bluuebunny/crossref_metadata_2025 huggingface dataset:
FicD Sensitizes Cellular Response to Glucose Fluctuations in Mouse Embryonic Fibroblasts
Authors: Gulen Burak , Kinch Lisa N. , Servage Kelly A. , Blevins Aubrie , Stewart Nathan M. , Gray Hillery F. , Casey Amanda K. , Orth Kim
Published: January 2024

During homeostasis, the endoplasmic reticulum (ER) maintains productive transmembrane and secretory protein folding that is vital for proper cellular function. The ER-resident HSP70 chaperone, BiP, plays a pivotal role in sensing ER stress to activate the unfolded protein response (UPR). BiP function is regulated by the bifunctional enzyme FicD that mediates AMPylation and deAMPylation of BiP in response to changes in ER stress. AMPylated BiP acts as a molecular rheostat to regulate UPR signaling, yet little is known about the molecular consequences of FicD loss. In this study, we investigate the role of FicD in mouse embryonic fibroblast (MEF) response to pharmacologically and metabolically induced ER stress. We find differential BiP AMPylation signatures when comparing robust chemical ER stress inducers to physiological glucose starvation stress and recovery. Wildtype MEFs respond to pharmacological ER stress by downregulating BiP AMPylation. Conversely, BiP AMPylation in wildtype MEFs increases upon metabolic stress induced by glucose starvation. Deletion of FicD results in widespread gene expression changes under baseline growth conditions. In addition, FicD null MEFs exhibit dampened UPR signaling, altered cell stress recovery response, and unconstrained protein secretion. Taken together, our findings indicate that FicD is important for tampering UPR signaling, stress recovery, and the maintenance of secretory protein homeostasis.

Significance Statement

The chaperone BiP plays a key quality control role in the endoplasmic reticulum, the cellular location for the production, folding, and transport of secreted proteins. The enzyme FicD regulates BiP’s activity through AMPylation and deAMPylation. Our study unveils the importance of FicD in regulating BiP and the unfolded protein response (UPR) during stress. We identify distinct BiP AMPylation signatures for different stressors, highlighting FicD’s nuanced control. Deletion of FicD causes widespread gene expression changes, disrupts UPR signaling, alters stress recovery, and perturbs protein secretion in cells. These observations underscore the pivotal contribution of FicD for preserving secretory protein homeostasis. Our findings deepen the understanding of FicD’s role in maintaining cellular resilience and open avenues for therapeutic strategies targeting UPR-associated diseases.
The cost and payout of age on germline regeneration and sexual maturation inPlatynereis dumerilii
Authors: Metzger Bria , Özpolat B. Duygu
Published: January 2024

Regeneration, regrowing lost and injured body parts, is an ability that generally declines with age or developmental transitions (i.e. metamorphosis, sexual maturation) in many organisms. Regeneration is also energetically a costly process, and trade-offs occur between regeneration and other costly processes such as somatic growth, or sexual reproduction. Here we investigate the interplay of regeneration, reproduction, and age in the segmented wormPlatynereis dumerilii.P. dumeriliican regenerate its whole posterior body axis, along with its reproductive cells, thereby having to carry out the two costly processes (somatic and germ cell regeneration) after injury. We specifically examine how age affects the success of germ cell regeneration and sexual maturation in developmentally young versus old organisms. We hypothesized that developmentally younger individuals (i.e. lower investment state, with gametes in early mitotic stages) will have higher regeneration success and reach sexual maturation faster than the individuals at developmentally older stages (i.e. higher investment state, with gametes in the process of maturation). Surprisingly, older amputated worms grew faster and matured earlier than younger amputees, even though they had to regenerate more segments and recuperate the more costly germ cells which were already starting to undergo gametogenesis. To analyze germ cell regeneration across stages, we used Hybridization Chain Reaction for the germline markervasa. We found that regenerated worms start repopulating new segments with germ cell clusters as early as 14 days post amputation. In addition,vasaexpression is observed in a wide region of newly-regenerated segments, which appears different from expression patterns during normal growth or regeneration in worms before gonial cluster expansion. Future studies will focus on determining the exact sources of gonial clusters in regeneration.

Funding

NIGMS 1R35GM138008-01, Hibbitt Fellowship, WashU Startup funds
JAK/STAT signaling promotes the emergence of unique cell states in ulcerative colitis
Authors: Maciag Grzegorz , Hansen Stine Lind , Krizic Kata , Kellermann Lauge , Ulyanchenko Svetlana , Maimets Martti , Baattrup Astrid Møller , Riis Lene Buhl , Khodosevich Konstantin , Sato Toshiro , Nielsen Ole Haagen , Jensen Kim B.
Published: January 2024

