bluuebunny/crossref_metadata_2025 huggingface dataset:
Bayesian nonparametric multiway regression for clustered binomial data
Authors: Lock Eric F. , Bandyopadhyay Dipankar
Published: March 2021

We introduce a Bayesian nonparametric regression model for data with multiway (tensor) structure, motivated by an application to periodontal disease (PD) data. Our outcome is the number of diseased sites measured over four different tooth types for each subject, with subject‐specific covariates available as predictors. The outcomes are not well characterized by simple parametric models, so we use a nonparametric approach with a binomial likelihood wherein the latent probabilities are drawn from a mixture with an arbitrary number of components, analogous to a Dirichlet process. We use a flexible probit stick‐breaking formulation for the component weights that allows for covariate dependence and clustering structure in the outcomes. The parameter space for this model is large and multiway: patients × tooth types × covariates × components. We reduce its effective dimensionality and account for the multiway structure, via low‐rank assumptions. We illustrate how this can improve performance and simplify interpretation while still providing sufficient flexibility. We describe a general and efficient Gibbs sampling algorithm for posterior computation. The resulting fit to the PD data outperforms competitors and is interpretable and well calibrated. An interactive visual of the predictive model is available at the website (https://ericfrazerlock.com/toothdata/ToothDisplay.html), and the code is available at the GitHub (https://github.com/lockEF/NonparametricMultiway).
Analysing the combination of cost reduction techniques in Android mutation testing
Authors: Polo‐Usaola Macario , Rodríguez‐Trujillo Isyed
Published: March 2021

When applied to mobile software, mutation testing is particularly costly due to the deployment of the app under test onto the device: if one deployment is made for each generated mutant, the execution time becomes unapproachable. This paper analyses how the combination of different cost reduction techniques improves the execution time of mutation testing in mobile apps. The techniques reviewed and combined are mutant schema, parallel execution and two different ways of executing tests against the mutants (all against all and all against mutants remaining alive), as well as greedy algorithm for reducing the test suite size. This paper also presents a mathematical model of cost reduction and checks its validity with several experiments. Furthermore, the exhaustive and long experimentation has led the authors to compile a set of good practices which are also presented in a set of lessons learned.
Effect of multi‐scale polypropylene fiber hybridization on compressive constitutive mechanics parameters of roller compacted concrete
Authors: Liang Ninghui , Yan Ru , Miao Qingxu , Cao Guojun , Liu Xinrong
Published: March 2021

To investigate the influence of hybrid effect of different sizes of polypropylene fibers (PPFs) on the compressive constitutive mechanical parameters of roller compacted concrete, nine groups of fiber reinforced concrete specimens containing different sizes of PPFs were designed and the uniaxial compressive testing was conducted. Based on the existing compressive constitutive model and the test stress–strain curves, the peak stress, peak strain, elastic modulus, and the post‐peak stage parameter with different fiber proportion were analyzed and discussed to find the optimum mixing proportion of different sizes of PPF, the calculation of compressive toughness factor were given. The results showed that the addition of PPF could improve the compressive properties of RCC. The axial compressive strength and compressive strain of RCC increased by 3%~16% and 7%~57%, respectively. Meanwhile, the coarse PPF can significantly enhance the ductility of RCC when subjected to uniaxial compressive loading, and the group of multi‐scale PPF hybridization had higher compressive toughness than groups blended with two types of PPF, showing a more obvious positive hybrid effect. Finally, multi‐scale fiber hybrid effect function was proposed, the results showed that the function can well reflect the influence of fiber hybrid effect on the compressive properties of RCC and can be used to predict the optimal fiber proportion of fiber reinforced concrete.
Predicting amyloid risk by machine learning algorithms based on the A4 screen data: Application to the Japanese Trial‐Ready Cohort study
Authors: Sato Kenichiro , Ihara Ryoko , Suzuki Kazushi , Niimi Yoshiki , Toda Tatsushi , Jimenez‐Maggiora Gustavo , Langford Oliver , Donohue Michael C. , Raman Rema , Aisen Paul S. , Sperling Reisa A. , Iwata Atsushi , Iwatsubo Takeshi
Published: March 2021

Background

Selecting cognitively normal elderly individuals with higher risk of brain amyloid deposition is critical to the success of prevention trials for Alzheimer's disease (AD).

Methods

Based on the Anti‐Amyloid Treatment in Asymptomatic Alzheimer's Disease study data, we built machine‐learning models and applied them to our ongoing Japanese Trial‐Ready Cohort (J‐TRC) webstudy participants registered within the first 9 months (n = 3081) of launch to predict standard uptake value ratio (SUVr) of amyloid positron emission tomography.

Results

Age, family history, online Cognitive Function Instrument and CogState scores were important predictors. In a subgroup of J‐TRC webstudy participants with known amyloid status (n = 37), the predicted SUVr corresponded well with the self‐reported amyloid test results (area under the curve = 0.806 [0.619–0.992]).

