bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioarchaeological Perspectives on Late Antiquity in Dalmatia: Paleogenetic, Dietary, and Population Studies of the Hvar - Radošević burial site
Authors: Zagorc Brina , Blanz Magdalena , Gelabert Pere , Sawyer Susanna , Oberreiter Victoria , Cheronet Olivia , Chen Hao Shan , Carić Mario , Visković Eduard , Olalde Iňigo , Ivanova-Bieg Maria , Novak Mario , Reich David , Pinhasi Ron
Published: May 2024

Late Antiquity Dalmatia was a time and place of political unrest in the Roman Empire that influenced the lives of the people living in that region. The Late Antique burial site of Hvar – Radošević, spanning the 3rdto 5thcenturies, is located on the Croatian Dalmatian island of Hvar. Given the time frame and its location on a busy marine trade route, study of this burial site offers us a glimpse into the lives of the Late Antique population living on this island. It comprises 33 individuals, with 17 buried within a confined grave tomb, and the remaining individuals buried in separate locations in the tomb’s proximity. Our objective was to provide new perspectives on the lives of people on the island during those times by studying ancestry, population structure, possible differences within the buried population, dietary habits, and general health.

Analysis of the ancestral origins of the individuals buried at Hvar – Radošević revealed a diverse population reflective of the era’s genetic variability. The identification of genetic outliers suggests affiliations with distinct regions of the Roman Empire, possibly linked to trade routes associated with the Late Antique port in ancient Hvar. Stable isotope ratio analysis (δ¹³C and δ¹⁵N) indicated a diet mainly consisting of C3plants, with minimal consumption of marine foods. High childhood mortality rates, physiological stress markers, and dental diseases suggest a low quality of life in the population. Assessment of kinship and dietary patterns revealed no discernible distinctions between individuals buried within the tomb and those buried outside, indicative of an absence of differential burial practices based on social status and familial ties.
Efficient Federated Learning for distributed NeuroImaging Data
Authors: Thapaliya Bishal , Ohib Riyasat , Geenjar Eloy , Liu Jingyu , Calhoun Vince , Plis Sergey
Published: May 2024

Recent advancements in neuroimaging have led to greater data sharing among the scientific community. However, institutions frequently maintain control over their data, citing concerns related to research culture, privacy, and accountability. This creates a demand for innovative tools capable of analyzing amalgamated datasets without the need to transfer actual data between entities. To address this challenge, we propose a decentralized sparse federated learning (FL) strategy. This approach emphasizes local training of sparse models to facilitate efficient communication within such frameworks. By capitalizing on model sparsity and selectively sharing parameters between client sites during the training phase, our method significantly lowers communication overheads. This advantage becomes increasingly pronounced when dealing with larger models and accommodating the diverse resource capabilities of various sites. We demonstrate the effectiveness of our approach through the application to the Adolescent Brain Cognitive Development (ABCD) dataset.
Excitoprotective effects of conditional tau reduction in excitatory neurons and in adulthood
Authors: Voskobiynyk Yuliya , Li Zhiyong , Cochran J. Nicholas , Davis M. Natalie , Carullo Nancy V.N. , Creed Rose B. , Buckingham Susan C. , Hall Alicia M. , Wilson Scott M. , Roberson Erik D.
Published: May 2024

Tau reduction is a promising therapeutic strategy for Alzheimer’s disease. In numerous models, tau reduction via genetic knockout is beneficial, at least in part due to protection against hyperexcitability and seizures, but the underlying mechanisms are unclear. Here we describe the generation and initial study of a new conditional Taufloxmodel to address these mechanisms. Given the protective effects of tau reduction against hyperexcitability, we compared the effects of selective tau reduction in excitatory or inhibitory neurons. Tau reduction in excitatory neurons mimicked the protective effects of global tau reduction, while tau reduction in inhibitory neurons had the opposite effect and increased seizure susceptibility. Since most prior studies used knockout mice lacking tau throughout development, we crossed Taufloxmice with inducible Cre mice and found beneficial effects of tau reduction in adulthood. Our findings support the effectiveness of tau reduction in adulthood and indicate that excitatory neurons may be a key site for its excitoprotective effects.

A new conditional tau knockout model was generated to study the protective effects of tau reduction against hyperexcitability. Conditional tau reduction in excitatory, but not inhibitory, neurons was excitoprotective, and induced tau reduction in adulthood was excitoprotective without adverse effects.
A Mendelian randomization study investigating the role of sleep traits and their joint effects on the incidence of atrial fibrillation
Authors: Arora Nikhil , Brumpton Ben Michael , Åsvold Bjørn Olav , Loennechen Jan Pål , Malmo Vegard , Bhatta Laxmi , Skarpsno Eivind Schjelderup , Richmond Rebecca Claire , Strand Linn Beate
Published: May 2024

