bluuebunny/crossref_metadata_2025 huggingface dataset:
A review on optimization of antenna array by evolutionary optimization techniques
Authors: Devisasi Kala D.D. , Sundari D. Thiripura
Published: December 2021

Purpose

Optimization involves changing the input parameters of a process that is experimented with different conditions to obtain the maximum or minimum result. Increasing interest is shown by antenna researchers in finding the optimum solution for designing complex antenna arrays which are possible by optimization techniques.

Design/methodology/approach

Design of antenna array is a significant electro-magnetic problem of optimization in the current era. The philosophy of optimization is to find the best solution among several available alternatives. In an antenna array, energy is wasted due to side lobe levels which can be reduced by various optimization techniques. Currently, developing optimization techniques applicable for various types of antenna arrays is focused on by researchers.

Findings

In the paper, different optimization algorithms for reducing the side lobe level of the antenna array are presented. Specifically, genetic algorithm (GA), particle swarm optimization (PSO), ant colony optimization (ACO), cuckoo search algorithm (CSA), invasive weed optimization (IWO), whale optimization algorithm (WOA), fruitfly optimization algorithm (FOA), firefly algorithm (FA), cat swarm optimization (CSO), dragonfly algorithm (DA), enhanced firefly algorithm (EFA) and bat flower pollinator (BFP) are the most popular optimization techniques. Various metrics such as gain enhancement, reduction of side lobe, speed of convergence and the directivity of these algorithms are discussed. Faster convergence is provided by the GA which is used for genetic operator randomization. GA provides improved efficiency of computation with the extreme optimal result as well as outperforming other algorithms of optimization in finding the best solution.

Originality/value

The originality of the paper includes a study that reveals the usage of the different antennas and their importance in various applications.
The impact of customer-centric business strategies on customer relationship management: pharmaceutical field-force perspective
Authors: Azeem Muhammad , Aziz Sania , Shahid Jawad , Hayat Aamir , Ahmed Munir , Khan Muhammad Imran
Published: December 2021

Purpose

In a modern business scenario, firms have implemented customer-centric approaches to enable customer relationship management (CRM) to trigger business excellence. Business strategies are modernizing business marketing operations that mainly focused on the retention of profitable customers. The purpose of this study is to empirically investigate the impact of marketing strategies (MS), information technology support (IT-S) and knowledge sharing (KS) in the effect of CRM in the pharmaceutical sector of Punjab, Pakistan.

Design/methodology/approach

Data were collected from the field force of national and international pharmaceuticals companies (N = 263) through a convenience sampling technique. Partial least squares structural equation modeling was used to examine data in SmartPLS 3.2.6.

Findings

The results indicated that IT-S and KS mediate the relationship between MS and CRM. More specifically, MS positively develops CRM through IT-S and KS.

Originality/value

This research contributes to the existing literature of pharmaceuticals by disclosing the field-force (medical representatives) specific role in developing CRM performance between pharmaceuticals firms and health-care physicians that are mainly based on knowledge advancement and influence these firms to adopt customer-centric business approaches to gain a competitive advantage to drive firm profitability.
On extreme value theory in the presence of technical trend: pre and post Covid-19 analysis of cryptocurrency markets
Authors: Thazhungal Govindan Nair Saji
Published: December 2021

Purpose

Research on price extremes and overreactions as potential violations of market efficiency has a long tradition in investment literature. Arguably, very few studies to date have addressed this issue in cryptocurrencies trading. The purpose of this paper is to consider the extreme value modelling for forecasting COVID-19 effects on cryptocoin markets. Additionally, this paper examines the importance of technical trading indicators in predicting the extreme price behaviour of cryptocurrencies.

Design/methodology/approach

This paper decomposes the daily-time series returns of four cryptocurrency returns into potential maximum gains (PMGs) and potential maximum losses (PMLs) at first and then tests their lead–lag relations under an econometric framework. This paper also investigates the non-random properties of cryptocoins by computing the incremental explanatory power of PML–PMG modelling with technical trading indicators controlled. Besides, this paper executes an event study to identify significant changes caused by COVID-19-related events, which is capable of analysing the cryptocoin market overreactions.

Findings

The findings of this paper produce the evidence of both market overreactions and trend persistence in the potential gains and losses from coins trading. Extreme price behaviour explains volatility and price trends in crypto markets before and after the outbreak of a pandemic that substantiate the non-random walk behaviour of crypto returns. The presence of technical trading indicators as control variables in the extreme value regressions significantly improves the predictive power of models. COVID-19 crisis affects the market efficiency of cryptocurrencies that improves the usefulness of extreme value predictions with technical analysis.

Research limitations/implications

This paper strongly supports for the robustness of technical trading strategies in cryptocurrency markets. However, the “beast is moving quick” and uncertainty as to the new normalcy about the post-COVID-19 world puts constraint on making best predictions.

Practical implications

The paper contributes substantially to our understanding of the pricing efficiency of cryptocurrency markets after the COVID-19 outbreak. The findings of continuing return predictability and price volatility during COVID-19 show that profitable investment opportunities for cryptocoin traders are prevailing in pandemic times.

