bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Pragmatic Approach for the Evaluation of Depth-Sensing Indentation in the Self-Similar Regime
Authors: Mahdavi Hamidreza , Poulios Konstantinos , Niordson Christian F. 
Published: August 2021

Abstract
This work evaluates and revisits elements from the depth-sensing indentation literature by means of carefully chosen practical indentation cases, simulated numerically and compared to experiments. The aim is not to provide a comprehensive study, but to close a series of debated subjects, which constitute major sources of inaccuracies in the evaluation of depth-sensing indentation data in practice, with the help of illustrative examples. First, own examples and references from the literature are presented in order to demonstrate how crucial self-similarity detection and blunting distance compensation are, for establishing a rigorous link between experiments and simple sharp indenter models. Moreover, it is demonstrated, once again, in terms of clear and practical examples, that no more than two parameters are necessary to achieve an excellent match between a sharp indenter finite element simulation and experimental force–displacement data. The clear conclusion is that reverse analysis methods promising to deliver a set of three unique material parameters from depth-sensing indentation cannot be reliable. Lastly, in light of the broad availability of modern finite element software, we also suggest to avoid the rigid indenter approximation, as it is shown to lead to unnecessary inaccuracies. All conclusions from the critical literature review performed lead to a new semi-analytical reverse analysis method, based on available dimensionless functions from the literature and a calibration against case specific finite element simulations. Implementations of the finite element model employed are released as supplementary material, for two major finite element software packages.
Anisotropic Mechanics of Vascular Smooth Muscle Cells Exposed to Dynamic Loads
Authors: Rothermel Taylor , Franczek Ian , Alford Patrick 
Published: August 2021

Abstract
Vascular smooth muscle cells (VSMCs) are the most prevalent cells in the arterial wall. In vivo, arteries are exposed to dynamic biaxial loads, thus when characterizing VSMC mechanics it is important to determine their anisotropic and time-dependent mechanical properties. Here, we use cellular microbiaxial stretching (CµBS) to apply complex deformations to single micropatterned VSMCs and measure the resulting changes in cell stress. Previously, CµBS has been used to measure VSMC mechanical properties in response to extensional strain. Here, we measure changes in cell stress in response to both extension and compression. Additionally, we measure immediate temporal changes in stress in response to cyclically applied deformations. We find that the VSMCs display clear hysteresis when incrementally stretched and compressed and demonstrate cycle-dependent stress-relaxation when exposed to cyclic step change extension and compression. Finally, we demonstrate that a Hill-type active fiber model is capable of replicating all observed hysteresis and cycle-dependent stress-relaxation, suggesting that the temporal stress-strain behavior of the cell is regulated by acto-myosin contraction and relaxation, rather than passive viscoelasticity. This study improves upon previous studies of cellular mechanical properties by considering cellular architecture and more complex deformations when measuring the time-dependent mechanical properties of VSMCs. These findings have important implications for modeling in mechanobiology as VSMCs are mechanosensitive and actively respond to changes in their mechanical environment to maintain vascular function.
Inversion-Based Hysteresis Compensation Using Adaptive Conditional Servocompensator for Nanopositioning Systems
Authors: Al-Nadawi Yasir K. , Tan Xiaobo , Khalil Hassan K. 
Published: August 2021

