bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypothesis-driven modeling of the human lung-ventilator system: A characterization tool for Acute Respiratory Distress Syndrome research
Authors: Stroh J.N. , Smith Bradford J. , Sottile Peter D. , Hripcsak George , Albers David J.
Published: November 2022

Mechanical ventilation is an essential tool in the management of Acute Respiratory Distress Syndrome (ARDS), but it exposes patients to the risk of ventilator-induced lung injury (VILI). The human lung-ventilator system (LVS) involves the interaction of complex anatomy with a mechanical apparatus, which limits the achievable flexibility and fidelity needed to provide individualized clinical support by modeling lung processes. This work proposes a hypothesis-driven strategy for LVS modeling, in which robust personalization is achieved using a pre-defined parameter basis in a non-physiological model. Model inversion, here via windowed data assimilation, forges observed waveforms into interpretable parameter values that characterize the data rather than quantifying physiological processes. Inference experiments performed on human pressure waveform data indicate the flexible model accurately estimates parameters for a variety of breath types, including breaths of markedly dyssynchronous LVSs. Parameter estimates generate static characterizations of the data that are 50–70% more accurate than breath-wise single-compartment model estimates. They also retain sufficient information to distinguish between the types of breath they represent. However, the fidelity and interpetability of model characterizations are tied to parameter definitions and model resolution. These additional factors must be considered in conjunction with the objectives of specific applications, such as identifying and tracking the development of human VILI.
Effect of Nrf2 Loss on Senescence and Cognition of Tau-Based P301S Mice
Authors: Riordan R. , Rong W. , Yu Z. , Ross G. , Valerio J. , Dimas-Muñoz J. , Heredia V. , Magnusson K. , Galvan V. , Perez V.I.
Published: November 2022

Cellular senescence may contribute to chronic inflammation involved in the progression of age-related diseases such as Alzheimer’s Disease (AD), and its removal prevents cognitive impairment in a model of tauopathy. Nrf2, the major transcription factor for damage response pathways and regulators of inflammation, declines with age. Our previous work showed that silencing Nrf2 gives rise to premature senescence in cells and mice. Others have shown that Nrf2 ablation can exacerbate cognitive phenotypes of some AD models. In this study we aimed to understand the relationship between Nrf2 elimination, senescence, and cognitive impairment in AD, by generating a mouse model expressing a mutant human tau transgene in an Nrf2 knockout (Nrf2KO) background. We assessed senescent cell burden and cognitive decline of P301S mice in the presence and absence of Nrf2. Lastly, we administered 4.5 month-long treatments with two senotherapeutic drugs to analyze their potential to prevent senescent cell burden and cognitive decline: the senolytic drugs Dasatinib and Quercetin (DQ) and the senomorphic drug rapamycin. Nrf2 loss accelerated the onset of hind-limb paralysis in P301S mice. At 8.5 months of age, P301S mice did not exhibit memory deficits, while P301S mice without Nrf2 were significantly impaired. However, markers of senescence were not elevated by Nrf2 ablation in any of tissues that we examined. Neither drug treatment improved cognitive performance, nor did it reduce expression of senescence markers in brains of P301S mice. Contrarily, rapamycin treatment at the doses used delayed spatial learning and led to a modest decrease in spatial memory. Taken together, our data suggests that the emergence of senescence may be causally associated with onset of cognitive decline in the P301S model, indicate that Nrf2 protects brain function in a model of AD through mechanisms that may include, but do not require the inhibition of senescence, and suggest possible limitations for DQ and rapamycin as therapies for AD.
YTHDF2 in dentate gyrus is the m6A reader mediating m6A modification in hippocampus-dependent learning and memory
Authors: Zhuang Mengru , Geng Xiaoqi , Han Peng , Liang Fanghao , Che Pengfei , Liu Chao , Yang Lixin , Yu Jun , Zhang Zhuxia , Dong Wei , Ji Sheng-Jian
Published: November 2022

N6-methyladenosine (m6A) has been demonstrated to regulate learning and memory in mice. To investigate the mechanism by which m6A modification exerts its function through its reader proteins in the hippocampus, as well as to unveil the specific subregions of the hippocampus that are crucial for memory formation, we generated dentate gyrus (DG)-, CA3-, and CA1-specificYthdf1andYthdf2conditional knockout (cKO) mice, respectively. Surprisingly, we found that only the DG-specificYthdf2cKO mice displayed impaired memory formation, which is inconsistent with the previous report showing that YTHDF1 was involved in this process. YTHDF2 controls the stability of its target transcripts which encode proteins that regulate the elongation of mossy fibers (MF), the axons of granule cells in DG. DG-specificYthdf2ablation caused MF overgrowth and impairment of the MF-CA3 excitatory synapse development and transmission in the stratum lucidum. Thus, this study identifies the m6A reader YTHDF2 in dentate gyrus as the only regulator that mediates m6A modification in hippocampus-dependent learning and memory.
Calcium and Bicarbonate Signaling Pathways have Pivotal, Resonating Roles in Matching ATP Production to Demand
Authors: Greiser Maura , Karbowski Mariusz , Kaplan Aaron D. , Coleman Andrew K. , Mannella Carmen A. , Lederer W. J. , Boyman Liron
Published: November 2022