The intestinal epithelium forms a barrier to the lumen and ensures uptake of vital nutrients. During inflammatory diseases, such as ulcerative colitis (UC), this barrier is compromised. Here, we perform single-cell RNA sequencing (scRNA-seq) of epithelial cells and outline patterns of cell fate decisions in healthy individuals and patients with UC. We demonstrate that lineage biased progenitors are major sources of normal tissue replenishment, and that patterns of cell behavior are profoundly altered in UC. We furthermore identify unique regenerative cell states linked to JAK/STAT activation extending into the non-inflamed areas of the colon. In organoid models, this can be mimicked by cytokine mediated activation of JAK/STAT leading to the emergence of cell populations with regenerative potential. These findings have profound implications for our understanding of tissue regeneration and illustrates how cytokine signaling influences cell fate decisions. This suggests widespread consequences in patients with chronic ulcerative conditions.
Randomizing the human genome by engineering recombination between repeat elements
Authors: Koeppel Jonas , Ferreira Raphael , Vanderstichele Thomas , Riedmayr Lisa M. , Peets Elin Madli , Girling Gareth , Weller Juliane , Liberante Fabio Giuseppe , Ellis Tom , Church George M. , Parts Leopold
Published: January 2024

While protein-coding genes are characterized increasingly well, 99% of the human genome is non-coding and poorly understood. This gap is due to a lack of tools for engineering variants that affect sequence to the necessary extent. To bridge this gap, we have developed a toolbox to create deletions, inversions, translocations, and extrachromosomal circular DNA at scale by highly multiplexed insertion of recombinase recognition sites into repetitive sequences with CRISPR prime editing. Using this strategy, we derived stable human cell lines with several thousand clonal insertions, the highest number of novel sequences inserted into single human genomes. Subsequent recombinase induction generated an average of more than one hundred megabase-sized rearrangements per cell, and thousands across the whole population. The ability to detect rearrangements as they are generated and to track their abundance over time allowed us to measure the selection pressures acting on different types of structural changes. We observed a consolidation towards shorter variants that preferentially delete growth-inhibiting genes and a depletion of translocations. We isolated and characterized 21 clones with multiple recombinase-induced rearrangements. These included viable haploid clones with deletions that span hundreds of kilobases as well as triploid HEK293T clones with aneuploidies and fold back chromosomes. We mapped the impact of these genetic changes on gene expression to decipher how structural variants affect gene regulation. The genome scrambling strategy developed here makes it possible to delete megabases of sequence, move sequences between and within chromosomes, and implant regulatory elements into new contexts which will shed light on the genome organization principles of humans and other species.
Genetic polymorphism and evidence of signatures of selection in thePlasmodium falciparumcircumsporozoite protein gene in Tanzanian regions with different malaria endemicity
Authors: Lyimo Beatus M. , Bakari Catherine , Popkin-Hall Zachary R. , Giesbrecht David J. , Seth Misago D. , Pereus Dativa , Moshi Ramadhan , Boniface Ruth , Mandara Celine I. , Madebe Rashid , Juliano Jonathan J. , Bailey Jeffrey A. , Ishengoma Deus S.
Published: January 2024

Background

In 2021 and 2023, the World Health Organization approved RTS,S/AS01 and R21/Matrix M malaria vaccines, respectively, for routine immunization of children in African countries with moderate to high transmission. These vaccines are made ofPlasmodium falciparumcircumsporozoite protein (Pfcsp)but polymorphisms in this gene raises concerns regarding strain-specific responses and the long-term efficacy of these vaccines. This study assessed thePfcspgenetic diversity, population structure and signatures of selection among parasites from areas of different malaria transmission in mainland Tanzania, to generate baseline data before the introduction of the malaria vaccines in the country.

Methods

The analysis involved 589 whole genome sequences generated by and as part of the MalariaGEN Community Project. The samples were collected between 2013 and January 2015 from five regions of mainland Tanzania: Morogoro and Tanga (Muheza) (moderate transmission areas), and Kagera (Muleba), Lindi (Nachingwea), and Kigoma (Ujiji) (high transmission areas). Wright’s inbreeding coefficient (Fws), Wright’s fixation index (FST), principal component analysis, nucleotide diversity, and Tajima’s D were used to assess within-host parasite diversity, population structure and natural selection.

Results

Based on Fws(< 0.95), there was high polyclonality (ranged from 69.23% in Nachingwea to 56.9% in Muheza). No population structure was detected in thePfcspgene in the five regions (mean FST= 0.0068). The average nucleotide diversity (π), nucleotide differentiation (K) and haplotype diversity (Hd) in the five regions were 4.19, 0.973 and 0.0035, respectively. The C-terminal region ofPfcspshowed high nucleotide diversity at Th2R and Th3R regions. Positive values for the Tajima’s D were observed in the Th2R and Th3R regions consistent with balancing selection. ThePfcspC-terminal sequences had 50 different haplotypes (H_1 to H_50) and only 2% of sequences matched the 3D7 strain haplotype (H_50).

