bluuebunny/crossref_metadata_2025 huggingface dataset:
Customer preference analysis towards online shopping decisions based on optimized feature extraction
Authors: Liu Weiguang , Alqhatani Abdulmajeed , Asiri Fatima , Salwana Ely
Published: October 2023

Online shopping has become an essential part of modern life, with food delivery being one of the most popular services. In this study, we investigate the factors influencing customers' preferences in online food ordering, such as easy payment, customization, and fast delivery. Analysing customer ratings and reviews is crucial in ensuring the quality of food services and promoting a healthy lifestyle. However, the trustworthiness of online reviews remains a challenge. Based on their rating, new customers can get help from online shoppers for their preferences or demands. Data are collected from customer reviews through online platforms to improve food service quality in online shopping. This work aims to predict the preferences of customers in online shopping based on optimized feature extraction using Principal Component Analysis with a Social Spider Optimization (PCA‐SSO) algorithm. Despite existing algorithms for analysing customer preferences, most may have inaccurate predictions or take time to analyse data. To overcome these challenges, this model of PCA‐SSO is proposed to predict customers' more accurate online shopping preferences. This model provides valuable implications for online shopping owners regarding customer satisfaction. Compared to the accuracy rates of KNN (78.22%), LDA (83.16%), and PCA (88.56%) algorithms, our proposed algorithm of PCA‐SSO achieved a higher accuracy of 93.54%.
Flexible CPA staffing in non‐Big 4 audit firms: Its determinants and implications for audit fees and audit quality
Authors: Kim Sehee , Cho Hyungjin , Cho Meeok , Lee Bryan Byung‐Hee , Lee Woo‐Jong
Published: October 2023

In this study, we discuss how small audit firms (i.e. non‐Big 4 audit firms) address the staffing crunch during the busy season. Using monthly certified public accountant (CPA) employment data from Korea, we find that the number of CPAs in non‐Big 4 audit firms peaks before the busy season but drops afterward, suggesting the prevalence of part‐time or short‐term employment (i.e. flexible staffing). Flexible CPA staffing is more prevalent in audit firms with lower sales, higher sales growth and lower profitability. We further document that the standard deviation of the changes in monthly CPA numbers within a year is negatively associated with audit fees, implying that flexible staffing enables small audit firms to charge lower fees to clients. Additionally, we find no evidence that flexible staffing significantly impairs audit quality. We also report evidence that non‐Big 4 audit firms attract more clients when they are more flexibly staffed than otherwise. Collectively, non‐Big 4 firms reduce operating leverage via flexible staffing arrangements and share the benefits with clients without compromising audit service quality.
Development of genome‐wide association studies on childhood obesity and its indicators: A scoping review and enrichment analysis
Authors: Zhou Feixiang , Tian Gang , Cui Yiran , He Simin , Yan Yan
Published: October 2023

Background

The progress of genome‐wide association studies (GWAS) in childhood obesity and its indicators is challenging and there are differences in genetic studies in children and adults.

Objective

To illustrate the history of the development of GWAS in childhood obesity and its indicators and summarize the GWAS loci.

Methods

PubMed, Web of Science, Embase and GWAS Catalog databases were systematically searched from 1 January 2005 to 19 October 2022 for literature related to GWAS of childhood BMI, body fatness and obesity. The nearest genes were used as positional genes to perform gene set analyses including the enrichment of pathways, tissues and diseases.

Results

Twenty articles published between 2007 and 2021 were included in this scoping review, which identified 116 SNPs reaching genome‐wide significance with childhood BMI (n = 50), body fatness (n = 31) and obesity (n = 35). The study populations were European in 16 studies, non‐European in three studies (1 East Asian; 1 American; 1 Mexican) and trans‐ancestry in one study. Several enriched pathways, tissues and diseases were identified through enrichment analysis of genes associated with childhood obesity and its indicators.

Conclusions

The innovations in tools and methods enable GWAS to better explore the genetic characteristics of obesity in children and adolescents. However, the number of GWAS in American, Asian and African populations is limited compared to the European population.
The interplay of logics and social media: An organisational field perspective
Authors: Karanasios Stan , Adrot Anouck , Hayes Peter , Cooper Vanessa
Published: October 2023

This paper examines what happens when multiple organisations with competing logics enact social media concurrently and in diverse ways. This is important in organisational fields such as emergency management where it becomes problematic if information provision is fragmented and inconsistent. A qualitative and multi‐level case study of an organisational field is undertaken, comprised of interviews with 45 representatives from 27 organisations, including emergency management organisations, government agencies, non‐government organisations, private organisations, and community groups. Based on our findings, we build understanding of how logics and the enactment of digital technology coevolve in an organisational field. We articulate a theoretical model that explains the reciprocity between logics and the enactment of social media. We also develop a framework that captures an organisational field‐level perspective on the range of ways that information flows across such a field. We contribute to theory on institutional dynamics and to understanding of the enactment of social media in organisational fields. Implications for practice are discussed.
Are firms doing good also doing well?—The CSR advertising‐analogous effect
Authors: Chiu She‐Chih , Lin Hsuan‐Chu
Published: October 2023

