bluuebunny/crossref_metadata_2025 huggingface dataset:
In-depth specificity profiling of Pro-Pro endopeptidases (PPEPs) using combinatorial synthetic peptide libraries
Authors: Claushuis Bart , Cordfunke Robert A. , de Ru Arnoud H. , Otte Annemarie , van Leeuwen Hans C. , Klychnikov Oleg I. , van Veelen Peter A. , Corver Jeroen , Drijfhout Jan W. , Hensbergen Paul J.
Published: November 2022

Proteases comprise the class of enzymes that catalyze the hydrolysis of peptide bonds, thereby playing a pivotal role in many aspects of life. The amino acids surrounding the scissile bond determine the susceptibility towards protease-mediated hydrolysis. A detailed understanding of the cleavage specificity of a protease can lead to the identification of its endogenous substrates, while it is also essential for the design of inhibitors. We developed a new method which combines the high diversity of a combinatorial synthetic peptide library with the sensitivity and detection power of mass spectrometry to determine protease cleavage specificity. We applied this method to study a group of bacterial metalloproteases that have the unique specificity to cleave between two prolines, i.e. Pro-Pro endopeptidases (PPEPs). We not only confirmed the prime-side specificity of PPEP-1 and PPEP-2, but also revealed some new unexpected peptide substrates. Moreover, we have characterized a new PPEP (PPEP-3) which has a prime-side specificity that is very different from that of the other two PPEPs. Importantly, the approach that we present in this study is generic and can be extended to investigate the specificity of other proteases.
Elevated α-synuclein attenuates phagocytosis inSNCAtriplication human iPSC-derived neuron:microglia co-cultures
Authors: Lieberman Richard , Elnaggar Khaled , Jesseman Kimberly , DeFrancisco Sarah , Degouveia Kelsey , Suneby Emma , Wu Hao , Rojas L. Alejandro , Graef John D.
Published: November 2022

Synucleinopathies such as Parkinson’s disease (PD) are characterized by pathologic production, aggregation, and cell-to-cell transmission of α-synuclein (α-syn) protein that results in impaired cellular function. While neurons of the substantia nigra pars compacta express high levels of α-synuclein and are highly vulnerable to its aberrant expression or conformation, brain-resident macrophages (microglia) are also sensitive to abnormal α-synuclein, with recent reports indicating that elevated levels impair phagocytic abilityin vivoandin vitro. To explore the impact of elevated α-syn on microglial function we employed a co-culture model containing iPSC-derived neurons and microglia-like cells. iPSCs from healthy control donors and a Parkinson’s donor with an allelic triplication of theSNCAgene locus were differentiated into neurons and microglia-like cells. In monoculture, neurons and microglia generated from theSNCAtriplication donor expressed higher levels ofSNCAtranscript and protein. Neurons were found to have significantly greater expression ofSNCAcompared to microglia, regardless of donor genotype. Co-cultures of neurons and microglia revealed that microglia cultured withSNCAtriplication neurons displayed reduction in phagocytosis of fluorescentE. coli, irrespective of microglia donor genotype.SNCAmRNA and protein expression could be reduced with treatment with an antisense oligonucleotide (ASO) targetingSNCA. ASO treatment partially rescued microglia phagocytosis inSNCAtriplication co-cultures and in co-cultures containingSNCAtriplication neurons and healthy control microglia. Our results complement and extend previous findings of impaired microglial function in the presence of elevated α-synuclein in a novel patient-derived co-culture model that utilizes more disease-relevant conditions rather than the relaying on the addition of exogenous α-synuclein.
Extracting electromyographic signals from multi-channel local-field-potentials using independent component analysis without direct muscular recording
Authors: Osanai Hisayuki , Yamamoto Jun , Kitamura Takashi
Published: November 2022

Electromyography (EMG) has been commonly used for precise identification of animal behavior. However, they are often not recorded together with in vivo electrophysiology due to the need for additional surgeries and setups and the high risk of mechanical wire disconnection. While independent component analysis (ICA) has been used to reduce noise from field potential data, there has been no attempt to proactively use the removed “noise”, of which EMG signals are thought to be one of the major sources. Here, we demonstrate that EMG signals can be reconstructed without direct EMG recording, using the “noise” ICA component from local field potentials. The extracted component is highly correlated with directly measured EMG, termed as IC-EMG. IC-EMG is useful for measuring an animal’s sleep/wake, freezing response and NREM/REM sleep states consistently with actual EMG. Our method has advantages in precise and long-term behavioral measurement in wide-ranged in vivo electrophysiology experiments.

Highlights

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EMG signals can be extracted from LFP signals without direct muscular recording

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The extracted signal is highly correlated with direct EMG recording signals

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The extracted signal is useful in measuring animal behaviors as well as actual EMG

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This method contributes to precise and stable long-term behavior measurement

In brief

Osanai et al. demonstrate electromyography (EMG) signals can be extracted from multi-channel local field potential (LFP) recordings using blind-source-separation technique without direct measurement of muscle activity. The proposed method adds precise and long-term behavioral measurements with EMG information in wide-ranged in vivo electrophysiology experiments.
The relationship between electronic human resource management and employee job satisfaction in organizational value-creation in Africa: the case of Zimbabwe
Authors: Nyathi Musa , Kekwaletswe Ray
Published: November 2022

Purpose

The purpose of this paper is to examine the mediating effect of employee job satisfaction on the relationship between electronic human resource management (e-HRM) use and e-HRM macro-level consequences.