Conclusions

The findings demonstrate high diversity of thePfcspgene with limited population differentiation. ThePfcspgene showed positive Tajima’s D values for parasite populations, consistent with balancing selection for variants within Th2R and Th3R regions. This data is consistent with other studies conducted across Africa and worldwide, which demonstrate low 3D7 haplotypes and little population structure. Therefore, additional research is warranted, incorporating other regions and more recent data to comprehensively assess trends in genetic diversity within this important gene. Such insights will inform the choice of alleles to be included in the future vaccines
Face-brain correlates as potential sex-specific biomarkers for schizophrenia and bipolar disorder
Authors: Hostalet Noemí , González Alejandro , Gonzàlez-Colom Rubèn , Salgado-Pineda Pilar , Canales-Rodríguez Erick J , Aguirre Candibel , Guerrero-Pedraza Amalia , Llanos-Torres María , Salvador Raymond , Pomarol-Clotet Edith , Sevillano Xavier , Martínez-Abadías Neus , Fatjó-Vilas Mar
Published: January 2024

Given the shared ectodermal origin and integrated development of the face and the brain, facial biomarkers emerge as potential candidates to assess vulnerability for disorders in which neurodevelopment is compromised, such as Schizophrenia (SZ) and bipolar disorder (BD).

The sample comprised 188 individuals (67 SZ patients, 46 BD patients and 75 healthy controls (HC)). Using a landmark-based approach on 3D facial reconstructions, we quantified global and local facial shape differences between SZ/BD patients and HC using geometric morphometrics. We assessed correlations between facial and brain cortical measures. The analyses were performed separately by sex.

Diagnosis explained 4.1% - 5.9% of global facial shape variance in males and females with SZ, and 4.5% - 4.1% in BD. Regarding local facial shape, we detected 43.2% of significantly different distances in males and 47.4% in females with SZ compared to HC, whereas in BD the percentages decreased to 35.8% and 26.8%, respectively. We detected that brain area and volume significantly explained 2.2% and 2% of facial shape variance in the male SZ - HC sample.

Our results support facial shape as a neurodevelopmental marker for SZ and BD and reveal sex- specific pathophysiological mechanisms modulating the interplay between the brain and the face.
Deep phenotyping of patient lived experience in functional bowel disorders
Authors: Ruffle James K. , Henderson Michelle , Ng Cho Ee , Liddle Trevor , Nelson Amy P. K. , Nachev Parashkev , Knowles Charles H , Yiannakou Yan
Published: January 2024

Clinical management relies on a diagnostic label as the primary guide to treatment. However, individual patients’ lived experiences vary more widely than standard diagnostic categories reflect. This is especially true for functional bowel disorders (FBDs), a heterogeneous and challenging group of gastrointestinal disorders where no definitive diagnostic tests, clinical biomarkers, or universally effective treatments exist. Characterising the link between disease and lived experience - in the face of marked patient heterogeneity - requires deep phenotyping of the interactions between multiple characteristics plausibly achievable only with complex modelling approaches. In a large patient cohort (n=1175), we developed a machine learning and Bayesian generative graph framework to better understand the lived experience of FBDs. Iterating through 59 factors available from routine clinical care, spanning patient demography, diagnosis, symptomatology, life impact, mental health indices, healthcare access requirements, COVID-19 impact, and treatment effectiveness, machine models were used to quantify the predictive fidelity of one feature from the remainder. Bayesian stochastic block models were used to delineate the network community structure underpinning the heterogeneous lived experience of FBDs. Machine models quantified patient personal health rating (R20.35), anxiety and depression severity (R20.54), employment status (balanced accuracy 96%), frequency of healthcare attendance (R20.71), and patient-reported treatment effectiveness variably (R2range 0.08-0.41). Contrary to the view of many healthcare professionals, the greatest determinants of patient-reported health and quality-of-life were life impact, mental well-being, employment status, and age, rather than diagnostic group and symptom severity. Patients responsive to one treatment were more likely to respond to another, leaving many others refractory to all. Clinical assessment of patients with FBDs should be less concerned with diagnostic classification than with the wider life impact of illness, including mental health and employment. The stratification of treatment response (and resistance) has implications for clinical practice and trial design, in need of further research.
Off-body Sleep Analysis for Predicting Adverse Behavior in Individuals with Autism Spectrum Disorder
Authors: Kiarashi Yashar , Suresha Pradyumna B , Rad Ali Bahrami , Reyna Matthew A , Anderson Conor , Foster Jenny , Lantz Johanna , Villavicencio Tania , Hamlin Theresa , Clifford Gari D
Published: January 2024

Poor sleep quality in Autism Spectrum Disorder (ASD) individuals is linked to severe daytime behaviors. This study explores the relationship between a prior night’s sleep structure and its predictive power for next-day behavior in ASD individuals. The motion was extracted using a low-cost near-infrared camera in a privacy-preserving way. Over two years, we recorded overnight data from 14 individuals, spanning over 2,000 nights, and tracked challenging daytime behaviors, including aggression, self-injury, and disruption. We developed an ensemble machine learning algorithm to predict next-day behavior in the morning and the afternoon. Our findings indicate that sleep quality is a more reliable predictor of morning behavior than afternoon behavior the next day. The proposed model attained an accuracy of 74% and a F1 score of 0.74 in target-sensitive tasks and 67% accuracy and 0.69 F1 score in target-insensitive tasks. For 7 of the 14, better-than-chance balanced accuracy was obtained (p-value<0.05), with 3 showing significant trends (p-value<0.1). These results suggest off-body, privacy-preserving sleep monitoring as a viable method for predicting next-day adverse behavior in ASD individuals, with the potential for behavioral intervention and enhanced care in social and learning settings.
Prevalence and types of strabismus in cerebral palsy: A global and historical perspective based on a systematic review and meta-analysis
Authors: Herron Michael S. , Wang Lingchen , von Bartheld Christopher S.
Published: January 2024

