correlator is one of a kind, we take the opportunity to analyze many of its properties: the coupling dependence of the diffusion constant, the dispersion relations of poles, and the convergence properties of all order hydrodynamics.
Supersymmetry anomaly in the superconformal Wess-Zumino model
Authors: Katsianis Georgios , Papadimitriou Ioannis , Skenderis Kostas , Taylor Marika
Published: February 2021

Abstract

We present a comprehensive analysis of supersymmetry anomalies in the free and massless Wess-Zumino (WZ) model in perturbation theory. At the classical level the model possesses $$ \mathcal{N} $$
N
= 1 superconformal symmetry, which is partially broken by quantum anomalies. The form of the anomalies and the part of the symmetry they break depend on the multiplet of conserved currents used. It was previously shown that the R-symmetry anomaly of the conformal current multiplet induces an anomaly in Q-supersymmetry, which appears first in 4-point functions. Here we confirm this result by an explicit 1-loop computation using a supersymmetric Pauli-Villars regulator.

The conformal current multiplet does not exist in the regulated theory because the regulator breaks conformal invariance, R-symmetry and S-supersymmetry explicitly. The minimal massive multiplet is the Ferrara-Zumino (FZ) one and the supersymmetry preserved by the regulator is a specific field dependent combination of Q- and S- supersymmetry of the conformal multiplet. While this supersymmetry is non anomalous, conformal invariance, R-symmetry and the original Q- and S-supersymmetries are explicitly broken by finite contact terms, both in the regulated and renormalized theories.

A conformal current multiplet does exist for the renormalized theory and may be obtained from the FZ multiplet by a set of finite local counterterms that eliminate the explicit symmetry breaking, thus restoring superconformal invariance up to anomalies. However, this necessarily renders both Q- and S-supersymmetries anomalous, as is manifest starting at 4-point functions of conformal multiplet currents. The paper contains a detailed discussion of a number of issues and subtleties related to Ward identities that may be useful in a wider context.
Gravitons in a Casimir box
Authors: Alessio Francesco , Barnich Glenn , Bronte Martin
Published: February 2021

Abstract

The partition function of gravitons with Casimir-type boundary conditions is worked out. The simplest box that allows one to achieve full analytical control consists of a slab geometry with two infinite parallel planes separated by a distance d. In this setting, linearized gravity, like electromagnetism, is equivalent to two free massless scalar fields, one with Dirichlet and one with Neumann boundary conditions, which in turn may be combined into a single massless scalar with periodic boundary conditions on an interval of length 2d. When turning on a chemical potential for suitably adapted spin angular momentum, the partition function is modular covariant and expressed in terms of an Eisenstein series. It coincides with that for photons. At high temperature, the result provides in closed form all sub-leading finite-size corrections to the standard (gravitational) black body result. More interesting is the low-temperature/small distance expansion where the leading contribution to the partition function is linear in inverse temperature and given in terms of the Casimir energy of the system, whereas the leading contribution to the entropy is proportional to the area and originates from gravitons propagating parallel to the plates.
Continuous flattening of the 2-dimensional skeleton of a regular 24-cell
Authors: Itoh Jin-ichi , Nara Chie
Published: February 2021

Bellow theorem says that any polyhedron with rigid faces cannot change its volume even if it is flexible. The problem on continuous flattenig of polyhedra with non-rigid faces proposed by Demaine et al. was solved for all convex polyhedra by using the notion of moving creases to change some of the faces. This problem was extended to a problem on continuous flattening of the 2-dimensional skeleton of higher dimensional polytopes. This problem was solved for all regular polytopes except three types, the 24-cell, the 120-cell, and the 600-cell. This article addresses the 24-cell and gives a continuous flattening motion for its 2-skeleton, which is related to the Jitterbug by Buckminster Fuller.
Early prediction of biomass in hybrid rye based on hyperspectral data surpasses genomic predictability in less-related breeding material
Authors: Galán Rodrigo José , Bernal-Vasquez Angela-Maria , Jebsen Christian , Piepho Hans-Peter , Thorwarth Patrick , Steffan Philipp , Gordillo Andres , Miedaner Thomas
Published: February 2021

Key message

Hyperspectral data is a promising complement to genomic data to predict biomass under scenarios of low genetic relatedness. Sufficient environmental connectivity between data used for model training and validation is required.

