bluuebunny/crossref_metadata_2025 huggingface dataset:
Enthesis strength, toughness and stiffness: an image-based model comparing tendon insertions with varying bony attachment geometries
Authors: Golman Mikhail , Birman Victor , Thomopoulos Stavros , Genin Guy M.
Published: December 2021

Tendons of the body differ dramatically in their function, mechanics and range of motion, but all connect to bone via an enthesis. Effective force transfer at the enthesis enables joint stability and mobility, with strength and stiffness arising from a fibrous architecture. However, how enthesis toughness arises across tendons with diverse loading orientations remains unclear. To study this, we performed simultaneous imaging of the bone and tendon in entheses that represent the range of tendon-to-bone insertions and extended a mathematical model to account for variations in insertion and bone geometry. We tested the hypothesis that toughness, across a range of tendon entheses, could be explained by differences observed in interactions between fibre architecture and bone architecture. In the model, toughness arose from fibre reorientation, recruitment and rupture, mediated by interactions between fibres at the enthesis and the bony ridge abutting it. When applied to tendons sometimes characterized as either energy-storing or positional, the model predicted that entheses of the former prioritize toughness over strength, while those of the latter prioritize consistent stiffness across loading directions. Results provide insight into techniques for surgical repair of tendon-to-bone attachments, and more broadly into mechanisms for the attachment of highly dissimilar materials.
Agent-based simulations for protecting nursing homes with prevention and vaccination strategies
Authors: Lasser Jana , Zuber Johannes , Sorger Johannes , Dervic Elma , Ledebur Katharina , Lindner Simon David , Klager Elisabeth , Kletečka-Pulker Maria , Willschke Harald , Stangl Katrin , Stadtmann Sarah , Haslinger Christian , Klimek Peter , Wochele-Thoma Thomas
Published: December 2021

Due to its high lethality among older people, the safety of nursing homes has been of central importance during the COVID-19 pandemic. With test procedures and vaccines becoming available at scale, nursing homes might relax prohibitory measures while controlling the spread of infections. By control we mean that each index case infects less than one other person on average. Here, we develop an agent-based epidemiological model for the spread of SARS-CoV-2 calibrated to Austrian nursing homes to identify optimal prevention strategies. We find that the effectiveness of mitigation testing depends critically on test turnover time (time until test result), the detection threshold of tests and mitigation testing frequencies. Under realistic conditions and in absence of vaccinations, we find that mitigation testing of employees only might be sufficient to control outbreaks if tests have low turnover times and detection thresholds. If vaccines that are 60% effective against high viral load and transmission are available, control is achieved if 80% or more of the residents are vaccinated, even without mitigation testing and if residents are allowed to have visitors. Since these results strongly depend on vaccine efficacy against infection, retention of testing infrastructures, regular testing and sequencing of virus genomes is advised to enable early identification of new variants of concern.
Challenges in dynamic mode decomposition
Authors: Wu Ziyou , Brunton Steven L. , Revzen Shai
Published: December 2021

Dynamic mode decomposition (DMD) is a powerful tool for extracting spatial and temporal patterns from multi-dimensional time series, and it has been used successfully in a wide range of fields, including fluid mechanics, robotics and neuroscience. Two of the main challenges remaining in DMD research are noise sensitivity and issues related to Krylov space closure when modelling nonlinear systems. Here, we investigate the combination of noise and nonlinearity in a controlled setting, by studying a class of systems with linear latent dynamics which are observed via multinomial observables. Our numerical models include system and measurement noise. We explore the influences of dataset metrics, the spectrum of the latent dynamics, the normality of the system matrix and the geometry of the dynamics. Our results show that even for these very mildly nonlinear conditions, DMD methods often fail to recover the spectrum and can have poor predictive ability. Our work is motivated by our experience modelling multilegged robot data, where we have encountered great difficulty in reconstructing time series for oscillatory systems with intermediate transients, which decay only slightly faster than a period.
Vibrometry as a noncontact alternative to dynamic and viscoelastic mechanical testing in cartilage
Authors: Espinosa M. Gabriela , Otarola Gaston A. , Hu Jerry C. , Athanasiou Kyriacos A.
Published: December 2021

Physiological loading of knee cartilage is highly dynamic and may contribute to the progression of osteoarthritis. Thus, an understanding of cartilage's dynamic mechanical properties is crucial in cartilage research. In this study, vibrometry was used as a fast (2 h), noncontact and novel alternative to the slower (30 h), traditional mechanical and biochemical assays for characterization of cartilage from the condyle, patella, trochlear groove and meniscus. Finite-element models predicted tissue resonant frequencies and bending modes, which strongly correlated with experiments (R2= 0.93). Vibrometry-based viscoelastic properties significantly correlated with moduli from stress relaxation and creep tests, with correlation strengths reaching up to 0.78. Loss modulus also strongly correlated with glycosoaminoglycan (GAG) content. Dynamic properties measured by vibrometry significantly differed among various knee cartilages, ranging between 6.1 and 56.4 MPa. Interestingly, meniscus viscoelastic properties suggest that contrary to common belief, it may lack shock absorption abilities; instead, condylar hyaline cartilage may be a better shock absorber. These data demonstrate for the first time that vibrometry is a noncontact approach to dynamic mechanical characterization of hyaline and fibrocartilage cartilage with concrete relationships to standard quasi-static mechanical testing and biochemical composition. Thus, with a single tool, vibrometry greatly facilitates meeting multiple regulatory recommendations for mechanical characterization of cartilage replacements.
Darwin's bark spider shares a spidroin repertoire with
Caerostris extrusa
but achieves extraordinary silk toughness through gene expression
Authors: Kono Nobuaki , Ohtoshi Rintaro , Malay Ali D. , Mori Masaru , Masunaga Hiroyasu , Yoshida Yuki , Nakamura Hiroyuki , Numata Keiji , Arakawa Kazuharu
Published: December 2021