Originality/value

The paper is unique to understand extreme return reversals behaviour of cryptocurrency markets regarding events related to COVID-19 breakout.
The role of innovation ecosystems in Industry 4.0 adoption
Authors: Matt Dominik T. , Molinaro Margherita , Orzes Guido , Pedrini Giulio
Published: December 2021

Purpose

The purpose of this paper is to identify actions and guidelines for enabling and fostering the Industry 4.0 adoption, as well as to understand the role of three ecosystem actors in these actions (i.e. companies, educational organizations and regional policy makers).

Design/methodology/approach

52 semi-structured expert interviews in the Tyrol-Veneto cross-border macro-region were carried out and interpreted using the innovation ecosystem concept. In particular, drawing from this latter, six ecosystem building blocks were identified and used to analyze the interviews' content.

Findings

The findings allow not only to build a comprehensive framework for action to support Industry 4.0 adoption, but also to confirm the importance of exploring Industry 4.0 through the lens of the ecosystem concept. Indeed, the authors show that R&D activities should be complemented with interorganizational actions, such as training and networking, and that all ecosystem actors should be involved in the Industry 4.0 adoption.

Originality/value

This is among the few studies that adopt the innovation ecosystem perspective to explore best practices for Industry 4.0 adoption, thus overcoming the weakness of existing papers based on a firm-level perspective. It also complements previous ecosystem-based research on Industry 4.0 by exploring the technology adoption side, rather than the technology provision one, and by considering the adoption of a wide set of technologies.
“It's the work climate that keeps me here”: the interplay between the HRM process and emergent factors in the construction of employee experiences
Authors: Laiho Maarit , Saru Essi , Seeck Hannele
Published: December 2021

Purpose

The purpose of this paper is to explore the interplay between human resource management (HRM) and emergent factors in constructing a strong HRM climate. Specifically, the paper aims to shed light on how employee perceptions of the HRM process and emergent factors together construct a strong HRM climate, i.e. employees' shared perceptions of HRM.

Design/methodology/approach

The paper uses qualitative interview data (managers and employees) from two organisations operating in Finland. The data are analysed based on a systematic data analysis and gives an illustration of the interplay between high-performance work system and the emergent factors.

Findings

The findings illustrate the three types of interplay between HPWS and emergent factors – supplementation, substitution and suffocation – that construct employee experience.

Originality/value

The paper extends earlier discussions on the relationship between HRM and employee experience by empirically examining how the HRM process – together with emergent factors – constructs a strong HRM climate. The present study contributes to further theorising and increasing our understanding of the creation of employee experience.
Parental mosaic cutaneous‐gonadal GJB2 mutation: From epidermal nevus to inherited ichthyosis‐deafness syndrome
Authors: Cohen‐Barak Eran , Mwassi Bannan , Zagairy Fadia , Danial‐Farran Nada , Khayat Morad , Tatour Yasmin , Ziv Michael
Published: December 2021

Ichthyosis and deafness syndrome is a group of devastating genodermatoses caused by heterozygous mutations in GJB2, encoding the gap junction protein connexin 26. These syndromes are characterized by severe skin disease, hearing loss, recurrent infections, and cutaneous neoplasms. Cutaneous somatic mutations in the same gene are associated with porokeratotic eccrine ostial dermal duct nevus. Here we report a family in which a parent presented with localized epidermal nevus and his child suffered with hystrix‐like ichthyosis with deafness. Histologic examination of the parent's cutaneous lesion revealed verrucous epidermal nevus without features of porokeratotic eccrine ostial dermal duct nevus. Genetic analysis identified the same pathogenic variant, GJB2 c.148G>A (p.D50N), in DNA extracted from the parent's cutaneous lesion and the child's leukocytes, but not in the parent's leukocytes. This study expands the phenotypic heterogeneity of GJB2 mosaic variants in addition to porokeratotic eccrine ostial dermal duct nevus, and emphasizes the importance of molecular diagnosis of mosaic skin diseases considering the risk of severe inherited diseases in the offspring.
Impacts of herbivory by ecological replacements on an island ecosystem
Authors: Moorhouse‐Gann Rosemary J. , Vaughan Ian P. , Cole Nik C. , Goder Martine , Tatayah Vikash , Jones Carl G. , Mike Daevid , Young Richard P. , Bruford Michael W. , Rivers Malin C. , Hipperson Helen , Russo Isa‐Rita M. , Stanton David W. G. , Symondson William O. C.
Published: December 2021

The use of ecological replacements (analogue species to replace extinct taxa) to restore ecosystem functioning is a promising conservation tool. However, this approach is controversial, in part due to a paucity of data on interactions between analogue species and established taxa in the ecosystem.

We conducted ecological surveys, comprehensively DNA barcoded an ecosystem's flora and inferred the diet of the introduced Aldabra giant tortoise, acting as an ecological replacement, to understand how it might have modified island plant communities on a Mauritian islet. Through further dietary analyses, we investigated consequential effects on the threatened endemic Telfair's skink.

Dietary overlap between tortoises and skinks was greater than expected by chance. However, there was a negative correlation between tortoise and skink preferences in herbivory and minimal overlap in the plants most frequently consumed by the reptiles.

