bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seroprevalence and risk factors ofToxoplasma gondiiinfection in wild ungulates that cohabit in a natural park with human–animal interaction in the Mediterranean ecosystem
Authors: Almería Sonia , Cano‐Terriza David , Prieto Paloma , Dubey Jitender P. , Jiménez‐Martín Débora , Castro‐Scholten Sabrina , Paniagua Jorge , García‐Bocanegra Ignacio 
Published: February 2021

AbstractThe possibility ofToxoplasma gondiitransmitted from game meat to humans is of public health concern. Here we determined seroprevalence and risk factors associated withT. gondiiin large game ungulates that cohabit in Sierras de Cazorla, Segura and Las Villas Natural Park (SCSV‐NP) (Southern Spain), a natural park with high human–animal interaction. Antibodies againstT. gondiiin 328 wild ungulates were assayed by the modified agglutination test (MAT ≥ 1:25). Antibodies were found in 39 (11.9%, 95% CI: 8.4–15.4) wild ungulates, with seroprevalence levels of 20.8% in wild boars (Sus scrofa) (5/24), 19.0% in fallow deer (Dama dama) (12/63), 13.9% in Iberian ibex (Capra pyrenaica hispanica) (14/101), 7.9% in red deer (Cervus elaphus) (6/76), and 3.1% in mouflons (Ovis aries musimon) (2/64). Significantly higher seroprevalence was observed in fallow deer and wild boars compared to mouflons. Animals living close to urban areas (<2 km) had 4.6‐times higher risk compared to those living at >5 km of urban areas. The results indicate high circulation ofT. gondiiin wild ungulates in SCSV‐NP, which is of animal and public health concern. The increased seroprevalence ofT. gondiidetected in wildlife ungulates living close to urban areas may increase human infection in those areas if meat from infected animals is consumed raw or undercooked.
El contexto vivo: reflexiones sobre una experiencia etnográfica colaborativa universitaria
Authors: Huerta-Cordova Vilma , Clemente-Olmos Ángeles , Córdova-Hernández Lorena 
Published: February 2021

Se describe un ejercicio etnográfico colaborativo desarrollado por universitarios futuros docentes de idiomas para la observación y descripción del contexto vivo de su investigación,cuyo producto final es un texto académico en coautoría que forma parte de su tesis de grado. En específico, este artículo analiza cómo los estudiantes se posicionaron como investigadores y, a partir de ello, cómo describieron las condiciones de su espacio de observación y visibilizaron a los actores sociales. Asimismo, se analizan sus testimonios sobre el aprendizaje adquirido en el momento de organizar la observación etnográfica, así como la negociación de los conflictos surgidos durante la colaboración.
Experimental Validation of a Bio-Inspired Thruster
Authors: Costa Daniele , Palmieri Giacomo , Scaradozzi David , Callegari Massimo 
Published: February 2021

Abstract
Bio-inspired solutions have been deeply investigated in the last two decades as a source of propulsive improvement for autonomous underwater vehicles. Despite the efforts made to pursue the substantial potential payoffs of marine animals' locomotion, the performance of biological swimmers is still far to reach. The possibility to design a machine capable of propelling itself like a marine animal strongly depends on the understanding of the mechanics principles underlying biological swimming. Therefore, the adoption of advanced simulation and measurement techniques is fundamental to investigate the fluid–structure interaction phenomena of aquatic animals' locomotion. Among those, computational fluid dynamics represents an invaluable tool to assess the propulsive loads due to swimming. However, the numerical predictions must be validated before they can be applied to the design of a bio-inspired robot. To this end, this paper presents the experimental setup devised to validate the fluid dynamics analysis performed on an oscillating foil. The numerical predictions led to the design of a strain gages-based sensor, which exploits the deflection and twisting of the foil shaft to indirectly measure the propulsive loads and obtain a complete dynamic characterization of the oscillating foil. The results obtained from the experiments showed a good agreement between the numerical predictions and the measured loads; the test equipment also allowed to investigate the potential benefits of a slender fish-like body placed before the spinning fin. Therefore, in future work, the system will be employed to validate the analysis performed on more sophisticated modes of locomotion.
Experimental Investigation of Leakage in the Modified Revolving Vane Expander
Authors: Naseri Ali , Norris Stuart E. , Subiantoro Alison 
Published: February 2021