Mitochondrial ATP production in cardiac ventricular myocytes must be continually adjusted to rapidly replenish the ATP consumed by the working heart. Two systems are known to be critical in this regulation: mitochondrial matrix Ca2+([Ca2+]m) and blood flow that is tuned by local ventricular myocyte metabolic signaling. However, these two regulatory systems do not account for the large physiological range of ATP consumption observed. We report here on the identity, location, and signaling cascade of a controversial third regulatory system -- CO2/bicarbonate. CO2is generated in the mitochondrial matrix as a metabolic waste product produced by oxidation of nutrients which power the production of ATP. It is a lipid soluble gas that equilibrates with bicarbonate (HCO3−) in aqueous solutions. The bicarbonate level is tracked by a bicarbonate-activated adenylyl cyclase, soluble adenylyl cyclase (sAC). Using structural Airyscan super-resolution imaging and functional measurements we find that sAC is primarily inside the mitochondria of ventricular myocytes where it generates cAMP when activated by HCO3−. This cAMP signaling cascade is shown to operate inside the mitochondrial inter-membrane space (IMS) by activating local EPAC1 (ExchangeProtein directlyActivated bycAMP) which turns on Rap1 (Ras-related protein 1). Thus, mitochondrial ATP production is shown to be increased by bicarbonate-triggered sAC signaling through Rap1. Additional evidence is presented indicating that the cAMP signaling itself does not occur directly in the matrix. We also show that this third signaling process involving bicarbonate and sAC activates the cardiac mitochondrial ATP production machinery by working independently of, yet in conjunction with, [Ca2+]m-dependent ATP production to meet the energy needs of cellular activity in both health and disease. Thus, the resonant, or complementary effects of bicarbonate and [Ca2+]msignaling arms tune mitochondrial ATP production to match the full scale of energy consumption in cardiac ventricular myocytes.
Site of vulnerability on SARS-CoV-2 spike induces broadly protective antibody to antigenically distinct omicron SARS-CoV-2 subvariants
Authors: Changrob Siriruk , Halfmann Peter J. , Liu Hejun , Torres Jonathan L. , McGrath Joshua J.C. , Ozorowski Gabriel , Li Lei , Kuroda Makoto , Maemura Tadashi , Huang Min , Wilbanks G. Dewey , Zheng Nai-Ying , Turner Hannah L. , Erickson Steven A. , Fu Yanbin , Singh Gagandeep , Krammer Florian , Sather D. Noah , Ward Andrew B. , Wilson Ian A. , Kawaoka Yoshihiro , Wilson Patrick C.
Published: November 2022

The rapid evolution of SARS-CoV-2 Omicron variants has emphasized the need to identify antibodies with broad neutralizing capabilities to inform future monoclonal therapies and vaccination strategies. Herein, we identify S728-1157, a broadly neutralizing antibody (bnAb) targeting the receptor-binding site (RBS) and derived from an individual previously infected with SARS-CoV-2 prior to the spread of variants of concern (VOCs). S728-1157 demonstrates broad cross-neutralization of all dominant variants including D614G, Beta, Delta, Kappa, Mu, and Omicron (BA.1/BA.2/BA.2.75/BA.4/BA.5/BL.1). Furthermore, it protected hamsters againstin vivochallenges with wildtype, Delta, and BA.1 viruses. Structural analysis reveals that this antibody targets a class 1 epitope via multiple hydrophobic and polar interactions with its CDR-H3, in addition to common class 1 motifs in CDR-H1/CDR-H2. Importantly, this epitope is more readily accessible in the open and prefusion state, or in the hexaproline (6P)-stabilized spike constructs, as compared to diproline (2P) constructs. Overall, S728-1157 demonstrates broad therapeutic potential, and may inform target-driven vaccine design against future SARS-CoV-2 variants.
Excessive Firing of Dyskinesia-Associated Striatal Direct Pathway Neurons is Gated By Dopamine and Excitatory Synaptic Input
Authors: Ryan Michael B. , Girasole Allison E. , McGregor Matthew M. , Brakaj Rea , Paletzki Ronald F. , Gerfen Charles R. , Nelson Alexandra B.
Published: November 2022

The striatum integrates dopaminergic and glutamatergic inputs to select preferred versus alternative actions, but the precise mechanisms remain unclear. One way to study action selection is when it breaks down. Here, we explored the cellular and synaptic mechanisms of levodopa-induced dyskinesia (LID), a complication of Parkinson’s disease therapy characterized by involuntary movements. We used an activity-dependent tool (FosTRAP) in conjunction with a mouse model of LID to investigate functionally distinct subsets of striatal direct pathway medium spiny neurons (dMSNs).In vivo, levodopa differentially activates dyskinesia-associated (TRAPed) dMSNs compared to other dMSNs. This activation is likely to be driven by two cellular mechanisms we identified throughex vivoelectrophysiology: higher sensitivity to dopamine and stronger excitatory input from the motor cortex and thalamus. Together, these findings suggest how intrinsic and synaptic properties of heterogeneous dMSN subpopulations integrate to support action selection.
Core material and surface chemistry of Layer-by-Layer (LbL) nanoparticles independently direct uptake, transport, and trafficking in preclinical blood-brain barrier (BBB) models
Authors: Lamson Nicholas G. , Pickering Andrew J. , Wyckoff Jeffrey , Ganesh Priya , Straehla Joelle P. , Hammond Paula T.
Published: November 2022