Abstract
Nanopositioning stages are widely used in high-precision positioning applications. However, they suffer from an intrinsic hysteretic behavior, which deteriorates their tracking performance. This study proposes an adaptive conditional servocompensator (ACS) to compensate the effect of the hysteresis when tracking periodic references. The nanopositioning system is modeled as a linear system cascaded with hysteresis at the input side. The hysteresis is modeled with a modified Prandtl–Ishlinskii (MPI) operator. With an approximate inverse MPI operator placed before the system hysteresis operator, the resulting system takes a semi-affine form. The design of the ACS consists of two stages: first, we design a continuously implemented sliding mode control (SMC) law. The hysteresis inversion error is treated as a matched disturbance, and an analytical bound on the inversion error is used to minimize the conservativeness of the SMC design. The second part of the controller is the ACS. Under mild assumptions, we establish the well-posedness and periodic stability of the closed-loop system. In particular, the solution of the closed-loop error system will converge exponentially to a unique periodic solution in the neighborhood of zero. The efficacy of the proposed controller is verified experimentally on a commercial nanopositioning device under different types of periodic reference inputs, via comparison with multiple inversion-based and inversion-free approaches.
Electromigration Analysis of Solder Joints for Power Modules Using an Electrical-Thermal-Stress Coupled Model
Authors: Kato Mitsuaki , Omori Takahiro , Goryu Akihiro , Fumikura Tomoya , Hirohata Kenji 
Published: August 2021

Abstract
Power modules are being developed to increase power output. The larger current densities accompanying increased power output are expected to degrade solder joints in power modules by electromigration. In previous research, numerical analysis of solder for electromigration has mainly examined ball grid arrays in flip-chip packages in which many solder balls are bonded under the semiconductor device. However, in a power module, a single solder joint is uniformly bonded under the power device. Because of this difference in geometric shape, the effect of electromigration in the solder of power modules may be significantly different from that in the solder of flip chips packages. This report describes an electromigration analysis of solder joints for power modules using an electrical-thermal-stress coupled analysis. First, we validate our numerical implementation and show that it can reproduce the vacancy concentrations and hydrostatic stress almost the same as the analytical solutions. We then simulate a single solder joint to evaluate electromigration in a solder joint in a power module. Once inelastic strain appears, the rate of increase in vacancy concentration slows, while the inelastic strain continuously increases. This phenomenon demonstrates that elastic-plastic-creep analysis is crucial for electromigration analysis of solder joints in power modules. Next, the solder joint with a power device and a substrate as used in power modules was simulated. Plasticity-creep and longitudinal gradient generated by current crowding have a strong effect on significantly reducing the vacancy concentration at the anode edge over a long period of time.
Coupled Time and Passage Spectral Method for an Efficient Resolution of Turbomachinery Far Upstream Wakes
Authors: Wang Dingxi , Zhang Sen , Huang Xiuquan , Huang Huang 
Published: August 2021

Abstract
The paper proposes a novel numerical method called coupled time and passage spectral method for an efficient resolution of far upstream wakes in an unsteady analysis of flow field within generic multiple blade rows. The proposed method is a very simple and natural extension of the time spectral form harmonic balance method. By including inter blade phase angle and passage index in a truncated Fourier series, the proposed method is capable of circumventing the limitations of the harmonic balance method in dealing with zero frequency harmonics and time harmonics with same frequency but different inter blade phase angles. Different from the harmonic balance method, which seeks solution at different time instants of the same passage, the coupled spectral method seeks solutions at different passages and time instants. Same as the harmonic balance method, all these solutions are connected via a spectral operator. Coupled time and passage sampling is performed using the modified Gram Schmidt process to choose the time and passage pairs which give the most orthogonal rows of an inverse Fourier transform matrix. The coupled time and passage spectral method requires minimal change to an existing harmonic balance solver. A numerical case study has been provided in the paper to demonstrate the expected capability against the harmonic balance method.
A Combined Volume of Fluid and Immersed Boundary Method for Modeling of Two-Phase Flows With High Density Ratio
Authors: Jin Qiu , Hudson Dominic , Price W. Geraint 
Published: August 2021