Background and Aims: Sleep disturbances can induce alterations in functional and electrical properties of the heart, thereby increasing susceptibility to atrial fibrillation (AF). We aimed to test the causal role of different sleep traits and their joint effects on the risk of AF. Methods: We used an observational cohort study design along with one-sample and factorial Mendelian randomization (MR) approaches to test for individual and joint associations of sleep traits (i.e., insomnia symptoms, sleep duration and chronotype) on the risk of AF using UK Biobank and the second survey of the Trøndelag Health Study (HUNT2). Results: Both the observational and the MR analysis showed that insomnia symptoms and genetic predisposition to insomnia symptoms increased risk of AF; however these MR findings were not consistent in HUNT2. One-sample MR analysis in UK Biobank showed that genetic predisposition to short sleep duration increased risk of AF and genetic predisposition to per additional hour of sleep decreased risk of AF; however these findings were not consistent in HUNT2 or in observational analysis. Factorial MR analysis in UK Biobank showed that participants with genetic predisposition to two sleep traits in combination (including insomnia symptoms, short sleep duration, and a morning chronotype) had higher risk of AF than those with genetic predisposition to only one sleep trait; however these findings were not consistent in HUNT2 or in observational analysis. We found no evidence of relative excess risk due to interaction (RERI) for any combinations of sleep traits. Conclusions: Our study indicates that insomnia symptoms and short sleep duration are causal risk factors for AF. However, having two sleep traits in combination did not increase risk beyond the additive risk of each individual trait. This reinforces clinical and public health efforts to effectively manage insomnia symptoms and short sleep, in order to mitigate the risk of AF and improve overall cardiovascular health.
A Generalized Signal Model for Dual-Module Velocity-Selective Arterial Spin Labeling
Authors: Liu Thomas T. , Chen Conan , Guo Jia , Wong Eric C. , Bolar Divya S.
Published: May 2024

Purpose

To develop a generalized signal model for dual-module velocity-selective arterial spin labeling (dm-VSASL) that can integrate arbitrary saturation and inversion profiles.

Theory and Methods

A recently developed mathematical framework for single-module VSASL is extended to address the increased complexity of dm-VSASL and to model the use of realistic velocity-selective profiles in the label-control and vascular crushing modules. Expressions for magnetization difference, arterial delivery functions, labeling efficiency, and cerebral blood flow (CBF) estimation error are presented. Sources of error are examined and timing requirements to minimize quantification errors are derived.

Results

For ideal velocity-selective profiles, the predicted signals match those of prior work. With realistic profiles, a CBF-dependent estimation error can occur when velocity-selective inversion (VSI) is used for the labeling modules and velocity-selective saturation (VSS) is used for the vascular crushing module. The error reflects a mismatch between the leading and trailing edges of the delivery function for the second bolus and can be minimized by choosing a nominal labeling cutoff velocity that is lower than the nominal saturation cutoff velocity. In the presence ofB0andB1inhomogeneities, the labeling efficiency of dual-module VSI is more attenuated than that of dual-module VSS.

Conclusion

The proposed signal model will enable researchers to more accurately assess and compare the performance of realistic dm-VSASL implementations and improve the quantification of dm-VSASL CBF measures.
The Role of Deep Learning in Diagnostic Imaging of Spondyloarthropathies: A Systematic Review
Authors: Omar Mahmud , Watad Abdulla , McGonagle Dennis , Soffer Shelly , Glicksberg Benjamin S , Nadkarni Girish N , Klang Eyal
Published: May 2024

Aim

Diagnostic imaging is an integral part of identifying spondyloarthropathies (SpA), yet the interpretation of these images can be challenging. This review evaluated the use of deep learning models to enhance the diagnostic accuracy of SpA imaging.

Methods

Following PRISMA guidelines, we systematically searched major databases up to February 2024, focusing on studies that applied deep learning to SpA imaging. Performance metrics, model types, and diagnostic tasks were extracted and analyzed. Study quality was assessed using QUADAS-2.

Results

We included 22 studies demonstrating that deep learning aids in diagnosing and classifying SpA, differentiating arthritis forms, and estimating disease progression and structural changes. These models, particularly those using advanced U-Net architectures, consistently outperformed traditional diagnostic methods, showing a notable increase in diagnostic accuracy.

Conclusion

Deep learning models are excellent for augmenting the accuracy of SpA imaging diagnostics. Despite their potential, challenges in overcoming retrospective study biases and integrating these models into clinical practice remain. Future directions should aim to validate these models in real-world clinical settings.
Unmasking the determinants of knowledge, attitude and practice of Personal Protective Equipment use among Nepalese farmers using pesticides
Authors: Piya Reecha , G.C Krishna , Rajbhandari Ajay K. , Kakchapati Sampurna
Published: May 2024

Background

Farmer using commercially available chemical pesticides are at high risk to develop various pesticide-related-illnesses. To mitigate the adverse effect of pesticides, it is crucial for famers to wear Personal Protective Equipment (PPE). This study aimed to assess the factors influencing knowledge, attitude, and practice (KAP) of PPE use among farmers using pesticides in mid-hills of Nepal.

Methods

We conducted a cross-sectional study among 256 farmers in Kirtipur Municipality. We collected data using structured questionnaire via telephone. Bi-variate and multivariate logistic regression was done to identify the association between individual, household and farming related characteristic with knowledge, attitude, and practice of PPE use.