This paper provides a theoretical framework and empirical support for an examination of corporate financial performance (CFP) from the perspective of an effect that is analogous to corporate social responsibility (CSR) advertising. We propose that not all companies are capable of “doing well by doing good.” Through an analytic model, we identify three key elements for determining a company's CSR advertising‐analogous effect on CFP: the incremental margin (gross profit rate), the sales–CSR elasticity and sales demand in the market (market share). By re‐examining the equivocal relationship between CSR and CFP based on a sample of publicly held US companies from 1991 to 2018, we document that companies in the best position to undertake CSR activities (with gross profit rates, sales–CSR elasticities and market shares above the industry medians) have a superior advertising‐analogous effect to other companies. Moreover, our empirical results show that companies in the best position to undertake CSR activities face less severe agency problems when they conduct more CSR activities than other companies. Finally, in a test of whether regular advertising expenditures and CSR devotion could jointly enhance current CFP, the results show that the positive joint effect is more pronounced for companies in the best position to undertake CSR activities than for other companies.
Effects of dietary hydrolysate supplementation on growth, body composition, hematological responses, and liver histology of juvenile giant trevally (Caranx ignobilis Forsskal, 1775)
Authors: Nguyen Minh Chau , Fotedar Ravi , Pham Hung Duc
Published: October 2023

A feeding study was conducted to investigate how fish protein hydrolysate (FPH) supplementation affected the growth, feed utilization, body composition, and hematology of juvenile giant trevally (Caranx ignobilis Forsskal, 1775). Seven isonitrogenous (52% protein) and isocaloric diets (10% lipid) were formulated, wherein shrimp hydrolysate (SH) and tuna hydrolysate (TH) were used to replace fishmeal at inclusion levels of 0 (control), 30, 60, and 90 g/kg and labeled as control, SH30, SH60, SH90, TH30, TH60, and TH90, respectively. Each diet was fed to triplicate groups of juvenile giant trevally for 8 weeks. The results showed higher final body weight and specific growth rate in fish fed SH30, SH60, TH30, and TH60 than fed control diet. No difference was observed in feed intake, but reduced feed conversion ratio (FCR) was found in fish fed SH30, SH60, TH30, and TH60, demonstrating these diets improved feed utilization. TH90 caused deposition of lipid droplet in the hepatocyte, a sign of liver damage. Total monounsaturated fatty acids, polyunsaturated fatty acids (PUFA), and highly unsaturated fatty acids in fish were not affected by FPH supplementation. Fish fed TH30 showed lower ∑n − 3 PUFA than the fish fed remaining dietary treatments. The elevated serum protein was seen in fish fed control, SH30, SH60, and TH30, demonstrating that these diets were beneficial for the innate immune response in giant trevally. The results indicate that TH and SH could be incorporated into diets of giant trevally at 30–60 g/kg, replacing 7%–13% fishmeal with enhanced growth and health benefits.
Experimental and numerical modelling of water waves in sewer networks during sewer/surface flow interaction using a coupled ODE‐SWE solver
Authors: Moodi Sadegh , Mahdizadeh Hossein , Shucksmith James , Rubinato Matteo , Azhdary Moghaddam Mehdi
Published: October 2023

Flooding in urban areas is expected to increase its magnitude and frequency in the future. Therefore, there is a strong need to better model sewer–surface flow interactions. Existing numerical methods are commonly based on simplified representations of sewer/surface mass exchange, and mainly validated in steady flow conditions. Current methodologies describing the propagation of transient conditions/waves through interaction nodes are simplified, rely on empirical coefficients and/or lack detailed validation. In this paper, an integrated numerical approach for modelling the propagation of water waves through interaction nodes (e.g., manholes) is presented. In this solution, the shallow water equations are used to simulate the free‐surface propagation inside the sewer network, and an ordinary differential equation is employed for modelling flow regimes through pipes and manholes. The model proposed is validated against the well‐known STAR‐CD modelling software for a number of test cases. Finally, further validation is performed against experimental data describing the evolution of water depth around a manhole in unsteady surcharging conditions.
Efficacy of the association of topical minoxidil and topical finasteride compared to their use in monotherapy in men with androgenetic alopecia: A prospective, randomized, controlled, assessor blinded, 3‐arm, pilot trial
Authors: Rossi Alfredo , Caro Gemma
Published: October 2023

Purpose

Topical minoxidil (MNX) 2%–5% and oral finasteride (F) 1 mg/day are the only two pharmacological treatments authorized for androgenetic alopecia (AGA). Recently, a 2.2 mg/mL topical formulation of F was developed to minimize the systemic adverse effects associated with the oral formula. MNX and F act through different mechanisms; therefore, their association could improve clinical efficacy. To evaluate the efficacy of the association of 5% MNX and 0.25% topical F compared to their use in monotherapy, a 6‐month, prospective, randomized, assessor‐blinded trial was conducted.

Patients and Methods

Forty‐two males, mean age 24 ± 3 years, with AGA (I–VII of Norwood‐Hamilton Grading Scale), treatment naive or free from any therapy for at least 6 months, were enrolled and randomly assigned to three arm treatment groups (2:1:1): group A (n = 19, the subjects applied 5% MNX in the morning and F spray in the evening), group B (n = 12, the subjects applied F spray in the evening), and group C (n = 11, the subjects applied 5% MNX twice daily). The efficacy of treatments was evaluated at baseline and after 3 and 6 months using a global photography score (GPAS; from −3 to +3) and trichoscopy evaluation and assessed by an investigator unaware of treatment allocation. At baseline and after treatments, the serum levels of follicle‐stimulating hormone (FSH), luteinizing hormone (LH), dehydroepiandrosterone sulfate (DHEA‐S), and testosterone were also evaluated.