The demand for sustainable sources of biomass is increasing worldwide. The early prediction of biomass via indirect selection of dry matter yield (DMY) based on hyperspectral and/or genomic prediction is crucial to affordably untap the potential of winter rye (Secale cerealeL.) as a dual-purpose crop. However, this estimation involves multiple genetic backgrounds and genetic relatedness is a crucial factor in genomic selection (GS). To assess the prospect of prediction using reflectance data as a suitable complement to GS for biomass breeding, the influence of trait heritability ($$H^{2}$$H2) and genetic relatedness were compared. Models were based on genomic (GBLUP) and hyperspectral reflectance-derived (HBLUP) relationship matrices to predict DMY and other biomass-related traits such as dry matter content (DMC) and fresh matter yield (FMY). For this, 270 elite rye lines from nine interconnected bi-parental families were genotyped using a 10 k-SNP array and phenotyped as testcrosses at four locations in two years (eight environments). From 400 discrete narrow bands (410 nm–993 nm) collected by an uncrewed aerial vehicle (UAV) on two dates in each environment, 32 hyperspectral bands previously selected by Lasso were incorporated into a prediction model. HBLUP showed higher prediction abilities (0.41 – 0.61) than GBLUP (0.14 – 0.28) under a decreased genetic relationship, especially for mid-heritable traits (FMY and DMY), suggesting that HBLUP is much less affected by relatedness and$$H^{2}$$H2. However, the predictive power of both models was largely affected by environmental variances. Prediction abilities for DMY were further enhanced (up to 20%) by integrating both matrices and plant height into a bivariate model. Thus, data derived from high-throughput phenotyping emerges as a suitable strategy to efficiently leverage selection gains in biomass rye breeding; however, sufficient environmental connectivity is needed.
Mid-infrared photodetector based on 2D material metamaterial with negative index properties for a wide range of angles near vertical illumination
Authors: Ponizovskaya Devine E.
Published: February 2021

We present the vertically illuminated Si compatible mid-infrared photodetectors based on graphene that forms negative-index metamaterial. The coupling into a 2D layer at the angles near normal to the surface is negligible without the help of a metamaterial. We propose a low loss metamaterial, the dielectric structure with the nano/microholes through 2D materials that supports a resonance and enhances quantum efficiency in a wide range of incident angles.
The linked legal data landscape: linking legal data across different countries
Authors: Filtz Erwin , Kirrane Sabrina , Polleres Axel
Published: February 2021

The European Union is working towards harmonizing legislation across Europe, in order to improve cross-border interchange of legal information. This goal is supported for instance via standards such as the European Law Identifier (ELI) and the European Case Law Identifier (ECLI), which provide technical specifications for Web identifiers and suggestions for vocabularies to be used to describe metadata pertaining to legal documents in a machine readable format. Notably, these ECLI and ELI metadata standards adhere to the RDF data format which forms the basis of Linked Data, and therefore have the potential to form a basis for a pan-European legal Knowledge Graph. Unfortunately, to date said specifications have only been partially adopted by EU member states. In this paper we describe a methodology to transform the existing legal information system used in Austria to such a legal knowledge graph covering different steps from modeling national specific aspects, to population, and finally the integration of legal data from other countries through linked data. We demonstrate the usefulness of this approach by exemplifying practical use cases from legal information search, which are not possible in an automated fashion so far.
Molecular evidence of species- and subspecies-level distinctions in the rare Orchis patens s.l. and implications for conservation
Authors: Calevo Jacopo , Gargiulo Roberta , Bersweden Leif , Viruel Juan , González-Montelongo Cristina , Rebbas Khellaf , Boutabia Lamia , Fay Michael F.
Published: February 2021