Spider silk is a protein-based material whose toughness suggests possible novel applications. A particularly fascinating example of silk toughness is provided by Darwin's bark spider (
Caerostris darwini
) found in Madagascar. This spider produces extraordinarily tough silk, with an average toughness of 350 MJ m
−1
and over 50% extensibility, and can build river-bridging webs with a size of 2.8 m
2
. Recent studies have suggested that specific spidroins expressed in
C. darwini
are responsible for the mechanical properties of its silk. Therefore, a more comprehensive investigation of spidroin sequences, silk thread protein contents and phylogenetic conservation among closely related species is required. Here, we conducted genomic, transcriptomic and proteomic analyses of
C. darwini
and its close relative
Caerostris extrusa
. A variety of spidroins and low-molecular-weight proteins were found in the dragline silk of these species; all of the genes encoding these proteins were conserved in both genomes, but their genes were more expressed in
C. darwini
. The potential to produce very tough silk is common in the genus
Caerostris
, and our results may suggest the existence of plasticity allowing silk mechanical properties to be changed by optimizing related gene expression in response to the environment.
Effects of various media on micellization, adsorption and thermodynamic behaviour of imipramine hydrochloride and antimicrobial surfactant mixtures
Authors: Alghamdi Yousef G. , Rub Malik Abdul , Kumar Dileep , Asiri Abdullah M.
Published: December 2021

The effect of various media (aqueous, NaCl, urea (U) and thiourea (TU)) on the micellization and adsorption activity of varied mixtures of imipramine hydrochloride (IMP) and benzethonium chloride (BZCl) is investigated via tensiometry. In an aqueous medium, the interactions between IMP and BZCl are also evaluated using UV–visible and FTIR spectroscopy. The interaction between components increases with increased mole fraction (α1) of BZCl in the mixed system (IMP + BZCl). Different parameters, such as micellar and the mixed monolayer component composition, the interaction parameters of the solution and the interface, the activity coefficients of the components in solution and at the interface, and thermodynamic parameters, are computed using different proposed theoretical models (i.e. Clint, Motomura, Rubingh and Rosen). Thecmcvalues obtained for the pure components and mixtures (IMP + BZCl) of all the compositions are found to be less in NaCl than in the aqueous solution while found more in the presence of U or TU. TU is more effective in increasing thecmcof the pure and mixed systems than U. The Gibbs free energy(ΔGmic∘)values of the studied pure and mixed systems are negative, showing the spontaneous nature of the reaction.
Impairment of T cells' antiviral and anti-inflammation immunities may be critical to death from COVID-19
Authors: Zhang Luhao , Li Rong , Song Gang , Scholes Gregory D. , She Zhen-Su
Published: December 2021

Clarifying dominant factors determining the immune heterogeneity from non-survivors to survivors is crucial for developing therapeutics and vaccines against COVID-19. The main difficulty is quantitatively analysing the multi-level clinical data, including viral dynamics, immune response and tissue damages. Here, we adopt a top-down modelling approach to quantify key functional aspects and their dynamical interplay in the battle between the virus and the immune system, yielding an accurate description of real-time clinical data involving hundreds of patients for the first time. The quantification of antiviral responses gives that, compared to antibodies, T cells play a more dominant role in virus clearance, especially for mild patients (96.5%). Moreover, the anti-inflammatory responses, namely the cytokine inhibition and tissue repair rates, also positively correlate with T cell number and are significantly suppressed in non-survivors. Simulations show that the lack of T cells can lead to more significant inflammation, proposing an explanation for the monotonic increase of COVID-19 mortality with age and higher mortality for males. We propose that T cells play a crucial role in the immunity against COVID-19, which provides a new direction–improvement of T cell number for advancing current prevention and treatment.
Anesthesia Inmutable Registry of Real-time Vital Signs and Waveforms using Blockchain
Authors: Gutiérrez Alejandro Figar , Garbino Jorge A. Martinez , Burgos Valeria , Rajah Taimoore , Risk Marcelo , Francisco Redelico
Published: December 2021

Healthcare has become one of the most important emerging application areas of blockchain technology.[1] Although the use of a cryptographic ledger within Anesthesia Information Management Systems (AIMS) remains uncertain. The need for a truly immutable anesthesia record is yet to be established, given that the current AIMS database systems have reliable audit capabilities. Adoption of AIMS has followed Roger’s 1962 formulation of the theory of diffusion of innovation. Between 2018 and 2020, adoption was expected to be the 84% of U.S. academic anesthesiology departments.[2] Larger anesthesiology groups with large caseloads, urban settings, and government affiliated or academic institutions are more likely to adopt and implement AIMS solutions, due to the substantial amount of financial resources and dedicated staff to support both the implementation and maintenance that are required. As health care dollars become scarcer, this is the most frequently cited constraint in the adoption and implementation of AIMS.[3]