Changes in the plant community associated with 7 years of tortoise grazing were characterised by a decrease in the percentage cover of native herbs and creepers, and an increase in the cover of an invasive herb when compared to areas without tortoises. However, tortoise dietary preferences themselves did not directly drive changes in the plant community.

Tortoises successfully dispersed the seeds of an endemic palm, which in time may increase the extent of unique palm‐rich habitat. We found no evidence that tortoises have increased the extent of plant species hypothesised to be part of a lost Mauritian tortoise grazed community.

Synthesis and applications. Due to a negative correlation in tortoise and skink dietary preferences and minimal overlap in the most frequently consumed taxa, the presence of tortoises is unlikely to have detrimental impacts on Telfair's skinks. Tortoise presence is likely to be beneficial to skinks in the long term by increasing the extent of palm‐rich habitat. Although tortoises are likely to play a role in controlling invasive plants, they are not a panacea for this challenge. After 7 years, tortoises have not resurrected a lost tortoise grazed community that we hypothesise might have existed in limited areas on the islet, indicating that further interventions may be required to restore this plant community.
Characterization of genetic fundamentals for piglet mortality at birth in Yorkshire, Landrace, and Duroc sows
Authors: An M. , Zhou G. , Li Y. , Xiang T. , Ma Y. , Liu X. , Li X. , Zhao S. , Zhu M.
Published: December 2021

Piglet mortality is an economically important complex trait that impacts sow prolificacy. Genetic analyses for piglet mortality at weaning have been reported in dozens of studies, but not for piglet mortality at birth. In this study, we used multi‐breed data sets from Yorkshire, Landrace, and Duroc sows to characterize the genetic fundamentals of piglet mortality at birth. The heritabilities from parity I to III were estimated to be 0.0630, 0.1031, and 0.1140 respectively. By using a combined strategy, a total of 21 SNPs were detected in three parities, of which six were observed in parity I, five in parity II and 10 in parity III. Genome annotation revealed that these SNPs were harbored within or close to 19 candidate genes. The candidate genes were found to associate with the reproductive system and embryonic development in the tissue expression database, which are reasonably related to piglet mortality. These findings are expected to provide much information for understanding the genetic and genomic fundamentals of farrowing mortality.
Examining the relationship between conspiracy theories and COVID‐19 vaccine hesitancy: A mediating role for perceived health threats, trust, and anomie?
Authors: McCarthy Molly , Murphy Kristina , Sargeant Elise , Williamson Harley
Published: December 2021

The COVID‐19 pandemic has led to an upswing in conspiracy theory beliefs, which creates challenges for effectively countering the pandemic, with higher rates of COVID‐19 vaccine hesitancy found among conspiracy theorists. Research suggests health risk perceptions, trust in government and anomie may mediate the relationship between COVID‐19 conspiracy theory beliefs and vaccine hesitancy. However, the mediating role of trust in government and anomie on vaccine hesitancy have not been empirically examined in the context of COVID‐19, and it is not clear whether different conspiracy theories have distinct mediational pathways to vaccine hesitancy. The current study examines the extent to which perceptions of the health threat posed by COVID‐19, trust in government and anomie can explain the relationship between distinct COVID‐19 conspiracy theories and COVID‐19 vaccine hesitancy. Drawing on data from a national online survey of 779 Australian adults, a series of path analyses examining the influence of three distinct conspiracy theories on vaccination hesitancy revealed two key mediational pathways, which varied across conspiracy theory types. Anomie and perceptions of the health threat posed by COVID‐19 were the most common mediators of this relationship. Implications for COVID‐19 vaccine hesitancy and for conspiracy theory research are discussed.
A framework for involving coproduction partners in research about young people with type 1 diabetes
Authors: Desborough Jane , Parkinson Anne , Lewis Fiona , Ebbeck Harry , Banfield Michelle , Phillips Christine
Published: December 2021

Background

Involvement of end‐users in research can enhance its quality, relevance, credibility and legitimacy; however, the processes through which these changes occur are unclear. Our aim was to explore a coproduction research team's experiences of their involvement in research about young people with type 1 diabetes mellitus (T1DM).

Methods

Semi‐structured interviews conducted with two young people with T1DM, two parents, one diabetes educator, one endocrinologist‐scientist and one research‐engineer explored experiences of coproduction research and its impact on both the research and the participants. Drawing on grounded theory, we undertook inductive analysis and storyline mapping to develop a theorized framework of mechanisms supporting the process of coproduction in T1DM research with young people.

Findings

The framework involving coproduction partners in research about young people with type 1 diabetes centres on the unique expertize that different team members bring to the research and describes conditions that enable expert contributions through the enactment of a variety of expert roles. The framework also describes outcomes—the impact of the expert contributions on both the research and the team members involved.