Characterizing genetic diversity and structure of populations is essential for the effective conservation of threatened species.Orchis patenssensu lato is a narrowly distributed tetraploid species with a disjunct distribution (i.e., Northern Italy, North Africa and the Canary Islands), which is facing a severe decline. In this study, we evaluated levels of genetic diversity and population structuring using 12 new nuclear microsatellite markers. Our analyses of genetic differentiation based on multiple approaches (Structure analysis, PCA analysis, andF-statistics using the ploidy-independentRho-index) showed that gene flow is low across the range ofO. patens s.l., particularly in the Canary Islands. Clear differences in allele frequencies between Italy, Algeria and the Canary Islands underlie the genetic differentiation retrieved. Our study provides support for the recognition ofO. canariensisas a sister species toO. patensand the separation of the Italian populations as a new subspecies ofO. patens. Despite the high heterozygosity values found in all populations (ranging from 0.4 to 0.7), compatible with the tetraploid status of the species, small population sizes and reduced gene flow will be likely detrimental for the different populations in the long term, and we recommend immediate conservation actions to counteract further fragmentation and population decline.
“We’re Just Geeks”: Disciplinary Identifications Among Business Students and Their Implications for Personal Responsibility
Authors: Blasco Maribel
Published: February 2021

This research shows how business students’ disciplinary specializations can affect their sense of personal responsibility by providing rationalizations for moral disengagement. It thereby conceptualizes business students’ disciplinary specializations as a key dimension of the business school responsibility learning environment. Students use four main rationalizations to displace responsibility variously away from their own disciplinary specializations, to claim responsibility as the prerogative of their specialization, and to shiftirresponsibility onto disciplinary out-groups. Yet despite their disciplinary identifications, students largely rationalized that their sense of responsibility was an individual matter that was unlikely to be affected by contextual influences, and they attributedirresponsible behavior to incorrigible ‘bad apples.’ A theoretical model is offered which illustrates these dynamics by combining Bandura’s social cognitive theory with social identity theory. The research is based on secondary data, specifically focus-group interviews conducted with undergraduate students at a major Scandinavian business school in connection with the implementation of the UN Principles for Responsible Management Education (PRME) initiative. The implications for management education include the need to strengthen students’ ‘disciplinary reflexivity,’ and to explicitly address the tension between students’ disciplinary solidarities and their faith in their own individual moral infallibility.
Change in mean and extreme temperature at Yingkou station in Northeast China from 1904 to 2017
Authors: Xue Xiaoying , Ren Guoyu , Sun Xiubao , Zhang Panfeng , Ren Yuyu , Zhang Siqi , Zhao Chunyu , Yu Xiujing
Published: February 2021

The understanding of centennial trends of extreme temperature has been impeded due to the lack of early-year observations. In this paper, we collect and digitize the daily temperature data set of Northeast China Yingkou meteorological station since 1904. After quality control and homogenization, we analyze the changes of mean and extreme temperature in the past 114 years. The results show that mean temperature (Tmean), maximum temperature (Tmax), and minimum temperature (Tmin) all have increasing trends during 1904–2017. The increase of Tmin is the most obvious with the rate of 0.34 °C/decade. The most significant warming occurs in spring and winter with the rate of Tmean reaching 0.32 °C/decade and 0.31 °C/decade, respectively. Most of the extreme temperature indices as defined using absolute and relative thresholds of Tmax and Tmin also show significant changes, with cold events witnessing a more significant downward trend. The change is similar to that reported for global land and China for the past six decades. It is also found that the extreme highest temperature (1958) and lowest temperature (1920) records all occurred in the first half of the whole period, and the change of extreme temperature indices before 1950 is different from that of the recent decades, in particular for diurnal temperature range (DTR), which shows an opposite trend in the two time periods.
Gait Patterns and Mood in Everyday Life: A Comparison Between Depressed Patients and Non-depressed Controls
Authors: Adolph Dirk , Tschacher Wolfgang , Niemeyer Helen , Michalak Johannes
Published: February 2021

Background

Previous laboratory findings suggest deviant gait characteristics in depressed individuals (i.e., reduced walking speed and vertical up-and-down movements, larger lateral swaying movements, slumped posture). However, since most studies to date assessed gait in the laboratory, it is largely an open question whether this association also holds in more naturalistic, everyday life settings. Thus, within the current study we (1) aimed at replicating these results in an everyday life and (2) investigated whether gait characteristics could predict change in current mood.

Methods

We recruited a sample of patients (n = 35) suffering from major depressive disorder and a sample of age and gender matched non-depressed controls (n = 36). During a 2-day assessment we continuously recorded gait patterns, general movement intensity and repetitively assessed the participant’s current mood.