We propose the use of a blockchain database for saving all incoming data from multiparametric monitors at the operating theatre. We present a proof of concept of the use of this technology for electronic anesthesia records even in the absence of an AIMS at site. In this paper we shall discuss its plausibility as well as its feasibility. The Electronic medical records (EMR) in AIMS might contain errors and artifacts that may (or may not) have to be dealt with. Making them immutable is a scary concept. The use of the blockchain for saving raw data directly from medical monitoring equipment and devices in the operating theatre has to be further investigated.
Sensitivity of SARS-CoV-2 antigen-detecting rapid tests for Omicron variant
Authors: Bekliz Meriem , Perez-Rodriguez Francisco , Puhach Olha , Adea Kenneth , Melancia Stéfane Marques , Baggio Stephanie , Corvaglia Anna-Rita , Jacquerioz-Bausch Frédérique , Alvarez Catia , Essaidi-Laziosi Manel , Escadafal Camille , Kaiser Laurent , Eckerle Isabella
Published: December 2021

Background

The emergence of each novel SARS-CoV-2 variants of concern (VOCs) requires investigation of its potential impact on the performance of diagnostic tests in use, including Antigen-detecting rapid diagnostic tests (Ag-RDT). Although anecdotal reports have been circulating that the newly emerged Omicron variant is in principle detectable by Ag-RDTs, few data on sensitivity are available.

Methods

We have performed 1) analytical sensitivity testing with cultured virus in eight Ag-RDTs and 2) retrospective testing in duplicates with clinical samples from vaccinated individuals with Omicron (n=18) or Delta (n=17) breakthrough infection on seven Ag-RDTs.

Findings

Overall, we have found large heterogenicity between Ag-RDTs for detecting Omicron. When using cultured virus, we observed a trend towards lower sensitivity for Omicron detection compared to earlier circulating SARS-CoV-2 and the other VOCs. When comparing performance for Delta and Omicron in a comparable set of clinical samples in seven Ag-RDTs, 124/252 (49.2%) of all test performed showed a positive result for Omicron compared to 156/238 (65.6%) for Delta samples. Sensitivity for both Omicron and Delta between Ag-RDTs was highly variable. Four out of seven Ag-RDTs showed significantly lower sensitivity (p<0.001) to detect Omicron when compared to Delta while three had comparable sensitivity to Delta.

Interpretation

Sensitivity for detecting Omicron is highly variable between Ag-RDTs, necessitating a careful consideration when using these tests to guide infection prevention measures. While analytical and retrospective testing may be a proxy and timely solution to generate performance data, it is not a replacement for clinical evaluations which are urgently needed. Biological and technical reasons for detection failure by some Ag-RDTs need to be further investigated.

Funding

This work was supported by the Swiss National Science Foundation (grant numbers 196383, 196644 and 198412), the Fondation Ancrage Bienfaisance du Groupe Pictet, the Fondation Privée des Hôpiteaux Universitaires de Genève and FIND, the global alliance for diagnostics.
Orthostatic intolerance in adults with long COVID was not associated with postural orthostatic tachycardia syndrome
Authors: Monaghan Ann , Jennings Glenn , Xue Feng , Byrne Lisa , Duggan Eoin , Romero-Ortuno Roman
Published: December 2021

In this observational cross-sectional study, we investigated predictors of orthostatic intolerance (OI) in adults with long COVID. Participants underwent a 3-minute active stand (AS) with Finapres® NOVA, followed by a 10-minute unmedicated 70-degree head-up tilt test. 85 participants were included (mean age 46 years, range 25-78; 74% women), of which 56 (66%) reported OI during AS (OIAS). OIAS seemed associated with female sex, more fatigue and depressive symptoms, and greater inability to perform activities of daily living (ADL), as well as a higher heart rate (HR) at the lowest systolic blood pressure (SBP) point before the 1st minute post-stand (mean HRnadir: 88 vs 75 bpm, P=0.004). In a regression model also including age, sex, fatigue, depression, ADL inability, and peak HR after the nadir SBP, HRnadir was the only OIAS predictor (OR=1.09, 95% CI: 1.01-1.18, P=0.027). 22 participants had initial (iOH) and 5 classical (cOH) orthostatic hypotension, but neither correlated with OIAS. 71 participants proceeded to tilt, of which 28 had OI during tilt (OItilt). Of the 53 who had a 10-minute tilt, 7 (13%) fulfilled hemodynamic postural orthostatic tachycardia syndrome (POTS) criteria, but 6 did not report OItilt. OIAS was associated with a higher initial HR on AS, which after 1 minute equalized with the non-OIAS group. Despite these initial orthostatic HR differences, POTS was infrequent and largely asymptomatic. ClinicalTrials.gov Identifier: NCT05027724 (retrospectively registered on August 30, 2021).
Dichotomous Activity and Function of Neurons with Low- and High-Frequency Discharge in the External Globus Pallidus of Non-Human Primates
Authors: Katabi Shiran , Adler Avital , Deffains Marc , Bergman Hagai
Published: December 2021