Development of new treatments for neurological disorders, especially brain tumors and neurodegenerative diseases, is hampered by poor accumulation of new therapeutic candidates in the brain. Drug carrying nanoparticles are a promising strategy to deliver therapeutics, but there is a major need to understand interactions between nanomaterials and the cells of the blood-brain barrier (BBB), and to what degree these interactions can be predicted by preclinical models. Here, we use a library of eighteen layer-by-layer electrostatically assembled nanoparticles (LbL-NPs) to independently assess the impact of nanoparticle core stiffness and surface chemistry onin vitrouptake and transport in three common assays, as well as intracellular trafficking in hCMEC/D3 endothelial cells. We demonstrate that nanoparticle core stiffness impacts the magnitude of material transported, while surface chemistry influences how the nanoparticles are trafficked within the cell. Finally, we demonstrate that these factors similarly dictatein vivoBBB transport using intravital imaging through cranial windows in mice, and we discover that a hyaluronic acid surface chemistry provides an unpredicted boost to transport. Taken together, these findings highlight the importance of considering factors such as assay geometry, nanomaterial labelling strategies, and fluid flow in designing preclinical assays to improve nanoparticle screening throughput for drug delivery to the brain.
Improving quantitative structure models of trees inspired by pipe and metabolic scaling theory
Authors: Hackenberg Jan , Bontemps Jean-Daniel
Published: November 2022

Purpose

We invent in this manuscript new tree parameters which can be derived from a single QSM. QSMs are topological ordered cylinder models of trees which describe the branching structure up to the tips. All new invented parameters have in common, that their defining point of view looks from the direction of the tips and not from the root along the tree.

Methods

We use new allometric power functions to predict the radius from the invented parameters. Then we improve the radii of the QMSs’ cylinders utilizing those functions.

Results

For validation we use QSMs produced from an open point cloud data set of tree clouds with SimpleForest software. We compare the QSM volume against the harvested reference data for 65felled trees. We also found QSM data of TreeQSM, a competitive and broadly accepted QSM modeling tool. Our RMSE was less than 40 % of the TreeQSM RMSE. For other error measures, ther2adj.and theCCC, the relative improvement looked even better with reaching only 27 % and 21 % of the TreeQSM errors respectively.

In a second validation part we show a way to run numerical tests against the West Brown Enquist (WBE) model. Expected power coefficients have been published for various allometric relations and we compare them to predicted values from QSM data. The deviation from the expected values ranges here from 8 % underestimation to 32 % overestimation.

Conclusions

Quality -With the invention of the QSM radius filter technique we improve tree volume prediction capabilities utilizing QSMs.

Quantity -More data can be collected with QSMs than with traditional methods.
Polarity and mixed-mode oscillations may underlie different patterns of cellular migration
Authors: Plazen Lucie , Rahbani Jalal Al , Brown Claire M. , Khadra Anmar
Published: November 2022

In mesenchymal cell motility, several migration patterns have been observed, including directional, exploratory and stationary. Two key members of the Rho-family of GTPases, Rac and Rho, along with an adaptor protein called paxillin, have been particularly implicated in the formation of such migration patterns and in regulating adhesion dynamics. Together, they form a key regulatory network that involves the mutual inhibition exerted by Rac and Rho on each other and the promotion of Rac activation by phosphorylated paxillin. Although this interaction is sufficient to generating wave-pinning that underscores cellular polarization comprised of cellular front (high active Rac) and back (high active Rho), it remains unclear how they interact collectively to induce other modes of migration detected in Chinese hamster Ovary (CHO-K1) cells. We previously developed a 6D reaction-diffusion model describing the interactions of these three proteins (in their active/phosphorylated and inactive/unphosphorylated forms) along with other auxiliary proteins, to decipher their role in generating wave-pinning. In this study, we explored, through computational modeling and image analysis, how differences in timescales within this molecular network can potentially produce the migration patterns in CHO-K1 cells and how switching between them could occur. To do so, the 6D model was reduced to an excitable 4D spatiotemporal model possessing three different timescales. The model produced not only wave-pinning in the presence of diffusion, but also mixed-mode oscillations (MMOs) and relaxation oscillations (ROs). Implementing the model using the Cellular Potts Model (CPM) produced outcomes in which protrusions in cell membrane changed Rac-Rho localization, resulting in membrane oscillations and fast directionality variations similar to those seen in CHO-K1 cells. The latter was assessed by comparing the migration patterns of CHOK1 cells with CPM cells using four metrics: instantaneous cell speed, exponent of mean square-displacement (calledα-value), directionality ratio and protrusion rate. Variations in migration patterns induced by mutating paxillin’s serine 273 residue was also captured by the model and detected by a machine classifier, revealing that this mutation alters the dynamics of the system from MMOs to ROs or nonoscillatory behaviour through variation in the concentration of an active form of an adhesion protein called p21-Activated Kinase 1 (PAK). These results thus suggest that MMOs and adhesion dynamics are the key ingredients underlying CHO-K1 cell motility.
Cut homeodomain transcription factor is a novel regulator of cortex glia morphogenesis and maintenance of neural niche
Authors: Yadav Vaishali , Mishra Ramkrishna , Das Papri , Arya Richa
Published: November 2022