Abstract
A combined volume of fluid and immersed boundary method is developed to simulate two-phase flows with high density ratio. The problems of discontinuity of density and momentum flux are known to be challenging in simulations. In order to overcome the numerical instabilities, an extra velocity field is designed to extend velocity of the heavier phase into the lighter phase and to enforce a new boundary condition near the interface, which is similar to nonslip boundary conditions in fluid–structure interaction problems. The interface is captured using a volume of fluid method, and a new boundary layer is built on the lighter phase side by an immersed boundary method. The designed boundary layer helps to reduce the spurious velocity caused by the imbalance of dynamic pressure gradient and density gradient and to prevent tearing of the interface due to the tangential velocity across the interface. The influence of time-step, density ratio, and spatial resolution is studied in detail for two set of cases, steady stratified flow and convection of a high-density droplet, where direct comparison is possible to potential flow analysis (i.e., infinite Reynold s number). An initial study for a droplet splashing on a thin liquid film demonstrates applicability of the new solver to real-life applications. However, detailed comparisons should be performed in the future for finite Reynold s number cases to fully demonstrate the improvements in accuracy and stability of high-density ratio two-phase flow simulations offered by the new method.
Condition Setting in Sport: A Case Study Approach to Explore Program Planning by Canadian University Coaches
Authors: Staehli Julie-Anne , Martin Luc J. , Côté Jean 
Published: August 2021

Based on a condition-setting approach derived from organizational psychology, the authors investigated the conditions that university sport coaches considered and implemented prior to a competitive season. Using a collective case study approach, semistructured interviews were conducted at two time points, with five head coaches across different sports. Student-athletes from each team (n = 5) and the high performance director from the institution were also interviewed. The data were analyzed thematically to highlight the relevant conditions for coaches and their individual athletes and were then generalized across teams within the institution. The authors’ results support the utility of the condition-setting approach outlined by Hackman for sport. Specifically, coaches emphasized the need to (a) create a team vision with clear objectives, (b) opt for athletes of best fit, (c) assign team roles and expectations, (d) confirm and allocate necessary resources, and (e) have competent and prepared team coaching. Despite the generalizability of these themes, the authors’ results highlight the need to consider the context, as both the university environment generally and each specific program were bound by unique constraints (e.g., funding). Herein, the authors discuss their findings in relation to the broader literature, propose future directions, and provide practical implications for sport coaches and institutions.
Preliminary Evidence for a Relationship Between Anxiety, Anger, and Impulsivity in Collegiate Athletes With Sport-Related Concussion
Authors: Byrd Megan M. , Kontos Anthony P. , Eagle Shawn R. , Zizzi Samuel 
Published: August 2021

This study used an exploratory mixed-method sequential design to examine anger, impulsivity, and anxiety following sport-related concussions (SRC). Ten college athletes (M = 20.10 years, SD = 2.92) completed four measures 1–10 days postconcussion (Visit 1) and 11–20 days postconcussion (Visit 2). At return to play or 30 days postconcussion, the athletes completed a semistructured interview (follow-up) to assess their lived experiences of the emotional sequelae of concussions. All participants indicated experiencing some level of anxiety at Visit 1, with half the participants scoring above the measure’s threshold for probable clinical diagnosis of anxiety. The results found a significant decrease in symptoms and anxiety at Visit 2. Inductive coding revealed frustration, irritability, impulsive behavior, and fear of the unknown as themes pertaining to athletes’ experiences. The findings highlight the need for sports medicine and sport psychology professionals to provide athletes with information to normalize their emotional responses during recovery.
Vector of Trophic Resource Partitioning in the Variability of Individuals of the Generalized form of the Large African Barbs of the Barbus (= Labeobarbus) Intermedius Complex, Ethiopia, Tana, Langano and Awasa Lakes
Authors: Mironovsky A. N. 
Published: August 2021

Abstract
Analysis of the diversification of barbs of the generalized form of the Barbus (= Labeobarbus) intermedius complex in the monomorphic populations of Langano and Awasa lakes and in the polymorphic population of Lake Tana makes it possible to reveal parameters of the variability that is directed to trophic resource partitioning. The great similarity of the parameters revealed in the three studied water bodies shows that in monomorphic populations the structure of variability directed to trophic resource partitioning is identical to that in the polymorphic population. The concept of “vector of trophic resource partitioning” is introduced. In the polymorphic population, this vector makes the main contribution to the diversification of individuals, while its importance is secondary in monomorphic populations. It is concluded that the different evolutionary potential of polymorphic and monomorphic populations is determined by the specific weight of diversification caused by the vector of trophic resource partitioning. The original method of data analysis used in the study may be promising for studying similar situations in other systematic groups.
Development and validation of a risk-adjustment model for mortality and hospital length of stay for trauma patients: a prospective registry-based study in Australia
Authors: Earnest Arul , Palmer Cameron , O'Reilly Gerard , Burrell Maxine , McKie Emily , Rao Sudhakar , Curtis Kate , Cameron Peter 
Published: August 2021