Design/methodology/approach

Data were collected through a survey involving 32 organizations, using e-HRM applications. A purposive sampling technique was employed. A structural equation modeling technique with the use of the process macro approach was used to analyze collected data.

Findings

E-HRM use has a positive and significant effect on e-HRM macro-level consequences and constituent elements of e-HRM operational, relational and transactional consequences. Employee job satisfaction partially mediates the relationship between e-HRM use and e-HRM macro-level consequences.

Practical implications

The use of e-HRM, complemented by human resource best practices, enhances employee job satisfaction. At an indirect level, job satisfaction partially mediates the effect of e-HRM use on e-HRM macro-level consequences. Organizations should invest in job satisfaction-enhancing practices to ensure attainment of intended organization-wide consequences on a more consistent basis.

Originality/value

The study broadens the scope through which the association between e-HRM use, e-HRM macro-level consequences and employee job satisfaction are viewed. The study illustrates the limitations of the deterministic view of e-HRM use, while supporting the assumptions of the moderate determinism approach, which pin the success of e-HRM systems on the performance and satisfaction of e-HRM actors. The level of employee job satisfaction mediates the relationship between e-HRM use and e-HRM macro-level consequences. The study, to the authors' knowledge, is the first in establishing such an effect.
Copyright implications for the aggregation of audiovisual content in Greece
Authors: Malliari Afrodite , Nitsos Ilias , Zapounidou Sofia , Doropoulos Stavros
Published: November 2022

Purpose

This paper aims to attempt to provide an overview of the copyright legal framework for audiovisual resources in Europe and Greece, how Audiovisual (AV) content is currently licensed by Greek providers and how licenses or copyright exceptions enable its reuse. The motivation for this work was the development of an aggregation service for audiovisual resources in Greece, the Open AudioVisual Archives (OAVA) platform.

Design/methodology/approach

Copyright licenses and exceptions in the European Union and in Greek Legislation have been thoroughly reviewed along with the reuse of content, based on the terms of Fair Use, Rights Statements and Creative Commons. Licensing issues for the most well-known aggregation services, such as Europeana, Digital Public Library of America, Trove, Digital New Zealand and the National Digital Library of India, have also been studied and considered. Audiovisual content providers in Greece have been recorded, and their licensing preferences have been analyzed. Pearson’s chi-square test was applied to test the relationship between the provider’s type, resources’ genre and licenses used.

Findings

Despite the abundance of copyright legislation in the European Union and in Greece, audiovisual content providers in Greece seem to ignore it or find it difficult to choose the right license. More than half of them choose to publish their resources on popular audiovisual platforms using the default licensing option provided. Creative Commons licenses are preferred for audiovisual content that falls into the following categories: open courses (almost exclusively) and interviews and digital collection/research projects (about half of the content).

Originality/value

This paper examines audiovisual content aggregation, in the EU and Greece, from a legal point of view. To the best of the authors’ knowledge, it is the first attempt to record and analyze the licensing preferences of Greek AV content providers.
Investigating the effects of high-involvement climate and public service motivation on engagement, performance, and meaningfulness in the public sector
Authors: Scrimpshire Alex J. , Edwards Bryan D. , Crosby Durand , Anderson Scott J.
Published: November 2022

Purpose

Despite much research, too many employees are disengaged in their work. As such, the present research uses a public sector setting to investigate variables (e.g. public service motivation and high-involvement climate) most likely associated with engagement and demonstrates a conceptual and empirical link to relevant outcomes (e.g. job performance and perceived meaningfulness).

Design/methodology/approach

Across a work week, the authors analyze the drivers and outcomes of public service employees’ engagement levels and the mediating effect of employee engagement.

Findings

Employee engagement mediated the positive relationship between the authors’ independent variables of public service motivation and high-involvement climate and our outcomes of supervisor-rated employee performance and meaningfulness. All direct and indirect effects were statistically significant and positive.

Research limitations/implications

The authors’ sample is a nonprofit government agency, so the results may lack generalizability. Although self-determination theory (SDT) guided their choice of variables and hypotheses, they did not measure the specific needs satisfaction (competence, relatedness, and autonomy) associated with the SDT.

Practical implications

Managers in public-service organizations may want to recruit those high in public service motivation and institute a high-involvement climate via manager skill training.

Originality/value

This article follows a meta-analysis call on SDT to test the impact of variables that fall under the identified form of autonomous motivation, and investigate their impact on engagement and other positive organizational outcomes (e.g. job performance and perceived meaningfulness). Additionally, the author followed calls to extend engagement research to focus on specific industry sectors, such as the public sector.
Did subsidies included in the 2009 Stimulus Package encourage enrolment in COBRA?
Authors: Zimmer David M.
Published: November 2022