Cortex glia inDrosophilacentral nervous system forms a niche around neural cells for necessary signals to establish cross-talk with their surroundings. These cells grow and expand their thin processes around neural cell bodies. Although essential for the development and function of the nervous system, how these cells make extensive and intricate connected networks remain largely unknown. Here we show that Cut, a homeodomain transcription factor, directly regulates the fate of the cortex glia, impacting NSC homeostasis. Focusing on the thoracic ventral nerve cord (tVNC), we found that Cut is required for normal growth and development of cortex glia and timely increase in DNA content to undergo endomitosis. Knockdown of Cut in cortex glia significantly reduces the growth of cellular processes, the network around NSCs, and their progeny’s cell bodies. Conversely, overexpression of Cut induces overall growth of the main processes at the expense of side ones. Whereas the Cut knockdown slowdown the timely increase of DNA, Cut overexpression results in a significant increase in nuclear size and volume and a threefold increase in DNA content of cortex glia. Further, we note that constitutively high Cut also interfered with nuclei separation during endomitosis. Since cortex glia form syncytial networks around neural cells, the finding identifies Cut as a novel regulator of glial growth and endomitosis to support a functional nervous system.

Article Summary

Cut homeodomain transcription factor is crucial for cortex glia growth and the formation of complex cellular processes around neural cells. This regulation ensures a timely increase in DNA content, allowing the cells to enter endomitosis. Constitutively high Cut levels increase the DNA content of these cells to several folds. The finding emphasizes the need to investigate if activated CUX1, the human homolog of Cut, in glioma enhances chromosomal instability and, in conjunction with other mutations, enhances their tumorigenic potential.
LRRK2 regulates synaptic function through BDNF signaling and actin cytoskeleton
Authors: Tombesi Giulia , Kompella Shiva , Favetta Giulia , Chen Chuyu , Zhao Yibo , Sevegnani Martina , Marte Antonella , Battisti Ilaria , Morosin Ester , Ornaghi Marta , Iannotta Lucia , Plotegher Nicoletta , Civiero Laura , Onofri Franco , Eickholt Britta J , Piccoli Giovanni , Arrigoni Giorgio , Beccano-Kelly Dayne , Manzoni Claudia , Parisiadou Loukia , Greggio Elisa
Published: November 2022

Parkinson’s disease (PD) is a multisystemic disorder that manifests through motor and non-motor symptoms. Motor dysfunction is the most debilitating and it is caused by the degeneration of dopamine-producing neurons in the substantia nigra pars compacta (SNpc). A body of evidence indicates that synapse demise precedes by years neuronal death. Still, early synaptic dysfunctions in PD are poorly deciphered.

Here we combined literature metanalysis, proteomics and phosphoproteomics with biochemical, imaging and electrophysiological measurements in neurons, brains and synaptosomes from knockout and knockin mouse models, as well as human iPSC-derived neurons associated with the PD-kinase LRRK2.

We show that phosphorylation of LRRK2 at Ser935, which controls LRRK2 subcellular localization, rapidly increases upon brain-derived neurotrophic factor (BDNF) stimulation of differentiated SH-SY5Y cells and primary mouse neurons. Affinity-purification coupled with mass spectrometry (AP-MS/MS) analysis revealed that LRRK2 interactome is significantly reshaped upon BDNF stimulation, with an interconnected network of actin cytoskeleton-associated proteins increasing their binding to LRRK2. Accordingly, LRRK2 knockout neurons exhibit decreased TrkB signaling and fail to induce BDNF-dependent spinogenesis.In vivo, one-month oldLrrk2knockout mice display defects in spine maturation, a phenotype that disappears with age. In human iPSC-derived cortical neurons, BDNF increases the frequency of miniature excitatory post-synaptic currents (mEPSC) in wild-type but not in the presence of LRRK2 knockout, functionally supporting a distinctive role of LRRK2 in BDNF-synaptic signaling. Finally, Lrrk2 G2019S PD mutant synaptosomes display differentially phosphorylated proteins enriched in categories related to postsynaptic structural organization.

Taken together, our study discloses a critical function of LRRK2 in BDNF-dependent synaptic processes and identifies the postsynaptic actin cytoskeleton as a convergent site of LRRK2 pathophysiological activity.
Cancer treatment patterns and factors affecting receipt of treatment in older adults: results from the ASPREE Cancer Treatment Substudy (ACTS)
Authors: Muhandiramge Jaidyn , Warner Erica T. , Zalcberg John R. , Haydon Andrew , Polekhina Galina , van Londen G J. , Gibbs Peter , Bernstein Wendy B. , Tie Jeanne , Millar Jeremy L. , Mar Victoria J. , McNeil John J. , Woods Robyn L. , Orchard Suzanne G. ,   ASPREE Investigator Group
Published: November 2022