Abstract
This study focuses on the leakage characteristics of a modified revolving vane expander (M-RVE) using both static and dynamic leakage analysis. The no-expansion scenario showed a maximum volumetric efficiency of 18.7% was achieved at 5.5 bar(g) suction pressure, showing the severity of internal leakages. The blocker angle study demonstrated the importance of the correct opening-angle selection to avoid under or over-expansion. The maximum volumetric efficiencies for opening angles of 94 deg and 145 deg were 2.8% and 8.3%, respectively, at suction and discharge pressures of 6.5 bar(g) and 1 atm, respectively. The static leakage test demonstrated that the M-RVE housing was properly sealed, and the observed leakage in the dynamic test was mostly due to internal leakages. The results showed that the leakages through the radial clearance, endface, and vane side gaps make up 54%, 33%, and 8.5% of the overall leakage. Comparison between the theoretical and experimental data of the leakages through the radial clearance gap showed significant deviations at higher suction pressures. The reasons are thought to be due to the shafts' tilt, and the cylinder and rotor head deflections. It is believed that the deflection of the shaft created new leakage paths or changed the geometry of the current paths.
Enhanced Tribological Properties of an Advanced Al–Al2O3 Composite Infiltrated With a Tin-Based Alloy
Authors: Stanev Lenko , Kolev Mihail , Drenchev Ludmil 
Published: February 2021

AbstractIn this article, a new hybrid material is elaborated, which combines the advantages of the mechanically more resistive alloy-based composites and the effective lubricating properties of tin-based alloys with the purpose of enhancing the tribological properties and especially to enhance resistance under extreme and transient operating conditions for the application of sliding bearings. The hybrid material consists of an aluminum composite skeleton obtained via a replication method with NaCl particles as spacers and a tin-based alloy that is infiltrated into the composite skeleton. The hybrid material is characterized in respect to its microstructure and tribological parameters, such as the wear-rate and coefficient of friction. Data from the conducted tribological tests using the pin-on-disk method under dry friction conditions are obtained and compared with the results of the same tribological tests for the Al alloy, Al alloy-based porous skeleton, Al alloy-based porous composite skeleton, and tin-based alloy. It is concluded that the new hybrid material possesses superior tribological properties in comparison with the tin-based alloy, Al alloy, Al alloy-based porous skeleton, and Al alloy-based porous composite skeleton.
Sensor Egregium—An Atomic Force Microscope Sensor for Continuously Variable Resonance Amplification
Authors: Shihab Rafiul , Jalil Tasmirul , Gulsacan Burak , Aureli Matteo , Tung Ryan 
Published: February 2021

Abstract
Numerous nanometrology techniques concerned with probing a wide range of frequency-dependent properties would benefit from a cantilevered sensor with tunable natural frequencies. In this work, we propose a method to arbitrarily tune the stiffness and natural frequencies of a microplate sensor for atomic force microscope applications, thereby allowing resonance amplification at a broad range of frequencies. This method is predicated on the principle of curvature-based stiffening. A macroscale experiment is conducted to verify the feasibility of the method. Next, a microscale finite element analysis is conducted on a proof-of-concept device. We show that both the stiffness and various natural frequencies of the device can be controlled through applied transverse curvature. Dynamic phenomena encountered in the method, such as eigenvalue curve veering, are discussed and methods are presented to accommodate these phenomena. We believe that this study will facilitate the development of future curvature-based microscale sensors for atomic force microscopy applications.
Three-Dimensional Aeroelastic Model for Successive Analyses of High-Aspect-Ratio Wings
Authors: Otsuka Keisuke , Wang Yinan , Makihara Kanjuro 
Published: February 2021