Results

The study found that the knowledge, attitude, and practice of PPE use was 53.75%, 55.11%, and 47.16%, respectively. The farmers with primary level schooling (AOR= 2.63; 95% CI 1.00-6.88) and secondary level schooling or higher (AOR= 4.19; 95% CI 1.64-0.68) had higher odds of having knowledge on PPE use rather than the farmers with no formal schooling. Farmers of upper lower socioeconomic status had higher odds (AOR=6.40; 95% CI 1.68-24.45) of having positive attitude towards PPE use compared to farmers of upper middle and upper socio-economic status. On the contrary, farmers with good knowledge (AOR=0.20; CI 0.09-0.48) and experience of pesticide-related-illness (AOR=0.29; 95% CI 0.13-0.65) had lower odds of having positive attitude towards PPE use. Married farmers (AOR=10.63; 95% CI 1.11-101.95), farmers using pesticides for more than 10 years (AOR=5.22; 95% CI 1.27-21.43), and farmers using pesticides for 10 hours or more in their lifetime (AOR=4.86; 95% CI 1.63-14.50) had higher odds of wearing basic set of PPE while handling pesticides. However, farmers who were involved in farming for more than 10 years (AOR=0.26; 95% CI 0.07-1.03), farmers who were using pesticide applying methods other than knapsack sprayer (AOR=0.03; 95% CI 0.00-0.34), and farmers having positive attitude towards PPE use (AOR=0.28; 95% CI 0.11-0.70) had lower odds of wearing basic set of PPE while handling pesticides.

Conclusion

Farmers in Nepal have a positive outlook on PPE use but multitude of factors including knowledge, farming related factors and socio-economic condition have acted as barrier to its use. Tailored educational programs that not only encompasses knowledge dissemination but also cultivation of positive safety attitudes towards PPE can help increase PPE use.
Physician burnout in the context of the COVID-19 pandemic: prevalence and associated factors among resident doctors and consultants in Delta State, Nigeria
Authors: Moeteke Nnamdi Stephen , Erhirhie Ezinneamaka
Published: May 2024

Background

Residents Doctors (RDs) and consultants carry out the most specialised medical care. The strain of their job predisposes them to the three domains of burnout: Emotional Exhaustion (EE), Depersonalisation (DP), and diminished Personal Accomplishment (PA). Globally, this public health crisis has worsened with the overwhelming effect of COVID-19 on health systems.

Aim

This study assessed the prevalence and associated factors of burnout among RDs and Consultants in tertiary hospitals in Delta State, Nigeria during the pandemic.

Methods

A cross-sectional design was employed. Previously validated instruments were used to collect data via an online survey. The questionnaire was sent to physicians selected by multistage sampling. The proportion of participants with a high grade in each of the domains of burnout was obtained. Stepwise analyses from bivariate to multivariate were done to obtain adjusted odds ratios.

Results

The prevalence of high-grade burnout in EE, DP, and PA was 35.1%, 13.2%, and 33.3% respectively. Relative to those ≤ 30 years, the age group 41 – 50 years had less likelihood of high EE (AOR 0.050; 95% CI 0.004 – 0.651). Other independent predictors of high EE were manageable workload (AOR 0.094; 95% CI 0.027 – 0.328), reward for work (AOR 0.427; 95% CI 0.205 – 0.892), and good leadership (AOR 0.525; 95% CI 0.113 – 0.929).

Conclusion and Contribution

This study suggests that the determinants of burnout among RDs and consultants are mainly contextual factors in the work setting. Promoting an institutional culture of leadership, a manageable workload, and appropriate rewards could help control physician burnout.
Functional Magnetic Resonance Spectroscopy of Prolonged Motor Activation using Conventional and Spectral GLM Analyses
Authors: Morelli Maria , Dudzikowska Katarzyna , Deelchand Dinesh K. , Quinn Andrew J. , Mullins Paul G. , Apps Matthew A. J. , Wilson Martin
Published: May 2024

Background

Functional MRS (fMRS) is a technique used to measure metabolic changes in response to increased neuronal activity, providing unique insights into neurotransmitter dynamics and neuroenergetics. In this study we investigate the response of lactate and glutamate levels in the motor cortex during a sustained motor task using conventional spectral fitting and explore the use of a novel analysis approach based on the application of linear modelling directly to the spectro-temporal fMRS data.

Methods

fMRS data were acquired at a field strength of 3 Tesla from 23 healthy participants using a short echo-time (28ms) semi-LASER sequence. The functional task involved rhythmic hand clenching over a duration of 8 minutes and standard MRS preprocessing steps, including frequency and phase alignment, were employed. Both conventional spectral fitting and direct linear modelling were applied, and results from participant-averaged spectra and metabolite-averaged individual analyses were compared.

Results

We observed a 20% increase in lactate in response to the motor task, consistent with findings at higher magnetic field strengths. However, statistical testing showed some variability between the two averaging schemes and fitting algorithms. While lactate changes were supported by the direct spectral modelling approach, smaller increases in glutamate (2%) were inconsistent. Exploratory spectral modelling identified a 4% decrease in aspartate, aligning with conventional fitting and observations from prolonged visual stimulation.

Conclusion

We demonstrate that lactate dynamics in response to a prolonged motor task are observed using short-echo time semi-LASER at 3 Tesla, and that direct linear modelling of fMRS data is a useful complement to conventional analysis. Future work includes mitigating spectral confounds, such as scalp lipid contamination and lineshape drift, and further validation of our novel direct linear modelling approach through experimental and simulated datasets.
Phylogenomics of neglected flagellated protists supports a revised eukaryotic tree of life
Authors: Torruella Guifré , Galindo Luis Javier , Moreira David , López-García Purificación
Published: May 2024