Cancer treatment planning in older adults is complex and requires careful balancing of survival, quality of life benefits, and risk of treatment-related morbidity and toxicity. As a result, treatment selection in this cohort tend to differ from younger patients. However, there are very few studies describing cancer treatment patterns in older cohorts. We used data from the ASPirin in Reducing Events in the Elderly (ASPREE) trial and the ASPREE Cancer Treatment Substudy (ACTS) to describe cancer treatment patterns in the elderly. We used a multivariate logistic regression model to identify factors affecting receipt of treatment. Of 1,893 eligible Australian and United States (US) participants with incident cancer, 1,569 (81%) received some form of cancer treatment. Non-metastatic breast cancers most frequently received treatment (98%), while haematological malignancy received the lowest rates of treatment (60%). Factors associated with not receiving treatment were older age (OR 0.94, 95% CI 0.91-0.96), residence in the US (OR 0.35, 95% CI 0.22-0.56), smoking (OR 0.60, 95% CI 0.37-0.98), and diabetes (OR 0.58, 95% CI 0.41-0.82). After adjustment for treatment patterns in sex-specific cancers, sex did not impact receipt of treatment. This study is one of the first describing cancer treatment patterns and factors affecting receipt of treatment across common cancer types in older adults. We found that most older adults with cancer received some form of cancer treatment, typically surgery or systemic therapy, although this varied with factors including cancer type, age, sex, and country of residence.
Syncytin-mediated open-ended membrane tubular connections facilitate the intercellular transfer of cargos including Cas9 protein
Authors: Zhang Congyan , Schekman Randy
Published: November 2022

Much attention has been focused on the possibility that cytoplasmic proteins and RNA may be conveyed between cells in extracellular vesicles (EVs) and tunneling nanotube (TNT) structures. Here, we set up two quantitative delivery reporters to study cargo transfer between cells. We found that EVs are internalized by reporter cells but do not efficiently deliver functional Cas9 protein to the nucleus. In contrast, donor and acceptor cells co-cultured to permit cell contact resulted in a highly effective transfer. Among our tested donor and acceptor cell pairs, HEK293T and MDA-MB-231 recorded optimal intercellular transfer. Depolymerization of F-actin greatly decreased Cas9 transfer whereas inhibitors of endocytosis or knock-down of genes implicated in this process had little effect on transfer. Imaging results suggest that intercellular transfer of cargos occurred through open-ended membrane tubular connections. In contrast, cultures consisting only of HEK293T cells form close-ended tubular connections ineffective in cargo transfer. Depletion of human endogenous fusogens, syncytins, especially syncytin-2 in MDA-MB-231 cells, significantly reduced Cas9 transfer. Full-length mouse syncytin, but not truncated mutants, rescued the effect of depletion of human syncytins on Cas9 transfer. Mouse syncytin overexpression in HEK293T cells partially facilitated Cas9 transfer among HEK293T cells. These findings suggest that syncytin may serve as the fusogen responsible for the formation of an open-ended connection between cells.
Shape-induced superstructure formation in concentrated ferrofluids under applied magnetic fields
Authors: Bender Philipp , Wetterskog Erik , Salazar-Alvarez German , Bergström Lennart , Hermann Raphael P. , Brückel Thomas , Wiedenmann Albrecht , Disch Sabrina
Published: November 2022

The field-induced ordering of concentrated ferrofluids based on spherical and cuboidal maghemite nanoparticles is studied using small-angle neutron scattering, revealing a qualitative effect of the faceted shape on the interparticle interactions as shown in the structure factor and correlation lengths. Whereas a spatially disordered hard-sphere interaction potential with a short correlation length is found for ∼9 nm spherical nanoparticles, nanocubes of a comparable particle size exhibit a more pronounced interparticle interaction and the formation of linear arrangements. Analysis of the anisotropic two-dimensional pair distance correlation function gives insight into the real-space arrangement of the nanoparticles. On the basis of the short interparticle distances found here, oriented attachment, i.e. a face-to-face arrangement of the nanocubes, is likely. The unusual field dependence of the interparticle correlations suggests a field-induced structural rearrangement.
Bis(acetylacetonato-κ2
O,O′)(N,N,N′,N′-tetramethylethylenediamine-κ2
N,N′)magnesium(II)
Authors: Halz Jan Henrik , Heiser Christian , Merzweiler Kurt
Published: November 2022

The title complex, [Mg(C5H7O2)2(C6H16N2)], has been synthesized from magnesium acetylacetonate [Mg(acac)2] and tetramethylethylenediamine (TMEDA) in n-hexane. The monomeric complex consists of a central magnesium(II) atom, which is surrounded nearly octahedrally by two chelating acetylacetonato ligands and one chelating TMEDA ligand. [Mg(C5H7O2)2(C6H16N2)] is isotypic with its Zn analogue.
Determinants of idiosyncratic risk: evidence from BRICS countries
Authors: Kausar Saba , Shah Syed Zulfiqar Ali , Rashid Abdul
Published: November 2022

Purpose

This study examines the determinants of idiosyncratic risk (IR) or unsystematic risk. The study also examines the determinants of IR by dividing the firms into different categories: beta-based firms, liquid and illiquid firms and financially constrained (FC) and unconstrained (FUC) firms.

Design/methodology/approach

The fixed effects static panel data model specifications are formulated based on Hausman (1978) test for BRICS (Brazil, Russia, India, China, and South Africa) member countries over the period 2000–2019. Moreover, the t-test is applied to see whether the returns of different types of portfolios are significantly different.

Findings

The portfolio analysis results show that, on average, high IR firms tend to be small in size, highly leveraged, have low competitiveness, low profitability, less dividend yield and low returns for all the sampled countries. The sample paired t-test also confirms that a significant difference exists between extreme portfolios: small and large size and low IR and high IR portfolios. The panel regression results show that firm size, market power, price-to-earnings ratio, return on equity (ROE) and dividend yield negatively relates to IR. Yet, both leverage and liquidity are positively related to IR. However, the sign of momentum returns is mostly positive for the entire sample. The coefficient values for high-beta, FC and illiquid firms are more significant and large than the firms' counterparts for all BRICS member countries. These results support the hypothesis of an under-diversified portfolio and suggest that the above-mentioned firm-specific variables are the significant determinants of unsystematic risk.

