bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential biotransformation ability may alter fish biodiversity in polluted waters
Authors: Franco Marco E. , Hollender Juliane , Schirmer Kristin
Published: July 2024

Divergence in the activity of biotransformation pathways could lead to species sensitivity differences to chemical stress. To explore this hypothesis, we evaluated the biotransformation capacity of five fish species that are representatives of Swiss biodiversity assemblages and that inhabit watercourses surrounded by different land use. We report important interspecific differences regarding the presence and activity of major biotransformation pathways, such as the invasive pumpinkseed (Lepomis gibbosus) displaying micropollutant clearance between 3- and 7–fold higher than native species (e.g.Salmo trutta, Squalius cephalus) collected in the same areas. These differences were exacerbated by urban and agricultural influence, which increased biotransformation potential at the enzyme level by as much as 11-fold and micropollutant clearance by approximately 2-fold compared to biotransformation levels in areas with minimal human influence. In the context of the chemical defensome, we argue that fish with low biotransformation activity carry a greater burden on chemical stress, making them less likely to cope with additional stressors and sustain their population in competition with species with a higher biotransformation capacity.
Bifunctional probes reveal the rules of intracellular ether lipid transport
Authors: Böhlig Kristin , Iglesias-Artola Juan M. , Lennartz H. Mathilda , Link Anna C. , Drobot Björn , Nadler André
Published: July 2024

Ether glycerophospholipids bear a long chain alcohol attached via an alkyl or vinyl ether bond at thesn1position of the glycerol backbone. Emerging evidence suggests that ether lipids play a significant role in physiology and human health but their precise cellular functions remain largely unknown. Here, we introduce bifunctional ether lipid probes bearing diazirine and alkyne groups to study ether lipid biology. To interrogate the kinetics of intracellular ether lipid transport in mammalian cells we used a combination of fluorescence imaging, machine learning-assisted image analysis and mathematical modelling. We find that alkyl-linked ether lipids are transported up to twofold faster than vinyl-linked plasmalogens, suggesting that the lipid transport machinery can distinguish between linkage types differing by as little as two hydrogen atoms. We find that ether lipid transport predominantly occurs via non-vesicular pathways, with varying contributions from vesicular mechanisms between cell types. Altogether, our results suggest that differential recognition of alkyl- and vinyl ether lipids by lipid transfer proteins contributes to their distinct biological functions. In the future, the probes reported here will enable studying ether lipid biology in much greater detail through identification of interacting proteins and in-depth characterization of intracellular ether lipid dynamics.
The zebrafish (Danio rerio) snoRNAome
Authors: Hamar Renáta , Varga Máté
Published: July 2024

Small nucleolar RNAs (snoRNAs) are one of the most abundant and evolutionary ancient group of functional non-coding RNAs. They were originally described as guides of post-transcriptional rRNA modifications, but emerging evidence suggests that snoRNAs fulfil an impressive variety of cellular functions, some of which are only being discovered. To reveal the true complexity of snoRNA-dependent functions, we need to catalogue first the complete repertoire of snoRNAs in a given cellular context. While the systematic mapping and characterization of 'snoRNAomes' for some species have been described recently, this has not been done hitherto for the zebrafish (Danio rerio). Using size-fractionated RNA sequencing data from adult zebrafish tissues, we created an interactive 'snoRNAome' database for this species. Our custom-designed analysis pipeline allowed us to identify with high-confidence 68 previously unannotated snoRNAs in the zebrafish genome, resulting in the most complete set of snoRNAs to date in this species. Reanalyzing multiple previously published datasets, we also provide evidence for the dynamic expression of some snoRNAs during the early stages of zebrafish development and tissue-specific expression patterns for others in adults. To facilitate further investigations into the functions of snoRNAs in zebrafish, we created a novel interactive database, snoDanio, which can be used to explore small RNA expression from transcriptomic data.
PRAME expression in melanoma is negatively regulated by TET2-mediated DNA hydroxymethylation
Authors: Fang Rui , Vallius Tuulia , Zhang Arianna , Cura Devon Van , Alicandri Francisco , Fischer Grant , Draper Elizabeth , Xu Shuyun , Pelletier Roxanne , Katsyv Igor , Sorger Peter K. , Murphy George F. , Lian Christine G.
Published: July 2024

Preferentially Expressed Antigen in Melanoma (PRAME) and Ten-Eleven Translocation (TET) dioxygenase-mediated 5-hydroxymethylcytosine (5hmC) are emerging melanoma biomarkers. We observed an inverse correlation between PRAME expression and 5hmC levels in benign nevi, melanoma in situ, primary invasive melanoma, and metastatic melanomas via immunohistochemistry and multiplex immunofluorescence: nevi exhibited high 5hmC and low PRAME, whereas melanomas showed the opposite pattern. Single-cell multiplex imaging of melanoma precursors revealed that diminished 5hmC coincides with PRAME upregulation in premalignant cells. Analysis of TCGA and GTEx databases confirmed a negative relationship between TET2 and PRAME mRNA expression in melanoma. Additionally, 5hmC levels were reduced at the PRAME 5’ promoter in melanoma compared to nevi, suggesting a role for 5hmC in PRAME transcription. Restoring 5hmC levels via TET2 overexpression notably reduced PRAME expression in melanoma cell lines. These findings establish a function of TET2-mediated DNA hydroxymethylation in regulating PRAME expression and demonstrate epigenetic reprogramming as pivotal in melanoma tumorigenesis.