Results

We replicated previous laboratory results and found that patients as compared to non-depressed controls showed reduced walking speed and reduced vertical up-and-down movements, as well as a slumped posture during everyday life episodes of walking. Moreover, independent of clinical diagnoses, higher walking speed, and more vertical up-and-down movements significantly predicted more subsequent positive mood, while changes in mood did not predict subsequent changes in gait patterns.

Conclusion

In sum, our results support expectations that embodiment (i.e., the relationship between bodily expression of emotion and emotion processing itself) in depression is also observable in naturalistic settings, and that depression is bodily manifested in the way people walk. The data further suggest that motor displays affect mood in everyday life.
How to detect and reduce potential sources of biases in studies of SARS-CoV-2 and COVID-19
Authors: Accorsi Emma K. , Qiu Xueting , Rumpler Eva , Kennedy-Shaffer Lee , Kahn Rebecca , Joshi Keya , Goldstein Edward , Stensrud Mats J. , Niehus Rene , Cevik Muge , Lipsitch Marc
Published: February 2021

In response to the coronavirus disease (COVID-19) pandemic, public health scientists have produced a large and rapidly expanding body of literature that aims to answer critical questions, such as the proportion of the population in a geographic area that has been infected; the transmissibility of the virus and factors associated with high infectiousness or susceptibility to infection; which groups are the most at risk of infection, morbidity and mortality; and the degree to which antibodies confer protection to re-infection. Observational studies are subject to a number of different biases, including confounding, selection bias, and measurement error, that may threaten their validity or influence the interpretation of their results. To assist in the critical evaluation of a vast body of literature and contribute to future study design, we outline and propose solutions to biases that can occur across different categories of observational studies of COVID-19. We consider potential biases that could occur in five categories of studies: (1) cross-sectional seroprevalence, (2) longitudinal seroprotection, (3) risk factor studies to inform interventions, (4) studies to estimate the secondary attack rate, and (5) studies that use secondary attack rates to make inferences about infectiousness and susceptibility.
Primary Physical Science for Student Teachers at Kindergarten and Primary School Levels: Part II—Implementation and Evaluation of a Course
Authors: Corni Federico , Fuchs Hans U.
Published: February 2021

This is the second of two papers on a novel physical science course for student teachers that develops and uses an imaginative approach to Primary Physical Science Education. General philosophical, cognitive, developmental, and scientific issues have been presented in the first paper; here, we briefly recapitulate the most important aspects. In the main part of the current paper, we present in some detail concrete elements of the implementation of the course at three Italian universities where Primary Physical Science Education has been taught for more than 6 years. After a brief description of the course structure, we discuss which parts of macroscopic physics are taught, and how this is done in lectures and labs. Most importantly, we show how the science is entwined with methods related to pedagogy and didactics that (1) help our students approach the science and (2) can be transferred quite readily to teaching children in kindergarten and primary school. These methods include the design of direct physical experience of forces of nature, embodied simulations, writing and telling of stories of forces of nature, and design and performance of Forces-of-Nature Theater plays. The paper continues with a brief description of feedback from former students who have been teaching for some time, and an in-depth analysis of the research and teaching done by one of the students for her master thesis. We conclude the paper by summarizing aspects of both the philosophy and the design of the course that we believe to be of particular value.
Non-invasive measurement of pulse pressure variation using a finger-cuff method (CNAP system): a validation study in patients having neurosurgery
Authors: Flick Moritz , Hoppe Phillip , Matin Mehr Jasmin , Briesenick Luisa , Kouz Karim , Greiwe Gillis , Fortin Jürgen , Saugel Bernd
Published: February 2021