Results

All treatments resulted in an increase in hair density compared to baseline. However, this improvement was significant only for group A (MNX + F), both at three (+56 density/cm2, p < 0.05) and six (+81 density/cm2, p < 0.001) months. The mean change from baseline in hair density was higher for group A compared to other groups and statistically different compared to group B (F) (p < 0.01), both after 3 and 6 months. Group A showed a global photographic assessment score (GPAS) significantly higher compared to group B (p < 0.001) and group C (p < 0.05) both at 3 and 6 months (2.0 ± 0.7 vs. 0.6 ± 0.8 and 1.3 ± 0.6; respectively). A significantly greater percentage of subjects in Group A achieved a GPAS score of ≥2 in comparison with Groups B and C both after 3 and 6 months (79% vs. 8% and 41%, respectively). No significant differences were observed in mean hair diameter and hormonal levels between the three groups. Good tolerability was observed in all treated groups.

Conclusion

The association of 5% MNX lotion and 0.25% F in spray formulation in patients with AGA showed a significantly higher clinical and instrumental efficacy compared to the monotherapies, with comparable tolerability and safety profile.
Why do students leave school early in OECD countries? The role of regional labor markets and school policies
Authors: Bonnet Julien , Murtin Fabrice
Published: October 2023

This paper examines the determinants of early school leaving (ESL) in a panel of 371 regions of OECD countries observed between 1998 and 2019. The empirical analysis includes both local factors previously emphasized by micro‐economic studies and national‐level factors such as education policies. We find that labor market opportunities for young people, as captured by the youth unemployment rate or the size of low‐skill sectors, can pull students out of school. Conversely, late access to a large number of vocational education tracks, high preprimary enrollment and continuous training for teachers are strongly and negatively correlated with ESL rates.
Trends in urolith composition and factors associated with different urolith types in dogs from the Republic of Ireland and Northern Ireland between 2010 and 2020
Authors: Stavroulaki E. M. , Ortega C. , Lawlor A. , Lulich J. , Cuq B.
Published: October 2023

Objectives

The purpose of this study was to determine changes in urolith trends and factors associated with different urolith types in dogs from the Republic of Ireland and Northern Ireland between 2010 and 2020.

Materials and Methods

A laboratory database was searched for canine urolith submissions between 2010 and 2020. Trends in urolith composition between 2014 and 2020, and associations between patient characteristics with each urolith type were evaluated.

Results

A total of 1162 submissions were included. Struvite (39.0%), calcium oxalate (27.8%) and compound (10.2%) were the most prevalent uroliths. Calcium oxalate urolith (CaOx) incidence significantly increased from 27.8% to 31.2% and that of struvite significantly decreased from 41.7% to 33.0% between 2014 and 2020. Struvite uroliths were overrepresented among females compared to males (odds ratio 8.7, 95% confidence interval 6.6 to 11.5). Males (odds ratio 9.6, 95% confidence interval 6.9 to 13.3) and dogs >7 years of age (odds ratio 4.1, 95%, confidence interval 3.0 to 5.4) were more likely to have CaOx while males (odds ratio 9.6, 95% confidence interval 5.3 to 17.8) and dogs ≤7 year of age, purine uroliths (odds ratio 3.0, 95% confidence interval 1.8 to 5.0). Incidence was higher in bichon frise (odds ratio 1.7, 95% confidence interval 1.3 to 2.4) and Yorkshire terrier (odds ratio 2.8, 95% confidence interval 1.9 to 4.1) for CaOx and higher in shih‐tzu for compound uroliths (odds ratio 1.7, 95% confidence interval 1.1 to 2.7) compared to the remaining reported breeds.

Clinical Significance

Factors associated with different uroliths were similar to the ones previously reported. Proportion of CaOx submissions increased and that of struvite decreased over the study period which was in agreement with the changes identified in other European countries.
The nature of bank money, a case study of transformation in the Czech banking sector
Authors: Jonáš Jan
Published: October 2023

The article examines the nature of bank money on two complementary levels. The first level deals with theoretical considerations. Here, the departure point is Social Positioning Theory, which provides a framework to investigate the nature of money. Within the theory, the paper situates bank money in credit‐debt relations, that are themselves integral part of a wider productive‐consumptive nexus of the economy. In this perspective, bank money is the relation, accounting economic positions of participating members, resulting from their economic activities realized within the context of the overall society. The second level uses the methods of Oral History and Memory Studies and, through semi‐structured interviews, provides empirical material illustrating ideas about the nature of money in a specific historical form. The article thus explores the contrasting experiences of banking in the context of a centrally planned economy and banking in the transformation to a market economy. These two contrasting episodes are illustrative because of the significant change in the form of bank money, which brings to light various aspects of its nature. Moreover, the article utilizes interviews that present the lived experience of bankers with years of involvement in the sector, enriching the perspective on the issue under study.
Post‐fledging survival of wedge‐tailed shearwaters is linked to pre‐fledge mass, which has decreased over 40 years
Authors: Swanson Narelle , Vaughan Neil , Belling Neil , Roman Lauren
Published: October 2023