Purpose

Strabismus is more frequent in cerebral palsy (CP) than in the normal population, but reports differ how much it is increased. We here examined the global prevalence and types of strabismus in CP, whether esotropia or exotropia is more frequent, and whether the prevalence differs between ethnicities and/or country income levels, and between generations.

Methods

We compiled in a systematic review and meta-analysis the results of 147 CP studies that report the prevalence of strabismus or the ratio of esotropia to exotropia, and we conducted subgroup analyses for region (income level) and ethnicity. We performed a pooled analysis for the CP strabismus prevalence, and estimated the global number of CP cases with strabismus.

Results

The pooled prevalence of strabismus in CP is 49.8% in high-income countries and 39.8% in lower-income countries. We estimate the global number of strabismus cases in CP as 12.2 million, with 7.6 million males and 4.6 million females, based on current estimates of 29.6 million global CP cases. Esotropia is more frequent than exotropia in Caucasians, while exotropia is more frequent than esotropia in Hispanic and in some Asian and African populations. The strabismus prevalence in CP increases with increasing country income levels.

Conclusion

Generational changes in strabismus prevalence appear to reflect a transition of CP types and an increase in prevalence as countries attain higher income and more effective maternal health care. The distribution of esotropia and exotropia in CP patients largely reflects the horizontal strabismus type that is predominant in the subject’s ethnicity.
READv2: Advanced and user-friendly detection of biological relatedness in archaeogenomics
Authors: Alaçamlı Erkin , Naidoo Thijessen , Aktürk Şevval , Güler Merve N. , Mapelli Igor , Vural Kıvılcım Başak , Somel Mehmet , Malmström Helena , Günther Torsten
Published: January 2024

The possibility to obtain genome-wide ancient DNA data from multiple individuals has facilitated an unprecedented perspective into prehistoric societies. Studying biological relatedness in these groups requires tailored approaches for analyzing ancient DNA due to its low coverage, post-mortem damage, and potential ascertainment bias. Here we present READv2 (Relatedness Estimation from Ancient DNA version 2), an improved Python 3 re-implementation of the most widely used tool for this purpose. While providing increased portability and making the software future-proof, we are also able to show that READv2 (a) is orders of magnitude faster than its predecessor; (b) has increased power to detect pairs of relatives using optimized default parameters; and, when the number of overlapping SNPs is sufficient, (c) can differentiate between full-siblings and parent-offspring, and (d) can classify pairs of third-degree relatedness. We further use READv2 to analyze a large empirical dataset that has previously needed two separate tools to reconstruct complex pedigrees. We show that READv2 yields results and precision similar to the combined approach but is faster and simpler to run. READv2 will become a valuable part of the archaeogenomic toolkit in providing an efficient and user-friendly classification of biological relatedness from pseudohaploid ancient DNA data.
Neuropilin-1 controls vascular permeability through juxtacrine regulation of endothelial adherens junctions
Authors: Pal Sagnik , Su Yangyang , Nwadozi Emmanuel , Claesson-Welsh Lena , Richards Mark
Published: January 2024

Neuropilin-1 (NRP1) regulates endothelial cell (EC) biology through modulation of vascular endothelial growth factor receptor 2 (VEGFR2) signalling by presenting VEGFA to VEGFR2. How NRP1 impacts VEGFA-mediated vascular hyperpermeability has however remained unresolved, described as exerting either a positive or a passive function. Using EC-specificNrp1knock-out mice, we discover that EC-expressed NRP1 exerts an organotypic role. In the ear skin, VEGFA/VEGFR2-mediated vascular leakage was increased following loss of EC NRP1, implicating NRP1 in negative regulation of VEGFR2 signalling. In contrast, in the back skin and trachea, loss of EC NRP1 decreased vascular leakage. In accordance, phosphorylation of vascular endothelial (VE)-cadherin was increased in the ear skin but suppressed in the back skin ofNrp1iECKO mice. NRP1 expressed on perivascular cells has been shown to impact VEGF-mediated VEGFR2 signalling. Importantly, expression of NRP1 on perivascular cells was more abundant in the ear skin than in the back skin. Global loss of NRP1 resulted in suppressed VEGFA-induced vascular leakage in the ear skin, implicating perivascular NRP1 as a juxtacrine co-receptor of VEGFA in this compartment. Altogether, we demonstrate that perivascular NRP1 is an active participant in EC VEGFA/VEGFR2 signalling and acts as an organotypic modifier of EC biology.
Temporal Dynamics of Brain Mediation in Predictive Cue-induced Pain Modulation
Authors: Gim Suhwan , Hong Seok-Jun , Reynolds Losin Elizabeth A. , Woo Choong-Wan
Published: January 2024