The finger-cuff system CNAP (CNSystems Medizintechnik, Graz, Austria) allows non-invasive automated measurement of pulse pressure variation (PPVCNAP). We sought to validate the PPVCNAP-algorithm and investigate the agreement between PPVCNAP and arterial catheter-derived manually calculated pulse pressure variation (PPVINV). This was a prospective method comparison study in patients having neurosurgery. PPVINV was the reference method. We applied the PPVCNAP-algorithm to arterial catheter-derived blood pressure waveforms (PPVINV−CNAP) and to CNAP finger-cuff-derived blood pressure waveforms (PPVCNAP). To validate the PPVCNAP-algorithm, we compared PPVINV−CNAP to PPVINV. To investigate the clinical performance of PPVCNAP, we compared PPVCNAP to PPVINV. We used Bland–Altman analysis (absolute agreement), Deming regression, concordance, and Cohen's kappa (predictive agreement for three pulse pressure variation categories). We analyzed 360 measurements from 36 patients. The mean of the differences between PPVINV−CNAP and PPVINV was −0.1% (95% limits of agreement (95%-LoA) −2.5 to 2.3%). Deming regression showed a slope of 0.99 (95% confidence interval (95%-CI) 0.91 to 1.06) and intercept of −0.02 (95%-CI −0.52 to 0.47). The predictive agreement between PPVINV−CNAP and PPVINV was 92% and Cohen’s kappa was 0.79. The mean of the differences between PPVCNAP and PPVINV was −1.0% (95%-LoA−6.3 to 4.3%). Deming regression showed a slope of 0.85 (95%-CI 0.78 to 0.91) and intercept of 0.10 (95%-CI −0.34 to 0.55). The predictive agreement between PPVCNAP and PPVINV was 82% and Cohen’s kappa was 0.48. The PPVCNAP-algorithm reliably calculates pulse pressure variation compared to manual offline pulse pressure variation calculation when applied on the same arterial blood pressure waveform. The absolute and predictive agreement between PPVCNAP and PPVINV are moderate.
The Return-to-Work Self-efficacy Questionnaire (RTW-SE): A Validation Study of Predictive Abilities and Cut-off Values for Patients on Sick Leave Due to Anxiety or Depression
Authors: Gjengedal Ragne G. H. , Lagerveld Suzanne E. , Reme Silje E. , Osnes Kåre , Sandin Kenneth , Hjemdal Odin
Published: February 2021

Purpose This study aimed to evaluate the validity of the Return-to-Work Self-efficacy Questionnaire (RTW-SE) in a Norwegian sample of patients with common mental disorders. The secondary aim was to provide validated cut-off scores for the RTW-SE. Methods Among patients receiving work-focused therapy (N = 626), the RTW-SE was measured pre-and post-treatment, and work status was assessed up to one-year post-treatment. The factor structure, internal consistency and construct validity were assessed. Furthermore, post-treatment cut-off scores were calculated using receiver operating characteristic (ROC) analysis for patients on sick leave at baseline (n = 314) and at the end of treatment (n = 145). The predictive ability of the suggested RTW-SE cut-off scores were investigated longitudinally. Results Exploratory principal component analysis identified a one-factor solution with high internal consistency (0.91). RTW-SE exhibited small to moderate negative correlations with measures of depression and anxiety, and was significantly different between subgroups of patients with different work status, supporting construct validity. Pre- and post-treatment RTW-SE scores significantly predicted full return to work at 3, 6 and 12 months post-treatment. ROC analysis suggested an upper cut-off score of 4.6, associated with full RTW, and lower cut-off score of 3.7, associated with partial RTW. These cut-offs showed acceptable discriminative ability and significant longitudinal predictive ability. Conclusion The RTW-SE possesses good psychometric properties and the suggested cut-off scores have significant predictive ability in a clinical setting.
Assessment of 232Th, 226Ra, 137Cs, and 40 K concentrations and annual effective dose due to the consumption of Vietnamese fresh milk
Authors: Duong Van-Hao , Nguyen Thanh-Duong , Hegedűs Miklós , Tóth-Bodrogi Edit , Kovács Tibor
Published: February 2021

Vietnam has little data on radionuclide concentrations in milk, despite steadily increasing domestic consumption. Eight milk brands were investigated by gamma-spectrometry, and the resulting ingestion dose was calculated. The 232Th, 226Ra, 137Cs, and 40K concentrations varied from 0.60 ± 0.19 to 1.21 ± 0.24, 1.45 ± 0.18 to 2.45 ± 0.24, below detection limit to 0.13 ± 0.06, and 341 ± 6 to 387 ± 7 Bq/kg (dry w.t). The total average Annual Effective Dose for all age groups were similar for all brands, and concentrations are far less than the WHO guidance level. All brands are safe for consumption.
Vacuum versus ambient pressure inert gas thermogravimetry: a study of silver carboxylates
Authors: Jurczyk Jakub , Glessi Cristiano , Madajska Katarzyna , Berger Luisa , Nyrud Jeroen Ingolf Ketele , Szymańska Iwona , Kapusta Czesław , Tilset Mats , Utke Ivo
Published: February 2021