Discussion

Our algorithms may be usable for automatic prioritization of candidate participants with higher amyloid risks to be preferentially recruited from the J‐TRC webstudy to in‐person study, maximizing efficiency for the identification of preclinical AD participants.
Foundational ontologies, ontology‐driven conceptual modeling, and their multiple benefits to data mining
Authors: Amaral Glenda , Baião Fernanda , Guizzardi Giancarlo
Published: March 2021

For many years, the role played by domain knowledge in all stages of knowledge discovery has been recognized. However, the real‐world semantics embedded in data is often still not fully considered in traditional data mining methods. In this article, we argue that the quality of data mining results is directly related to the extent that they reflect important properties of real‐world entities represented therein. Analyzing and characterizing the nature of these entities is the very business of the area of formal ontology. We briefly elaborate on two particular types of artifacts produced by this area: foundational ontologies and ontology‐driven conceptual modeling languages grounded on them. We then elaborate on the benefits they can bring to several activities in a data mining process.

This article is categorized under:

Fundamental Concepts of Data and Knowledge > Knowledge Representation

Fundamental Concepts of Data and Knowledge > Data Concepts
Pole skipping and chaos in anisotropic plasma: a holographic study
Authors: Sil Karunava
Published: March 2021

Abstract

Recently, a direct signature of chaos in many body system has been realized from the energy density retarded Green’s function using the phenomenon of ‘pole skipping’. Moreover, special locations in the complex frequency and momentum plane are found, known as the pole skipping points such that the retarded Green’s function can not be defined uniquely there. In this paper, we compute the correction/shift to the pole skipping points due to a spatial anisotropy in a holographic system by performing near horizon analysis of EOMs involving different bulk field perturbations, namely the scalar, the axion and the metric field. For vector and scalar modes of metric perturbations we construct the gauge invariant variable in order to obtain the master equation. Two separate cases for every bulk field EOMs is considered with the fluctuation propagating parallel and perpendicular to the direction of anisotropy. We compute the dispersion relation for momentum diffusion along the transverse direction in the shear channel and show that it passes through the first three successive pole skipping points. The pole skipping phenomenon in the sound channel is found to occur in the upper half plane such that the parameters Lyapunov exponentλLand the butterfly velocityvBare explicitly obtained thus establishing the connection with many body chaos.
Infiltration der Schädelkalotte durch ein dedifferenziertes kutanes Leiomyosarkom
Authors: Maier J. C. , Kofler K. , Forchhammer S. , Skardelly M. , Mentzel T. , Häfner H. M. , Kofler L.
Published: March 2021

Wir berichten über einen 81-jährigen Patienten mit bereits mehrfach voroperiertem Tumor der Kopfhaut. In der histologischen erneuten Aufarbeitung ließ sich ein dedifferenziertes Leiomyosarkom nachweisen, das bereits die Schädeldecke infiltriert hatte. In einem interdisziplinären Ansatz mit den Kollegen der Klinik für Neurochirurgie konnte eine Komplettexzision erreicht werden. Kutane Leiomyosarkome sind seltene Tumoren der Haut, die typischerweise als langsam wachsende, erythematöse Knoten imponieren. Aufgrund des Metastasierungspotenzials ist eine komplette, schnittrandkontrollierte Resektion erforderlich.
Neurovaskuläre Manifestationen von COVID‑19
Authors: Veltkamp Roland , Purrucker Jan C. , Weber Ralph
Published: March 2021

Bereits früh nach Beginn der COVID‑19(„coronavirus disease 2019“)-Pandemie wurden Schlaganfälle als Manifestation oder Komplikation einer SARS-CoV-2(„severe acute respiratory syndrome coronavirus 2“)-Infektion beschrieben. Aktuelle Metaanalysen berichten eine Schlaganfallrate von etwa 1,5 %. Schlaganfälle bei COVID‑19-Patienten treten zwar häufiger bei schweren Verläufen der Infektion und bei älteren Patienten mit kardiovaskulären Risiken auf. Nicht selten sind aber auch junge Patienten ohne Risikofaktoren betroffen. Die Schlaganfallmechanismen sind vorwiegend embolisch, die Thromben verschließen häufig große intrakranielle Gefäße und betreffen in mehr als 20 % mehrere Gefäßterritorien, während mikroangiopathische Infarkte selten sind. Die genaue Emboliequelle bleibt bei über 40 % der Betroffenen kryptogen. Die durch das Zusammentreffen einer SARS-CoV-2-Infektion und eines Schlaganfalls bedingte Mortalität beträgt mehr als 15–30 %. Während es in manchen europäischen Regionen zu erheblichen Einschränkungen der Akutversorgung von Schlaganfällen gekommen ist, sind die Behandlungsraten für die Rekanalisationstherapie in Deutschland während der 1. Pandemiewelle weitgehend stabil geblieben. Es stellten sich aber 20–30 % weniger Patienten mit v. a. leichteren Schlaganfällen und transitorischen ischämischen Attacken in Krankenhäusern vor. Die vorliegende Übersichtsarbeit fasst die aktuellen Erkenntnisse zur Epidemiologie und Pathogenese COVID‑19-assoziierter Schlaganfälle zusammen und beschreibt die bisherigen Auswirkungen der Pandemie auf die Schlaganfallakutversorgung.
IGFBP-1 expression is reduced in human type 2 diabetic glomeruli and modulates β1-integrin/FAK signalling in human podocytes
Authors: Lay Abigail C. , Hale Lorna J. , Stowell-Connolly Holly , Pope Robert J. P. , Nair Viji , Ju Wenjun , Marquez Eva , Rollason Ruth , Hurcombe Jenny A. , Hayes Bryony , Roberts Timothy , Gillam Lawrence , Allington Jonathan , Nelson Robert G. , Kretzler Matthias , Holly Jeff M. P. , Perks Claire M. , McArdle Craig A. , Welsh Gavin I. , Coward Richard J. M.
Published: March 2021