Practical implications

The securities exchange commission, as the supervisor of the public limited companies, needs to increase its role in investor protection related to the uncertainty of investment in the capital market. Accordingly, in making investment decisions in a stock exchange, investors can use the information that captures unsystematic risk for investment decision-making.

Originality/value

This study is the first to explore the determinants of IR in top emerging countries. Second, none of the existing studies has focused on the determinants of the IR based on different categories of firms.
Labor market transformation in the hospitality gig economy in a post pandemic era: impacts of institutional governance
Authors: Lin Pearl M.C. , Peng Kang-Lin , Wilson Au Wai Ching , Baum Tom
Published: November 2022

Purpose

The COVID-19 pandemic has caused the food delivery sector to boom as people continue to rely on services provided by online catering platforms (OCPs). However, because of the nature of sharing economy employment, gig workers’ contributions went largely ignored until intervention from institutional governance. This study aims to explore the impacts of labor market transformation after the Chinese Government issued guidance to promote gig workers’ welfare as a focal case.

Design/methodology/approach

Focus groups and the Delphi technique were used to explore associated impacts on OCPs and gig workers based on governance theory.

Findings

Results show that institutional governance negatively affected OCPs’ operating cost structure but sustained gig workers’ welfare. The dual effects of market mechanism and institutional governance in the sharing economy are needed to be balanced for labor market transformation.

Research limitations/implications

Long-term equilibrium can be fulfilled, given the growing food-related demand for the market mechanism. Social reciprocity is expected to be realized through institutional governance for gig workers’ welfare.

Originality/value

This study suggests that moving from market governance to stakeholder governance, as mediated by state governance, could transform gig workers’ labor structure in the gig economy. This study presents an integrated governance theory to enhance the epistemology of institutional governance.
Cognitive factors in discouraged borrowers: how entrepreneur's perception affects borrowing discouragement
Authors: Barasal Morales Adriano
Published: November 2022

Purpose

This paper aims to investigate how cognitive factors affect borrowing discouragement among entrepreneurs. Specifically, the study tests the effects of overconfidence, dispositional optimism and entrepreneurial self-efficacy (ESE) on borrowing discouragement.

Design/methodology/approach

The study relies on Fraser's (2014) theoretical model to formulate the hypotheses. The results are based on a small sample of French entrepreneurs drawn from the AMADEUS database. Hierarchical Probit estimations are used to access the effects of the cognitive factors on borrowing discouragement.

Findings

The findings suggest that optimistic entrepreneurs are less likely to feel discouraged, while miscalibrated entrepreneurs are more prone to feel borrowing discouragement. There was no significant result for ESE and discouragement.

Originality/value

The study brings new implications and insights to the literature that investigates factors that cause discouragement in entrepreneurs, as well as implications for policymakers.
Clustering of percentage gross spreads and the avoidance of underwriter switching
Authors: Lee Chin-Chong , Too Shaw Warn , Ooi Kuan San
Published: November 2022

Purpose

Both issuing firms and underwriters shall benefit from the associations in underwriting contracts for seasoned equity offerings (SEOs). Issuing firms that are offered underwriting contracts with clustered gross spreads do not have strong incentives to switch away from the firms' prior SEO underwriters, and thus these existing underwriters are able to maintain or gain greater market share. This study investigates how the clustering of percentage gross spreads affects the likelihood of underwriter switching.

Design/methodology/approach

Using the investment bank-underwritten SEOs in Hong Kong, the authors find that the percentage gross spreads of 40% of these SEOs are clustered at 2.5%. The seemingly unrelated bivariate probit model, Weibull survival mixed model and trivariate probit model are applied to analyse this phenomenon.

Findings

The authors' study provides first direct evidence that the clustering of percentage gross spreads lowers the likelihood of underwriter switching. Investment banks as underwriters can explicitly price underwriting contracts at a clustered level, more likely in periods of greater market volatility, and intentionally retain the banks' client firms using pricing arrangements. The authors' finding and approach offer more direct and distinct support that the issuer–underwriter association can be relationship-based.

Originality/value

Whilst the clustering of fees is interpreted as a type of anticompetitive price sitting, the authors contribute to literature by providing new empirical evidence on why percentage gross spreads as a price dimension are clustered. On top of contract efficiency and collusion, this study's new evidence provides a third view for the clustering of gross spreads.
Corporate social responsibility disclosure and banks' performance: the role of economic performance and institutional quality
Authors: AlAjmi Jasim , Buallay Amina , Saudagaran Shahrokh
Published: November 2022

Purpose

This study aims to examine the moderating role of a country's economic activities and institutional quality (IQ) on the relationship between corporate social responsibility disclosure (CSRD) and banks' operational, financial and market performance.

Design/methodology/approach

This study examines 245 banks from emerging markets for 13 years (2008–2020), yielding unbalanced panel of 1899 bank-year observations. The independent variable is CSRD. The dependent variables are return on asset (ROA), return on equity (ROE) and Tobin Q. The authors used ordinary least square (OLS), panel fixed-effect and instrumental variables-generalized method of moments (IV-GMM) to estimate the parameters of the models.