A comparative study of vacuum versus ambient pressure inert gas thermogravimetry was performed on silver carboxylates compounds. Some of the complexes from this group have been previously successfully applied as precursors for both chemical vapour deposition and electron beam-induced deposition. Considerable differences were found between the thermogravimetry methods, which we associate with changes in evaporation dynamics. Vacuum thermogravimetry sublimation onsets consistently occurred at lower temperatures than ambient pressure N2-flow thermogravimetry, where the differences reached up to 120 °C. Furthermore, compound sublimation during N2-TGA was suppressed to such an extent that significant thermal decomposition of the compounds into metal and volatile organic fragments was observed while at vacuum the same complexes sublimed as intact molecules. Moreover, thermal stability of silver complexes was investigated using isothermal thermogravimetry. These findings are interesting for the field of thin film synthesis and nanomanufacturing via chemical vapour deposition, atomic layer deposition and focused electron beam induced deposition. In all three methods, delivery of functional precursor over the substrate is crucial. The presented results prove that vacuum thermogravimetry can be used as fast method of pre-screening for novel, especially low-volatility precursors.

Graphic abstract
The gas evolution of a modified cellulose mixture used for gating systems in the no-bake mould process
Authors: Zawieja Zbigniew , Sawicki Jacek
Published: February 2021

This paper shows the results of a study of gas evolution from a patented modified cellulose mix used in the production of no-bake casting moulds. The modified cellulose mixture was used for investigation with additives such as expanded perlite, expanded vermiculite and microspheres. The binder was an inorganic resin based on commercial technology, called Geopol. Samples were tested in different compositions in order to show the influence of all the additives mentioned. Two different methods were used—one was based on TG–TDG–MS investigation and the other was based on pyrolysis combined with a gas composition analyser. Investigations of both methods were carried out at temperatures up to 900 °C. The results showed that the gas emissions during thermal degradation of all the modified mixtures did not constitute substances that are hazardous or dangerous to health. Therefore, the material proposed can be used as a solution that is more environmentally friendly when compared to formulas which exist on the market and are abundant in harmful compounds.
Information measures and design issues in the study of mortality deceleration: findings for the gamma-Gompertz model
Authors: Böhnstedt Marie , Gampe Jutta , Putter Hein
Published: February 2021

Mortality deceleration, or the slowing down of death rates at old ages, has been repeatedly investigated, but empirical studies of this phenomenon have produced mixed results. The scarcity of observations at the oldest ages complicates the statistical assessment of mortality deceleration, even in the parsimonious parametric framework of the gamma-Gompertz model considered here. The need for thorough verification of the ages at death can further limit the available data. As logistical constraints may only allow to validate survivors beyond a certain (high) age, samples may be restricted to a certain age range. If we can quantify the effects of the sample size and the age range on the assessment of mortality deceleration, we can make recommendations for study design. For that purpose, we propose applying the concept of the Fisher information and ideas from the theory of optimal design. We compute the Fisher information matrix in the gamma-Gompertz model, and derive information measures for comparing the performance of different study designs. We then discuss interpretations of these measures. The special case in which the frailty variance takes the value of zero and lies on the boundary of the parameter space is given particular attention. The changes in information related to varying sample sizes or age ranges are investigated for specific scenarios. The Fisher information also allows us to study the power of a likelihood ratio test to detect mortality deceleration depending on the study design. We illustrate these methods with a study of mortality among late nineteenth-century French-Canadian birth cohorts.
Factor Structure and Equivalence of Maternal Resources for Care in Bangladesh, Vietnam, and Ethiopia
Authors: Basnet Sulochana , Frongillo Edward A. , Nguyen Phuong Hong , Moore Spencer , Arabi Mandana
Published: February 2021

Objectives

Resources for care among women are crucial for children’s growth and development. The objectives of this cross-sectional study were to determine if: (1) the factor structure of measures of maternal resources for care was comparable across countries and consistent with the theoretical constructs and (2) the measures showed equivalence across contexts.