Pain is not a mere reflection of noxious input. Rather, it is constructed through the dynamic integration of prior predictions with incoming sensory input. However, the temporal dynamics of the behavioral and neural processes underpinning this integration remain elusive. Here, we identified a series of brain mediators that integrated cue-induced expectations with noxious inputs into ongoing pain predictions using a semicircular scale designed to capture rating trajectories. Temporal mediation analysis revealed that during the early-to-mid stages of integration, the frontoparietal and dorsal attention network regions, such as the lateral prefrontal, premotor, and parietal cortex, mediated the cue effects. Conversely, during the mid-to-late stages of integration, the somatomotor network regions mediated the effects of stimulus intensity, suggesting that the integration occurs along the cortical hierarchy from transmodal to unimodal brain systems. Our findings advance the understanding of how the brain integrates prior and sensory information into pain experience over time.
Reductive dehalogenation by diverse microbes is central to biogeochemical cycles in deep-sea cold seeps
Authors: Han Yingchun , Deng Zhaochao , Peng Yongyi , Peng Jiaxue , Cao Lei , Xu Yangru , Yang Yi , Zhou Hao , Zhang Chen , Zhang Dongdong , Wang Minxiao , Zhang Chunfang , Greening Chris , Dong Xiyang
Published: January 2024

Reductive dehalogenation is crucial for halogen cycling and environmental remediation, yet its ecological role is not completely understood, especially in deep-sea environments. To address this gap, we investigated the diversity of reductive dehalogenases (RDases) and ecophysiology of organohalide reducers in deep-sea cold seeps, which are environments rich in halogenated compounds. Through genome- resolved metagenomic analysis of 165 global cold seep sediment samples, we identified four types of RDases, namely prototypical respiratory, transmembrane respiratory, and cytosolic RDases, and one novel clade. Cold seeps were found to harbor a higher abundance of these RDase genes compared to other marine sediments, establishing them as unique hotspots for microbial reductive dehalogenation activity. These RDases are encoded by a wide range of microorganisms across four archaeal and 36 bacterial phyla, significantly expanding the known diversity of organohalide reducers. Halogen geochemistry, laboratory incubations with various halogenated compounds, metatranscriptomic data, and metabolomic profiling confirmed the presence of organohalides at concentrations of up to 18 mg/g in these sediments and demonstrated their active microbial reduction. This process is tightly linked to other biogeochemical cycles, including carbon, hydrogen, nitrogen, sulfur, and trace elements. RDases from cold seeps have diverse N-terminal structures across different gene groups, and reductive dehalogenase genes in these environments are mostly functionally constrained and conserved. These findings collectively suggest that reductive dehalogenation is a central process in deep-sea environments, mediated by a diverse array of microbes and novel enzymes.
Numerical analysis of a baryon and its dilatation modes in holographic QCD
Authors: Hori Keiichiro , Suganuma Hideo , Kanda Hiroki
Published: January 2024

We investigate a baryon and its dilatation modes in holographic QCD based on the Sakai-Sugimoto model, which is expressed as a 1+4 dimensional U(Nf) gauge theory in the flavor space. For spatially rotational symmetric systems, we apply a generalized version of the Witten Ansatz, and reduce 1+4 dimensional holographic QCD into a 1+2 dimensional Abelian Higgs theory in a curved space. In the reduced theory, the holographic baryon is described as a two-dimensional topological object of an Abrikosov vortex. We numerically calculate the baryon solution of holographic QCD using a fine and large lattice with spacing of 0.04 fm and size of 10 fm. Using the relation between the baryon size and the zero-point location of the Higgs field in the description with the Witten Ansatz, we investigate a various-size baryon through this vortex description. As time-dependent size-oscillation modes (dilatation modes) of a baryon, we numerically obtain the lowest excitation energy of 577 MeV and deduce the dilatational excitation of a nucleon to be the Roper resonance N*(1440).

Published by the American Physical Society
2024
Behavior of strain stripe networks in barium titanate nanocrystals on crossing its ferroelectric phase transition
Authors: Diao Jiecheng , Wu Longlong , Suzana Ana F. , Bozin Emil S. , Zatterin Edoardo M. , Leake Steven J. , Harder Ross J. , Cha Wonsuk , Abeykoon Milinda , Fan Jiadong , Jiang Huaidong , Robinson Ian K.
Published: January 2024

Nanoscale strain networks are reported in BaTiO3 (BTO) crystals of 300 nm size using Bragg coherent diffractive imaging. BTO nanocrystals with clear facets were chosen to identify the crystallographic directions, allowing the strain field direction and periodicity to be studied in detail. Stripes of strain were observed, which were both stable and preserved in tetragonal and cubic phases at elevated temperatures, above the tetragonal-to-cubic phase transition. A finite element analysis approach was used to simulate the domain structures inside a BTO crystal and to understand the origins of the strain stripes as piezoelectric blocks. A 180∘ domain model gives a better qualitative match to the experimental images.