Seabird populations are declining across their global range due to a variety of threats, including shifting food webs from climate change. The impact of these threats is exacerbated in long‐lived species with low reproductive output and high investment in a few offspring, where juvenile survival is of substantial importance to populations. Changes to post‐fledging survival and recruitment of adults are difficult to detect, necessitating better information to forecast juvenile survival before fledglings take to sea. To achieve this goal, we test the hypothesis that there is an ideal mass range for fledglings, outside of which survival is limited, providing an early warning signal for future recruitment failures. Here we present a long‐term study of chick banding, weighing and resighting of wedge‐tailed shearwaters, Ardenna pacifica, a globally widespread but declining tropical/subtropical seabird in a sea‐surface warming hotspot across a span of 43 years. We provide data on 1615 fledgling birds banded most years between 1977 and 2020, with 111 resighted as adults. We found that fledglings weighing 380–470 g have the best chance to survive to adulthood and those weighing 330–540 g have a possible chance of survival. We detected a gradual decline in masses since data collection began, with chicks fledging, on average, 1.6 g lighter each year. This decline has been sharpest since 1996, with fledging masses decreasing at an average rate of 3.8 g annually. Should this 1.6 g decline continue, the average fledgling will cross out of the ‘survivable’ mass range by 2047/2048. We contextualise these findings with observed declines reported in some populations across the species South Pacific range, adding to the conversation about challenges to seabirds in regions experiencing rapid change.
Individual choice and objective demand in a Classical framework
Authors: D’Agata Antonio
Published: October 2023

Taking a cue from some passages of The Wealth of Nations, this paper defines notions of maximum willingness to pay and of individual surplus expressed in hours of labour for a two‐good pre‐capitalist economy. From the individual surplus, a consistent objective theory of individual choice is constructed, and a demand schedule free from subjective elements is derived.
The miR156/SPL12 module orchestrates fruit colour change through directly regulating ethylene production pathway in blueberry
Authors: Li Hongxue , Wang Shouwen , Zhai Lulu , Cui Yuhai , Tang Guiliang , Huo Junwei , Li Xuyan , Bian Shaomin
Published: October 2023

Colour change is an important event during fruit ripening in blueberry. It is well known that miR156/SPLs act as regulatory modules mediating anthocyanin biosynthesis and ethylene plays critical roles during colour change, but the intrinsic connections between the two pathways remain poorly understood. Previously, we demonstrated that blueberry VcMIR156a/VcSPL12 affects the accumulation of anthocyanins and chlorophylls in tomato and Arabidopsis. In this study, we first showed that VcMIR156a overexpression in blueberry led to enhanced anthocyanin biosynthesis, decreased chlorophyll accumulation, and, intriguingly, concomitant elevation in the expression of ethylene biosynthesis genes and the level of the ethylene precursor ACC. Conversely, VcSPL12 enhanced chlorophyll accumulation and suppressed anthocyanin biosynthesis and ACC synthesis in fruits. Moreover, the treatment with ethylene substitutes and inhibitors attenuated the effects of VcMIR156a and VcSPL12 on pigment accumulation. Protein‐DNA interaction assays indicated that VcSPL12 could specifically bind to the promoters and inhibit the activities of the ethylene biosynthetic genes VcACS1 and VcACO6. Collectively, our results show that VcMIR156a/VcSPL12 alters ethylene production through targeting VcACS1 and VcACO6, therefore governing fruit colour change. Additionally, VcSPL12 may directly interact with the promoter region of the chlorophyll biosynthetic gene VcDVR, thereby activating its expression. These findings established an intrinsic connection between the miR156/SPL regulatory module and ethylene pathway.
Arteriovenous malformations as a presenting sign of PTEN hamartoma tumor syndrome: A case series
Authors: Dykman Morgan , Pillai Nishitha R. , Lenhart Kelsey , Nicholson Cynthia , Boull Christina , Fritz Erin , Flanagan Siobhan , Maguiness Sheilagh
Published: October 2023

High‐flow vascular malformations have been associated with multiple syndromes including capillary malformation–arteriovenous malformation (CM–AVM) syndrome, hereditary hemorrhagic telangiectasia syndrome, and less commonly, phosphatase and tensin homolog hamartoma tumor syndrome (PHTS). We present a series of three patients with clinically challenging complex AVMs who were found to have underlying PHTS. In all patients, diagnosis was delayed, and the presence of the AVM prompted sampling and genetic testing for PHTS in the absence of other clinical features of the condition. This series highlights the importance of screening for PHTS in the setting of high‐flow vascular malformations.
Impact of temporal variations and risk factors associated with udder inflammation in Hardhenu cattle (Bos taurus × Bos indicus)
Authors: Pushpa  , Magotra Ankit , Kamaldeep  , Sindhu Vikas , Chaudhary Pradeep
Published: October 2023