Aims/hypothesis

Podocyte loss or injury is one of the earliest features observed in the pathogenesis of diabetic kidney disease (DKD), which is the leading cause of end-stage renal failure worldwide. Dysfunction in the IGF axis, including in IGF binding proteins (IGFBPs), is associated with DKD, particularly in the early stages of disease progression. The aim of this study was to investigate the potential roles of IGFBPs in the development of type 2 DKD, focusing on podocytes.

Methods

IGFBP expression was analysed in the Pima DKD cohort, alongside data from the Nephroseq database, and in ex vivo human glomeruli. Conditionally immortalised human podocytes and glomerular endothelial cells were studied in vitro, where IGFBP-1 expression was analysed using quantitative PCR and ELISAs. Cell responses to IGFBPs were investigated using migration, cell survival and adhesion assays; electrical cell-substrate impedance sensing; western blotting; and high-content automated imaging.

Results

Data from the Pima DKD cohort and from the Nephroseq database demonstrated a significant reduction in glomerular IGFBP-1 in the early stages of human type 2 DKD. In the glomerulus, IGFBP-1 was predominantly expressed in podocytes and controlled by phosphoinositide 3-kinase (PI3K)–forkhead box O1 (FoxO1) activity. In vitro, IGFBP-1 signalled to podocytes via β1-integrins, resulting in increased phosphorylation of focal-adhesion kinase (FAK), increasing podocyte motility, adhesion, electrical resistance across the adhesive cell layer and cell viability.

Conclusions/interpretation

This work identifies a novel role for IGFBP-1 in the regulation of podocyte function and that the glomerular expression of IGFBP-1 is reduced in the early stages of type 2 DKD, via reduced FoxO1 activity. Thus, we hypothesise that strategies to maintain glomerular IGFBP-1 levels may be beneficial in maintaining podocyte function early in DKD.

Graphical abstract
Watershed subarachnoid hemorrhage after middle cerebral artery rescue stenting in patients with acute ischemic stroke
Authors: Diana Francesco , Di Gregorio Maria , Frauenfelder Giulia , Saponiero Renato , Romano Daniele Giuseppe
Published: March 2021

Cortical subarachnoid hemorrhage is an infrequent subtype of non-aneurysmal subarachnoid hemorrhage, rarely reported in watershed territories (wSAH) after carotid stenting. It has never been reported after treatment of middle cerebral artery stenosis (MCAS) that is increasingly used in selected patients, as rescue treatment of failed mechanical thrombectomy, due to recent advancements in endovascular interventions. We present a series of patients with MCAS that developed a wSAH after stenting.
Effectiveness of Pain Control of Local Anaesthetic Wound Infusion Following Elective Midline Laparotomy: A Randomized Trial
Authors: Gathege Daniel , Abdulkarim Abdallah , Odaba David , Mugambi Stanley
Published: March 2021

Background

Post‐operative pain control is an important pillar in enhanced recovery after surgery. There is a paucity of data that compares efficacy of pain control between continuous local anaesthetic wound infusion and thoracic epidural analgesia in elective midline laparotomy patients

Objective

To evaluate pain control between continuous local anaesthetic wound infusion and thoracic epidural analgesia in elective laparotomy patients.

Design

A randomized, single‐blind, controlled clinical trial.

Setting

Aga Khan University Hospital, Nairobi, Kenya.

Population

Patients underwent elective laparotomy.

Methods

Thirty‐eight patients scheduled for elective laparotomy were randomized into two equal groups to receive either continuous local anaesthetic wound infusion or thoracic epidural analgesia. Data on the baseline patient characteristics, total morphine consumption at 72 h, visual analogue scores and rates of adverse effects were collected.

Results

Baseline characteristics of the participants were similar. Continuous local anaesthetic wound infusion was equivalent to thoracic epidural analgesia in terms of pain scores and total morphine consumption at 72 h. Duration of hospital stay was shorter in the intervention arm. There were more surgical site infections in the intervention arm, while catheter dislodgement rate was higher in the thoracic epidural arm.

Conclusion

Continuous local anaesthetic wound infusion is equivalent to thoracic epidural analgesia in management of post‐operative pain following elective midline laparotomy.

Clinical trial registration

Pan African Clinical Trial registry, number PACTR201808607220790.
Does non-visible haematuria require urgent assessment? A retrospective cohort study from a university teaching hospital
Authors: Lucocq James , Ali Adnan , Harrison William , Khalil Tarek , Powar Gursunil , Raza Kamran , Nandwani Ghulam
Published: March 2021

Objectives

It is not certain from current evidence which patient groups with non-visible haematuria (NVH) require urgent investigation and which investigations are sufficient. We report referral outcomes data from Scotland to identify patient groups who will benefit from urgent assessment to rule out urological cancer (UC) and whether full set of investigations are necessary in all referred patients.