Abstract
Next-generation civil aircraft and atmospheric satellites will have high-aspect-ratio wings. Such a design necessitates successive analysis of static, frequency, and time-domain dynamic responses based on a three-dimensional nonlinear beam model. In this study, a new successive-analysis framework based on an absolute nodal coordinate formulation with mean artificial strains (ANCF-MAS) is developed. While retaining the advantages of other three-dimensional (3D) ANCF approaches, such as constancy of the mass matrix and absence of velocity-dependent terms, ANCF-MAS uses the elastic force of the mean artificial strains to remove cross-sectional deformations that cause locking problems. The equation becomes a differential equation with an easily linearized elastic force that enables not only static and dynamic analyses but also frequency analysis using standard eigenvalue solvers. The solutions converge to the analytical frequencies without suffering from locking problems. A proposed successive-analysis method with model-order reduction reveals that the frequencies vary with the nonlinear static deformation because of the 3D deformation coupling. This reduced-order model agrees well with nonlinear models even when the wing experiences a large nonlinear dynamic deformation.
Elastic Solution of a Polygon-Shaped Inclusion With a Polynomial Eigenstrain
Authors: Wu Chunlin , Yin Huiming 
Published: February 2021

Abstract
This paper presents the Eshelby’s tensor of a polygonal inclusion with a polynomial eigenstrain, which can provide an elastic solution to an arbitrary, convex inclusion with a continuously distributed eigenstrain by the Taylor series approximation. The Eshelby’s tensor for plane strain problem is derived from the fundamental solution of isotropic Green’s function with the Hadmard regularization, which is composed of the integrals of the derivatives of the harmonic and biharmonic potentials over the source domain. Using the Green’s theorem, they are converted to two line (contour) integrals over the polygonal cross section. This paper evaluates them by direct analytical integrals. Following Mura’s work, this paper formulates the method to derive linear, quadratic, and higher order of the Eshelby’s tensor in the polynomial form for arbitrary, convex polygonal shapes of inclusions. Numerical case studies were performed to verify the analytic results with the original Eshelby’s solution for a uniform eigenstrain in an ellipsoidal domain. It is of significance to consider higher order terms of eigenstrain for the polygon-shape inclusion problem because the eigenstrain distribution is generally non-uniform when Eshelby’s equivalent inclusion method is used. The stress disturbance due to a triangle particle in an infinite domain is demonstrated by comparison with the results of the finite element method (FEM). The present solution paves the way to accurately simulate the particle-particle, partial-boundary interactions of polygon-shape particles.
Exploring System of Systems Resilience Versus Affordability Trade-Space Using a Bio-Inspired Metric
Authors: Chatterjee Abheek , Malak Richard , Layton Astrid 
Published: February 2021

Abstract
The objective of this study is to investigate the value of an ecologically inspired architectural metric called the degree of system order in the system of systems (SoS) architecting process. Two highly desirable SoS attributes are the ability to withstand and recover from disruptions (resilience) and affordability. In practice, more resilient SoS architectures are less affordable, and it is essential to balance the trade-offs between the two attributes. Ecological research analyzing long-surviving ecosystems (nature’s resilient SoS) using the degree of system order metric has found a unique balance of efficient and redundant interactions in their architecture. This balance implies that highly efficient ecosystems tend to be inflexible and vulnerable to perturbations, while highly redundant ecosystems fail to utilize resources effectively for survival. Motivated by this unique architectural property of ecosystems, this study investigates the response to disruptions versus affordability trade space of a large number of feasible SoS architectures. Results indicate that the most favorable SoS architectures in this trade space share a specific range of values of degree of system order. This suggests that degree of system order can be a key metric in engineered SoS development. Evaluating the degree of system order does not require detailed simulations and can, therefore, guide the early-stage SoS design process toward more optimal SoS architectures.
Motoric and Perceptual Kinesthetic Symmetry in Bi-Manual Interactions
Authors: Mohanty Ronak R. , Adhikari Riddhi R. , Krishnamurthy Vinayak R. 
Published: February 2021