The 2009 Stimulus Package in the US introduced a 65 per cent subsidy for COBRA coverage for individuals who experienced employment separation between 1 September 2008 and 2 June 2010. This paper provides evidence that the subsidy led to statistically significant and non‐trivial increases in the probability that job separators enrolled in COBRA, but only among those who qualified for the subsidy. Specifically, the subsidy appears to have boosted the probability of COBRA enrolment among subsidy qualifiers by approximately 80 per cent. Among people who separated from jobs in manufacturing and business/professional services – two industries hit hard by the recession – the subsidy boosted enrolment probabilities among subsidy qualifiers by 60 per cent and 80 per cent, respectively.
‘Burr holes in the bush’: Clinician preparedness for undertaking emergency intracranial haematoma evacuation surgery in rural and regional Queensland
Authors: Raman Vignesh , Maclachlan Liam , Redmond Michael
Published: November 2022

Objectives

Delayed inter‐hospital transfers of deteriorating neurotrauma patients from rural and regional hospitals to tertiary centres have seen the need for non‐neurosurgeons to undertake emergency intracranial haematoma evacuation surgery locally. In the present study, the authors contributed to the paucity in the literature regarding the widespread availability of cranial access equipment in non‐tertiary centres and patient outcomes in Queensland.

Methods

We surveyed delegates (senior theatre nurses or surgical service directors) from rural and regional Queensland hospitals if they were located outside the local catchment of a tertiary centre and had a CT scanner. Questions regarded availability, location and storage conditions of mechanical cranial access kits, as well as last usage, and associated patient outcomes.

Results

Twenty‐six delegates from eligible hospitals responded. Eighteen hospitals offered surgical services. Eleven hospitals housed complete mechanical cranial access kits. Five hospitals housed incomplete kits. Thirteen hospitals housed their equipment sterile in the operating theatre or ED. Eleven hospitals reported using the equipment, with last usage ranging from 4 months to over 30 years. Two hospitals reported using the equipment within 12 months while a further five reported using it within 10 years. Two hospitals reported ‘good’ outcomes, two ‘ok’ and one ‘poor’.

Conclusions

The availability of cranial access equipment outside Queensland tertiary centres has been limited. Inter‐hospital transfers are likely to persist in Queensland and haematoma evacuation surgery has been a life‐saving endeavour, so improving access to cranial access equipment in hospitals where it is currently lacking is highly warranted.
Knockout of cryptochrome 1 disturbs the locomotor circadian rhythm and development of Plutella xylostella
Authors: Chen Shao‐Ping , Wang Dan‐Feng , Ma Wei‐Feng , Lin Xiao‐Lu , Yang Guang
Published: November 2022

Cryptochrome 1 (CRY1) functions as a light‐responsive photoreceptor, which is crucial for circadian rhythms. The identity and function of CRY1 in Plutella xylostella remain unknown. In this study, cry1 was cloned and identified in P. xylostella. Then, a cry1‐knockout strain (Cry1‐KO) of P. xylostella with a 2‐bp deletion was established from the strain Geneva 88 (G88) using the CRISPR/Cas9 technology. No daily temporal oscillation of cry1 was observed in G88 and Cry1‐KO, and cry1 mean daily transcription of Cry1‐KO was lower than that of G88. Both G88 and Cry1‐KO demonstrated rhythmic locomotion under the light/dark condition with Cry1‐KO being more active than G88 in the daytime, whereas Cry1‐KO completely lost rhythmicity under constant darkness. The developmental period of pre‐adult of Cry1‐KO was longer than that of G88; the lifespan of the Cry1‐KO male adult was shorter than that of G88; the fecundity of Cry1‐KO was lower than that of G88; and Cry1‐KO showed lower intrinsic rate of increase (r), net reproduction rate (R0), finite increase rate (λ), and longer mean generation time (T) than G88. Our results indicate that cry1 is involved in the regulation of locomotor circadian rhythm and development in P. xylostella, providing a potential target gene for controlling the pest and a basis for further investigation on circadian rhythms in lepidopterans.
A cross‐sectional survey on principal investigators' clinical research knowledge in Japan
Authors: Sekine Miwa , Kataoka Koshi , Nishizaki Yuji , Matsuyama Kotone , Otsuka Toshiaki , Sato Kensuke , Idei Mayumi , Sanada Shoji
Published: November 2022

Principal investigators (PIs) play a key role in clinical research, and must thus understand the role of clinical research support staff to conduct successful and appropriate clinical research. This study evaluates clinical research capabilities by examining the clinical research knowledge of PIs and clinical research support staff. The participants of this cross‐sectional study were academic researchers and clinical research support staff from Japanese universities and research institutions. The participants comprised of 54 respondents, among whom 36 were PIs (physicians) and 18 were clinical research support staff. A self‐administered electronic survey was created and evaluated by experts, with 50 knowledge items. Mann–Whitney U tests were used to determine the significance of the differences in knowledge between clinical research support staff and PIs. We compared the correct answer rate of clinical research support staff and PIs for each knowledge category and observed that the clinical research support staff scored significantly higher than the PIs in all aspects of clinical research knowledge sections, including total score. Our findings showed that PIs did not have the same amount of clinical research knowledge as the clinical research support staff. Clinical research knowledge is essential for investigators, especially PIs, to protect patients and promote medical breakthroughs. Thus, more accessible clinical research education and mandatory knowledge testing will allow PIs to lead successful clinical research and further the level of medical research in Japan.
Frühzeitiges Absetzen des paramedianen Stirn‐Interpolationslappens unter Verwendung von kutanem Ultraschall
Authors: González Jose Castiñeiras , Argüero Eduardo Zorita , Canga Paula Fernández , Prieto Manuel Ángel Rodríguez
Published: November 2022

Hintergrund und Ziele

Der paramediane Stirnlappen ist ein Interpolationslappen, bei dem Gewebe von der Stirn in die Nasenregion transplantiert wird. Die Blutversorgung erfolgt über die Arteria supratrochlearis. Üblicherweise wird der vaskuläre Stiel zwischen dem 14. und dem 21. postoperativen Tag abgesetzt; diese Zeit könnte allerdings zu lang bemessen sein. Wir wollen zeigen, dass der paramediane Stirnlappen bereits vor der in der Literatur angegebenen Zeit abgesetzt werden kann, und demonstrieren den Nutzen des kutanen Ultraschalls für die Bestimmung des optimalen Zeitpunkts.