Materials and methods

Data were collected from electronic patient records for patients referred with NVH to secondary care urology services between July 2017 and May 2020. The correlations between risk factors and final diagnosis were assessed using categorical variables in a multivariate logistic regression analysis and using chi-squared models. Statistical analysis was performed using IBM SPSS data editor version 25.

Results

Our study cohort comprised 525 patients (43.4% males; median age 66 years), in which UC was diagnosed in 25 patients (4.8%). Age > 60 years had sensitivity and NPV for UC of 92% and 99%, respectively. Univariate and multivariate analysis showed male sex, age ≥ 60 years and smoking were significant predictors of UC in patients with NVH (p < 0.05). There was no significant difference in UC in patients with history of LUTS, anticoagulation and previous UC.

Conclusion

The risk of urologic cancer in NVH patients is significant and male gender, age ≥ 60 years and smoking are significant predictors of UC. Patients with risk factors of UC require complete assessment of both the upper and lower urinary tract; however, in the absence of risk factors, patients do not require urgent or complete assessment.
The extracellular matrix complexity of idiopathic epiretinal membranes and the bilaminar arrangement of the associated internal limiting membrane in the posterior retina
Authors: Altera Annalisa , Tosi Gian Marco , Regoli Marì , De Benedetto Elena , Bertelli Eugenio
Published: March 2021

Purpose

To study the composition of the internal limiting membrane (ILM) of the retina, the extracellular matrix (ECM) of idiopathic epiretinal membranes (iERMs), and the relationships occurring between the two membranes.

Methods

Forty-six iERMs, 24 of them associated with the ILM, were collected and included in this study. The investigation has been carried out by immunofluorescence and confocal microscopy on glutaraldehyde- and osmium-fixed epon-embedded samples and on frozen samples. Sections were double or triple labelled with antibodies against vimentin; collagens I, III, IV, α5(IV), and VI; laminin 1 + 2; laminin α2-, α4-, α5-, β1-, β2-, β3-, γ1-, and γ2-chains; entactin; and fibronectin.

Results

iERM thickness was not uniform. Almost 14% of iERMs showed thickenings due to folding of their ECM component under the cell layer. The vitreal side of iERMs was often shorter than the attached ILM. In this case, the ILM resulted folded under the iERM. ILMs contained laminin 111; laminin α2-, α5-, β1-, β2-, and γ1-chains; entactin; collagens I; α5(IV); [α1(IV)]2α2(IV); and VI. Laminins, entactin, and α5(IV) were gathered on the retinal half of the ILM, whereas collagens [α1(IV)]2α2(IV) and I were restricted to the vitreal side. Collagen VI was detected on both sides of the ILM. iERMs expressed laminin 111, collagens III, [α1(IV)]2α2(IV) and VI, entactin, and fibronectin. Entactin co-localized with laminins and collagen IV.

Conclusions

Analysis of laminins and collagen chain expression indicates that ILM contains laminin 111 (former laminin 1), laminin 521 (former laminin 11), laminin 211 (former laminin 2), collagen [α1(IV)]2α2(IV), and collagen α3(IV)α4(IV)α5. In contrast, iERMs express only collagen [α1(IV)]2α2(IV) and laminin 111. In addition, both iERMs and ILMs contain entactin. The presence of three major constituents of the basement membranes co-localized together in iERMs is suggestive for a deranged process of basement membrane formation which fails to assemble properly. In view of the many interactions occurring among its proteins, the ECM of either the iERMs or the ILMs can account for their reciprocal adhesiveness. In addition, the peculiar deposition of the ECM observed in some samples of iERM is suggestive for its involvement in the formation of macular puckers.
The complexity of verifying population protocols
Authors: Esparza Javier , Jaax Stefan , Raskin Mikhail , Weil-Kennedy Chana
Published: March 2021

Population protocols (Angluin et al. in PODC, 2004) are a model of distributed computation in which indistinguishable, finite-state agents interact in pairs to decide if their initial configuration, i.e., the initial number of agents in each state, satisfies a given property. In a seminal paper Angluin et al. classified population protocols according to their communication mechanism, and conducted an exhaustive study of the expressive power of each class, that is, of the properties they can decide (Angluin et al. in Distrib Comput 20(4):279–304, 2007). In this paper we study the correctness problem for population protocols, i.e., whether a given protocol decides a given property. A previous paper (Esparza et al. in Acta Inform 54(2):191–215, 2017) has shown that the problem is decidable for the main population protocol model, but at least as hard as the reachability problem for Petri nets, which has recently been proved to have non-elementary complexity. Motivated by this result, we study the computational complexity of the correctness problem for all other classes introduced by Angluin et al., some of which are less powerful than the main model. Our main results show that for the class of observation models the complexity of the problem is much lower, ranging from $$\varPi _2^p$$

Π
2
p

to .
The initial run-in and long-term drift of the adhesive force between polycrystalline silicon MEMS sidewalls
Authors: Kokorian Jaap , van Spengen W. Merlijn
Published: March 2021