Methods

The study included 4400, 4029 and 2746 women from Bangladesh, Vietnam, and Ethiopia, respectively. The measures of resources for care were maternal education, knowledge, height, body mass index, mental well-being, financial autonomy, decision-making, employment, support in chores, and perceived support.

Results

The factor analysis demonstrated that a two-factor solution best explained the structure of resources for care in all three countries. The first factor was associated with financial autonomy and employment in all three countries and with decision-making in two countries. The second factor was associated with education and knowledge in all three countries. The measures of resources for care had measurement equivalence across countries.

Conclusion for Practice

Resources for care were structurally similar and measurement equivalent across countries and can be used for measurement in low- and middle-income countries. Additional work examining the structure and cross-context equivalence of resources for care in other settings is warranted.
Leveraging circuit theory and nonlinear dynamics for the efficiency improvement of energy harvesting
Authors: Bonnin Michele , Traversa Fabio L. , Bonani Fabrizio
Published: February 2021

We study the performance of vibrational energy harvesting systems with piezoelectric and magnetic inductive transducers, assuming the power of external disturbance concentrated around a specific frequency. Both linear and nonlinear harvester models are considered. We use circuit theory and equivalent circuits to show that a large improvement in both the harvested energy and the power efficiency is obtained, for linear systems, through a proper reactive modification of the load. For nonlinear systems, we use methods of nonlinear dynamics to derive analytical formulae for the output voltage, the harvested energy and the power efficiency. We show that also for the nonlinear case, the modified load significantly boosts the performance.
Tracking developments in artificial intelligence research: constructing and applying a new search strategy
Authors: Liu Na , Shapira Philip , Yue Xiaoxu
Published: February 2021

Artificial intelligence, as an emerging and multidisciplinary domain of research and innovation, has attracted growing attention in recent years. Delineating the domain composition of artificial intelligence is central to profiling and tracking its development and trajectories. This paper puts forward a bibliometric definition for artificial intelligence which can be readily applied, including by researchers, managers, and policy analysts. Our approach starts with benchmark records of artificial intelligence captured by using a core keyword and specialized journal search. We then extract candidate terms from high frequency keywords of benchmark records, refine keywords and complement with the subject category “artificial intelligence”. We assess our search approach by comparing it with other three recent search strategies of artificial intelligence, using a common source of articles from the Web of Science. Using this source, we then profile patterns of growth and international diffusion of scientific research in artificial intelligence in recent years, identify top research sponsors in funding artificial intelligence and demonstrate how diverse disciplines contribute to the multidisciplinary development of artificial intelligence. We conclude with implications for search strategy development and suggestions of lines for further research.
Factors affecting the citations of papers in tribology journals
Authors: Liskiewicz T. , Liskiewicz G. , Paczesny J.
Published: February 2021

The citations count is flawed but it still the most common way of measuring the academic impact used by scholarly journals (Impact Factor), individual researchers (h-index) and funding agencies (a proxy for quality of research). Individual papers should attract citations depending upon the importance and usefulness of the results presented. However, large enough data sets reveal that there are parameters independent of individual papers' quality that can determine an average citation rate. Here, we examine papers (4756 in total) published in six selected tribology journals in a six-year window between January 2010 and December 2015. Citations were retrieved from the Web of Science and compared with their (1) manuscript length, (2) number of authors, (3) number of affiliated institutions, (4) number of international co-authors, (5) number of cited references, (6) number of words in the title, and (7) mode of publication (open versus paid access). The results revealed that citations received by papers published in tribology journals are affected by all of these parameters. This is a significant finding for authors wishing to increase the impact of their research. This knowledge can be used effectively at the manuscript planning and writing stages to support scientific merit. We suggest that the significance of parameters not directly related to the quality of a scholarly paper will become more critical with the rise of alternative ways of measuring impact including novel generation of paper metrics (e.g., Eigenfactor, SJR), social mentions, and viral outreach.