To date, there is a consensus that there are at least two neuronal populations in the non-human primate (NHP) external globus pallidus (GPe): the low- and high-frequency discharge (LFD and HFD) neurons. Nevertheless, almost all NHP physiological studies have neglected the functional importance of LFD neurons. This study examined the discharge features of these two GPe neuronal subpopulations recorded in four NHPs engaged in a classical conditioning task with cues predicting reward, neutral and aversive outcomes. The results show that LFD neurons tended to burst, encoded the salience of behavioral cues, and exhibited correlated spiking activity. By contrast, the HFD neurons tended to pause, encoded cue valence, and exhibited uncorrelated spiking activity. Overall, these findings point to the dichotomic organization of the NHP GPe which is likely to be critical to the implementation of normal basal ganglia functions and computations.
Safety of the single-dose Ad26.CoV2.S vaccine among healthcare workers in the phase 3b Sisonke study in South Africa
Authors: Takuva Simbarashe , Takalani Azwidhwi , Seocharan Ishen , Yende-Zuma Nonhlanhla , Reddy Tarylee , Engelbrecht Imke , Faesen Mark , Khuto Kentse , Whyte Carmen , Bailey Veronique , Trivella Valentina , Peter Jonathan , Opie Jessica , Louw Vernon , Rowji Pradeep , Jacobson Barry , Groenewald Pamela , Dorrington Rob E. , Laubscher Ria , Bradshaw Debbie , Moultrie Harry , Fairall Lara , Sanne Ian , Gail-Bekker Linda , Gray Glenda , Goga Ameena , Garrett Nigel ,   the Sisonke study team
Published: December 2021

Background

The Sisonke open-label phase 3b implementation study aimed to assess the safety and effectiveness of the Janssen Ad26.CoV2.S vaccine among health care workers (HCWs) in South Africa. Here, we present the safety data.

Methods

We monitored adverse events (AEs) at vaccination sites, through self-reporting triggered by text messages after vaccination, health care provider reports and by active case finding. The frequency and incidence rate of non-serious and serious AEs were evaluated from day of first vaccination (17 February 2021) until 28 days after the final vaccination (15 June 2021). COVID-19 breakthrough infections, hospitalisations and deaths were ascertained via linkage of the electronic vaccination register with existing national databases.

Findings

Of 477,234 participants, 10,279 (2.2%) reported AEs, of which 139 (1.4%) were serious. Women reported more AEs than men (2.3% vs. 1.6%). AE reports decreased with increasing age (3.2% for 18–30, 2.1% for 31-45, 1.8% for 46-55 and 1.5% in >55-year-olds). Participants with previous COVID-19 infection reported slightly more AEs (2.6% vs. 2.1%). The commonest reactogenicity events were headache and body aches, followed by injection site pain and fever, and most occurred within 48 hours of vaccination. Two cases of Thrombosis with Thrombocytopenia Syndrome and four cases of Guillain-Barre Syndrome were reported post-vaccination. Serious AEs and AEs of special interest including vascular and nervous system events, immune system disorders and deaths occurred at lower than the expected population rates.

Interpretation

The single-dose Ad26.CoV2.S vaccine had an acceptable safety profile supporting the continued use of this vaccine in our setting.

Funding

Funding was provided by the National Treasury of South Africa, the National Department of Health, Solidarity Response Fund NPC, The Michael & Susan Dell Foundation, The Elma Vaccines and Immunization Foundation - Grant number 21-V0001, and the Bill & Melinda Gates Foundation – grant number INV-030342.
Specific methylation marks in promoter regions are associated to the pathogenic process of Chronic Chagas disease Cardiomyopathy by modifying transcription factor binding patterns
Authors: Brochet Pauline , Ianni Barbara , Laugier Laurie , Frade Amanda Farage , Nunes João Paulo Silva , Teixeira Priscila Camillo , Mady Charles , Ferreira Ludmila Rodrigues Pinto , Ferré Quentin , Santos Ronaldo Honorato Barros , Kuramoto Andreia , Cabantous Sandrine , Steffen Samuel , Stolf Antonio Noedir , Pomerantzeff Pablo , Fiorelli Alfredo Inacio , Bocchi Edimar A , Pissetti Cristina Wide , Saba Bruno , da Silva Cândido Darlan , Dias Fabrício , Sampaio Marcelo , Gaiotto Fabio Antônio , Marin-Neto José Antonio , Fragata Abílio , Zaniratto Ricardo Costa Fernandes , Siqueira Sergio , de lima Peixoto Giselle , Rigaud Vagner Oliveira-Carvalho , Bacal Fernando , Buck Paula , Ribeiro Rafael Almeida , Lin-Wang Hui Tzu , Marin-Neto José Antonio , Schmidt André , Martinelli Martino , Hirata Mario Hiroyuki , Donadi Eduardo , Pereira Alexandre Costa , Rodrigues Virmondes , Puthier Denis , Kalil Jorge , Spinelli Lionel , Cunha-Neto Edecio , Chevillard Christophe
Published: December 2021

Chagas disease, caused by Trypanosoma cruzi, is an endemic parasitical disease of Latin America, affecting 7 million people. Although most patients are asymptomatic, 30% develop complications, including Chronic Chagasic Cardiomyopathy (CCC), which ranges from moderate to severe stages depending on the cardiac ejection fraction. The pathogenic process remains poorly understood, although genetic and epigenetic factors have already been proposed.