In this paper we measure the evolution of adhesion between two polycrystalline silicon sidewalls of a microelectromechanical adhesion sensor during three million contact cycles. We execute a series of AFM-like contact force measurements with comparable force resolution, but using real MEMS multi-asperity sidewall contacts mimicking conditions in real devices. Adhesion forces are measured with a very high sub-nanonewton resolution using a recently developed optical displacement measurement method. Measurements are performed under well-defined, but different, low relative humidity conditions. We found three regimes in the evolution of the adhesion force. (I) Initial run-in with a large of cycle-to-cycle variability, (II) Stability with low variability, and (III) device-dependent long term drift. The results obtained demonstrate that although a short run-in measurement shows stabilization, this is no guarantee for long-term stable behavior. Devices performing similarly in region II, can drift very differently afterwards. The adhesion force drift during millions of cycles is comparable in magnitude to the adhesion force drift during initial run-in. The boundaries of the drifting adhesion forces are reasonably well described by an empirical model based on random walk statistics. This is useful knowledge when designing polycrystalline silicon MEMS with contacting surfaces.
A review of nonlinear FFT-based computational homogenization methods
Authors: Schneider Matti
Published: March 2021

Since their inception, computational homogenization methods based on the fast Fourier transform (FFT) have grown in popularity, establishing themselves as a powerful tool applicable to complex, digitized microstructures. At the same time, the understanding of the underlying principles has grown, in terms of both discretization schemes and solution methods, leading to improvements of the original approach and extending the applications. This article provides a condensed overview of results scattered throughout the literature and guides the reader to the current state of the art in nonlinear computational homogenization methods using the fast Fourier transform.
Clinical characterization of 266 patients and family members with cleft lip and/or palate with associated malformations and syndromes
Authors: Bartzela Theodosia , Theuerkauf Björn , Reichardt Elisabeth , Spielmann Malte , Opitz Charlotte
Published: March 2021

Objectives

To clinically characterize patients and family members with cleft lip and/or palate (CL/P) and associated congenital malformations or syndromes and propose possible inheritance patterns.

Materials and methods

An observational study of patients with CL/P, including medical and family history and intra- and extra-oral examination of their family members, was performed.

Results

Two hundred sixty-six patients, 1257 family members, and 42 pedigrees were included in the study. The distribution of patients according to the cleft type was 57.9% with CLP, 25.2% with cleft palate (CPO), and 12.8% with cleft lip with/without alveolus (CL/A). Seventy-four (27.8%) patients had associated malformations, and 24 (9.2%) a syndrome. The skeletal (27.7%), cardiovascular (19.3%) systems, and eyes (22.9%) were most commonly affected. Pierre Robin Sequence (7 patients) and van der Woude (4) were the most common syndromes. The majority of patients with CPO (19/24) had an associate syndrome. The families had an average of 2.45 affected members.

Conclusion

Individual and interfamilial phenotypic variability in patients with CL/P makes the understanding of etiopathogenesis challenging.

Clinical relevance

The overall prevalence of individuals with CL/P and their pedigrees with associated malformations and syndromes emphasize the need for early identification, interdisciplinary, and long-term planning.
Social relationship dynamics mediate climate impacts on income inequality: evidence from the Mexican Humboldt squid fishery
Authors: Elsler Laura G. , Frawley Timothy Haight , Britten Gregory L. , Crowder Larry B. , DuBois Timothy C. , Radosavljevic Sonja , Gilly William F. , Crépin Anne-Sophie , Schlüter Maja
Published: March 2021

Small-scale fisheries are critically important for livelihoods around the world, particularly in tropical regions. However, climate variability and anthropogenic climate change may seriously impact small-scale fisheries by altering the abundance and distribution of target species. Social relationships between fishery users, such as fish traders, can determine how each individual responds and is affected by changes in fisheries. These informal cooperative and competitive relationships provide access, support, and incentives for fishing and affect the distribution of benefits. Yet, individuals’ actions and impacts on individuals are often the primary focus of the economic analyses informing small-scale fisheries’ formal management. This focus dismisses relevant social relationships. We argue that this leads to a disconnect between reality and its model representation used in formal management, which may reduce formal fisheries management’s efficiency and efficacy and potentially trigger adverse consequences. Here, we examine this argument by comparing the predictions of a simple bioeconomic fishery model with those of a social-ecological model that incorporates the dynamics of cooperative relationships between fish traders. We illustrate model outcomes using an empirical case study in the Mexican Humboldt squid fishery. We find that (1) the social-ecological model with relationship dynamics substantially improves accuracy in predicting observed fishery variables to the simple bioeconomic model. (2) Income inequality outcomes are associated with changes in cooperative trade relationships. When environmental temperature is included in the model as a driver of species production dynamics, we find that climate-driven temperature variability drives a decline in catch that, in turn, reduce fishers’ income. We observe an offset of this loss in income by including cooperative relationships between fish traders (oligopoly) in the model. These relationships break down following species distribution changes and result in an increase in prices fishers receive. Finally, (3) our social-ecological model simulations show that the current fishery development program, which seeks to increase fishers’ income through an increase in domestic market demand, is supported by predictions from the simple bioeconomic model, may increase income inequality between fishers and traders. Our findings highlight the real and urgent need to re-think fisheries management models in the context of small-scale fisheries and climate change worldwide to encompass social relationship dynamics.
Are the existing guidelines sufficient for the assessment of bathing water quality? The example of Polish lakes
Authors: Pronin Eugeniusz
Published: March 2021