Conclusion

The findings of this small exploratory study provide a sound foundation to develop further understanding about structures and processes that are integral for the success of coproduction research teams. The framework may provide a guide for researchers planning to incorporate coproduction, on elements that are important for this model of research to succeed. It may also inform coproduction impact assessment research and be used for hypothesis testing and expansion in future studies.
Tracking the changing discourse on development in the International Labour Review
Authors: GHOSH Jayati , RANI Uma
Published: December 2021

The introduction to this Centenary Issue presents the discourse of development as reflected in a number of articles published in the International Labour Review (ILR) between 1971 and 2020. The 13 articles selected for inclusion in this issue provide various perspectives on development at different points in time, focusing on income, structural transformation, improvement of the lives of people through social development, and the interactions of economic growth with employment and labour markets. By highlighting aspects of the relationship between economic development and labour, these analytical and empirical contributions are still relevant today to help us to understand development processes and policy discussions.
New important data on the transmission of cutaneous human papillomaviruses
Authors: Kreuter A. , Wieland U.
Published: December 2021

Linked article: E. Ghorzang et al. J Eur Acad Dermatol Venereol 2022; 36: 119–125. https://doi.org/10.1111/jdv.17684.
Behavior‐based price discrimination with nonuniform distribution of consumer preferences
Authors: Esteves Rosa‐Branca , Liu Qihong , Shuai Jie
Published: December 2021

Existing theories of competition with behavior‐based price discrimination (BBPD, also known as price discrimination based on purchase history), typically assume that consumer valuations are distributed uniformly. This assumption implies that the availability of BBPD creates a prisoner's dilemma in which firms are worse off and consumers better off in equilibrium, relative to uniform pricing. In this paper, we consider a wider class of consumer distributions and show that profit and welfare results change qualitatively. When consumers are sufficiently massed at the center of the market (e.g., triangular distribution), BBPD boosts industry profits at the expense of consumers. Otherwise, the usual findings prevail. Our results highlight how assumptions on the density of consumer valuations play a decisive role on pricing and welfare outcomes.
Associations of MCM8 rs3761873 and rs16991617 variants with abnormal uterine bleeding induced by copper intrauterine device
Authors: Shen Yupei , Xu Linfen , Zhu Weiqiang , Zhang Zhaofeng , Liu Junwei , Jiang Lifang , Liu Xiaoli , Mao Yanyan , Xu Jianhua , Yan Xiaoqin , Sun Junjie , Liu Fang , Xiong Xiumei , Chen Xiujuan , Che Yan , Du Jing
Published: December 2021

Aim

Intrauterine device (IUD) is a commonly used contraceptive method worldwide. Abnormal uterine bleeding (AUB) is one of the most common side effects of Cu‐IUDs. Since AUB varies among Cu‐IUD users, changes in the bleeding‐related genetic factors may contribute to AUB. This study aimed to determine the genetic risk factors of AUB after Cu‐IUD insertion.

Methods

We conducted a case–control study on women who experienced AUB after Cu‐IUD insertion (case:control = 62:59). Six candidate variants were genotyped using the Sequenom MassARRAY. Genotype and allele frequencies were analyzed using SHEsisPlus. We performed Pearson's Chi‐squared test to analyze categorical data, and ESEfinder to predict the impact on splicing regulation.

Results

MCM8 coding sequence variants: rs3761873‐A>C was in Exon 7 and rs16991617 A>G was in Exon 12 of all 19 exons, both of which were significantly different between cases and controls (pallele = 0.039 and pgenotype = 0.092). rs6022 and rs6029 in F5 gene and rs3761873 and rs16991617 in the MCM8 gene showed strong linkage disequilibrium (R2 > 0.8). ESEfinder indicated that the variants of MCM8 may affect the splicing regulation.

Conclusions

MCM8 rs376187 and rs16991617 were associated with AUB in Cu‐IUDs users. MCM8 may play a role in AUB by regulating functions of reproductive organs and primary ovarian insufficiency. Our findings may improve the understanding of the genetic basis of AUB caused by Cu‐IUDs.
Effect of urine‐specific gravity on performance of bacteriuria in predicting urine culture results
Authors: Torre M. , Furrow E. , Foster J. D.
Published: December 2021

Objective

To determine the effect of urine‐specific gravity (USG) on using microscopic evaluation of bacteriuria to predict urine culture results in dogs and cats.

Materials and Methods

We performed a retrospective medical record review of canine and feline patients that had a urinalysis and urine culture performed simultaneously. The sensitivity, specificity, positive predictive value and negative predictive value of microscopic bacteriuria for predicting urine culture results were calculated, stratified by USG. Multivariable regression was performed to test the effect of USG, pyuria, haematuria and species on the agreement between microscopic bacteriuria and culture results.

Results

A total of 481 dogs and 291 cats with paired urinalysis and urine culture results were included in the study. Microscopic bacteriuria had moderate sensitivity (76% in dogs, 64% in cats) and high specificity (97% in dogs, 96% in cats) for predicting urine culture bacterial growth. Samples with rod bacteria were more likely to have bacterial growth than those with cocci (OR=Infinity, 95% CI 4.8 – Infinity). As compared to isosthenuric+hyposthenuric samples (USG ≤1.012), agreement was lower in moderately concentrated (OR=0.44, 95% CI 0.19 to 0.91) samples. Absence of bacteriuria, pyuria and haematuria had a high negative predictive value for no bacterial growth (96%).