Published by the American Physical Society
2024
Thermodynamic bound on spectral perturbations, with applications to oscillations and relaxation dynamics
Authors: Kolchinsky Artemy , Ohga Naruo , Ito Sosuke
Published: January 2024

In discrete-state Markovian systems, many important properties of correlation functions and relaxation dynamics depend on the spectrum of the rate matrix. Here we demonstrate the existence of a universal trade-off between thermodynamic and spectral properties. We show that the entropy production rate, the fundamental thermodynamic cost of a nonequilibrium steady state, bounds the difference between the eigenvalues of a nonequilibrium rate matrix and a reference equilibrium rate matrix. Using this result, we derive thermodynamic bounds on the spectral gap, which governs autocorrelation times and the speed of relaxation to a steady state. We also derive the thermodynamic bounds on the imaginary eigenvalues, which govern the speed of oscillations. We illustrate our approach using a simple model of biomolecular sensing.

Published by the American Physical Society
2024
Penetration of arbitrary double potential barriers with probability unity: Implications for testing the existence of a minimum length
Authors: Yang Yong
Published: January 2024

Quantum tunneling across double potential barriers is studied. With the assumption that the real space is a continuum, it is rigorously proved that large barriers of arbitrary shapes can be penetrated by low-energy particles with a probability of unity, i.e., realization of resonant tunneling (RT), by simply tuning the interbarrier spacing. The results are demonstrated by tunneling of electrons and protons, in which resonant and sequential tunneling are distinguished. The critical dependence of tunneling probabilities on the barrier positions not only demonstrates the crucial role of phase factors but also points to the possibility of ultrahigh accuracy measurements near resonance. By contrast, the existence of a nonzero minimum length puts upper bounds on the barrier size and particle mass, beyond which effective RT ceases. A scheme is suggested for dealing with the practical difficulties arising from the delocalization of particle position due to the uncertainty principle. This work opens a possible avenue for experimental tests of the existence of a minimum length based on atomic systems.

Published by the American Physical Society
2024
Reducing the Instability of an Optical Lattice Clock Using Multiple Atomic Ensembles
Authors: Zheng Xin , Dolde Jonathan , Kolkowitz Shimon
Published: January 2024

The stability of an optical atomic clock is a critical figure of merit for almost all clock applications. To this end, much optical atomic clock research has focused on reducing clock instability by increasing the atom number, lengthening the coherent interrogation times, and introducing entanglement to push beyond the standard quantum limit. In this work, we experimentally demonstrate an alternative approach to reducing clock instability using a phase estimation approach based on individually controlled atomic ensembles in a strontium (Sr) optical lattice clock. We first demonstrate joint Ramsey interrogation of two spatially resolved atom ensembles that are out of phase with respect to each other, which we call “quadrature Ramsey spectroscopy,” resulting in a factor of 1.36(5) reduction in absolute clock instability as measured with interleaved self-comparisons. We then leverage the rich hyperfine structure of Sr87 to realize independent coherent control over multiple ensembles with only global laser addressing. Finally, we utilize this independent control over four atom ensembles to implement a form of phase estimation, achieving a factor of greater than 3 enhancement in coherent interrogation time and a factor of 2.08(6) reduction in instability over an otherwise identical single-ensemble clock with the same local oscillator and the same number of atoms. We expect that multiensemble protocols similar to those demonstrated here will result in reduction in the instability of any optical lattice clock with an interrogation time limited by the local oscillator.

Published by the American Physical Society
2024
Visibilizing and managing paradox: redefining the role of non-executive directors
Authors: Pina e Cunha Miguel , Nogueira Leite António , Rego Arménio , Hernández-Linares Remedios
Published: January 2024

Purpose

This paper aims to discuss the work of non-executive directors (NEDs) as inherently paradoxical. Paradox refers to the presence of persistent contradictions between interdependent forces. Those persistent tensions are explored, and approaches are indicated to stimulate the adaptive use of paradoxes as forces of innovation and renewal.

Design/methodology/approach

This conceptual approach can be read as an invitation for corporate governance scholars to embrace the logic of paradox to expand the understanding of this topic. Paradox is not conceptualized as an alternative to dominant structural views, including board composition, but as a complementary conceptual perspective, a meta-theoretical lens to shed light on the tensions inherent to governance.

Findings

The authors propose that paradox theory offers a fresh conceptual lens to study the role of NEDs. This approach may help NEDs to turn tensions and paradoxes visible to develop a rich understanding of their work, as well as helping them navigate the complexities of organizing, a process rich in inherent paradoxicality.

Originality/value

Organizational paradox theory is a bourgeoning field of study, but the conceptual lens of paradox has still been underexplored in the study of corporate governance.
Do CEO characteristics affect earnings management?
Authors: Putra Adhitya Agri , Setiawan Doddy
Published: January 2024

Purpose

This research paper aims to examine the effect of chief executive officer (CEO) characteristics on earnings management.