Findings

The authors find that the CSRD scores negatively influence banks’ performance. The moderator of CSRD and the level of economic activities have a positive relationship with banks' performance. However, the moderator (CSRD and IQ), while showing positive relationship with banks' performance, has a significant effect only on banks' operational and financial performance.

Originality/value

This study provides new evidence on the ways in which economic performance and IQ (IQ) influence the CSRD practices of banks in emerging markets.

Peer review

The peer review history for this article is available at https://publons.com/publon/10.1108/IJSE-11-2020-0757.
Immersive robotic telepresence system to support a person with intellectual and motor disabilities perform a daily task: a case study
Authors: Desideri Lorenzo , Cesario Lisa , Sidoti Chiara , Malavasi Massimiliano
Published: November 2022

Purpose

In this proof-of-concept study, the authors assessed the feasibility of using a humanoid robot controlled remotely via an immersive telepresence system to support a person with intellectual and motor disabilities performing a daily task (i.e. setting a table for lunch).

Design/methodology/approach

The system involved a head-mounted display and two joysticks. A teleoperator was able to see through the video cameras of the robot and deliver the instructions verbally to the participant located in a different room. To assess the system, a baseline phase (A) was followed by an intervention (i.e. tele-operated support) phase (B) and a return to a baseline phase (A).

Findings

Data showed a marked increase in the average frequency of task steps correctly performed from baseline (M = 15%) to intervention (M = 93%). Accuracy reached 100% in the return to baseline.

Originality/value

These preliminary findings, along with qualitative feedback from users, suggest that an immersive telepresence system may be used to provide remote support to people with intellectual and motor disabilities.
Ambidextrous leadership and sustainability performance: serial mediation effects of employees' green creativity and green product innovation
Authors: Lyu Chaolin , Peng Can , Li Ruixue , Yang Xiaona , Cao Dongqin
Published: November 2022

Purpose

The purpose of this study is to explore the relationship between ambidextrous leadership and sustainability performance. In addition, this study also discusses how ambidextrous leadership affects sustainability performance through employees' green creativity and green product innovation.

Design/methodology/approach

This study obtained research data from a questionnaire survey of 307 manufacturing enterprise leaders in China and used regression and bootstrap analysis to test the research hypotheses.

Findings

(1) Ambidextrous leadership positively influences sustainability performance. (2) Employees' green creativity mediates the relationship between ambidextrous leadership and sustainability performance. (3) Green product innovation also mediates the relationship between ambidextrous leadership and sustainability performance. (4) The intermediary chain constructed by employees' green creativity and green product innovation has serial mediation effects on the relationship between ambidextrous leadership and sustainability performance.

Originality/value

This study contributes to the literature on leadership and corporate sustainability by clarifying the relationship between ambidextrous leadership and sustainability performance. Meanwhile, this study reveals the influence mechanism of ambidextrous leadership on sustainability performance by analyzing the serial mediation effects of employees' green creativity and green product innovation.
Environmental disclosure and its relation to waste performance
Authors: Benjamin Samuel Jebaraj , Biswas Pallab Kumar , Wellalage Nirosha Hewa , Man Yimei
Published: November 2022

Purpose

This paper aims to examine the association between environmental disclosure and waste performance.

Design/methodology/approach

This study is based on a sample of S&P 500 firms over a nine-year period from 2010 to 2018. The pooled ordinary least squares (OLS), logistic, propensity score matching (PSM) and instrumental variable-generalized method of moments regressions analyses have been used to examine the data.

Findings

The findings show a significant positive relationship between waste performance and environmental disclosure, suggesting that firms with superior waste performance tend to disclose more environmental information. Further, the authors distinguish between “hard” and “soft” environmental disclosures and find that the effect of waste performance is consistently positive and significant for each type. The observed positive and significant association of waste performance with environmental disclosure remains unchanged, regardless of the industry affiliation of firms, although firms from industries that are less environmentally sensitive provide a slightly higher level of environmental disclosure. The authors also explore possible channels that may explain the association between waste performance and environmental disclosure and find that litigation risk and cash holdings positively moderate the association. The finding remains robust to a number of alternative estimation approaches.

Originality/value

Overall, the authors present important evidence that waste performance is an important indicator of environmental disclosure. The findings are useful for corporations and stakeholders and have important implications around the globe as the authors continue to grapple with the ongoing issue of waste.
Russia’s invasion of Ukraine increased the synchronisation of global commodity prices
Authors: Ihle Rico , Bar‐Nahum Ziv , Nivievskyi Oleg , Rubin Ofir D.
Published: November 2022

The Russian Federation’s efforts to expand its regional political influence culminated in launching a full‐scale war of aggression on Ukraine on 24 February 2022. As both countries are large exporters of commodities crucial for global food and energy security, the resulting abrupt supply chains disruptions created substantial uncertainty in commodity markets worldwide. This study quantifies to what extent this major shock induced global commodity prices to move more synchronously by gauging their time‐varying comovement. Using the concordance index, it analyses the development of 15 key global commodity price indices from January 2010 to July 2022. We find that the supply chains disruptions increased synchronisation of grain, energy and fertiliser prices at the global level in direction and magnitude. Moreover, they resulted in contagion across numerous food and non‐food markets, creating a global covariate shock to food and energy security. Notably, the increased synchronisation at broad scale restricts the ability of consumers to mitigate the adverse effects of food and energy price inflation by resorting to inexpensive alternatives. Hence, policymakers must improve the resilience of global food supply chains sustainably such that adverse effects of attaining the Sustainable Development Goals in crises can be minimised.
Distribution ratios of ethanol and water between whole blood, plasma, serum, and erythrocytes: Recommendations for interpreting clinical laboratory results in a legal context
Authors: Jones Alan Wayne , Tilson Christopher
Published: November 2022