Based on bulk RNA-seq and EPIC methylation data, we investigated the genetic and epigenetic deregulations present in the moderate and severe stages of CCC. We identified 4 main biological processes associated with the pathology development, including immune response, ion transport, cardiac muscle processes and nervous system. An in-depth study of the transcription factors binding sites in the differentially methylated regions corroborated the importance of these processes. We also conducted a methylation study on blood to identify potential biomarkers for CCC. Our data revealed 198 differentially methylated positions (DMPs) that could serve as biomarkers of the disease, of which 61 are associated with disease severity.
The N-linker region of hERG1a upregulates hERG1b potassium channels
Authors: Johnson Ashley A. , Crawford Taylor R. , Trudeau Matthew C.
Published: December 2021

A major physiological role of hERG1 (human Ether-á-go-go-Related Gene) potassium channels is to repolarize cardiac action potentials. Two isoforms, hERG1a and hERG1b, associate to form the native cardiac IKr current in vivo. Inherited mutations in hERG1a or hERG1b cause prolonged cardiac repolarization, Long QT Syndrome and sudden death arrhythmia. hERG1a subunits assemble with and enhance the number of hERG1b subunits at the plasma membrane, but the mechanism for the increase in hERG1b by hERG1a is not well understood. Here, we report that the hERG1a N-terminal PAS (Per-Arnt-Sim) domain-N-linker region expressed in trans with hERG1b markedly increased hERG1b currents and increased biotin-labelled hERG1b protein at the membrane surface. hERG1b channels with a deletion of the 1b domain did not have a measurable increase in current or biotinylated protein when co-expressed with hERG1a PAS domain-N-linker regions indicating that the 1b domain was required for the increase in hERG1b. Using a biochemical pull-down interaction assay and a FRET hybridization experiment, we detected a direct interaction between the hERG1a PAS domain-N-linker region and the hERG1b N-terminal 1b domain. Using engineered deletions and alanine mutagenesis, we identified a short span of amino acids at positions 216-220 within the hERG1a N-linker region that were necessary for the upregulation of hERG1b. Taken together, we propose that direct structural interactions between the hERG1a N-linker region and the hERG1b N-terminal 1b domain increase hERG1b at the plasma membrane. Mechanisms that enhance hERG1b current would be anticipated to shorten action potentials, which could be anti-arrhythmic, and may point toward hERG1b or the hERG1a N-linker as molecular targets for therapy for Long QT syndrome.

Significance Statement

Potassium (K) ion channels help to control the membrane voltage in cardiac cells and are responsible for maintaining the normal rhythm of the heart. A decrease in the number of K channels causes cardiac arrhythmia and sudden death. One K channel (KCNH2b, hERG1b) weakly forms channels at the cell membrane. Here we describe a new mechanism for upregulation of hERG1b. An N-terminal domain of a related K channel (KCNH2a, hERG1a), expressed in trans as a separate piece, interacts with hERG1b and increases the number of hERG1b channels at the membrane. A loss of hERG channels is pro-arrhythmic and an increase in hERG channels is considered anti-arrhythmic, thus the hERG1a N-terminal domain is a potential therapeutic for cardiac arrhythmias.
Porphyrin in prebiotic catalysis: Ascertaining a route for the emergence of early metalloporphyrins
Authors: Dagar Shikha , Sarkar Susovan , Rajamani Sudha
Published: December 2021

Metal ions are known to catalyze certain prebiotic reactions. However, the transition from metal ions to extant metalloenzymes remains unclear. Porphyrins are found ubiquitously in the catalytic core of many ancient metalloenzymes. In this study, we evaluated the influence of porphyrin-based organic scaffold, on the catalysis, emergence and putative molecular evolution of prebiotic metalloporphyrins. We studied the effect of porphyrins on the transition metal ion-mediated oxidation of hydroquinone (HQ). We report a change in the catalytic activity of the metal ions in the presence of porphyrin. This was observed to be facilitated by the coordination between metal ions and porphyrins or by formation of non-coordinated complexes. The metal-porphyrin complexes also oxidized NADH, underscoring its versatility at oxidizing more than one substrate. Our study highlights the selective advantage that some of the metal ions would have had in the presence of porphyrin, underscoring their role in shaping the evolution of protometalloenzymes.
Molecular basis of transcriptional repression of anti-CRISPR by anti-CRISPR-associated 2
Authors: Lee So Yeon , Kim Gi Eob , Park Hyun Ho
Published: December 2021