Eukaryotes evolved from prokaryotic predecessors in the early Proterozoic1,2and radiated from their already complex last common ancestor3, diversifying into several supergroups with unresolved deep evolutionary connections4. They evolved extremely diverse lifestyles, playing crucial roles in the carbon cycle5,6. Heterotrophic flagellates are arguably the most diverse eukaryotes4,7-9and often occupy basal positions in phylogenetic trees. However, many of them remain undersampled4,10and/orincertae sedis4,11-18. Progressive improvement of phylogenomic methods and a wider protist sampling have reshaped and consolidated major clades in the eukaryotic tree13-19. This is illustrated by the Opimoda14, one of the largest eukaryotic supergroups (Amoebozoa, Ancyromonadida, Apusomonadida, Breviatea, CRuMs, Malawimonadida, and Opisthokonta –including animals and fungi–)4,14,19-22. However, their deepest evolutionary relationships still remain uncertain. Here, we sequenced transcriptomes of poorly studied flagellates23,24(fourteen apusomonads25,26, seven ancyromonads27and one cultured Mediterranean strain ofMeteora sporadica17) and conducted comprehensive phylogenomics analyses with an expanded taxon sampling of early-branching protists. Our findings support the monophyly of Opimoda, with CRuMs being sister to the Amorphea (amoebozoans, breviates, apusomonads, and opisthokonts), and ancyromonads and malawimonads forming a moderately supported clade. By mapping key complex phenotypic traits onto this phylogenetic framework, we infer an opimodan biflagellate ancestor with an excavate-like feeding groove, which ancyromonads subsequently lost. While breviates and apusomonads retained the ancestral biflagellate state, some early-diverging Amorphea lost one or both flagella, facilitating the evolution of amoeboid morphologies, novel feeding modes, and palintomic cell division resulting in multinucleated cells. These innovations likely facilitated the subsequent evolution of fungal and metazoan multicellularity.
Decoding glycosylation potential from protein structure across human glycoproteins with a multi-view recurrent neural network
Authors: Kellman Benjamin P. , Mariethoz Julien , Zhang Yujie , Shaul Sigal , Alteri Mia , Sandoval Daniel , Jeffris Mia , Armingol Erick , Bao Bokan , Lisacek Frederique , Bojar Daniel , Lewis Nathan E.
Published: May 2024

Glycosylation is described as a non-templated biosynthesis. Yet, the template-free premise is antithetical to the observation that different N-glycans are consistently placed at specific sites. It has been proposed that glycosite-proximal protein structures could constrain glycosylation and explain the observed microheterogeneity. Using site-specific glycosylation data, we trained a hybrid neural network to parse glycosites (recurrent neural network) and match them to feasible N-glycosylation events (graph neural network). From glycosite-flanking sequences, the algorithm predicts most human N-glycosylation events documented in the GlyConnect database and proposed structures corresponding to observed monosaccharide composition of the glycans at these sites. The algorithm also recapitulated glycosylation in Enhanced Aromatic Sequons, SARS-CoV-2 spike, and IgG3 variants, thus demonstrating the ability of the algorithm to predict both glycan structure and abundance. Thus, protein structure constrains glycosylation, and the neural network enables predictivein silicoglycosylation of uncharacterized or novel protein sequences and genetic variants.
Efficient Genetic Code Expansion Without Host Genome Modifications
Authors: Costello Alan , Peterson Alexander A. , Lanster David L. , Li Zhiyi , Carver Gavriela D. , Badran Ahmed H.
Published: May 2024

Supplementing translation with non-canonical amino acids (ncAAs) can yield protein sequences with new-to-nature functions, but existing ncAA incorporation strategies suffer from low efficiency and context dependence. We uncover codon usage as a previously unrecognized contributor to efficient genetic code expansion using non-native codons. Relying only on conventionalE. colistrains with native ribosomes, we develop a novel plasmid-based codon compression strategy that minimizes context dependence and improves ncAA incorporation at quadruplet codons. We confirm that this strategy is compatible with all known genetic code expansion resources, which allows us to identify 12 mutually orthogonal tRNA–synthetase pairs. Enabled by these findings, we evolve and optimize five tRNA–synthetase pairs to incorporate a broad repertoire of ncAAs at orthogonal quadruplet codons. Finally, we extend these resources to anin vivobiosynthesis platform that can readily create >100 new-to-nature peptide macrocycles bearing up to three unique ncAAs. Given the generality of our approach and streamlined resources, our findings will accelerate innovations in multiplexed genetic code expansion and enable the discovery of chemically diverse biomolecules for researcher-defined applications.
Cortico-amygdala synaptic structural abnormalities produced by templated aggregation of α-synuclein
Authors: Gcwensa Nolwazi Z. , Russell Dreson L. , Long Khaliah Y. , Brzozowski Charlotte F. , Liu Xinran , Gamble Karen L. , Cowell Rita M. , Volpicelli-Daley Laura A.
Published: May 2024