The safety of beachgoers and swimmers is determined by the presence or absence of microbial contaminants and cyanobacterial toxins in the water. This study compared the assessment of bathing waters according to the Bathing Water Directive, which is based on the concentration of fecal contaminants, with some modifications, and a new method based on the concentration of chlorophyll-a, which corresponds to the World Health Organization (WHO) guidelines used for determining cyanobacterial density in the water posing threat to people health. The results obtained from the method based on chlorophyll-a concentration clearly showed that the number of bathing waters in Poland with sufficient and insufficient quality were higher in 2018 and 2019, compared to the method based on microbial contamination. The closing of bathing waters based only on the visual confirmation of cyanobacterial blooms might not be enough to prevent the threat to swimmers’ health. The multivariate analyses applied in this study seem to confirm that chlorophyll-a concentration with associated cyanobacterial density might serve as an additional parameter for assessing the quality of bathing waters, and in the case of small water reservoirs, might indirectly inform about the conditions and changes in water ecosystems.
A Gamma Ornstein–Uhlenbeck model driven by a Hawkes process
Authors: Bernis Guillaume , Brignone Riccardo , Scotti Simone , Sgarra Carlo
Published: March 2021

We propose an extension of the $$\Gamma $$
Γ
-OU Barndorff-Nielsen and Shephard model taking into account jump clustering phenomena. We assume that the intensity process of the Hawkes driver coincides, up to a constant, with the variance process. By applying the theory of continuous-state branching processes with immigration, we prove existence and uniqueness of strong solutions of the SDE governing the asset price dynamics. We propose a measure change of self-exciting Esscher type in order to describe the relation between the risk-neutral and the historical dynamics, showing that the $$\Gamma $$
Γ
-OU Hawkes framework is stable under this probability change. By exploiting the affine features of the model we provide an explicit form for the Laplace transform of the asset log-return, for its quadratic variation and for the ergodic distribution of the variance process. We show that the proposed model exhibits a larger flexibility in comparison with the $$\Gamma $$
Γ
-OU model, in spite of the same number of parameters required. We calibrate the model on market vanilla option prices via characteristic function inversion techniques, we study the price sensitivities and propose an exact simulation scheme. The main financial achievement is that implied volatility of options written on VIX is upward shaped due to the self-exciting property of Hawkes processes, in contrast with the usual downward slope exhibited by the $$\Gamma $$
Γ
-OU Barndorff-Nielsen and Shephard model.
Spotting ignition of larch (Larix gmelinii) fuel bed by different firebrands
Authors: Yang Guang , Ning Jibin , Shu Lifu , Zhang Jili , Yu Hongzhou , Di Xueying
Published: March 2021

Spot fire increase the difficulty of fire-fighting and threaten public safety, and therefore it is important to study ignition probabilities of fuel bed by different firebrands, in order to understand ignition mechanisms and analyze the formation of spot fires. This will provide an important basis for further study to improve the fire-fighting efficiency and reduce casualties. In this study, the ignition probabilities of larch (Larix gmelinii) fuel beds with different moisture levels and packing ratios by diffreent firebrands, including cones and twigs of different sizes, was investigated. Ignition experiments were conducted at different wind speeds generated by fans. The results show that, regardless of moisture content and packing ratio, ignition probability is zero when there is no wind. Both moisture content and wind speed significantly influence ignition probability, while packing ratio has almost no effect. The maximum moisture content at which firebrand ignition occurred was 50%, and ignition probability increased with wind speed and decreased with moisture content. Cones have the highest ignition probability, followed by large twigs and by small twigs. Ignition probability is also affected by firebrand shapes and sizes that determine their potential heat and contact area to the fuel bed. Two empirical models were established to link ignition probability with fuel properties and wind speed. This study will help clarify the mechanism of spot ignition and reduce corresponding losses.
PET Stress Testing with Coronary Flow Capacity in the Evaluation of Patients with Coronary Artery Disease and Left Ventricular Dysfunction: Rethinking the Current Paradigm
Authors: Bober Robert M. , Milani Richard V. , Krim Selim R. , Morin Daniel P.
Published: March 2021

Purpose of Review

Cardiomyopathy with underlying left ventricular (LV) dysfunction is a heterogenous group of disorders that may be present with, and/or secondary to, coronary artery disease (CAD). The purpose of this review is to demonstrate, via case illustrations, the benefits offered by cardiac positron-emission tomography (PET) stress testing with coronary flow capacity (CFC) in the evaluation and treatment of patients with left ventricular (LV) dysfunction and CAD.

Recent Findings

CFC, a metric that is increasing in prominence, represents the integration of several absolute perfusion metrics into clinical strata of CAD severity. Our prior work has demonstrated improvement in regional perfusion metrics as a result of revascularization to territories with severe reduction in CFC. Conversely, when CFC is adequate, there is no change in regional perfusion metrics following revascularization, despite angiographically severe stenosis. Furthermore, Gould et al. demonstrated decreased rates of myocardial infarction and death following revascularization of myocardium with severely reduced CFC, with no clinical benefit observed following revascularization of patients with preserved CFC. In a series of cases, we present pre-revascularization and post-revascularization PET scans with perfusion metrics in patients with LV dysfunction and CAD. In these examples, we demonstrate improvement in LV function and perfusion metrics following revascularization only in cases where baseline CFC is severely reduced.