This study aimed to explore the occurrence and risk factors associated with clinical mastitis within the Hardhenu cattle herd over a span of 14 years (2008–2021). A comprehensive analysis of 1515 lactation records was conducted to ascertain the incidence of clinical mastitis. The investigation determined an overall incidence rate of 26.80% in the studied population. A significant relationship between the year and clinical mastitis incidence was established through Chi‐square analysis (p < .05). Temporal variations in clinical mastitis odds were apparent, with the highest odds (ranging from 0.91 to 1.00) observed during the initial years of 2008–2009 and 2009–2010. Logistic regression revealed that odds values for clinical mastitis incidence were highest in 2008–2009 (1.00), succeeded by 2009–2010 (0.91), 2012–2013 (0.88), 2018–2019 (0.67) and reaching the lowest in 2021–2022 (0.35). Subsequent rankings included 2010–2011 (0.39), 2014–2015 (0.43) and 2019–2020 (0.45). Parity was found to be significantly associated with clinical mastitis occurrence. When compared to Parity 3, both Parity 1 (odds ratio: 1.516, 95% confidence interval: 0.881–2.612) and Parity 2 (odds ratio: 2.626, 95% confidence interval: 1.568–4.398) exhibited higher odds values for clinical mastitis incidence. While the period of calving did not exert a significant influence on clinical mastitis incidence, a heightened occurrence was observed during the rainy season within the targeted population. These findings offer valuable insights into the patterns of incidence, temporal fluctuations, and non‐genetic determinants impacting clinical mastitis within the Hardhenu cattle. The implications of this study can facilitate the development of targeted strategies and management protocols aimed at enhancing udder health and overall productivity in dairy cattle.
The impact of policy uncertainty on foreign direct investment: Micro‐evidence from Japan's international investment agreements
Authors: Inada Mitsuo , Jinji Naoto
Published: October 2023

This study proposes an empirical strategy to identify the impact of policy uncertainty (PU) at the host economy‐sector‐reservation level on foreign direct investment (FDI) by exploiting sectoral differences in PU before and after the entry into force of international investment agreements (IIAs). These sectoral differences arise because IIAs mitigate PU in host economies, but sectors included in negative lists of IIAs continue to face different degrees of PU owing to exemptions from certain obligations, such as national treatment and the most favored nation in IIAs. Using this empirical strategy, we evaluate how the activities of Japanese multinational enterprises and their foreign affiliates are affected by Japan's 22 IIAs, including bilateral investment treaties and economic partnership agreements with investment provisions, during 1995–2016 at the microdata level. We find that PU regarding a combination of national treatment and most favored nation has a negative impact on FDI. In particular, PU discourages the establishment of new foreign affiliates. However, PU does not necessarily induce affiliates to exit the market.
Genomic asymmetric epigenetic modification of transposable elements is involved in gene expression regulation of allopolyploid Brassica napus
Authors: Xiao Yafang , Xi Zengde , Wang Fei , Wang Jianbo
Published: October 2023

Polyploids are common and have a wide geographical distribution and environmental adaptability. Allopolyploidy may lead to the activation of transposable elements (TE). However, the mechanism of epigenetic modification of TEs in the establishment and evolution of allopolyploids remains to be explored. We focused on the TEs of model allopolyploid Brassica napus (AnAnCnCn), exploring the TE characteristics of the genome, epigenetic modifications of TEs during allopolyploidization, and regulation of gene expression by TE methylation. In B. napus, approximately 50% of the genome was composed of TEs. TEs increased with proximity to genes, especially DNA transposons. TE methylation levels were negatively correlated with gene expression, and changes in TE methylation levels were able to regulate the expression of neighboring genes related to responses to light intensity and stress, which promoted powerful adaptation of allopolyploids to new environments. TEs can be synergistically regulated by RNA‐directed DNA methylation pathways and histone modifications. The epigenetic modification levels of TEs tended to be similar to those of the diploid parents during the genome evolution of B. napus. The TEs of the An subgenome were more likely to be modified, and the imbalance in TE number and epigenetic modification level in the An and Cn subgenomes may lead to the establishment of subgenome dominance. Our study analyzed the characteristics of TE location, DNA methylation, siRNA, and histone modification in B. napus and highlighted the importance of TE epigenetic modifications during the allopolyploidy process, providing support for revealing the mechanism of allopolyploid formation and evolution.
Validation of Metabolic Models for Estimation of Energy Expenditure During Isolated Concentric and Eccentric Muscle Contractions
Authors: Lentz-Nielsen Nicki , Boysen Mads Daabeck , Munk-Hansen Mathias , Laursen Andreas David , Steffensen Mike , Engelund Bjørn Keller , Iversen Kristoffer , Larsen Ryan Godsk , de Zee Mark
Published: October 2023

Musculoskeletal modeling uses metabolic models to estimate energy expenditure of human locomotion. However, accurate estimation of energy expenditure is challenging, which may be due to uncertainty about the true energy cost of eccentric and concentric muscle contractions. The purpose of this study was to validate three commonly used metabolic models, using isolated isokinetic concentric and eccentric knee extensions/flexions. Five resistance-trained adult males (25.6 ± 2.4 year, 90.6 ± 7.5 kg, 1.81 ± 0.09 m) performed 150 repetitions at four different torques in a dynamometer. Indirect calorimetry was used to measure energy expenditure during these muscle contractions. All three models underestimated the energy expenditure (compared with indirect calorimetry) for up to 55.8% and 78.5% for concentric and eccentric contractions, respectively. Further, the coefficient of determination was in general low for eccentric contractions (R2 < 0.46) indicating increases in the absolute error with increases in load. These results show that the metabolic models perform better when predicting energy expenditure of concentric contractions compared with eccentric contractions. Thus, more knowledge about the relationship between energy expenditure and eccentric work is needed to optimize the metabolic models for musculoskeletal modeling of human locomotion.
A Novel Design of Parabolic Trough Solar Collector’s Absorber Tube
Authors: Djenane Mohamed Salim , Hadji Seddik , Touhami Omar , Zitouni Abdel Halim
Published: October 2023