Clinical Significance

Microscopic bacteriuria has a high specificity in predicting urine culture results, regardless of USG. The finding that microscopic bacteriuria has better agreement with urine culture results in isosthenuric+hyposthenuric urine argues against reflex culture in these samples, especially if pyuria and haematuria are also absent. Urine microscopy can aid clinicians in determining the likelihood of urine culture growth.
Adenovirus vector encoding TPPII ignites HBV‐specific CTL response by activating autophagy in CD8+ T cell
Authors: Tan Quanhui , chen Jie , Gao Gao , Yizhang  , Chen Xiaohua , Yu Yongsheng , Zang Guoqin , Tang Zhenghao
Published: December 2021

Early studies have shown that autophagy and TPPII are associated with HBV infection. In this study, adenovirus vector containing TPPII was constructed to immunize HBV transgenic mice in vivo to explore the potential mechanism of autophagy and HBV infection. Our goal is to provide new ideas for immunotherapy of hepatitis B. First, adenovirus vector containing TPPII was constructed. Then, we used adenovirus to immunize HBV transgenic mice and ATG5 knockout HBV transgenic mice. The autophagy of CD8+ T cells was detected by transmission electron microscopy and immunofluorescence electron microscopy, Western blot was used to detect the expression of autophagy LC3 and BECN1, CTL reaction, HBV DNA and HBsAg in serum, HBsAg and HBcAg in liver tissues by immunohistochemistry, to further examine the possible mechanisms involved in autophagy. Adv‐HBcAg‐TPPII promotes autophagy of CD8+ T lymphocyte, activates CTL response, inhibits HBV DNA replication and HBsAg expression, and PI3K/ Akt /m TOR signalling pathway may be involved in autophagy. This study demonstrates that autophagy of CD8+ T cells was induced by Adv‐HBcAg‐TPPII and the molecular mechanism may be related to the PI3K/ Akt /m TOR signalling pathway, providing a possible theoretical basis for immunotherapy of hepatitis B.
A multi‐country, multi‐commodity Ricardian trade model with link commodities and Keynesian unemployment
Authors: Sato Hideo
Published: December 2021

This study constructs a multi‐country, multi‐commodity Ricardian trade model with link commodities, defined as commodities commonly produced in more than one country, and Keynesian unemployment arising from deficient effective demand. Given production techniques, available labour, and demand in each country, the model determines patterns of international division of labour, commodity prices, wage rates, outputs, and employment in each country. The main results indicate that demand changes effectuate quantity adjustments without price changes, each country must expand domestic demand to increase domestic employment, and each country must raise the labour productivity of link commodities to increase relative domestic wage rates.
Molecular phylogeny of Nanophyton L. (Chenopodioideae): emphasis on the similar species N. erinaceum and N. mongolicum
Authors: Wen Zhi‐Bin , Song Feng , Feng Ying , Zhang Hong‐xiang
Published: December 2021

Nanophyton L. has been treated as a monotypic genus, but seven other Nanophyton species have been published based on morphological features. To examine the phylogenetic relationships between Nanophyton species, especially the similar species N. erinaceum and N. mongolicum, all species in Nanophyton except N. pulvinatum and different populations of N. erinaceum and N. mongolicum in China were sampled from herbarium specimens. Samples were analyzed based on two molecular markers (ITS and psbB‐psbH) using maximum likelihood and Bayesian inference methods. Our results provided support for the following conclusions: 1) Nanophyton is monophyletic and composed of two monophyletic clades. One clade may be recognized as N. sect. Nanophyton, but contrary to the current taxonomy it includes only N. erinaceum. The other clade represent N. sect. Montana and include all other Nanophyton species, but intragenetic variation within this clade is low. 2) Variable sites in both ITS and psbB‐psbH sequences well distinguish N. erinaceum from N. mongolicum, and samples from different populations of N. erinaceum and N. mongolicum in China formed well‐supported, distinct clades. 3) Nanophyton erinaceum is a typical Central Asian species, mainly distributed in western Siberia and Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Mongolia and northwestern China (north Xinjiang)), while N. mongolicum is a Mongolian floristic element species mainly found from the Altai region of northern Xinjiang (China) to Mongolian Altai (Mongolia).
Utility‐pole Detection Based on Interwoven Column Generation from Terrestrial Mobile Laser Scanner Data
Authors: Talebi Nahr Siamak , Saadatseresht Mohammad
Published: December 2021

Mobile lidar scanning is one of the recent technologies that is used to map street scenes rapidly. Among street objects, utility‐poles are more critical to energy companies to monitor regularly through time. This paper presents a novel approach to detect utility‐poles from mobile lidar data in complex city scenes. After removing ground points, the scene is gridded into blocks based on a shared‐partitioning algorithm. Next, an interwoven column generation algorithm is used to create columns. Finally, each of these columns is considered to be a utility‐pole or not. The proposed algorithm is tested on two test areas. The algorithm achieved Completeness, Correctness and Quality of 92.8%, 97.5% and 90.6% in Area 1, and 92.8%, 92.2% and 86.1% in Area 2. The total number of utility‐poles in both areas was 265. The algorithm shows promising results in utility‐pole detection in complex city scenes with attached walls.
A Novel and Inexpensive Technique for High-Tension Tendon Clamping With Expandable Mesh Sleeving for In Vitro Foot Biomechanics Testing
Authors: Golubovsky Joshua L. , Gillespie Callan M. , Nagle Tara F. , Loss Jeremy G. , Colbrunn Robb W.
Published: December 2021