Parkinson’s disease (PD) and Dementia with Lewy bodies (DLB) are characterized by neuronal α-synuclein (α-syn) inclusions termed Lewy Pathology, which are abundant in the amygdala. The basolateral amygdala (BLA), in particular, receives projections from the thalamus and cortex. These projections play a role in cognition and emotional processing, behaviors which are impaired in α-synucleinopathies. To understand if and how pathologic α-syn impacts the BLA requires animal models of α-syn aggregation. Injection of α-synuclein pre-formed fibrils (PFFs) into the striatum induces robust α-synuclein aggregation in excitatory neurons in the BLA that corresponds with reduced contextual fear conditioning. At early time points after aggregate formation, cortico-amygdala excitatory transmission is abolished. The goal of this project was to determine if α-syn inclusions in the BLA induce synaptic degeneration and/or morphological changes. In this study, we used C57BL/6J mice injected bilaterally with PFFs in the dorsal striatum to induce α-syn aggregate formation in the BLA. A method was developed using immunofluorescence and three-dimensional reconstruction to analyze excitatory cortico-amygdala and thalamo-amygdala presynaptic terminals closely juxtaposed to postsynaptic densities. The abundance and morphology of synapses were analyzed at 6- or 12-weeks post-injection of PFFs. α-Syn aggregate formation in the BLA did not cause a significant loss of synapses, but cortico-amygdala and thalamo-amygdala presynaptic terminals and postsynaptic densities with aggregates of α-synuclein show increased volumes, similar to previous findings in human DLB cortex, and in non-human primate models of PD. Transmission electron microscopy showed that PFF-injected mice showed reduced intervesicular distances similar to a recent study showing phospho-serine-129 α-synuclein increases synaptic vesicle clustering. Thus, pathologic α-synuclein causes major alterations to synaptic architecture in the BLA, potentially contributing to behavioral impairment and amygdala dysfunction observed in synucleinopathies.
Clostridium ablates tumors by degrading collagen mesh and inducing ferroptosis
Authors: Yang Fengmin , Meng Lu , Chen Huan , Wang Xinyue , Zhang Mengmeng , Cao Zhenping , Pang Yan , Liu Jinyao
Published: May 2024

The supportive role of extracellular matrix in tumor growth and the drug resistance of tumor cells stand the major challenges in treating cancer. Here, we report the discovery of an oncolytic Clostridium strain, named RJ-1, which simultaneously expresses collagenases and produces iron-containing particles through intrabacterial mineralization. The secreted collagenases degrade pre-existing collagen mesh and show a collagen concentration-dependent degradation feature. Iron-containing particles released from RJ-1 by autolysis generate ferrous ions in the lysosomal acid environment following cell uptake and subsequently induce ferroptosis via the Fenton reaction. Due to selective germination in tumor sites, systemic administration of RJ-1 spores synchronously destructs dense tumor extracellular matrix and causes non-apoptotic tumor cell death. In collagen-dense tumor-bearing mice, a single intravenous injection achieves a favorable tolerance and rapid oncolysis of giant tumors with a size of ∼1000 mm3. This work finds a dual collagenase-expressing and iron-concentrating bacterium, proposing an alternative strategy to combat tumors.
A positive feedback loop between germ cells and gonads induces and maintains cnidarian sexual reproduction
Authors: Curantz Camille , Doody Ciara , Horkan Helen R , Krasovec Gabriel , Weavers Paris K , DuBuc Timothy Q , Frank Uri
Published: May 2024

The fertile gonad includes cells of two distinct developmental origins: the somatic mesoderm and the germline. How somatic and germ cells interact to develop and maintain fertility is not well understood. Here, using grafting experiments and transgenic reporter animals, we find that a specific part of the gonad–the germinal zone–acts as a sexual organizer to induce and maintainde novogerm cells and somatic gonads in non-sexual tissue in the cnidarianHydractinia symbiolongicarpus. We further show that germ cells express a novel member of the TGF-β family (Gonadless,Gls) that induces somatic gonad morphogenesis. Loss ofGlsresulted in animals lacking somatic gonadal structures but having few, non-proliferative germ cells. We propose a model according to which a small number of primary germ cells drive gonad development though Gls morphogen secretion. The germinal zone in the newly formed gonad, in turn, provides positive feedback to induce secondary germ cells by activatingTfap2(the master regulator of germ cell fate) in resident pluripotent stem cells.De novoinduction of germ cells by gonads in adult life is absent in bilaterians with a sequestered germline. However, the contribution of germ cell signaling to the patterning of somatic gonadal tissue, as observed inHydractinia, may be a general animal feature.
Kekulé spirals and charge transfer cascades in twisted symmetric trilayer graphene
Authors: Wang Ziwei , Kwan Yves H. , Wagner Glenn , Bultinck Nick , Simon Steven H. , Parameswaran S. A.
Published: May 2024

We study the phase diagram of magic-angle twisted symmetric trilayer graphene in the presence of uniaxial heterostrain and interlayer displacement field. For experimentally reasonable strain, our mean-field analysis finds robust Kekulé spiral order whose doping-dependent ordering vector is incommensurate with the moiré superlattice, consistent with recent scanning tunneling microscopy experiments, and paralleling the behavior of closely related twisted bilayer graphene (TBG) systems. Strikingly, we identify a possibility absent in TBG: the existence of Kekulé spiral order even at zero strain for experimentally realistic values of the interlayer potential in a trilayer. Our studies also reveal a complex pattern of charge transfer between weakly and strongly dispersive bands in strained trilayer samples as the density is tuned by electrostatic gating, that can be understood intuitively in terms of the “cascades” in the compressibility of magic-angle TBG.

Published by the American Physical Society
2024
Mathematical modelling for compliance-assisted artificial muscle based ornithopter
Authors: S. Syam Narayanan , Pachamuthu Rajalakshmi , Biju Alex T. , Madupu Srilekha
Published: May 2024

Purpose

This study aims to discuss the mathematical modelling of a compliance-assisted flapping mechanism and morphable structures for an UAV.