This article reviews the scientific literature dealing with the distribution of ethanol and water between whole blood (WB), plasma, serum, and erythrocytes (red‐blood cells). Knowledge of the ethanol distribution ratio is important when analytical results derived from hospital clinical laboratories are interpreted in a forensic context, such as during the prosecution of traffic offenders. Statutory blood‐alcohol concentration (BAC) limits for driving are defined as the concentration of ethanol in WB and not in plasma, serum or red‐blood cells. These bio‐fluids differ in their water content and thereby the concentrations of ethanol. Plasma and serum contain ~90%–92% w/w water, WB ~78%–80% w/w and erythrocytes ~64%–66% w/w. The mean plasma/WB and serum/WB distribution ratios of ethanol are therefore expected to be ~1.15:1 (91/79 = 1.15), which is in good agreement with values determined empirically. However, in individual cases, the actual distribution ratio will depend on the person's age, gender, and biochemical and hematological properties of the blood specimen, such as its hematocrit. For legal purposes, we recommend that the concentration of ethanol in plasma or serum determined at hospital laboratories is divided by a factor of 1.2, which would provide a conservative estimate of the co‐existing BAC and the chance of overestimating the true value is only 1 in 2000 (0.05%).
Modifying factors of PD‐L1 expression on tumor cells in advanced non‐small‐cell lung cancer
Authors: Avilés‐Salas Alejandro , Flores‐Estrada Diana , Lara‐Mejía Luis , Catalán Rodrigo , Cruz‐Rico Graciela , Orozco‐Morales Mario , Heredia David , Bolaño‐Guerra Laura , Soberanis‐Piña Pamela Denisse , Varela‐Santoyo Edgar , Cardona Andrés F. , Arrieta Oscar
Published: November 2022

Background

Programmed death ligand‐1 (PD‐L1) expression predicts immunotherapy utility in nononcogenic addictive lung adenocarcinoma (ADC). However, its reproducibility and reliability may be compromised outside clinical trials. This study aimed to evaluate factors associated with PD‐L1 expression in lung ADC.

Methods

This observational study assessed 547 tumor samples with advanced lung ADC from January 2016 to December 2020 in a single cancer institution. Tumor samples were stained by at least one approved PD‐L1 clone, SP263 (Ventana) or 22C3 (Dako), and stratified in tumor proportion score (TPS) <1%, 1–49%, or ≥50%.

Results

Of all the tumor samples, positive PD‐L1 staining was higher in poorly differentiated tumors (67.3% vs. 32.7%, p < 0.001). Analytical factors associated with a PD‐L1 high expression (TPS ≥ 50%) were the SP263 clone (19.6% vs. 8.2%, p < 0.001), time of archival tumor tissue <12 months (15.3% vs. 3.8%, p = 0.024), whenever the analysis was performed in the most recent years (2019–2020) (19.0% vs. 8.3%, p < 0.001), and whenever the analysis was performed by pathologists in the academic setting (Instituto Nacional de Cancerologia, INCan) (19.9% vs. 11.9%, p = 0.001). In the molecular analysis, EGFR wild‐type tumors had an increased proportion of PD‐L1 positive and PD‐L1 high cases (60.2% vs. 47.9%, p = 0.006 and 17.4% vs.8.5%, p = 0.004). A moderate correlation (r = 0.69) in the PD‐L1 TPS% was observed between the two different settings (INCan vs. external laboratories).

Conclusion

Clinicopathological factors were associated with an increased PD‐L1 positivity rate. These differences were significant in the PD‐L1 high group and associated with the academic setting, the SPS263 clone, time of archival tumor tissue <12 months, and a more recent period in the PD‐L1 analysis.
Recent developments in empirical dynamic modelling
Authors: Munch Stephan B. , Rogers Tanya L. , Sugihara George
Published: November 2022

Ecosystems are complex and sparsely observed making inference and prediction challenging.

Empirical dynamic modelling (EDM) circumvents the need for a parametric model and complete observations of all system variables. Classical univariate approaches, which require time‐series observations of only a single focal variable, can produce verifiable out‐of‐sample forecasts; however, they can sometimes require long time series that may be difficult to obtain. More importantly, classical approaches limit the depth of mechanistic understanding that can be gained and the generalizability of forecasts to non‐analogue futures.

We review the main ideas of EDM and more recent extensions that expand their capabilities for improving forecasts and understanding mechanism.

Algorithms are now available that allow for missing data, unequal sampling intervals and combining short time series, which increase the number of datasets that can be used. Recent extensions of EDM to multivariate time series substantially expand the range of applications and mechanistic questions that can be addressed, including detecting causal coupling, tracking changing interactions in real time, leveraging short time series from information shared in coupled variables, modelling dynamically changing stability, scenario exploration, and management applications involving optimal control.