In vitro biomechanical testing is common in the field of orthopedics when novel devices are investigated prior to human trials. It is typically necessary to apply loads through tendons to simulate normal activities, such as walking during a foot and ankle study. However, attachment of tendons to linear actuators has proven challenging because of the tendency of clamps to either slip off or rupture the tendon. Various techniques have been utilized. Freeze clamping is generally accepted as the gold standard for very high load testing in excess of 3000 N, but is expensive, time-consuming, and requires significant ancillary equipment. Purely mechanical solutions such as metal jaw clamps, wire meshes, and others have been explored, but these techniques are either costly, have low load capacities, or have not proven to be reproducible. We have developed a novel tendon clamping technique that utilizes a slip-resistant polyester mesh sleeving that encases the tendon and is fixated at the bottom of the tendon/sleeve interaction with a giftbox suture. The loose end of the sleeving can then be tied in to the linear actuator or load cell apparatus using a timber hitch knot. The sleeving technique allows for loads of 2000–2500 N on the Achilles tendon, and is inexpensive, reproducible, and can be modified to apply loads to smaller tendons as well, though a length of tendon/sleeve overlap of at least 16 cm is required to reach maximum loads. This technique should assist researchers in integrating muscle forces into future biomechanical study designs.
Reaction Forces and Flexion–Extension Moments Imposed on Functional Spinal Units With Constrained and Unconstrained In Vitro Testing Systems
Authors: Zehr Jackie D. , Callaghan Jack P.
Published: December 2021

A mechanical goal of in vitro testing systems is to minimize differences between applied and actual forces and moments experienced by spinal units. This study quantified the joint reaction forces and reaction flexion–extension moments during dynamic compression loading imposed throughout the physiological flexion–extension range of motion. Constrained (fixed base) and unconstrained (floating base) testing systems were compared. Sixteen porcine spinal units were assigned to both testing groups. Following conditioning tests, specimens were dynamically loaded for 1 cycle with a 1 Hz compression waveform to a peak load of 1 kN and 2 kN while positioned in five different postures (neutral, 100% and 300% of the flexion and extension neutral zone), totaling ten trials per functional spinal unit (FSU). A six degree-of-freedom force and torque sensor was used to measure peak reaction forces and moments for each trial. Shear reaction forces were significantly greater (25.5 N–85.7 N) when the testing system was constrained compared to unconstrained (p < 0.029). The reaction moment was influenced by posture (p = 0.037), particularly in C5C6 spinal units. In 300% extension (C5C6), the reaction moment was, on average, 9.9 N·m greater than the applied moment in both testing systems and differed from all other postures (p < 0.001). The reaction moment error was, on average, 0.45 N·m at all other postures. In conclusion, these findings demonstrate that comparable reaction moments can be achieved with unconstrained systems, but without inducing appreciable shear reaction forces.
Commutation Loss in Hydrostatic Pumps and Motors
Authors: Mommers Robin , Achten Peter , Achten Jasper , Potma Jeroen
Published: December 2021

In mobile hydraulic applications, more efficient machinery generally translates to smaller batteries or less diesel consumption, and smaller cooling solutions. A key part of such systems are hydrostatic pumps and motors. While these devices have been around for a long time, some of the causes of energy loss in pump and motors are still not properly defined. This paper focuses on one of the causes of energy loss in pumps and motors, by identifying the energy loss as a result of the process of commutation.

By nature, all hydrostatic pumps and motors have some form of commutation: the transition from the supply port to the discharge port of the machine (and vice versa). During commutation, the connection between the working chamber and the ports is temporarily closed. The chamber pressure changes by compression or decompression that is the result of the rotation of the working mechanism. Ideally, the connection to one of the ports is opened once the chamber pressure equals the port pressure. When the connection is opened too early or too late, energy is lost.

This paper describes a method to predict the commutation loss using a lumped parameter simulation model. To verify these predictions, experimental data of a floating cup pump was compared to the calculated values, which show a decent match. Furthermore, the results show that, depending on the operating conditions, up to 50% of all losses in this pump are caused by improper commutation.
Noise Attenuation in a Secondary Controlled Electro-Hydraulic Actuator Using an Extended Kalman Filter
Authors: Simonsen Niklas , Sørensen Emil Munk , Binsbergen-Galán Mikkel van , Kleine Stine Flindt Hornemann , Nielsen Mikkel Hvid , Schmidt Lasse
Published: December 2021