Design/methodology/approach

A compliance-assisted flapping wing was designed and modelled mathematically, and signals for the corresponding curves were calculated. The actual wing tip trace of a hummingbird was taken, and variables a, b, h and k were calculated from the image. This data was given to the mathematical model for plotting the graph, and the curve was compared with the input curve. The wing frame and mechanism for control surfaces using morphing is modelled along with single pivoted spine for centre of gravity augmentation and flight orientation control.

Findings

The model efficiently approximates the 2D path of the wing using line segments using the muscle and compliance mechanism.

Practical implications

Using a compliance-assisted flapping mechanism offers practical advantages. It allows us to synchronize the flapping frequency with the input signal frequency, ensuring efficient operation. Additionally, the authors can enhance the torque output by using multiple muscle strands, resulting in a substantial increase in the system’s torque-to-weight ratio. This approach proves to be more favourable when compared to conventional methods involving motors or servos, ultimately offering a more efficient and robust solution for practical application.

Social implications

This model focuses on creating a flexible and tunable mechanism that can at least trace four types of wing traces from the same design, for shifting from one mode of flight to another.

Originality/value

Conventional ornithopter flapping mechanisms are gear or servo driven and cannot trace a wing tip, but some can trace complicated curves, but only one at a time. This model can trace multiple curves using the same hardware, allowing the user to program the curve based on their needs or bird. The authors may vary the shape of the wing tip trace to switch between forward flight, hovering, backward flying, etc., which is not conceivable with any traditional flapping mechanism.
Banking sector and economic growth in the digital transformation era: insights from maximum likelihood and Bayesian structural equation modeling
Authors: Murrar Abdullah , Asfour Bara , Paz Veronica
Published: May 2024

Purpose

In the digital era, the banking sector has transformed into a powerful intermediary, effectively connecting surplus and deficit units. This dynamic landscape empowers savers to secure their finances and generate returns, while simultaneously enabling businesses and individuals to access capital for investment and promoting economic growth. This study explores the relationships among banking development dimensions – represented by primary assets and liabilities, bank capital (core capital and required reserves) and economic growth as measured by components of gross domestic product (GDP).

Design/methodology/approach

The study consolidated monthly balance sheets from digital banks over a 20-year period, resulting in an aggregate monthly balance sheet that reflects the financial position of all digital banks in the Palestinian economy. The research employs both maximum likelihood and Bayesian structural equation modeling to measure the causal pathways of the consolidated balance sheet with the individual components of GDP.

Findings

The results revealed that bank main assets (investments and loans) and liabilities (deposits) collectively explain for 97% of bank capital. Investments and loans demonstrate significant negative correlations with bank capital, while deposits exhibit a positive impact. This leads to a fundamental conclusion that a substantial proportion of retained earnings within the banking sector is reinvested, fueling expansion and growth. Additionally, the results showed a significant relationship between bank capital and various GDP components, including private consumption, gross investment and net exports (p = 0.000). However, while the relationship between bank capital and government spending was insignificant in the maximum likelihood estimation, Bayesian estimation revealed a slight yet positive impact of bank capital on government spending.

Originality/value

This research stands out due to its unique exploration of the intricate relationship between bank sector development dimensions, primary assets and liabilities and their impact on bank capital in the digital era. It offers fresh insights by dividing this connection into specific dimensions and constructs, utilizing a comprehensive two-decade dataset covering the digital banks records.
Challenges in construction material supply for post-disaster transport infrastructure recovery: a case study of the 2016 Kaikōura earthquake in New Zealand
Authors: Liu Kenan , Chang-Richards Alice , Costello Seosamh B. , L'Hermitte Cecile , Trent Nadia M. , Li Nan
Published: May 2024

Purpose

This paper aims to investigate the challenges faced by the transport infrastructure sector in its civil construction material supply processes, following the 2016 Kaikoura earthquake in New Zealand.

Design/methodology/approach

A case study approach was adopted, which included on-site observations, semi-structured interviews and literature-based desktop reviews.

Findings

The research findings show that there were supply problems for aggregates, concrete, stormwater pipes and some specialised products for the repair and rebuild of transport facilities. Those supply problems were largely caused by (1) difficulty in predicting material requirements, (2) constrained supply capability, (3) inadequate local freight capacity, (4) legal, cultural and/or environmental considerations on resource exploitation and utilisation, (5) impacts of COVID-19 and (6) ineffective communication and coordination.

Research limitations/implications

For future research, it is recommended that a comparative analysis of multiple disaster cases be undertaken to further explore the generalisability of the research findings.

Originality/value

The research findings will inform the development of post-earthquake recovery policies and material supply chain operation strategies, in order to expedite the recovery of transport networks if a future earthquake strikes.
The role of value co-creation on retailer loyalty and omni-channel shopping frequency
Authors: Kesenduran Nur , Yumurtacı Hüseyinoğlu Işık Özge , Erboz Gizem
Published: May 2024

Purpose

Drawing upon the social network theory (SNT), the aim of this study is to examine the impact of value co-creation (VCC) on retailer loyalty (RL) and omni-channel shopping frequency (OCF) from the consumer perspective.

Design/methodology/approach

Grounded on SNT, the research focuses on VCC in omni-channel retailing. A paper-based questionnaire was used to examine the role of VCC on OCF and RL, and hypotheses were tested using structural equation modeling (SEM).

Findings

The findings supported the impact of VCC on RL, and in turn, the impact of RL on OCF. However, the results of the analysis reveal that RL has no mediator role between VCC and OCF.