Design/methodology/approach

Research samples are manufacturing firms listed in the Indonesian Stock Exchange 2015–2021. CEO characteristics include narcissism, gender, age, tenure, experience, nationality and founding family status. Data analysis uses random-effect regression.

Findings

The result shows that higher narcissism CEOs have aggressive characteristics so they will be more likely to engage in accrual and real earnings management. Female CEOs, foreign CEOs and founding-family CEOs have higher monitoring and business ethics characteristics so they will be less likely to engage in accrual and real earnings management. CEOs with higher education levels have higher thinking complexity so they will be more likely to engage in accrual earnings management with higher regulator and auditor monitoring barriers than real earnings management. CEOs with financial and accounting experience are familiar with accounting standards and auditor monitoring barriers so they will be more likely to engage in accrual earnings management than real earnings management. On the other hand, there are no effects of CEO age and tenure on earnings management.

Originality/value

This research contributes to providing evidence of the effect of CEO characteristics on earnings management in a specific industry such as manufacturing firms and emerging markets such as Indonesia with the majority group firms being family firms.
Firm financial performance in the wake of political turmoil; whether political connection is propitious?
Authors: Khan Adnan Ullah , Iqbal Athar
Published: January 2024

Purpose

This study aims to investigate the effect of political turmoil on the firm financial performance, particularly in presence of politically affiliated board of directors.

Design/methodology/approach

The study applied panel regression analyses on a data set of Pakistan’s listed companies ranged over 14 years, spanning from 2007 to 2021. Political turmoil was first gauged through three determinants, i.e. political protest, government election and constitutional reform, and thereafter, economic uncertainty index was used as a proxy for political turmoil. For the purpose of political connection, the study used political affiliation of the board of directors.

Findings

The study finds that political turmoil has deleterious effect on the return on assets and Tobin’s Q. The study further unveils that politically affiliated firms are relatively insulated from the volatility posed by the political uncertainty and exhibit significantly better financial outcomes.

Practical implications

Findings of the study suggest that appropriate composition of the board is imperative in offsetting the risk posed by the political turmoil. Hence, the results are useful for investors, policymakers and regulators to ensure financial soundness of firms in the wake of political turmoil.

Originality/value

To the best of the authors’ knowledge, this is the first study that investigates the moderating impact of political connection on the performance of companies in presence of political turmoil.
Leadership skills and the glass ceiling in event management: a social role theory approach
Authors: Mistry Trishna G. , Wiitala Jessica , Clark Brianna S.
Published: January 2024

Purpose

Although event industry employees are predominantly female, there is a critical scarcity of women in leadership roles. Like other industries worldwide, women in the events industry experience several barriers to leadership roles. The unique characteristics of the events industry exacerbate these barriers and have led to more women leaving the company or even the industry. This study aims to investigate the impact of leadership barriers, including the perception of a glass ceiling and the importance of leadership skills in promotion decisions on career satisfaction, work-family conflict and turnover intention of employees in the events industry.

Design/methodology/approach

Data was collected from members of an international event association, and 427 responses were analyzed using partial least squares structural equation modeling.

Findings

Findings suggested the perception of a glass ceiling and the importance of leadership skills in promotion can impact career satisfaction, work-family conflict and turnover intention of employees in the events industry.

Originality/value

This study extends the scope of research on leadership barriers beyond assessing their causes by analyzing their outcomes in the event industry. To the best of the authors’ knowledge, this study is one of the first in event research and the broader hospitality industry to consider the perceptions of male and female employees regarding leadership barriers by using a foundation of the social role theory.
A method for predicting relative position errors in dual-robot systems via knowledge transfer from geometric and nongeometric calibration
Authors: Cao Siming , Wang Hongfeng , Guo Yingjie , Zhu Weidong , Ke Yinglin
Published: January 2024

Purpose

In a dual-robot system, the relative position error is a superposition of errors from each mono-robot, resulting in deteriorated coordination accuracy. This study aims to enhance relative accuracy of the dual-robot system through direct compensation of relative errors. To achieve this, a novel calibration-driven transfer learning method is proposed for relative error prediction in dual-robot systems.

Design/methodology/approach

A novel local product of exponential (POE) model with minimal parameters is proposed for error modeling. And a two-step method is presented to identify both geometric and nongeometric parameters for the mono-robots. Using the identified parameters, two calibrated models are established and combined as one dual-robot model, generating error data between the nominal and calibrated models’ outputs. Subsequently, the calibration-driven transfer, involving pretraining a neural network with sufficient generated error data and fine-tuning with a small measured data set, is introduced, enabling knowledge transfer and thereby obtaining a high-precision relative error predictor.

Findings

Experimental validation is conducted, and the results demonstrate that the proposed method has reduced the maximum and average relative errors by 45.1% and 30.6% compared with the calibrated model, yielding the values of 0.594 mm and 0.255 mm, respectively.