Patienten und Methoden

Unsere Studie mit Patienten, deren Nasendefekt durch eine paramediane Stirnlappenplastik rekonstruiert wurde, war als prospektive Beobachtungsstudie angelegt. Einschlusskriterium waren Hautdefekte von mehr als 2 cm Größe an der Nasenspitze, dem Nasenrücken oder den Nasenflügeln nach onkologischer Operation. Zwölf Patienten wurden in die Studie aufgenommen. Eine retrospektive Kohorte wurde zur Analyse der Kostenminderung herangezogen.

Ergebnisse

Die durchschnittliche Dauer bis zur etablierten Vaskularisierung betrug 6,6 Tage, gemessen mittels Ultraschall. Die durchschnittliche Zeit bis zum Absetzen des Transplantatstiels betrug 6,9 Tage. Es wurden keine schwerwiegenden Komplikationen beobachtet.

Schlussfolgerungen

Der paramediane Stirnlappen kann bereits vor der traditionell üblichen Zeit abgesetzt werden. Ultraschall ist eine zuverlässige und kostengünstige Methode, um die individuell am besten geeignete Zeit zum Absetzen des Transplantatstiels zu bestimmen.
S2k‐Leitlinie zur Diagnostik und Therapie des Schleimhautpemphigoids
Authors: Hofmann Silke C. , Günther Claudia , Böckle Barbara C. , Didona Dario , Ehrchen Jan , Gaskins Matthew , Geerling Gerd , Gläser Regine , Hadaschik Eva , Hampl Monika , Haßkamp Pia , Jackowski Jochen , Kiritsi Dimitra , Nast Alexander , Pleyer Uwe , Reichel Christoph , Roth Mathias , Schumann Michael , Sticherling Michael , Worm Margitta , Zillikens Detlef , Goebeler Matthias , Schmidt Enno
Published: November 2022

Das Schleimhautpemphigoid (SHP) ist eine Pemphigoid‐Erkrankung, die sich überwiegend an der Schleimhaut manifestiert. Betroffen sind vor allem die Schleimhäute von Mund, Augen, Nase und Pharynx, aber auch von Larynx, Trachea, Ösophagus sowie die Genital‐ und Perianal‐Region. Die Ausprägung der Erkrankung ist variabel und reicht von gingivalem Erythem und einzelnen oralen Läsionen bis zu schwerwiegenden trachealen Strikturen, die die Atmung behindern sowie konjunktivaler Vernarbung mit deutlichen Visuseinschränkungen und, nicht selten, Erblindung. Die Diagnose beruht neben dem klinisch vorherrschenden Schleimhautbefall auf der direkten Immunfluoreszenz eines nichtläsionalen Biopsats und der Serologie. Das hauptsächliche Zielantigen ist BP180 (Kollagen XVII) und Reaktivität mit Laminin 332 ist in circa 25 % der SHP‐Patienten mit einem Malignom assoziiert. Die Behandlung des SHP ist eine Herausforderung. Einerseits ist durch den Befall verschiedener Schleimhäute eine gute interdisziplinäre Zusammenarbeit der verschiedenen Fachdisziplinen gefordert, andererseits stehen auf Grund der Seltenheit der Erkrankung keine randomisierten kontrollierten klinischen Studien zur Verfügung. Ziel der Leitlinie ist es, das klinische Bild einschließlich Schweregrade und Scoring‐Systeme darzustellen sowie Anleitung zu geben für die Diagnosestellung und Therapie dieser komplexen Erkrankung. Beim SHP spielt die interdisziplinäre Zusammenarbeit eine wesentliche Rolle sowie die möglichst zeitnahe Diagnosestellung und Einleitung einer adäquaten Therapie, um irreversible Schäden der Schleimhäute mit schwerwiegenden Komplikationen zu vermeiden.
Reactivity to conditioned threat cues is distinct from exploratory drive in the elevated plus maze
Authors: Hilton Joe R. , Simpson Susannah R. , Sherman Emily R. , Raby‐Smith Will , Azvine Keemia , Arribas Maite , Zou Jiaqi , Deiana Serena , Hengerer Bastian , Cahill Emma N.
Published: November 2022