PET with CFC offers unique guidance regarding revascularization in patients with reduced LV function and CAD.
Continuous High-pressure Cooling-Assisted Homogenization Process for Stabilization of Apple Juice
Authors: Szczepańska Justyna , Skąpska Sylwia , Marszałek Krystian
Published: March 2021

The effect of high-pressure homogenization (HPH) at 100–200 MPa (with up to 5 passes) on the quality and storage stability of apple juice was investigated. The microbiological quality, polyphenol oxidase (PPO), peroxidase (POD), polygalacturonase (PG) and pectinmethylesterase (PME) activity, particle size distribution (PSD), apparent viscosity, turbidity, concentration of vitamin C, individual polyphenols and their total content (TPC), antioxidant activity, and colour of fresh, HPH-treated apple juice were all evaluated. The highest reduction in microorganisms (1.4 log) and oxidoreductase activity (~20%) was observed at 200 MPa, while hydrolases did not change significantly. HPH led to significant disintegration of the tissue and a decrease in viscosity. Vitamin C decreased by 62%, while TPC increased by 20% after HPH. Significant correlations were observed between antioxidant activity, TPC, and individual polyphenols. Chlorogenic, ferulic, and gallic acid were most stable at 200 MPa. The optimal shelf-life of the juice was estimated as 7 days.
Are narcissists resilient? Examining grandiose and vulnerable narcissism in the context of a three-dimensional model of resilience
Authors: Sękowski Michał , Subramanian Łukasz , Żemojtel-Piotrowska Magdalena
Published: March 2021

In this paper, we focused on the poorly understood and rarely researched relationship between resilience and narcissism, adopting the adjective-based measures of narcissism. We examine how levels of resilience are related to grandiose and vulnerable narcissism, based on a three-dimensional model of resilience (i.e., ecological resilience, engineering resilience, and adaptive capacity). Using self-report, cross-sectional data from a general Polish sample (N = 657), we found that grandiose narcissism was positively related to all three dimensions of resilience, while vulnerable narcissism was negatively related to them. Grandiose narcissism was most strongly associated with adaptive capacity where vulnerable narcissism was mostly strongly associated with engineering resilience. We discuss our findings in relation to the function of two forms of narcissism may yield different capacities for stress management and recovery after experiencing stressful events. Therefore, this research is focused on self-report and we look forward to expand our research by behavioral indices in the future.
Understanding the evaluation of mHealth app features based on a cross-country Kano analysis
Authors: Gimpel Henner , Manner-Romberg Tobias , Schmied Fabian , Winkler Till J.
Published: March 2021

While mobile health (mHealth) apps play an increasingly important role in digitalized health care, little is known regarding the effects of specific mHealth app features on user satisfaction across different healthcare system contexts. Using personal health record (PHR) apps as an example, this study identifies how potential users in Germany and Denmark evaluate a set of 26 app features, and whether evaluation differences can be explained by the differences in four pertinent user characteristics, namely privacy concerns, mHealth literacy, mHealth self-efficacy, and adult playfulness. Based on survey data from both countries, we employed the Kano method to evaluate PHR features and applied a quartile-based sample-split approach to understand the underlying relationships between user characteristics and their perceptions of features. Our results not only reveal significant differences in 14 of the features between Germans and Danes, they also demonstrate which of the user characteristics best explain each of these differences. Our two key contributions are, first, to explain the evaluation of specific PHR app features on user satisfaction in two different healthcare contexts and, second, to demonstrate how to extend the Kano method in terms of explaining subgroup differences through user characteristic antecedents. The implications for app providers and policymakers are discussed.
Making our “meta-hypotheses” clear: heterogeneity and the role of direct replications in science
Authors: Strømland Eirik
Published: March 2021

This paper argues that some of the discussion around meta-scientific issues can be viewed as an argument over different “meta-hypotheses” – assumptions made about how different hypotheses in a scientific literature relate to each other. I argue that, currently, such meta-hypotheses are typically left unstated except in methodological papers and that the consequence of this practice is that it is hard to determine what can be learned from a direct replication study. I argue in favor of a procedure dubbed the “limited homogeneity assumption” – assuming very little heterogeneity of effect sizes when a literature is initiated but switching to an assumption of heterogeneity once an initial finding has been successfully replicated in a direct replication study. Until that has happened, we do not allow the literature to proceed to a mature stage. This procedure will elevate the scientific status of direct replication studies in science. Following this procedure, a well-designed direct replication study is a means of falsifying an overall claim in an early phase of a literature and thus sets up a hurdle against the canonization of false facts in the behavioral sciences.
Finite-Time Adaptive Fuzzy Control for Nonlinear Systems with Unknown Backlash-Like Hysteresis
Authors: Diao Shuzhen , Sun Wei , Wang Le , Wu Jing
Published: March 2021