ObjectivesAdequate risk adjustment for factors beyond the control of the healthcare system contributes to the process of transparent and equitable benchmarking of trauma outcomes. Current risk adjustment models are not optimal in terms of the number and nature of predictor variables included in the model and the treatment of missing data. We propose a statistically robust and parsimonious risk adjustment model for the purpose of benchmarking.SettingThis study analysed data from the multicentre Australia New Zealand Trauma Registry from 1 July 2016 to 30 June 2018 consisting of 31 trauma centres.Outcome measuresThe primary endpoints were inpatient mortality and length of hospital stay. Firth logistic regression and robust linear regression models were used to study the endpoints, respectively. Restricted cubic splines were used to model non-linear relationships with age. Model validation was performed on a subset of the dataset.ResultsOf the 9509 patients in the model development cohort, 72% were male and approximately half (51%) aged over 50 years . For mortality, cubic splines in age, injury cause, arrival Glasgow Coma Scale motor score, highest and second-highest Abbreviated Injury Scale scores and shock index were significant predictors. The model performed well in the validation sample with an area under the curve of 0.93. For length of stay, the identified predictor variables were similar. Compared with low falls, motor vehicle occupants stayed on average 2.6 days longer (95% CI: 2.0 to 3.1), p<0.001. Sensitivity analyses did not demonstrate any marked differences in the performance of the models.ConclusionOur risk adjustment model of six variables is efficient and can be reliably collected from registries to enhance the process of benchmarking.
“If we can show that we are helping adolescents to understand themselves, their feelings and their needs, then we are doing [a] valuable job”: counselling young people on sexual health in the Brook Advisory Centre (1965–1985)
Authors: Rusterholz Caroline 
Published: August 2021

First opened in 1964 in London, the Brook Advisory Centres (BAC) were the first centres to provide contraceptive advice and sexual counselling to unmarried people in postwar Britain. Drawing on archival materials, medical articles published by BAC members and oral history interviews with former counsellors, this paper looks at tensions present in sexual health counselling work between progressive views on young people’s sexuality and moral conservatism. In so doing, this paper makes two inter-related arguments. First, I argue that BAC doctors, counsellors and social workers simultaneously tried to adopt a non-judgmental listening approach to young people’s sexual needs and encouraged a model of heteronormative sexual behaviours that was class-based and racialised. Second, I argue that emotional labour was central in BAC staff’s attempt to navigate and smooth these tensions. This emotional labour and the tensions within it is best illustrated by BAC’s pyschosexual counselling services, which on the one hand tried to encourage youth sexual pleasure and on the other taught distinctive gendered sexual roles that contributed to pathologising teenage sexual behaviours and desire.In all, I contend that, in resorting to an emotionally orientated counselling, BAC members reconfigured for the young the new form of sexual subjectivity that had been in the making since the interwar years, that is, the fact that individuals regarded themselves as sexual beings and expressed feelings and anxieties about sex. BAC’s counselling work was as much a rupture with the interwar contraceptive counselling tradition—since it operated in a new climate, stressed a non-judgmental listening approach and catered for the young—as it was a continuity of some of the values of the earlier movement.
Development of a machine learning-based real-time location system to streamline acute endovascular intervention in acute stroke: a proof-of-concept study
Authors: Lim Dee Zhen , Yeo Melissa , Dahan Ariel , Tahayori Bahman , Kok Hong Kuan , Abbasi-Rad Mohammad , Maingard Julian , Kutaiba Numan , Russell Jeremy , Thijs Vincent , Jhamb Ashu , Chandra Ronil V , Brooks Mark , Barras Christen , Asadi Hamed 
Published: August 2021