Fear and anxiety are adaptive states that allow humans and animals alike to respond appropriately to threatening cues in their environment. Commonly used tasks for studying behaviour akin to fear and anxiety in rodent models are Pavlovian threat conditioning and the elevated plus maze (EPM), respectively. In threat conditioning the rodents learn to associate an aversive event with a specific stimulus or context. The learnt association between the two stimuli (the ‘memory’) can then be recalled by re‐exposing the subject to the conditioned stimulus. The elevated plus maze is argued to measure the agoraphobic avoidance of the brightly lit open maze arms in crepuscular rodents. These two tasks have been used extensively, yet research into whether they interact is scarce. We investigated whether recall of an aversive memory, across contextual, odour or auditory modalities, would potentiate anxiety‐like behaviour in the elevated plus maze. The data did not support that memory recall, even over a series of time points, could influence EPM behaviour. Furthermore, there was no correlation between EPM behaviour and conditioned freezing in independent cohorts tested in the EPM before or after auditory threat conditioning. Further analysis found the production of 22 kHz ultrasonic vocalisations revealed the strongest responders to a conditioned threat cue. These results are of particular importance for consideration when using the EPM and threat conditioning to identify individual differences and the possibility to use the tasks in batteries of tests without cross‐task interference.
Plakophilin 1 deficiency in prostatic tumours is correlated with immune cell recruitment and controls the up‐regulation of cytokine expression post‐transcriptionally
Authors: Kim Martin , Reidenbach Sonja , Schlechter Tanja , Rothmann Ann Christin , Will Rainer , Hofmann Ilse
Published: November 2022

Plakophilin (PKP1) 1 is a member of the arm‐repeat family of catenins and acts as a structural component of desmosomes, which are important stabilizers of cell–cell adhesion. Besides this, PKP1 also occurs in a non‐junctional, cytoplasmic form contributing to post‐transcriptional regulation of gene expression. Moreover, PKP1 is expressed in the prostate epithelium but its expression is frequently downregulated in prostate cancers with a more aggressive phenotype. This observation may imply a tumour‐suppressive role of PKP1. We found that, in prostatic adenocarcinomas with PKP1 deficiency, the occurrence of T‐cells, B‐cells, macrophages and neutrophils were significantly increased. In a PKP1‐deficient prostatic cancer cell line expressing IL8, these levels were statistically meaningfully reduced upon PKP1 re‐expression. When analysing prostatic PKP1 knockdown cell lines, the mRNA and protein levels of additional cytokines, namely CXCL1 and IL6, were upregulated. The effect was rescued upon re‐expression of a PKP1 RNAi‐resistant form. The corresponding mRNAs were co‐precipitated with cytoplasmic PKP1, indicating that they are components of PKP1‐containing mRNA ribonucleoprotein particles. Moreover, the mRNA half‐lives of CXCL1, IL8 and IL6 were significantly increased in PKP1‐deficient cells, showing that these mRNAs were stabilized by PKP1. In an in vitro migration assay, the higher cytokine concentrations led to higher migration rates of THP1 and PBMC cells. This finding implies that PKP1 loss of expression in vivo correlates with the recruitment of immune cells into the tumour area to set up a tumour‐specific environment. One may speculate that this newly established tumour environment has tumour‐suppressive characteristics and thereby accelerates tumour progression and metastasis.
Accounting for carbon flows into and from (bio)plastic in a national climate inventory
Authors: Sandberg Erik , Krook‐Riekkola Anna
Published: November 2022

Despite the time‐dependent behavior of carbon stored in plastic materials, literature assessing carbon flows into and from plastic typically applies a static approach. To better understand the climate impacts of such storage, this study explores how carbon stored in plastics can contribute over time to the national climate inventory with various emphasis on recycling. This is accomplished by implementing material stock change estimations for carbon in plastic materials that follow first‐order decay and include impacts from recycling rates in the Integrated MARKAL‐EFOM System model generator for Sweden (TIMES‐Sweden). Thereafter, three approaches to how carbon released from the plastic material stock is accounted for in the national climate inventory were applied to determine how each approach affects resulting emission and net‐zero pathways in different recycling rate scenarios. An accounting approach that follows the first‐order decay pattern of material stocks was found to be important for capturing the impacts of recycling and for neither over‐ nor underestimating the emission impact from carbon stored in plastics. Accounting for carbon stored in plastics may provide important incentives for producing renewable plastics and reducing dependence on carbon removal technologies. Because of its synergies with recycling, the carbon storage potential of plastic products is well worth recognizing and promoting in a policy setting that aims for circularity. For Sweden, this reduces the need for bioenergy carbon capture and storage and makes more biomass‐based carbon and electricity available for use elsewhere in the energy system.
Testing Nano‐Powder and Fused‐Glass Mineral Reference Materials for In SituRb‐Sr Dating of Glauconite, Phlogopite, Biotite and Feldspar via LA‐ICP‐MS/MS
Authors: Redaa Ahmad , Farkaš Juraj , Gilbert Sarah , Collins Alan S. , Löhr Stefan , Vasegh Davood , Forster Marnie , Blades Morgan , Zack Thomas , Giuliani Andrea , Maas Roland , Baldermann Andre , Dietzel Martin , Garbe‐Schönberg Dieter
Published: November 2022