Practical implications

The study shows the increasing role of VCC on RL, and the important role of RL on OCF. The findings reveal that RL has a significant role for VCC and OCF separately but does not have a mediator role between VCC and OCF. Moreover, the study extends the knowledge on VCC in omni-channel retailing.

Originality/value

The new research model, which was hypothesized from SNT, was validated. In the omni-channel retailing context, the study revealed the consumer perspective on VCC, and also the linkages between VCC, RL and OCF.
Is cryptocurrency a new digital gold? Evidence from the macroeconomic shocks in selected emerging economies
Authors: Majumder Sayantan Bandhu
Published: May 2024

Purpose

The purpose of the study is to analyze the hedging abilities of the cryptocurrencies vis-à-vis gold against macroeconomic shocks in four emerging economies, India, China, Brazil and Russia.

Design/methodology/approach

Using the monthly data from January 2013 to April 2023, the paper analyses the response of Cryptocurrencies vis-à-vis gold prices to three different macroeconomic shocks, namely, the economic policy uncertainty shock, the financial uncertainty shock and the inflation shock, within a VAR framework with the help of the Generalized Impulse Response Function.

Findings

Both gold and cryptocurrencies have limited hedging abilities against macroeconomic shocks across countries. In India, bitcoin has become the new digital gold, while in China, it is not bitcoin but rather gold that retains its hedging abilities. Neither bitcoin nor gold, Binance Coin or Cardano, are found to be the new digital gold in Brazil and Russia.

Originality/value

The paper compares the top nine cryptocurrencies with the traditional asset gold in terms of their hedging potential against macroeconomic shocks in emerging countries.
Investors’ demand in Initial Public Offering (IPO): Shariah compliance, corporate governance and macroeconomic factors
Authors: Al Masud Abdullah , Uluyol Burhan
Published: May 2024

Purpose

Initial Public Offering (IPO) is a major milestone for a company. It allows a private company to issue shares to a much broader group of investors and become public. But conclusive evidence of the driving forces behind investors’ demand is yet to be identified. Therefore, the major purpose of this study is to assess the level of investors’ demand in IPO and how investors’ demand in IPOs is affected.

Design/methodology/approach

The study will employ 80 IPO companies of a Muslim-majority country, Bangladesh, starting from 2013 to 2021 with application of linear and quantile regressions. Apart from that, t-test will be used to compare means of groups of Shariah-compliant and non-Shariah-compliant firms and IPOs under fixed-price and book-building mechanism.

Findings

Oversubscription is higher for IPOs issued through fixed-price method compared to book-building method, but no significant difference is found in oversubscription for Shariah firms compared to non-Shariah firms based on t-tests. The authors found IPO size, firm size, IPO risk, proportion of shares offered to public, and bank interest rate to have significant impact on the IPO demand. Some models found non-Shariah compliance status of IPO companies to be a significant factor for the investors to demand IPO. Quantile regression results found board independence to have a positive association with larger, less-subscribed firms and board size to have a negative relation with IPO demand, for smaller firms with high demand.

Research limitations/implications

Future studies may apply the findings to other settings, especially into the reasons behind preference for non-Shariah-compliant firms and higher demand for IPOs during higher interest rate. Equity issuing firms and issue managers can benefit from this study by wisely deciding on the proportion of shares for public, issue size and board of director composition. Shariah considerations cannot be ignored given that more information on Shariah compliance is disseminated among investors despite current non-preference for Shariah-compliant IPOs. On the other hand, institutional investors and general investors should consider firm-specific, governance and macroeconomic factors in IPO investment. Likewise, regulators would do well to bring in quality IPOs with characteristics mentioned in this study for ensuring stability of the market.

Originality/value

The main contribution of the study is identifying determinants of IPO demand: faith, governance, macro issues – understanding whether one or many of the above factors drive investor demand in IPOs of a Muslim-majority country will be the main contribution.
How supervisor perceived overqualification influences exploitative leadership: the mediating role of job anxiety and the moderating role of psychological entitlement
Authors: Guo Linyi , Du Jing , Zhang Juncheng
Published: May 2024

Purpose

Drawing on appraisal theory of emotion, this study aims to establish and test a moderated mediation model underlying the process of exploitative leadership by investigating the mediating role of job anxiety and the moderating role of psychological entitlement.

Design/methodology/approach

We collected two-wave questionnaire data from 355 supervisors with matched responses from 1,065 subordinates in Hubei province of China. Hierarchical multiple regression and PROCESS macro were applied to test our hypotheses.

Findings

The results indicated that supervisor perceived overqualification prompted supervisor job anxiety, which then led to raised exploitative leadership. Additionally, we found that supervisor psychological entitlement intensified the direct effect of supervisor perceived overqualification on supervisor job anxiety as well as the indirect effect of supervisor perceived overqualification on exploitative leadership through supervisor job anxiety.

Originality/value

Although researchers have documented a growing number of consequences of exploitative leadership, less focus has been placed on its antecedents. The study extends our understanding of why, how and when supervisors engage in exploitative behaviors.
Remote yet connected: two focus areas for elevating organisational belonging in virtual teams
Authors: Turnbull Helen
Published: May 2024

Purpose

This viewpoint paper aims to provide recommendations in two key leadership areas to improve belonging and connectedness in remote teams.

Design/methodology/approach

This paper synthesises recent academic and contextual literature regarding virtual teams, organisational belonging and generations coupled with the authors’ practical experience as a leader within a multi-national organisation.