CRISPR–Cas systems are well known host defense mechanisms that are conserved in bacteria and archaea. To counteract CRISPR–Cas systems, phages and viruses have evolved to possess multiple anti-CRISPR (Acr) proteins that can inhibit the host CRISPR–Cas system via different strategies. The expression of acr genes is controlled by anti-CRISPR-associated (Aca) proteins that bind to an upstream promoter and regulate the expression of acr genes during transcription. Although the role of Aca as a transcriptional repressor has been demonstrated, the mechanism of action of Aca has not been determined. Here, the molecular mechanism underlying the Aca2-mediated transcriptional control of acr genes was elucidated by determining the crystal structure of Aca2 from Oceanimonas smirnovii at a high resolution of 1.92 Å. Aca2 forms a dimer in solution, and dimerization of Aca2 is critical for specific promoter binding. The promoter-binding strategy of dimeric Aca2 was also revealed by performing mutagenesis studies. The atomic structure of the Aca family shown in this study provides insights into the fine regulation of host defense and immune-escape mechanisms and also demonstrates the conserved working mechanism of the Aca family.
A case for glycerol as an acceptable additive for single-particle cryoEM samples
Authors: Basanta Benjamin , Hirschi Marscha M. , Grotjahn Danielle A. , Lander Gabriel C.
Published: December 2021

Buffer-composition and sample-preparation guidelines for cryo-electron microscopy are geared towards maximizing imaging contrast and reducing electron-beam-induced motion. These pursuits often involve the minimization or the complete removal of additives that are commonly used to facilitate proper protein folding and minimize aggregation. Among these admonished additives is glycerol, a widely used osmolyte that aids protein stability. In this work, it is shown that the inclusion of glycerol does not preclude high-resolution structure determination by cryoEM, as demonstrated by an ∼2.3 Å resolution reconstruction of mouse apoferritin (∼500 kDa) and an ∼3.3 Å resolution reconstruction of rabbit muscle aldolase (∼160 kDa) in the presence of 20%(v/v) glycerol. While it was found that generating thin ice that is amenable to high-resolution imaging requires long blot times, the addition of glycerol did not result in increased beam-induced motion or an inability to pick particles. Overall, these findings indicate that glycerol should not be discounted as a cryoEM sample-buffer additive, particularly for large, fragile complexes that are prone to disassembly or aggregation upon its removal.
Product characterization of a traditional sausage aiming at geographical indication certification and entrepreneurship prospects: an empirical study of Goan “choris”
Authors: Rajkumar Solomon , Nayar Renuka , Rajagopal Kavitha , Valsalan Namratha , Chinnasamy Sudharsan , Vasudevan V. N. , Thankachan Sathu , Manjunath N.
Published: December 2021

Purpose

The purpose of this paper is the physico-chemical, microbiological, colorimetric, sensorial characterization of choris, a traditional smoked pork sausage produced in the state of Goa (India), including its storage stability (0–180 days) at room temperature, aiming at the geographical indication certification and entrepreneurship prospects.

Design/methodology/approach

A total of 48 samples of “choris” were collected from 24 villages of Goa and were analyzed at different intervals (0–180 days) for physico-chemical, proximate, microbiological, colorimetric and sensory attributes during the storage at room temperature.

Findings

The mean pH of 4.45 and water activity (aw) of 0.78 were recorded. The pH, tyrosine value, fat percentage and free fatty acid content registered a significant increase, whereas moisture content, aw and moisture–protein ratio reduced as storage progresses. The colorimetric values lightness (L*), hue angle (H*) and redness index values reduced significantly during storage. The mean total viable count, yeast and mold, and lactic acid bacteria count were found to proliferate significantly as storage advanced. Nevertheless, the hedonic scores not reaching an unacceptable level (= 4) at the end of the storage period.

Originality/value

In accordance with the various parameters adopted during the study, choris could be characterized as “naturally fermented dry smoked” sausages, which were shelf-stable at room temperature for 180 days. The product characterization of choris is essential to guarantee the genuineness, safety and consumer's acceptability. This study will also rebound in an augmented uniformity of the product, which will favor the geographical indication certification and the entrepreneurship prospects of this traditional product.
Solving 2D boundary-value problems using discrete partial differential operators
Authors: Jaraczewski Marcin , Sobczyk Tadeusz
Published: December 2021

Purpose

Discrete differential operators of periodic base functions have been examined to solve boundary-value problems. This paper aims to identify the difficulties of using those operators to solve ordinary linear and nonlinear differential equations with Dirichlet and Neumann boundary conditions.

Design/methodology/approach

This paper presents a promising approach for solving two-dimensional (2D) boundary problems of elliptic differential equations. To create finite differential equations, specially developed discrete partial differential operators are used to replace the partial derivatives in the differential equations. These operators relate the value of the partial derivatives at each point to the value of the function at all points evenly distributed over the area where the solution is being sought. Exemplary 2D elliptic equations are solved for two types of boundary conditions: the Dirichlet and the Neumann.

Findings

An alternative method has been proposed to create finite-difference equations and an effective method to determine the leakage flux in the transformer window.

Research limitations/implications

The proposed approach can be classified as an extension of the finite-difference method based on the new formulas approximating the derivatives. This method can be extended to the 3D or time-periodic 2D cases.

Practical implications

This paper presents a methodology for calculations of the self- and mutual-leakage inductances for windings arbitrarily located in the transformer window, which is needed for special transformers or in any case of the internal asymmetry of windings.