Conventionally, variable-speed electro-hydraulic linear actuators utilize the speed control loops of electric machines and associated drives to control the pump flows, thereby realizing primary control functions. An alternative control approach is secondary control, which realizes a pressure coupling between the motor/pump and cylinder via the electromagnetic motor torque, with a flow reaction. Secondary controls in such drives has theoretically been shown to enable significantly higher control band-widths compared to primary control approaches. The theoretical bandwidth improvement is possible as the secondary control approach utilizes the faster dynamics of the electric machine, whereas the primary control approach revolves about the slower hydraulic dynamics present in the speed control loop. This paper considers the design and implementation of a secondary control function in a variable-speed electro-hydraulic actuator test bench, in order to validate the properties of such controls. Initial results show that the proposed secondary control approach is highly sensitive to measurement noise, which proves to be a limiting factor for the achievable control bandwidth, if smooth operation of the system is to be maintained. To attenuate the noise impact an extended Kalman filter is proposed in conjunction with the secondary control approach. Results demonstrate that the inclusion of the extended Kalman filter significantly reduces the impact of signal noise on the internal drive states, thereby enabling increased bandwidth and expanding the application range for this control method.
Investigating the Condition Monitoring Potential of Oil Conductivity for Wear Identification in Electro Hydrostatic Actuators
Authors: Duensing Yannick , Richert Oliver , Schmitz Katharina
Published: December 2021

To meet future goals of more electric airplanes conventional hydraulic airplane control systems, consisting of redundant centralized pumps within the airplane’s fuselage, need to be substituted for compact electro-hydraulic actuators (EHA). The capsulated architecture of EHAs results in higher safety due to separate hydraulic circuits, simple practicability of redundancy, decreased maintenance because of simplified error location detection as well as an overall reduction in weight and complexity of the airplane control system. Currently, EHAs are only used as backup devices as the reliability does not achieve normative requirements for a frontline application. Thus, recent studies aim to increase the reliability. The axial piston pump of current EHA is the source of most failures. High dynamic requirements and challenging operation points and environments result in wear of contact pairs such as swash plate/piston shoes, pistons/cylinder block and cylinder block/valve plate. In the scope of the project MODULAR at ifas one goal is to increase the robustness of the contact surfaces. A second goal addresses the topic of developing a condition monitoring approach to constantly track the pumps’ health status. Next to signals such as pressures and temperatures, acceleration and oil status signals describing the actual particle contamination are needed. In this contribution different methods of oil status detection are explained and the method of electric conductivity analysis for condition monitoring is further investigated. Filtered HLP46 is used and impurities in form of metallic powders are added. Furthermore, degraded oil of a disc-on-disc Tribometer test bench is measured and compared.
Novel Methods and Technologies for Assessing Usability of Off-Road Machines in R&D Phase - The Lutergo Laboratory
Authors: Zhidchenko Victor , Hekmatmanesh Amin , Handroos Heikki , Kilpeläinen Asko , Kauranen Kari
Published: December 2021

A novel intelligent experimental research environment (LUTERGO laboratory) for developing the usability of off-road machines was created at LUT University. The environment combines a real-time simulator and an experimental system for measuring human body responses when driving the virtual prototypes of machines. Based on the quantities measured from the operator, such as heart rate, electrodermal, muscular, and brain activity, the stress level of the operator can be evaluated. It is assumed that by combining simulated machine data and biosignals, the usability of every virtual prototype of a new machine can be assessed during the R&D process. This is an alternative to a traditional approach when usability is studied with physical prototypes after conceptual R&D phases using qualitative data from questionnaires.

The paper describes the structure and capabilities of the LUTERGO laboratory. Results of the initial tests are presented, which studied the influence of hydraulic valve dynamics on excavator vibration and operator biosignals. The results show that the biosignal parameters used as stress indicators change following the variation of time constant for directional valves controlling the main boom cylinders of the excavator. The paper concludes with future research directions using the novel environment.
Gain-Scheduled Position Control of a Pneumatic Muscle Actuator
Authors: Cotton Matthew , Plummer Andrew
Published: December 2021

Pneumatic artificial muscles (PAMs) are high power-to-weight ratio actuators with considerable potential in biomimetic robotics and orthotics due to their similarities with human skeletal muscle. However, precise position control is difficult to achieve due to the highly nonlinear nature of the actuators and the pneumatic systems driving them. A wide range of nonlinear controllers have been proposed to-date, but none have been shown to be entirely satisfactory, and are often optimised for only one region of the PAM’s travel.

In this paper, a gain-scheduled position controller is designed that aims to achieve equal tracking performance across the entire travel of the PAM. Selected scheduling variables include actuator displacement and error direction, with controller gains defined by ‘normalisation curves’ determined by data from open-loop characterisation tests. The experimental system consists of a Festo PAM, a pair of on-off valves driven by pulse-width modulated signals, and sensors for PAM displacement and pressure. Controller performance is tested using several dynamic position tracking tests, and the results are compared to an equivalent linear controller. The gain-scheduled approach successfully counteracts the differing inflation / deflation dynamics of the system, showing improved tracking performance over the linear controller with considerably less variability due to operating region.
Investigating the Influence of Design Parameters on the Fluid-Structure Interaction in Fast Switching Valves
Authors: Pedersen Henrik C. , Andersen Torben O. , Bender Niels C.
Published: December 2021

When considering digital displacement machines, one of the key elements are the fast switching valves. However, the dynamic requirements and conflicting design objectives mean that designing these fast-switching valves is a complex process, which pushes the technology to the limit. Optimization approaches are therefore required just to find feasible and, secondly, optimal solutions. However, dynamic CFD simulation is required to accurately describe dynamic fluid effects as fluid stiction, -drag and -end damping. This limits the possibilities to use optimization approaches due to the computational burden imposed, the need for dynamic mesh generation, and the design parameterization. Hence, this paper investigates analytical approximations and the error size introduced by simplifying dynamic fluid friction effects into a lumped parameter form.