Abstract
Bi-manual (two-handed) actions have shown notable success in rehabilitative and therapeutic applications from the point of motor symmetry. Recent studies have shown that symmetry in actions is attributed to sensorimotor perception than mere co-activation of homologous muscles. In this paper, we present a study of symmetric and asymmetric haptic (specifically force) feedback on human perception and motor action during bi-manual spatial tasks. To the best of our knowledge, ours is the first procedure to specifically test the perceptual aspect of bi-manual actions in contrast to other works that typically characterize the physical/bio-mechanical aspects. Thereby in our experiment, healthy individuals were tasked with stretching a virtual spring using two symmetrically located haptics devices that provide an equal amount of resistive force on each hand while pulling the spring. In this experiment, we implement four kinesthetic conditions, namely (1) feedback on both hands, (2) feedback only on dominant hand, (3) feedback only on non-dominant hand, and (4) no feedback as our control. Our first goal was to determine if there exists a range of spring stiffness in which the individual incorrectly perceives bi-manual forces when the feedback is deactivated on one hand. Subsequently, we also wanted to investigate what range of spring stiffness would lead to such perceptual illusions. Our analysis shows that not only does such a range exist, it is wide enough so as to be potentially utilized in future rehabilitative applications.
Design and Prototyping of Rotational Bi-Stable Mechanism Using Permanent Magnets
Authors: Yang Hyeon-Ho , Han Jae-Hung 
Published: February 2021

Abstract
Diverse applications including switches, deployable structures, and reconfigurable robots can benefit from bi-stability characteristics. However, the complexity of the implementation and the limitation of the structural configuration makes it difficult to apply conventional bi-stable mechanisms to the structures that require rotational bi-stability. In this paper, an implementation method using cylindrical magnets for the rotational bi-stable mechanism is proposed. The proposed bi-stable mechanism consists of a revolute joint with two links. It has rotational bi-stability through the magnetic force relationship between the array of magnets on each link. To identify the characteristics of the proposed bi-stable mechanism, a cylindrical permanent magnet is considered as an electromagnet model that consists of one ring with a virtual electric current. The magnetic field of the cylindrical permanent magnet can be calculated using the Biot–Savart law. Similarly, the magnetic force between two cylindrical permanent magnets is calculated using the Lorentz force law. The criteria of the magnet array for symmetric bi-stability are described and the potential energy diagram of the rotation link is considered as the performance criterion to identify the stable state. The proposed bi-stable mechanism was applied to the prototype of a deployable structure consisting of two links. The load testing of the structure against external torque was performed and it was obtained that the rotation link can stay within 5 deg angle to the maximum load applied and was experimentally verified with good agreement.
Development of the retina and its relation with myopic shift varies from childhood to adolescence
Authors: Jin Peiyao , Deng Junjie , Lv Minzhi , Sun Sifei , Zhu Jianfeng , Xu Xun , He Xiangui , Zou Haidong 
Published: February 2021

AimsTo elucidate the influence of age and myopic shift on retinal development.MethodsThis 1-year longitudinal study included 769 participants aged 6–17 years. Cycloplegic refraction, axial length and swept-source optical coherence tomography were examined at baseline and follow-up. The thickness changes in the retina, ganglion cell complex (GCC) and outer retinal layers (ORL) in the macular region were calculated, and their relation with age and myopic shift was analysed with multiple linear regression analysis.ResultsThe thickness of the central foveal retinal layers was increased in children (<10 years) but unchanged or decreased in adolescents (>13 years). The thickness changes in the retina, GCC and ORL decreased with age (r=−0.24,–0.23, −0.15, respectively, all p<0.01). Multiple regression analysis showed that the changes in central foveal retinal thickness (RT) and GCC thickness were independently associated with age and baseline spherical equivalent (SE), while the changes in ORL thickness were associated with age and SE changes. In children 8–9 years, a greater increase was observed in central foveal ORL thickness in those with no myopic shift (p<0.01). The thickness of the most parafoveal and perifoveal retinal layers was less increased or more decreased in children <9 years with myopic shift (p<0.05).ConclusionsRetinal development and its relation with myopic shift varies from childhood to adolescence. Myopia-related retinal thinning may result from less increase in the RT in childhood rather than a decrease in RT in adolescents. Children under 9 years old could be at a critical age for future myopia-related retinal thinning.
Downregulation of epithelial sodium channel (ENaC) activity in human airway epithelia after low temperature incubation
Authors: Yadav Sangya , Shaughnessy Ciaran A , Zeitlin Pamela L , Bratcher Preston E 
Published: February 2021