Reference materials (RMs) with well‐characterised composition are necessary for reliable quantification and quality control of isotopic analyses of geological samples. For in situ Rb‐Sr analysis of silicate minerals via laser ablation inductively coupled plasma tandem mass spectrometry (LA‐ICP‐MS/MS) with a collision/reaction cell, there is a general lack of mineral‐specific and matrix‐matched RMs, which limits wider application of this new laser‐based dating technique to certain minerals. In this work, pressed nano‐powder pellets (NP) of four RMs, GL‐O (glauconite), Mica‐Mg (phlogopite), Mica‐Fe (biotite) and FK‐N (K‐feldspar), were analysed and tested for in situ Rb‐Sr dating, complemented by isotope dilution (ID) MC‐ICP‐MS Rb‐Sr analyses of GL‐O and Mica‐Mg. In addition, we attempted to develop alternative flux‐free and fused ‘mineral glasses’ from the above RMs for in situ Rb‐Sr dating applications. Overall, the results of this study showed that among the above RMs only two NP (Mica‐Mg‐NP and GL‐O‐NP) were suitable and robust for in situ dating applications. These two nano‐powder reference materials, Mica‐Mg‐NP and GL‐O‐NP, were thus used as primary RMs to normalise and determine Rb‐Sr ages for three natural minerals: MDC phlogopite and GL‐O glauconite grains, and also Mica‐Fe‐NP (biotite). Our in situ analyses of the above RMs yielded Rb‐Sr ages that are in good agreement (within 8%) of published ages, which suggests that both Mica‐Mg‐NP and GL‐O‐NP are suitable RMs for in situ Rb‐Sr dating of phlogopite, glauconite and biotite. However, using secondary RMs is recommended to monitor the quality of the obtained ages.
Social capital and capital allocation efficiency
Authors: Bhandari Avishek , Bhuyan Md Nazmul Hasan
Published: November 2022

Based on the social norms and structural theories of social capital, this study examines the relationship between community social capital and the firms’ capital allocation efficiency. We hypothesize and find that the community social capital of a firm's headquarter area has a negative and statistically significant impact on its capital allocation inefficiency, which is robust to alternative proxies for community social capital and capital allocation inefficiency, propensity score matching and instrumental variable regressions. In addition, we find that the effect of community social capital is more pronounced for firms with poor internal ethical culture and weak network connections to outside executives and directors, implying that community social capital becomes important in these situations. This finding links prior social norms and networks literature to capital allocation studies in that the norms and networks components of community social capital discipline self‐interested managers’ behavior and reduce information asymmetry‐two channels of capital allocation efficiency. Overall, community social capital works as a compensatory monitoring and information transfer mechanism and improves the firms’ capital allocation efficiency.
When self‐love is threatened: Adopting a dual‐type view to understand leader narcissism and its impacts on LMX and newcomer work outcomes
Authors: Liu Haiyang , Liu Yihao , Chiang Jack Ting‐Ju , Wang Siting , Wang Hui
Published: November 2022

The extant literature has revealed that leader narcissism has paradoxical impacts on follower outcomes. In this research, we argue that its paradoxical effects can be disentangled by the presence of two distinct types of leader narcissism—narcissistic admiration and narcissistic rivalry—which can shape leaders’ initial relationship‐building with new followers (i.e., newcomers) differently. Integrating a dual‐type view of narcissism with leader–member exchange (LMX) theory and conducting a multi‐wave, multi‐source field study with 151 leader‐newcomer dyads, we found that leader narcissistic admiration is negatively related to leader perceived threat of a newcomer whereas leader narcissistic rivalry is positively related to it. Leader perceived threat of a newcomer, in turn, reduces the newcomer's LMX perceptions and ultimately hinders the newcomer's job satisfaction and task performance. Moreover, leader perceived similarity with a newcomer was found to strengthen the negative (positive) effect of leader narcissistic admiration (rivalry) on leader perceived threat of a newcomer. We did not find support for the moderation effect of newcomer acceptance seeking from the leader. This research sheds light on the value of adopting a content‐specific and multidimensional approach in studying leader narcissism.
Dogtoothand Wittgenstein's builders: A future in language?
Authors: Simons Daniel
Published: November 2022

This article grows out of the conviction that (some) films can philosophise. It looks to juxtapose the filmDogtoothand Wittgenstein's builders' example, such that they are seen as philosophising in similar ways over similar issues. Both strike me as probing the possibility—or denial—of a future with language. Using Stanley Cavell and Rush Rhees' responses to Wittgenstein's builders, I register the significance and meaning of themes from the film and Wittgenstein's work in a mutually enlightening way: language, games and breaking free. This results in two different pictures of our hope of a future in and with language.
Actions speak louder than words: Imputing users’ reputation from transaction history
Authors: Deng Jiaying , Ghasemkhani Hossein , Tan Yong , Tripathi Arvind K
Published: November 2022

The choice of market mechanism is key to success for any online marketplace. In recent years, as peer‐to‐peer (P2P) lending has seen phenomenal growth, leading P2P lending platforms have used various market mechanisms and, in some cases, even switched from one mechanism to another, chasing higher market share and overall growth. While Prosper.com, a leading P2P lending platform, has switched from the auction lending model to a fixed price lending model, recent studies show that overall social welfare was higher with the auction lending model. While the auction lending model gives more power to the lenders, the success of the auction lending model hinges on the accuracy of lenders’ assessment of the credit risk of the borrowers. Building on extant literature and in support of the auction lending model to increase social welfare, we design an artifact to dynamically estimate borrower reputation to help the lenders and improve the allocative efficiency in P2P lending markets. We posit that borrowers’ reputation built on transactional data, readily available on P2P lending platforms, represents the collective perception of the lenders about the borrowers. We propose a dynamic latent class model of reputation and use the latent instrumental variable approach to deal with endogeneity. We test our artifact using real‐world P2P lending data. We show that accounting for reputation improves the model's explanatory power and provides a way to empirically model the evolution and impact of reputation in online platforms where repeated transactions are performed.
Broken Beds, but better science; using multiple hypotheses to interpret geological data
Authors: Gallois Arnaud , Burgess Peter , Bosence Dan , Hollis Cathy
Published: November 2022