Findings

Two focus areas related to leaders as critical actors in organisations and the improvement of leaders’ social skills to drive improved socialisation, connection and belonging in the workplace.

Originality/value

In the changing working landscape of continued remote working, wider workforce demographics and declining organisational engagement this paper contributes to literature by presenting two key areas coupled with practical recommendations for HR professionals, leaders, and organisations to focus on to improve belonging.
Berry anthocyanins prevent α‐dicarbonyls and advanced glycation end product formation in phosphate‐buffered saline‐based model systems, cookie and ground pork
Authors: Hsiao Yu‐Wen , Hsia Shih‐Min , Pan Min‐Hsiung , Ho Chi‐Tang , Hung Wei‐Lun
Published: May 2024

α‐Dicarbonyls and advanced glycation end products (AGEs) are the heat‐induced potential toxicants commonly found in thermally processed foods due to the Maillard reaction. Research has shown that both α‐dicarbonyls and AGEs can cause oxidative stress and inflammation and have a positive link with several chronic diseases, such as diabetes. This study found that commonly consumed berry fruits exhibited excellent methylglyoxal (MGO)‐trapping and antiglycative activities, positively associated with their total phenolic and flavonoid contents. Blackcurrant exhibited the strongest MGO‐trapping and antiglycative activities among the tested berry fruits. In addition, we demonstrated that fortification with blackcurrant significantly reduced α‐dicarbonyls and AGEs formation in the chocolate cookies and marinated ground pork. Delphinidin and cyanidin glycosides were identified as the primary bioactive compounds of blackcurrant that trapped MGO to form the corresponding mono‐ and di‐MGO adducts. This study suggested that blackcurrant anthocyanins might serve as a novel additive to reduce the consumption of dietary reactive carbonyl species and AGEs from both animal‐ and plant‐derived processed foods.

Practical Application

The levels of α‐dicarbonyls and advanced glycation end products in ground pork and cookies were significantly reduced when fortified with blackcurrant. The blackcurrant anthocyanins might be a novel agent inhibiting α‐dicarbonyls and dietary advanced glycation end products formation in thermally processed foods.
Glucagon‐like‐peptide‐1 receptor agonists versus dipeptidyl peptidase‐4 inhibitors and cardiovascular outcomes in diabetes in relation to achieved glycemic control. A Danish nationwide study
Authors: Zareini Bochra , Sørensen Katrine Kold , Pedersen‐Bjergaard Ulrik , Loldrup Fosbøl Emil , Køber Lars , Torp‐Pedersen Christian
Published: May 2024

Aim

To compare the cardiovascular preventive effect associated with glucagon‐like‐peptide‐1 receptor agonists (GLP‐1 RA) versus dipeptidyl peptidase‐4 inhibitors (DPP‐4i) according to the achieved target level of glycated hemoglobin (HbA1c).

Methods

We used retrospective Danish registries to include type 2 diabetes patients already in metformin treatment initiating GLP‐1 RA or DPP‐4i between 2007 and 2021. Patients were included 6 months after GLP‐1 RA or DPP‐4i initiation. The last available HbA1c measurement before inclusion was collected. The achieved HbA1c level was categorized according to a target level below or above 53 mmol/mol (7%). The primary outcome was a composite of nonfatal myocardial infarction, nonfatal stroke, and all‐cause death. We used a multivariable Cox proportional hazard model to estimate the effect of HbA1c levels on the outcome among GLP‐1 RA users compared to DPP‐4i users.

Results

The study included 13 634 GLP‐1 RA users (median age 56.9, interquartile range [IQR]: 48.5–65.5; 53% males) and 39 839 DPP‐4i users (median age 63.4, IQR: 54.6–71.8; 61% males). The number of GLP‐1 RA and DPP‐4i users according to achieved HbA1c levels were as follows: HbA1c ≤ 53 mmol/mol (≤7.0%): 3026 (22%) versus 4824 (12%); HbA1c > 53 mmol/mol (>7.0%): 6577 (48%) versus 17 508 (44%); missing HbA1c: 4031 (30%) versus 17 507 (44%). During a median follow‐up of 5 years (IQR: 2.6–5.0), 954 GLP‐1 RA users experienced the primary outcome compared to 7093 DPP‐4i users. The 5‐year risk (95% confidence interval [CI]) of the outcome associated with GLP1‐RA versus DPP‐4i according to HbA1c categories was as follows: HbA1c ≤ 53 mmol/mol: 10.3% (8.2–12.3) versus 24.3% (22.7–25.8); HbA1c > 53 mmol/mol: 16.0% (14.3–17.6) versus 21.1% (20.3–21.9); missing HbA1c: 17.1% (15.7–18.5) versus 25.6% (24.9–26.3). The preventive effect associated with GLP‐1 RA versus DPP‐4i was significantly enhanced when achieving lower HbA1c levels: HbA1c ≤ 53 mmol/mol: 0.65 (0.52–0.80); HbA1c > 53 mmol/mol: 0.92 (0.83–1.03); missing HbA1c: 0.92 (0.84–1.02) (p value for interaction <.001).

Conclusion

GLP‐1 RA use was associated with a lower rate of major adverse cardiovascular outcomes. The association was stronger in patients achieving the target glycemic level and weaker in patients not achieving the target glycemic level, suggestive of an interaction between achieved HbA1c level and GLP‐1 RA.

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