Originality/value

The presented methodology allows us to obtain the magnetic vector potential distribution in the transformer window only, for example, to omit the magnetic core of the transformer from calculations.
Restaurant management and food waste reduction: factors affecting attitudes and intentions in restaurants of Spain
Authors: Filimonau Viachaslau , Coşkun Ayşen , Derqui Belen , Matute Jorge
Published: December 2021

Purpose

Although the challenge of food waste (FW) in the foodservice sector is significant, restaurant managers do not always engage in its reduction. The psychological reasons for this disengagement remain insufficiently understood. This study aims to explore the antecedents of behavioural intention of restaurateurs (not) to reduce FW. The influence of three factors is tested, namely, market orientation; environmental apathy alongside selected neutralization techniques, namely, appeal to higher loyalties; denial of injury and denial of responsibility.

Design/methodology/approach

The study uses the method of a large-scale managerial survey (n = 292) administered in the commercial foodservice sector of Spain. The data are analysed via structural equation modelling with partial least squares.

Findings

The study finds that market orientation affects managerial intention to reduce FW but not their attitude, while environmental apathy influences managerial attitudes but not their behavioural intention. The study confirms the negative effect of such neutralizers as the appeal to higher loyalties and the denial of injury on suppressing managerial intention to reduce FW. Contrary to initial anticipations, another established neutralizer, the denial of responsibility, exerts no significant effect.

Practical implications

The study elaborates on the interventions necessitated to neutralize the effect of the neutralizers on managerial (un)willingness to reduce FW in the commercial foodservice sector.

Originality/value

This is the first known attempt to understand the drivers of managerial engagement in FW reduction in the commercial foodservice sector through the prism of environmental apathy, market orientation and neutralization theory.
Research on optimization design of men's suit considering users' perception
Authors: Zhou Xiaoxi , Xu Yue , Chen Tui
Published: December 2021

Purpose

This paper aims to identify the relationship between users' perception image, clothing design features and users' preference and propose a clothing design scheme based on users perception image and users' preference.

Design/methodology/approach

In this paper, men's suit is composed into multiple design features under the design elements. Using the orthogonal experiment method, 16 schemes of the representative suit are designed. Through perception evaluation experiment, users' perception images and preference degree of the samples are obtained. By partial least squares (PLS) analysis method, the models between users' perception image, suit design features and users' preference are built.

Findings

The interrelationship between the three is identified by establishing PLS models between users' perception image, suit design features and users' preference. According to the coefficients of the models, the optimization schemes of men's suits considering users' perception image and preference are proposed. Verification results show that the optimization schemes are significantly better than other schemes.

Originality/value

The results of this paper can be used for consumer demand-oriented clothing design and provide references and methods for converting consumer's perceived needs into clothing design features.
Determinants of profitability in Chinese companies
Authors: Alarussi Ali Saleh , Gao Xiaoyu
Published: December 2021

Purpose

This study is conducted to determine the factors that affect profitability in Chinese listed companies (by using financial ratios). Four independent variables liquidity, intangible assets, working capital and company leverage were empirically tested for their relationships with profitability besides two control variables which are firm size and company efficiency.

Design/methodology/approach

This study used secondary data extracted manually from the annual reports of non-financial Chinese listed companies on the Shanghai stock exchange (http://www.szse.cn/); the data set covers 100 companies during the period of 2017–2019, and a random selection method was used in order to achieve credibility and fairness as much as possible.

Findings

The findings show firm size, working capital and intangible assets have positive and significant relationships with profitability [return on assets (ROA) and earnings per share (EPS)]. Positive working capital is important to lower the cost of capital and improve companies' profitability. Intangible assets are also an essential source to improve profitability due to their low costs. In addition, the findings display a negative and strong relationship between liquidity and profitability, meaning that companies suffer low profit due to inefficient use of liquid items. Interestingly, leverage, which is measured by debt ratio and leverage ratio, shows mixed results; debt ratio shows a positive and strong association with ROA but not with EPS; while leverage ratio displays a strong but negative association with ROA but not with EPS. These results confirm the inverted U-shape relationship between leverage and profitability, which depends on the balance between benefit and cost of debt.

Social implications

Profitability is also important for employees and society where business organization provides sustainability and stability for both of them. Employees can then significantly contribute to achieve higher firm's profitability by efficiently using firm's resources.

Originality/value

This study differs than previous studies in number of aspects: First, this study focuses on financial ratios to explain profitability in Chinese companies. This study provides empirical results about the factors connected to profitability and help stakeholders to make their right decisions. Second, it examines the impact of four independent factors and two control variables that some of them are new in Chinese context such as intangible assets. Third previous studies focus on financial industry such as banks; however, this study focuses on non-financial industry.
Impact of knowledge sharing on employees' service quality: the moderating role of artificial intelligence
Authors: Nguyen Tuyet-Mai , Malik Ashish
Published: December 2021

Purpose

A growing number of international travellers have influenced how hotels manage their customer satisfaction reviews and ratings. This study examines the influence of knowledge sharing on employee service quality and customer satisfaction in the hotel industry. Another purpose of this study is to investigate the moderating effect of artificial intelligence (AI) system quality on the relationship between knowledge sharing on employee service quality and customer satisfaction.