This paper proposes an investigation of a novel design of receiver absorber tube (circular–trapezoidal shaped) for parabolic trough concentrator (PTC) system aiming at catching a part of the lost (reflected) solar rays due to effects related to the incidence angle deviation and thus improving the PTC's thermal performance. Although they are always present in PTC, the effects of the deviation angle are often not considered in the literature. These effects are considered here in view of presenting a better and more useful focal area, the optimal circular–trapezoidal absorber tube shape is determined according to the maximal limit of the deviation angle that allows catching the maximum amount of solar rays. The corresponding model is established considering it as a two-dimensional problem and the derived deviation angle coefficient is compared to that obtained for a traditional circular-shaped tube. Moreover, the energy balance model is adapted to simulate the thermal efficiency of the considered tubes as a function of the deviation angle with some assumptions. The obtained results prove that from a deviation angle value of 0.1 deg, the gain in efficiency becomes more significant; it can reach 5% and even be higher for a deviation angle value of 0.5 deg. Finally, comsol multiphysics software package was used to determine the pressure drops, temperature, and velocity field distributions, considering a deviation angle value of 0.2 deg. The results confirm that the proposed tube absorbs more heat than the traditional one.
Nano Magnesium Silicate Hydroxide as Synergistic Lubricant Additive With Micro Carbon Sphere for Enhanced Tribological Properties
Authors: Gao Rongqin , Chang Qiuying , Lichun Hao , He Yang
Published: October 2023

In this study, the tribological properties of the mixture of nano magnesium silicate hydroxide (MSH) and micro carbon sphere (CS) are studied, and a superior synergistic anti-wear performance is exhibited under 600 N and 600 RPM. For determining the anti-wear mechanism, an easy two-step experimental method is innovatively used. It is proved that the decomposition of MSH is the key to exhibit the synergistic anti-wear effect with amorphous carbon (a-C). Results show that the H+ protons released by MSH decomposition can effectively convert Fe2O3 to Fe3O4 on worn surfaces. Besides, MSH also helps the formed a-C layer exist in low H content with stronger adhesion on the iron surface, and the detached H atoms from C–H further facilitate the reduction of Fe2O3. It is believed that the critical role of lamellate clay in synergy with a-C as a lubricant additive is determined, and a basis for the further anti-wear mechanism study of various a-C-modified clay composite is provided.
Damage Simulation Method for Adhesively Bonded Composite Structures Based on XFEM and Cohesive Hybrid Model
Authors: Zhang Yang , Soman Rohan , Radzieński Maciej , Ostachowicz Wiesław
Published: October 2023

The increasing use of bonded composites has increased interest in detecting potential defects. In this study, we examined the structural integrity of the bonded zone of the single lap joint and characterized the associated crack propagation by using the extend finite element method (XFEM) technique. Furthermore, a probabilistic machine learning approach is employed to estimate the remaining useful life of the structure. Our findings provide valuable insights into detecting the health condition of bonded composites and can aid in developing effective maintenance strategies for ensuring long-term safety and reliability.
Eddy-Current Evaluation of Platinum Aluminide Coatings
Authors: Ribichini Remo , Giolli Carlo , Scrinzi Erica
Published: October 2023

Platinum Aluminide (PtAl) diffusion coatings play an essential role in the protection of mechanical components exposed to high temperatures, such as gas turbine blades and nozzles. The formation of an adherent oxide scale inhibits substrate oxidation or hot corrosion that would otherwise lead to mechanical degradation and premature failure of parts. Nondestructive evaluation methods of Platinum Aluminide coatings are of significant practical interest in industry to optimize maintenance and repair operations while keeping safety and quality requirements. This article describes the application of a frequency sweeping eddy current technique to measure impedance spectra. Such electrical measurements are then inverted with a classical physics-based model to obtain coating properties (thickness, conductivity) or used to directly estimate useful residual life parameters using data-driven models together with the results of destructive analyses. The article shows the validation of this approach, first on a set of samples artificially aged at different temperature and time exposures up to several years and then the validation on actual parts, that have been removed from service and analyzed in the laboratory. A comparison of the data-driven versus physics model is also presented, showing the pro and cons of each approach.
A Relationship Between the POD Qualification of an Inspector and the Estimated Upper Bound Failure Probability of a Fatigue-Loaded Component When No Crack Was Found
Authors: Fong Jeffrey T. , Finney Ned A. , Doctor Steven R. , Heckert N. Alan
Published: October 2023