In this study, we propose a multiple hypotheses approach to improve interpretations of limited remotely sensed datasets, such as sparsely exposed outcrops, subsurface datasets, or planetary objects using semi‐quantitative scoring and ranking of observable features. This method is demonstrated using an outcrop example from the Broken Beds of the Upper Jurassic–Lower Cretaceous Purbeck Limestone Group exposed along Britain's Jurassic Coast. Four published hypotheses regarding their origin are refined, represented in matrix form, scored and ranked based on carefully selected outcrop features. Semi‐quantitative scoring utilises knowledge of likely processes governing the occurrence of a range of features, some of which might be ignored or down‐played to favour a single hypothesis. Furthermore, by integrating expertise from different sub‐disciplines (e.g. basin analysis, sedimentology, diagenesis), we also consider the combined evidence of multiple features. This new method results in an interpretation that favours a multi‐process origin for the Broken Beds due to evaporite dissolution, overpressure release and tectonic folding, with identified uncertainty, all useful to guide further data collection.
Particulate Deposition Effects on Internal Swirl Cooling of Turbine Blades
Authors: Yang Xing , Hao Zihan , Seibold Florian , Feng Zhenping , Ligrani Phillip , Weigand Bernhard
Published: November 2022

Particulate deposition effects on flow and heat transfer in an internal swirl tube subjected to fly ash ingestion were investigated by constructing an unsteady simulation framework, in which a particle–wall interaction model and a mesh morphing technique were implemented. Swirling flows in the swirl tube were induced by two tangential jet nozzles. Particles having a mean diameter of 6.5 μm were released from the nozzle inlets to model an exposure duration of 4500 h for engine operation in real fly ash environment using scale factors in the unsteady simulations. Particle deposition and its dynamic process were examined, and the effects of deposition on the swirling flow were quantified by comparing time-averaged velocity profiles, vorticity, pressure loss, and heat transfer with those from a clean tube without deposition. Results reveal that the most upstream section of the swirl tube captures the majority of the particles and the deposition distributions show a spiral pattern over the tube wall. The total mass of the deposits within the tube linearly increases, while local deposition thickness has a nonlinear relationship with the exposure time due to the interaction of the particles with the swirling flow. The deposition can generate a maximum of 15% reduction in cross-sectional area of the tube within the exposure duration, resulting in a reduced swirl number, because of the accelerated axial velocity and the decreased circumferential velocity, and further lower heat transfer in the downstream section of the tube relative to the clean tube case. However, as the heat transfer in the upstream deposition section is enhanced by the roughness due to the deposition, area-averaged heat transfer throughout the entire swirl tube is slightly improved by 4.0% but simultaneously a 179% higher pressure loss is observed, leading to an overall thermal performance value of 0.79 (relative to 1.0 for a clean tube), indicating substantial degradation of cooling performance in the fouled swirl tube.
Comparative Study of First-Order Moving Asymptotes Optimizers for the Moving Morphable Components Topology Optimization Framework
Authors: Rochefort-Beaudoin Thomas , Vadean Aurelian , Gamache Jean-François , Achiche Sofiane
Published: November 2022

Machine learning-accelerated topology optimization faces the challenge of generating large amounts of optimal topologies for supervised learning on a training dataset. This data generation step is challenging for the method of Moving Morphable Components (MMC) which presents an oscillatory behavior near local optimum that negatively affects its convergence speed and therefore present a high data generation cost. This paper presents a comparative study of the most-used first-order optimizers applied to minimum compliance problems under the MMC framework for topology optimization. The Method of Moving Asymptotes (MMA), its Globally Convergent version (GCMMA) and the hybrid MMA-GCMMA optimizer are compared using their final compliance and the total number of iterations until convergence as performance metrics. An extensive set of diversified boundary conditions for a rectangular beam minimum compliance problem is used as case study. The method of performance profiles is utilized to provide for each solver a probability distribution of outperforming its counterparts. Numerical results show that using a hybrid optimizer can accelerate the convergence speed of the MMC framework while still producing equally compliant topologies when compared to the MMA optimizer.
Resilience Modeling in Complex Engineered Systems With Human-Machine Interactions
Authors: Irshad Lukman , Hulse Daniel
Published: November 2022

In recent times, there has been a growing interest in resilience-based design. Resilience-based design operates on the concept that failures and unexpected events will happen, and when they occur, complex engineered systems should be able to operate within acceptable bounds and recover reasonably. Humans can contribute to the resilience of a system by quickly detecting unforeseen events and taking corrective measures. To this effect, researchers have proposed guidelines and design approaches that can help promote human-system resilience. However, there is no early design stage tool to validate if a system is indeed resilient after applying these guidelines and design methods. In this research, we integrate the Human Error and Functional Failure Reasoning (HEFFR) framework into the fmd-tools toolkit to enable designers to model the combined (machine, human, and joint) failures, including their propagation and dynamic effects, during early design stages. This integrated tool also allows designers to model the effects of performance shaping factors, team dynamics, and human-machine interactions in systems of systems. A demonstrative example of a remotely operated rover is explored to demonstrate how this approach can be applied to understand resilience in complex engineered systems with human interactions.
Quantifying Vision Obscuration of A-Pillar Concept Variants Using Digital Human Modeling
Authors: Srinivasan Sriram , Demirel H. Onan
Published: November 2022