Design/methodology/approach

The research design was developed using the positivism approach and quantitative method. Data were collected via a self-administered survey from Vietnamese hotels that used AI systems in employees' work tasks. Three hundred and fifty pairs of questionnaires for frontline employees and customers were collected and used for the data analysis. Structural equation modelling was accessed to examine the framework model.

Findings

This research shows that the increase of knowledge sharing behaviours significantly influenced customer perceptions of employees' service quality. Furthermore, employee service quality positively affected customer satisfaction. An indirect impact of knowledge sharing on customer satisfaction via employee service quality was found. AI system quality moderated the effect of knowledge sharing on employee service quality whereby the higher the AI system quality, the stronger the impact of knowledge sharing on employee service quality. Therefore, a moderated mediation of employee service quality was found in examining the relationship between knowledge sharing and customer satisfaction.

Research limitations/implications

This study's findings direct hotel knowledge management and marketing strategies to attract international customers. The study provides hotel managers with directions to increase customer satisfaction to create a competitive advantage in international marketing strategies.

Originality/value

This study's distinctive contribution lies in examining the phenomenon of employee service quality at the intersection of knowledge sharing and customer satisfaction and the use of AI systems from an emerging market context. Furthermore, the moderation role of AI quality has rarely been explored.
How international marketers make decisions: exploring approaches to learning and using heuristics
Authors: Guercini Simone , Freeman Susan Maria
Published: December 2021

Purpose

The paper addresses the following research question: how do decision-makers use heuristics in their international business (IB) environment? Whereas, the literature has focused on entrepreneurial companies, here contrasting approaches to learning and using heuristics in international marketing (IM) decisions are examined and discussed.

Design/methodology/approach

The paper aims to address a gap in the study of micro-foundations of internationalization, exploiting research from other disciplinary fields. It combines a multidisciplinary literature review and longitudinal case studies to illustrate different approaches in learning and using heuristics by international marketers.

Findings

International marketers can adopt “closed” heuristics that are consolidated and consistently followed, or “open” heuristics, which are constantly being adapted and learned. Established multinationals learn heuristics in international marketing decision-making, following both “closed” and “open” models.

Originality/value

This paper offers an original contribution by presenting different approaches not yet examined in the literature, focusing on how international marketers make decisions through learning and using heuristic rules. The focus is on established exporters, in contrast to the literature that has largely paid attention to the effectiveness of heuristics in new entrepreneurial firms.
Fundamental elements of university-industry interaction from a grounded theory approach
Authors: Bürger Rafaela , Fiates Gabriela Gonçalves Silveira
Published: December 2021

Purpose

This work aims to analyze the university–industry interaction in innovation ecosystems. The problem under study addresses how agents can operate in university–industry interactions to enhance the connections, specifically in the aspect of operational mechanisms of an innovation ecosystem.

Design/methodology/approach

The study is qualitative, applied through grounded theory approach, cross-sectional and multiple sources of evidence – semi-structured interviews were conducted. An explanatory conceptual model was subsequently compared with the literature and validated with specialists.

Findings

The results showed that the university–industry interaction is influenced by several factors, such as networking, legal support, facilitating agents, management practices. Despite this, some other factors were identified for the improvement of U–I relationships, such as: strengthening of triple helix, greater legal certainty and encouragement of open innovation.

Research limitations/implications

The small sample size and the heterogeneity among the universities interviewed did not allow full saturation to occur. In spite of that, a significant level of saturation with respect to the challenges and barriers was observed.

Practical implications

This work has a direct dialogue with researchers, managers and actors involved in university–industry interaction with regard to increasing the capacity for creation and dissemination of knowledge among organizations, educational institutions, government and companies.

Originality/value

By adopting a grounded theory approach, a detailed research agenda addresses research needs in two main areas: activities that precede the interaction between universities and companies, and the organization and management of the consequences of collaborative relationships.
Exploring decision-making biases among Iranian entrepreneurs: some novel insights
Authors: Nouri Pouria
Published: December 2021

Purpose

Decision-making biases play decisive roles not only in entrepreneurs’ decisions but also in the fate of entrepreneurial businesses. While the extant literature in this regard is relatively rich, it has predominantly focused on certain biases like overconfidence and overoptimism at the expense of other possibly influential biases, which could influence entrepreneurial decisions. Thus, to address this serious research gap, this paper aims to explore four of the less-researched biases of escalation of commitment, the illusion of control, confirmation and the belief in the law of small numbers in entrepreneurial decisions.

Design/methodology/approach

By taking a qualitative approach, the data for this study were collected through face-to-face interviews with 19 Iranian habitual (experienced) entrepreneurs running small businesses and analyzed by a qualitative thematic analysis.

Findings

According to the results, the environmental uncertainty, the reluctance to lose face and the experiences of previous failures contributed to the escalation of commitment, while disregard for external factors beyond one’s control caused the illusion of control, factors like prior successful businesses in the same sector, looking for resorts to manage uncertainty, along with the decision to exploit opportunities resulted in the confirmation bias, while the expenses of conducting sweeping pilot tests in the market and the reluctance to reveal a business secret to the competitors were the main contributors of the belief in the law of small numbers.

Originality/value

This study is a pioneer in scrutinizing four less-researched but important biases in entrepreneurs and, thus extending the line of research in this regard.