The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) Committee has recently developed a new Section XI (Nuclear Components Inspection) Division 2 Code named “Reliability and Integrity Management (RIM).” RIM incorporates a new concept known as “System-Based Code (SBC)” originally due to Asada and his colleagues, where an integrated approach from design to service inspection is introduced using three new types of statistical quantities: (1) ”system reliability index,” or “system failure probability,” for any system consisting of structures and components, (2) “structural failure probability”. or “structural co-reliability,” for any structure, and (3) “component failure probability,” or “component co-reliability” for any component. In a recent paper published in the International Journal of Pressure Vessels and Piping (Vol. 173 (2019), pp. 79-93). Fong, Heckert, Filliben, and Freiman developed a new theory of fatigue and creep rupture life modeling for metal alloys at room and elevated temperatures such that the upper bound of failure probability (FPUB) of an uncracked component can be rigorously estimated from fatigue or creep rupture test data with simple loading histories. This led to the publication of a second paper, ASME PVP2021-62169 (Fong, Marcal, Rainsberger, Heckert, Filliben, Doctor, and Finney, Jr.), where the methodology was applied to the inspection results of both uncracked and cracked components by NDE inspectors with probability of detection (POD) qualification at certain statistical level of confidence.(e.g., 95 %). In a numerical example presented in that ASME PVP-2021-62169 paper, a quantitative relationship was shown between the POD qualification at certain statistical level of confidence of an NDE inspector and the estimated FPUB curve of an uncracked component when the inspector reports a result of either a crack or “no crack.” This result is significant to the NDE industry, and we discuss it in this paper and propose to use the result as a basis for revising the Article 14 (Examination System Qualification) of the ASME Section V (2015) Code.
Acoustic Emission Source Localization in Plates Through Support Vector Machine with Genetic Optimization
Authors: Kalimullah Nur M. M. , Ojha Shivam , Shelke Amit , Habib Anowarul
Published: October 2023

Support vector machine (SVM) is used as the classifier as well as a regressor in the machine learning techniques. However, the application of SVM for acoustic emission (AE) source localization is limited. For the composite materials, the use of guided ultrasonic waves (GUV) helps in identifying the location of defects as they can be transmitted and simultaneously received by the sparse array of piezoelectric sensors. Various methods based on minimizing the error function and Bayesian filters have already been implemented to identify the location of the acoustic emission (AE) source. The current study focuses on identifying the location of impact in the plate using guided waves through a layered support vector machine framework. Under the framework, the carbon-fiber-reinforced polymer (CFRP) plate is divided into several small regions. The SVM classifier is trained for each of these regions, and thus a set of layers containing different SVM classifiers is formed. The training dataset is generated through the centroidal Voronoi tessellations. The test point generated through Markov Chain is passed through the different layers of SVM to identify the region of AE source location. Moreover, the proposed approach is validated using an experimental program that makes use of a CFRP composite panel instrumented with a sparse array of piezoelectric transducers.
Numerical Simulation Study on Nondestructive Evaluation of Surface Crack Defects of Ferromagnetic Materials by Wideband Ultrasonic Surface Waves
Authors: Liu Zenghua , Guo Yanhong , Zhao Xin
Published: October 2023

The key parts of ferromagnetic materials that have served in high temperature environment for a long time are prone to cracks, and the growth of cracks seriously threatens the safe operation of the components. Aiming at the surface crack defects of ferromagnetic materials, based on numerical simulation, this study uses wideband ultrasonic surface waves to carry out nondestructive evaluation of surface crack defects. The wideband ultrasonic surface waves are generated and received by the wideband ultrasonic surface waves transducers. Based on time-frequency analysis method, the interaction law between ultrasonic surface wave with different frequency components and surface crack defects is studied. Ultrasonic characteristic parameters with different frequency components are extracted, and a neural network model with ultrasonic characteristic parameters as input and surface crack defects information as output is constructed to evaluate surface cracks defects. The results show when the crack length is between the wavelength depth of high-frequency ultrasonic surface waves and the wavelength depth of low-frequency ultrasonic surface waves, the prediction error of crack length is large. The prediction error of crack length can be reduced and the ability of nondestructive evaluation of surface crack defects can be improved when using wideband ultrasonic characteristic parameters for crack nondestructive evaluation.
Ultrasonic Guided Waves Measurements using Bragg Gratings in Optical Fibers under Varying Environmental Conditions
Authors: Recoquillay Arnaud , Roussel Nicolas , Maurin Laurent , Laffont Guillaume , Chapuis Bastien
Published: October 2023

Fiber Bragg Gratings (FBGs) are promising ultrasound transducers, especially for Structural Health Monitoring (SHM), since they can be seamlessly integrated into structures and multiplexed, and can also sustain harsh environments (extreme temperatures, radiations, electromagnetic environments…). However, their widespread use for ultrasound measurements has been limited until now because the sensitivity of the edge filtering technique, as implemented so far, is strongly impacted by environmental conditions such as temperature or deformation of the host structure, leading to a loss in sensitivity. Indeed, edge filtering is based on a narrow band light source locked on the side of the reflection spectrum of the FBG. Under varying environmental conditions, this reflection spectrum will shift and, without proper action, the setting will be lost. We present here a solution enabling measurements under varying environmental conditions based on the low frequency tracking of the setting point in order to keep the sensitivity of this method at an acceptable level. The tracking is based on a retroaction loop on the DC output of the photodiode, giving an image of the relative position of the narrow band light source and the reflection spectrum of the FBG. The setup was successfully tested during the 4-points bending test of a composite panel sollicited at increasing strain rates.
Molecular dynamics simulation of amine formation in plasma-enhanced chemical vapor deposition with hydrocarbon and amino radicals
Authors: Harumningtyas Anjar Anggraini , Ito Tomoko , Isobe Michiro , Zajíčková Lenka , Hamaguchi Satoshi
Published: October 2023