Pillars in modern vehicles provide structural integrity by surrounding the greenhouse (windshield, rear, and side windows) and joining the roof with the frame. The forward-most roof support posts, A-pillars, straddle the windshield and have an essential design impact that affects the aerodynamic performance, roof crush, and frontal impact performance. Although they protect the driver and passengers, A-pillars also create obstruction zones by limiting drivers’ forward field of view (FOV). Therefore, the reduced forward vision caused by the obstruction zones leads to unforeseeable accidents or mishaps. We argue that providing a better pillar design that embodies a human-centered design approach could avoid such incidents. In this research, we propose an early design framework that integrates methods of generative design (GD) and digital human modeling (DHM) to demonstrate a proof-of-concept study that focuses on quantifying A-pillar obstruction in realistic traffic scenarios. This research also aims to illustrate how the framework functions through a case study, which compares concept pillar designs with cutout sections (see-through holes) to current pillar models (without see-through holes) in reducing the obstruction zones. The framework is used to assess whether the concept design approach improves the overall drivers’ visibility of traffic objects that would otherwise be obscured behind current pillars.
On the Influence of Mean Value on Random Fatigue Damage Computation
Authors: Sgamma Michele , Bucchi Francesco , Frendo Francesco
Published: November 2022

The frequency-domain approach to fatigue life estimation in random loading has been largely investigated due to its computational advantages, and several methods for the frequency translation of most common time-domain methods have been proposed. However, the largest part of frequency methods only focuses on the estimation of the marginal amplitude probability density function of cycles and do not consider the damage increment caused by the positive mean value of the counted cycles. This paper aims to deepen the effect of the random mean value of the cycles on fatigue damage estimation by simulating a large number of time histories with different power spectral densities and computing the resulting damage for a steel material using time-domain instruments like rainflow count, Goodman correction for mean value and Palmgren-Miner linear rule for damage cumulation. The influence of the presence of a non-zero global mean value of the process on the damage computation due to the random cycle mean value has been investigated. The study of the effect of signal PSD resulted in a non-monotonic influence on the ratio between the total damage and an approximated damage that does not consider random mean values. Finally, some further simulations have been done to study the effect of variations in the S-N curve of the material.
Upper Extremity Joint Torque Estimation Through an EMG-Driven Model
Authors: Tahmid Shadman , Font-Llagunes Josep Maria , Yang James
Published: November 2022

Cerebrovascular accidents like a stroke can affect lower limb as well as upper extremity joints (i.e., shoulder, elbow or wrist) and hinder the ability to produce necessary torque for activities of daily living. In such cases, muscles’ ability to generate force reduces, thus affecting the joint’s torque production. Understanding how muscles generate force is a key element to injury detection. Researchers developed several computational methods to obtain muscle forces and joint torques. Electromyography (EMG) driven modeling is one of the approaches to estimate muscle forces and obtain joint torques from muscle activity measurements. Musculoskeletal models and EMG-driven models require necessary muscle-specific parameters for the calculation. The focus of this research is to investigate the EMG-driven approach along with an upper extremity musculoskeletal model to determine muscle forces of two major muscle groups, biceps brachii and triceps brachii, consisting of seven muscle-tendon units. Estimated muscle forces were used to determine the elbow joint torque. Experimental EMG signals and motion capture data were collected for a healthy subject. The musculoskeletal model was scaled to match the geometric parameters of the subject. First, the approach calculated muscle forces and joint moment for simple elbow flexion-extension. Later, the same approach was applied to an exercise called triceps kickback, which trains the triceps muscle group. Individual muscle forces and net joint torques for both tasks were estimated.
A Morphological Evaluation of Shoulder Parameters: A Medical Support Tool for the Diagnosis
Authors: Ghidotti Anna , Locatelli Fabio , Belotti Nicolò , Regazzoni Daniele , Rizzi Caterina
Published: November 2022

Shoulder disorders are very common in the middle-aged population, due to several causes. The traditional diagnosis relies on the knowledge and the experience of the physician but a clinical misinterpretation in this early phase can have serious consequences for the patient’s health. The aim of this study is to investigate morphological shoulder parameters, as indicators of healthy or pathological conditions. In this way, it is possible to generate a quantitative report, based on measurements. It can be exploited as a medical support tool for physicians to either confirm the diagnosis, or to raise reasonable doubts, as far as the results differed. However, not all the shoulder disorders can be identified through this approach. Magnetic Resonance and Computed Tomography images of pathological shoulders have been employed for the study. The predefined morphological parameters have been measured on 2D medical images as well as from 3D reconstructed virtual model. Critical Shoulder Angle has been identified as the most significant parameter. It is well known that it is affected by Glenoid Inclination, Lateral Acromial Extension and Acromial Height. However, the contribution of each factor is not clear. Hence, a statistical analysis has been performed to understand how its sub-parameters influence it.