BackgroundDelivery of acute stroke endovascular intervention can be challenging because it requires complex coordination of patient and staff across many different locations. In this proof-of-concept paper we (a) examine whether WiFi fingerprinting is a feasible machine learning (ML)-based real-time location system (RTLS) technology that can provide accurate real-time location information within a hospital setting, and (b) hypothesize its potential application in streamlining acute stroke endovascular intervention.MethodsWe conducted our study in a comprehensive stroke care unit in Melbourne, Australia that offers a 24-hour mechanical thrombectomy service. ML algorithms including K-nearest neighbors, decision tree, random forest, support vector machine and ensemble models were trained and tested on a public WiFi dataset and the study hospital WiFi dataset. The hospital dataset was collected using the WiFi explorer software (version 3.0.2) on a MacBook Pro (AirPort Extreme, Broadcom BCM43x×1.0). Data analysis was implemented in the Python programming environment using the scikit-learn package. The primary statistical measure for algorithm performance was the accuracy of location prediction.ResultsML-based WiFi fingerprinting can accurately predict the different hospital zones relevant in the acute endovascular intervention workflow such as emergency department, CT room and angiography suite. The most accurate algorithms were random forest and support vector machine, both of which were 98% accurate. The algorithms remain robust when new data points, which were distinct from the training dataset, were tested.ConclusionsML-based RTLS technology using WiFi fingerprinting has the potential to streamline delivery of acute stroke endovascular intervention by efficiently tracking patient and staff movement during stroke calls.
Fresh Tissue Multi-omics Profiling Reveals Immune Classification and Suggests Immunotherapy Candidates for Conventional Chondrosarcoma
Authors: Li Binghao , Li Guoqi , Yan Xiaobo , Zhu Dan , Lin Patrick P. , Wang Zenan , Qu Hao , He Xuexin , Fu Yanbiao , Zhu Xiuliang , Lin Peng , Zhang Jiangnan , Li Xiaoya , Dai Hui , Chen Huabiao , Poznansky Mark C. , Lin Nong , Ye Zhaoming 
Published: August 2021

Abstract

Purpose:
There is still no standard nonsurgical regimen for conventional chondrosarcoma (CHS). We aimed to identify whether any CHSs have a favored microenvironment for immunotherapy via multidimensional evaluation of the immunologic characteristics of this tumor.

Experimental Design:
We obtained 98 newly-diagnosed CHS fresh tumors from several institutions and performed comprehensive analysis of data from CyTOF, whole-exome sequencing, and flow cytometry in 22 cases. Clinical data from immunotherapy responders and nonresponders were compared to explore possible biomarkers of immunotherapy response. Mechanism studies were conducted to interpret the biomarker phenotype.

Results:
Based on the integrated data of single-cell CyTOF and flow cytometry, the CHS immune-microenvironment phenotypes were classified into three groups: subtype I, the “granulocytic–myeloid-derived suppressor cell (G-MDSC) dominant” cluster, with high number of HLA-DR− CD14− myeloid cells; subtype II, the “immune exhausted” cluster, with high exhausted T-cell and dendritic-cell infiltration; and subtype III, the “immune desert” cluster, with few immune cells. Immune cell–rich subtypes (subtype I and II) were characterized by IDH mutation, pathologic high grade, and peritumoral edema, while subtype I cases were exclusively featured by myxoid transformation. In clinical practice involving 12 individuals who received PD-1 antibody immunotherapy, all of the 3 cases with controlled diseases were retrospectively classified as subtype II. In mechanism, IDH mutation significantly elevated chemokine levels and immune-cell infiltration in immune-inactivated tumors.

Conclusions:
This study is the first to provide immune characterization of CHS, representing a major step to precise immunotherapy against this malignancy. Immunotherapy is promising for the “immune exhausted” subtype of patients with CHS.