Molecular dynamics simulations were performed to examine the amine formation in carbon-based polymer films deposited by plasma-enhanced chemical vapor deposition (PECVD) with methane (CH4) and nitrogen (N2) gases. In the simulations, the interactions between the deposited film surface and incident precursors were examined, where nitrogen species were assumed to be supplied only as amino radicals (NH2) such that the amount of primary amine (−NH2) could be maximized in the deposited film. Carbon was supplied as CH2 or CH3 radicals as well as CH2+ or CH3+ ions with an ion kinetic energy up to 100 eV, as typical in such PECVD experiments. It has been found that, even under such “ideal” conditions for the maximum primary-amine content, hydrogen (H) atoms of incident NH2 radicals tend to be transferred to surrounding C atoms in the polymerization process, leaving a relatively small amount of primary amine (the concentration ratio of primary amino groups NH2 to nitrogen atoms N ∼10%) in the deposited polymer films. The simulation results indicate that an increase of NH2 radicals in the gas phase of PECVD hardly increases the primary-amine content in the deposited films and, therefore, the primary-amine content may not depend strongly on the plasma conditions as long as a sufficient amount of nitrogen and hydrogen is supplied during the plasma polymerization process. The primary-amine content predicted by the simulations was found to be consistent with earlier experimental observations.
Personality and Attitudinal Predictors of Sportspersonship in Recreational Sport
Authors: Fozzard Tanya , Mojtahedi Dara
Published: October 2023

Respect and fair treatment among competitors are necessary for maintaining quality and enjoyment in sporting competitions. Yet despite the existence of rules and expectations, many athletes choose to violate such sporting norms. The present study examined whether individual differences in Sportspersonship within recreational sports could be explained by personality and sport-related attitudes. Ultimate Frisbee players (N = 828) completed an online survey consisting of personality (dark triad, HEXACO-60, and Sportspersonship), demographic, and attitudinal questionnaires. Psychopathy was associated with low Sportspersonship, whereas Honesty-Humility, Agreeableness, and Openness to Experience predicted greater Sportspersonship. Additionally, participants holding positive attitudes about the conduct of other players and the efficacy of self-governed regulation displayed higher Sportspersonship. Positive associations between personality traits and Sportspersonship may be attributed to positive views toward cooperation and enjoyment of the experience, whereas negative associations between Psychopathy and Sportspersonship are likely to be linked to the callous and risk-taking nature of such individuals.
Chromatin analysis of adult pluripotent stem cells reveals a unique stemness maintenance strategy
Authors: Poulet Axel , Kratkiewicz Arcadia J. , Li Danyan , van Wolfswinkel Josien C.
Published: October 2023

Many highly regenerative organisms maintain adult pluripotent stem cells throughout their life, but how the long-term maintenance of pluripotency is accomplished is unclear. To decipher the regulatory logic of adult pluripotent stem cells, we analyzed the chromatin organization of stem cell genes in the planarian
Schmidtea mediterranea
. We identify a special chromatin state of stem cell genes, which is distinct from that of tissue-specific genes and resembles constitutive genes. Where tissue-specific promoters have detectable transcription factor binding sites, the promoters of stem cell–specific genes instead have sequence features that broadly decrease nucleosome binding affinity. This genic organization makes pluripotency-related gene expression the default state in these cells, which is maintained by the activity of chromatin remodelers ISWI and SNF2 in the stem cells.
SpikingJelly: An open-source machine learning infrastructure platform for spike-based intelligence
Authors: Fang Wei , Chen Yanqi , Ding Jianhao , Yu Zhaofei , Masquelier Timothée , Chen Ding , Huang Liwei , Zhou Huihui , Li Guoqi , Tian Yonghong
Published: October 2023

Spiking neural networks (SNNs) aim to realize brain-inspired intelligence on neuromorphic chips with high energy efficiency by introducing neural dynamics and spike properties. As the emerging spiking deep learning paradigm attracts increasing interest, traditional programming frameworks cannot meet the demands of the automatic differentiation, parallel computation acceleration, and high integration of processing neuromorphic datasets and deployment. In this work, we present the SpikingJelly framework to address the aforementioned dilemma. We contribute a full-stack toolkit for preprocessing neuromorphic datasets, building deep SNNs, optimizing their parameters, and deploying SNNs on neuromorphic chips. Compared to existing methods, the training of deep SNNs can be accelerated 11×, and the superior extensibility and flexibility of SpikingJelly enable users to accelerate custom models at low costs through multilevel inheritance and semiautomatic code generation. SpikingJelly paves the way for synthesizing truly energy-efficient SNN-based machine intelligence systems, which will enrich the ecology of neuromorphic computing.
Neither naïve nor anergic, “autoimmune” not allergic
Authors: Çakan Elif , Pillai Shiv
Published: October 2023

Insulin-specific B cells called BND2 B cells accumulate in the peripheral blood of patients with very early onset type 1 diabetes.