This study considers the tracking control problem of the nonstrict-feedback nonlinear system with unknown backlash-like hysteresis, and a finite-time adaptive fuzzy control scheme is developed to address this problem. More precisely, the fuzzy systems are employed to approximate the unknown nonlinearities, and the design difficulties caused by the nonlower triangular structure are also overcome by using the property of fuzzy systems. Besides, the effect of unknown hysteresis input is compensated by approximating an intermediate variable. With the aid of finite-time stability theory, the proposed control algorithm could guarantee that the tracking error converges to a smaller region. Finally, a simulation example is provided to further verify the above theoretical results.
Dynamic centrality measures for cattle trade networks
Authors: Hoscheit Patrick , Anthony Éric , Vergu Elisabeta
Published: March 2021

We study network centrality measures that take into account the specific structure of networks with time-stamped edges. In particular, we explore how such measures can be used to identify nodes most relevant for the spread of epidemics on directed, temporal contact networks. We present a percolation study on the French cattle trade network, proving that time-aware centrality measures such as the TempoRank significantly outperform measures defined on the static network. In order to make TempoRank amenable to large-scale networks, we show how it can be efficiently computed through direct simulation of time-respecting random walks.
Spectroscopic ellipsometry investigation to study the microstructure evolution in boron-doped amorphous silicon films as a result of hydrogen dilution
Authors: Kanneboina Venkanna , Agarwal Pratima
Published: March 2021

Spectroscopic ellipsometry (SE) is a sophisticated technique to find the optical constants, bandgap and microstructure of thin layer. SE is used to study the microstructure evolution in boron-doped amorphous silicon films for different hydrogen flow rates (HFR). Spectral dependance of the real and imaginary parts of pseudo-dielectric constant is obtained at a fix angle of incidence (70°). Tauc–Lorentz (T–L) optical model is used to estimate the thickness, bandgap, optical constant and thickness of the top rough layer of the films, whereas Bruggeman effective medium approximation (BEMA) is applied to find the volume fractions of amorphous, crystalline and void phases. A shift in peak position from 3.65 to 4.1 eV in dielectric constant is observed as the hydrogen flow rate is increased from 30 to 70 SCCM. This is accompanied by the emergence of a peak near 3.4 eV, which belongs to the direct bandgap of c-Si. These observations suggest an improvement in microstructure of the films deposited at higher HFR. It is also supported by the observation that films deposited at higher HFR have higher magnitude of amplitude parameter and less broadening. Fitting of experimental data using BEMA also suggests that crystalline fraction increases and amorphous fraction decreases at higher HFR. The bandgap and thickness of top rough layer estimated from SE data are matched well with those obtained using transmission data and atomic force microscopy.
China and the global search for health security: history, vaccines, and governance
Authors: Zha Daojiong
Published: March 2021

China is a key player, not just an actor, in the global search for health security. Reiteration of this point is useful for International Relations studies, which often portray China as a factor to contend with, especially given the background of the country as the first to report the outbreak of the COVID-19 pandemic. This paper adopts an analytical framework developed through a summary of routines in Chinese engagement in global health from a practitioner’s perspective: aid, interdependence, governance and knowledge. These are the core elements in a country’s pursuit of engagement with the rest of the world. After the introduction, the second section of the paper reviews contributions from China in the history of global plague control over the past century. The third section discusses structural issues affecting access to vaccines, which are essential for bringing COVID-19 under effective control. The fourth section identifies a number of challenges China is facing in global health governance. The final section offers a few concluding thoughts, reiterating the nature of interdependence in the global search for enhancement of health security.
Elasto-capillary circumferential buckling of soft tubes under axial loading: existence and competition with localised beading and periodic axial modes
Authors: Emery Dominic , Fu Yibin
Published: March 2021

We provide an extension to previous analysis of the localised beading instability of soft slender tubes under surface tension and axial stretching. The primary questions pondered here are as follows: under what loading conditions, if any, can bifurcation into circumferential buckling modes occur, and do such solutions dominate localisation and periodic axial modes? Three distinct boundary conditions are considered: in case 1 the tube’s curved surfaces are traction-free and under surface tension, whilst in cases 2 and 3 the inner and outer surfaces (respectively) are fixed to prevent radial displacement and surface tension. A linear bifurcation analysis is conducted to determine numerically the existence of circumferential mode solutions. In case 1 we focus on the tensile stress regime given the preference of slender compressed tubes towards Euler buckling over axisymmetric periodic wrinkling. We show that tubes under several loading paths are highly sensitive to circumferential modes; in contrast, localised and periodic axial modes are absent, suggesting that the circumferential buckling is dominant by default. In case 2, circumferential mode solutions are associated with negative surface tension values and thus are physically implausible. Circumferential buckling solutions are shown to exist in case 3 for tensile and compressive axial loads, and we demonstrate for multiple loading scenarios their dominance over localisation and periodic axial modes within specific parameter regimes.
Economic Principles of Commodity Taxation
Authors: Christiansen Vidar , Smith Stephen
Published: March 2021

This Element provides a broad overview of economic aspects of commodity taxation, focussing in particular on theory and on policy applications in OECD countries. Some major papers in public economics have discussed whether these taxes should be levied at a uniform rate, or whether different commodities should be taxed differently, for reasons of either equity or efficiency. The authors begin with this question, and then discuss further issues, including the economic incidence of indirect commodity taxes, the properties of the VAT, the taxation of financial services, the international aspects of commodity taxation, and environmental and health policy aspects.