IntroductionThe incubation of airway epithelia cells at low temperatures is a common in vitro experimental approach used in the field of cystic fibrosis (CF) research to thermo-stabilise F508del-CFTR and increase its functional expression. Given that the airway epithelium includes numerous ion transporters other than CFTR, we hypothesised that there was an impact of low temperature incubation on CFTR-independent ionoregulatory mechanisms in airway epithelia derived from individuals with and without CF.MethodsAfter differentiation at the air–liquid interface, nasal epithelia were incubated at either 37°C or 29°C (low temperature) for 48 hours prior to analysis in an Ussing chamber.ResultsWhile F508del-CFTR activity was increased after low temperature incubation, activity of CFTR in non-CF epithelia was unchanged. Importantly, cultures incubated at 29°C demonstrated decreased transepithelial potential difference (TEPD) and short-circuit currents (Isc) at baseline. The predominant factor contributing to the reduced baseline TEPD and Isc in 29°C cultures was the reduced activity of the epithelial sodium channel (ENaC), evidenced by a reduced responsiveness to amiloride. This effect was observed in cells derived from both non-CF and CF donors.DiscussionSignificant transcriptional downregulation of ENaC subunits β and γ were observed, which may partially explain the decreased ENaC activity. We speculate that low temperature incubation may be a useful experimental paradigm to reduce ENaC activity in in vitro epithelial cultures.
Bowel cancer screening workforce survey: developing the endoscopy workforce for 2025 and beyond
Authors: Ravindran Srivathsan , Munday Jane , Veitch Andrew M , Broughton Raphael , Thomas-Gibson Siwan , Penman Ian D , McKinlay Alistair , Fearnhead Nicola S , Coleman Mark , Logan Robert 
Published: February 2021

AimThe demand for bowel cancer screening (BCS) is expected to increase significantly within the next decade. Little is known about the intentions of the workforce required to meet this demand. The Joint Advisory Group on Gastrointestinal Endoscopy (JAG), the British Society of Gastroenterology (BSG) and Association of Coloproctology of Great Britain and Ireland (ACPGBI) developed the first BCS workforce survey. The aim was to assess endoscopist career intentions to aid in future workforce planning to meet the anticipated increase in BCS colonoscopy.MethodsA survey was developed by JAG, BSG and ACPGBI and disseminated to consultant, clinical and trainee endoscopists between February and April 2020. Descriptive and comparative analyses were undertaken, supported with BCS data.ResultsThere were 578 respondents. Screening consultants have a median of one programmed activity (PA) per week for screening, accounting for 40% of their current endoscopy workload. 38% of current screening consultants are considering giving up colonoscopy in the next 2–5 years. Retirement (58%) and pension issues (23%) are the principle reasons for this. Consultants would increase their screening PAs by 70% if able to do so. The top three activities that endoscopists would relinquish to further support screening were outpatient clinics, acute medical/surgical on call and ward cover. An extra 155 colonoscopists would be needed to fulfil increased demand and planned retirement at current PAs.ConclusionThis survey has identified a serious potential shortfall in screening colonoscopists in the next 5–10 years due to an ageing workforce and job plan pressures of aspirant BCS colonoscopists. We have outlined potential mitigations including reviewing job plans, improving workforce resources and supporting accreditation and training.