Originality/value

First, the proposed calibration-driven transfer method innovatively adopts the calibrated model as a data generator to address the issue of real data scarcity. It achieves high-accuracy relative error prediction with only a small measured data set, significantly enhancing error compensation efficiency. Second, the proposed local POE model achieves model minimality without the need for complex redundant parameter partitioning operations, ensuring stability and robustness in parameter identification.
How does globally responsible leadership promotes pro-environmental behavior through green management initiatives?
Authors: Rafiq Muhammad , Cham Tat-Huei , Tapsir Siti Hamisah , Mansoor Adil , Farrukh Muhammad
Published: January 2024

Purpose

This study aims to examine the association between globally responsible leadership (GRL) and pro-environmental behavior (PEB), specifically probing the mediating role of green management initiatives (GMI) in this relationship.

Design/methodology/approach

This study used a quantitative research design, using survey data from 390 participants working in manufacturing sector organizations in one of the emerging economies in the Asian region, namely, Pakistan. AMOS was used to test the hypothesized relationships.

Findings

The results reveal that GRL has a significant positive link with GMI and PEB. In addition, this study found that GMI mediates the association between GRL and PEB, suggesting that GRL indirectly promotes PEB through the implementation of GMI.

Research limitations/implications

This study has several limitations, including its reliance on self-reported data, its cross-sectional design and its focus on participants from only one nation. Future research may benefit from using mixed-study designs and diverse samples from multiple industries and nations.

Practical implications

The results suggest that businesses can promote PEB among their staff by adopting GRL and implementing GMI. In doing so, businesses can demonstrate their commitment to sustainability, enhancing their credibility and competitive advantage.

Originality/value

This research contributes several new insights to the existing literature on sustainable leadership. First, it provides empirical evidence to support the hypothesis that GRL, GMI and PEB are interrelated. Second, it highlights the mediating role of GMI in this relationship.
Electric vehicle subsidy structure considering network externality under carbon neutrality constraints
Authors: Chen Feng , Xu Suxiu , Zhai Yue
Published: January 2024

Purpose

Promoting electric vehicles (EVs) is an effective way to achieve carbon neutrality. If EVs are widely adopted, this will undoubtedly be good for the environment. The purpose of this study is to analyze the impact of network externalities and subsidy on the strategies of manufacturer under a carbon neutrality constraint.

Design/methodology/approach

In this paper, the authors propose a game-theoretic framework in an EVs supply chain consisting of a government, a manufacturer and a group of consumers. The authors examine two subsidy options and explain the choice of optimal strategies for government and manufacturer.

Findings

First, the authors find that the both network externalities of charging stations and government subsidy can promote the EV market. Second, under a relaxed carbon neutrality constraint, even if the government’s purchase subsidy investment is larger than the carbon emission reduction technology subsidy investment, the purchase subsidy policy is still optimal. Third, under a strict carbon neutrality constraint, when the cost coefficient of carbon emission reduction and the effectiveness of carbon emission reduction technology are larger, social welfare will instead decrease with the increase of the effectiveness of emission reduction technology and then, the manufacturer’s investment in carbon emission reduction technology is lower. In the extended model, the authors find the effectiveness of carbon emission reduction technology can also promote the EV market and social welfare (or consumer surplus) is the same whatever the subsidy strategy.

Practical implications

The network externalities of charging stations and the subsidy effect of the government have a superimposition effect on the promotion of EVs. When the network effect of charging stations is relatively strong, government can withdraw from the subsidized market. When the network effect of charging stations is relatively weak, government can intervene appropriately.

Originality/value

Comparing previous studies, this study reveals the impact of government intervention, network effects and carbon neutrality constraints on the EV supply chain. From a sustainability perspective, these insights are compelling for both EV manufacturers and policymakers.
Segmented compensation mechanism for technological innovation of civilian enterprises’ participation in military: a perspective of dual information asymmetry
Authors: Zhang Fan , Wen Haolin
Published: January 2024

Purpose

Based on dual information asymmetry, the two-stage segmented compensation mechanism for technological innovation of civilian enterprises’ participation in military (CEPIM) has been discussed.

Design/methodology/approach

On the basis of the traditional principal-agent problems, the incentive compatibility condition is introduced as well as the hybrid incentive compensation model is established, to solve optimal solution of the compensation parameters under the dynamic contract condition and the validity is verified by numerical simulation.

Findings

The results show that: (1) The two-stage segmented compensation mechanism has the functions of “self-selection” and “stimulus to the strong”, (2) It promotes the civilian enterprises to obtain more innovation benefit compensation through the second stage, (3) There is an inverted U-shaped relationship between government compensation effectiveness and the innovation ability of compensation objects and (4) The “compensable threshold” and “optimal compensation threshold” should be set, respectively, to assess the applicability and priority of compensation.

Originality/value

In this paper, through numerical simulation, the optimal solution for two-stage segmented compensation, segmented compensation coefficient, expected returns for all parties and excess expected returns have been verified under various information asymmetry. The results show that the mechanism of two-stage segmented compensation can improve the expected returns for both civilian enterprises and the government. However, under dual information asymmetry, for innovation ability of the intended compensation candidates, a “compensation threshold” should be set to determine whether the compensation should be carried out, furthermore an “optimal compensation threshold” should be set to determine the compensation priority.