Specifically, the article presents a comprehensive parameter study of selected design parameters’ influence on the fluid forces in fast switching annulus valves, based on both analytical expressions and results derived from dynamic CFD simulations. The focus is primarily on describing the effects and size of the flow forces resulting from changes in parametric design parameters that influence the flow geometry. The results reveal a fair correlation between the fluid force predicted by the rapidly executable lumped model and the CFD model.
Astrocytic lipid metabolism determines susceptibility to diet-induced obesity
Authors: Varela Luis , Kim Jae Geun , Fernández-Tussy Pablo , Aryal Binod , Liu Zhong Wu , Fernández-Hernando Carlos , Horvath Tamas L.
Published: December 2021

The present work highlights astrocytic fatty acid homeostasis as a critical regulator of susceptibility to develop obesity.
Grazoprevir/Elbasvir Treatment in Liver or Kidney Transplant Recipients with Genotype 1b Hepatitis C Virus Infection
Authors: Lai Ping-Chin , Chen Cheng-Hsu , Jeng Long-Bin , Yu Tung-Min , Tsai Shang-Feng , Wu Ming-Ju , Cheng Shao-Bin , Yang Sheng-Shun , Lee Teng-Yu
Published: December 2021

More options regarding the choice of direct-acting antivirals (DAAs) are helpful for avoiding individual limitations in treating hepatitis C virus (HCV) infection. We aimed to assess the efficacy and tolerability of grazoprevir (GZR)/elbasvir (EBR) treatment in genotype-1b (GT-1b) HCV-infected liver or kidney transplant recipients.
Distinct Interaction Mechanism of RNA Polymerase and ResD at Proximal and Distal Subsites for Transcription Activation of Nitrite Reductase in Bacillus subtilis
Authors: Jacob Hannah , Geng Hao , Shetty Dasvit , Halow Nathan , Kenney Linda J. , Nakano Michiko M.
Published: December 2021

A significant number of ResD-controlled genes have been identified, and transcription regulatory pathways in which ResD participates have emerged. Nevertheless, the mechanism of how ResD activates transcription of different genes in a nucleotide sequence-specific manner has been less explored.
Prostate-specific membrane antigen positron emission tomography compared to multiparametric MRI for prostate cancer diagnosis: a protocol for a systematic review and meta-analysis
Authors: Zhao Yi , Morka Naomi , Simpson Benjamin Scott S , Freeman Alex , Kirkham Alex , Kelly Daniel , Whitaker Hayley C , Emberton Mark , Norris Joseph M
Published: December 2021

Introduction

The introduction of multiparametric MRI (mpMRI) has improved almost every aspect of the prostate cancer diagnostic pathway. However, the novel imaging technique, prostate-specific membrane antigen positron emission tomography (PSMA PET) may have demonstrable accuracy in detecting and staging prostate cancer. Here, we describe a protocol for a systematic review and meta-analysis comparing mpMRI to PSMA PET for the diagnosis of suspected prostate cancer.

Methods and analysis

A systematic search of MEDLINE, EMBASE, PubMed and Cochrane databases will be conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines will be followed for screening, data extraction, statistical analysis and reporting. Included papers will be full-text articles providing original data, written in English articles and comparing the use of PSMA PET with mpMRI in the diagnosis of prostate cancer. All studies published between July 1977 and March 2021 will be eligible for inclusion. Study bias and quality will be assessed using Quadas-2 score. To ensure the quality of the reporting of studies, this protocol is written following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols 2015 checklist.

Ethics and dissemination

Ethical approval will not be required for this systematic review. Findings will be disseminated through peer-reviewed publications and presentations at both national and international conferences.

PROSPERO registration number

CRD42021239296.
Immunogenic ferroptosis and where to find it?
Authors: Demuynck Robin , Efimova Iuliia , Naessens Faye , Krysko Dmitri V
Published: December 2021

Ferroptosis is a recently discovered form of regulated cell death that is morphologically, genetically, and biochemically distinct from apoptosis and necroptosis, and its potential use in anticancer therapy is emerging. The strong immunogenicity of (early) ferroptotic cancer cells broadens the current concept of immunogenic cell death and opens up new possibilities for cancer treatment. In particular, induction of immunogenic ferroptosis could be beneficial for patients with cancers resistant to apoptosis and necroptosis. However, ferroptotic cancer cells may be a rich source of oxidized lipids, which contribute to decreased phagocytosis and antigen cross-presentation by dendritic cells and thus may favor tumor evasion. This could explain the non-immunogenicity of late ferroptotic cells. Besides the presence of lactate in the tumor microenvironment, acidification and hypoxia are essential factors promoting ferroptosis resistance and affecting its immunogenicity. Here, we critically discuss the crucial mediators controlling the immunogenicity of ferroptosis that modulate the induction of antitumor immunity. We emphasize that it will be necessary to also identify the tolerogenic (ie, immunosuppressive) nature of ferroptosis, which can lead to tumor evasion.