Teaser

Melanoma biomarker PRAME expression is negatively regulated epigenetically by TET2-mediated DNA hydroxymethylation
CO-OPTION OF NECK MUSCLES SUPPORTED THE VERTEBRATE WATER-TO-LAND TRANSITION
Authors: Heude Eglantine , Dutel Hugo , Sanchez-Garrido Frida , Prummel Karin D. , Lalonde Robert , Lam France , Mosimann Christian , Herrel Anthony , Tajbakhsh Shahragim
Published: July 2024

A major event in vertebrate evolution was the separation of the skull from the pectoral girdle and the acquisition of a functional neck, transitions which required profound developmental rearrangements of the musculoskeletal system. The neck is a hallmark of the tetrapod body plan and allows for complex head movements on land. While head and trunk muscles arise from distinct embryonic mesoderm populations, the origins of neck muscles remained elusive. Here, we combine comparative embryology and anatomy to reconstruct the mesodermal contribution to neck evolution. We demonstrate that head/trunk-connecting muscle groups have conserved mesodermal origins in fishes and tetrapods and that the neck evolved from muscle groups present in fishes. We propose that expansions of mesodermal populations into head and trunk domains during embryonic development underpinned the emergence and adaptation of the tetrapod neck. Our results provide evidence for exaptation of archetypal muscle groups in ancestral fishes, which were co-opted to acquire novel functions adapted to terrestrial lifestyle.
Patterns of neural activity in prelimbic cortex neurons correlate with attentional behavior in the rodent continuous performance test
Authors: Miranda-Barrientos Jorge , Adiraju Suhaas , Rehg Jason J. , Hallock Henry L. , Li Ye , Carr Gregory V. , Martinowich Keri
Published: July 2024

Sustained attention, the ability to focus on a stimulus or task over extended periods, is crucial for higher level cognition, and is impaired in individuals diagnosed with neuropsychiatric and neurodevelopmental disorders, including attention-deficit/hyperactivity disorder, schizophrenia, and depression. Translational tasks like the rodent continuous performance test (rCPT) can be used to study the cellular mechanisms underlying sustained attention. Accumulating evidence points to a role for the prelimbic cortex (PrL) in sustained attention, as electrophysiological single unit and local field (LFPs) recordings reflect changes in neural activity in the PrL in mice performing sustained attention tasks. While the evidence correlating PrL electrical activity with sustained attention is compelling, limitations inherent to electrophysiological recording techniques, including low sampling in single unit recordings and source ambivalence for LFPs, impede the ability to fully resolve the cellular mechanisms in the PrL that contribute to sustained attention.In vivoendoscopic calcium imaging using genetically encoded calcium sensors in behaving animals can address these questions by simultaneously recording up to hundreds of neurons at single cell resolution. Here, we usedin vivoendoscopic calcium imaging to record patterns of neuronal activity in PrL neurons using the genetically encoded calcium sensor GCaMP6f in mice performing the rCPT at three timepoints requiring differing levels of cognitive demand and task proficiency. A higher proportion of PrL neurons were recruited during correct responses in sessions requiring high cognitive demand and task proficiency, and mice intercalated non-responsive-disengaged periods with responsive-engaged periods that resemble attention lapses. During disengaged periods, the correlation of calcium activity between PrL neurons was higher compared to engaged periods, suggesting a neuronal network state change during attention lapses in the PrL. Overall, these findings illustrate that cognitive demand, task proficiency, and task engagement differentially recruit activity in a subset of PrL neurons during sustained attention.
An essential role for glial cells in postingestive nutrient sensing
Authors: Kulshrestha Divita , Koch Charlotte , Khalilov Majid , Schirmeier Stefanie
Published: July 2024

Behavioral flexibility is an essential trait for survival of any organism. For example, choosing an appropriate food source is vital. To do so, the food’s nutritive value needs to be evaluated. Several studies have demonstrated thatDrosophila melanogasterlarvae and adults, as mammals, are able to distinguish between nutritious and non-nutritious carbohydrates independent of their taste. Several groups of neurons have been implicated in postprandial sugar sensing in adult flies (Dus et al., 2011, 2015; Miyamoto et al., 2012; Park et al., 2016; Musso et al., 2023). In larvae, neurons expressing Gr43a, a fructose receptor, have been shown to be implicated in postingestive glucose sensing (Mishra et al., 2013). How can a fructose sensor mediate glucose sensing? We show that postingestive glucose, and also sorbitol, sensing involves carbohydrate conversion into fructose via the polyol pathway in glial cells. Glia-derived fructose is subsequently sensed via Gr43a expressed in neurons, which leads to behavioral adaptation. Thus, in postingestive nutrient sensing, the glial cells play a central role in information processing and regulation of behavior.
Expanding the substrate selectivity of the fimsbactin biosynthetic adenylation domain, FbsH
Authors: Ahmed Syed Fardin , Balutowski Adam , Yang Jinping , Wencewicz Timothy A. , Gulick Andrew M.
Published: July 2024

Nonribosomal peptide synthetases (NRPSs) produce diverse natural products including siderophores, chelating agents that many pathogenic bacteria produce to survive in low iron conditions. Engineering NRPSs to produce diverse siderophore analogs could lead to the generation of novel antibiotics and imaging agents that take advantage of this unique iron uptake system in bacteria. The highly pathogenic and antibiotic-resistant bacteriaAcinetobacter baumanniiproduces fimsbactin, an unusual branched siderophore with iron-binding catechol groups bound to a serine or threonine side chain. To explore the substrate promiscuity of the assembly line enzymes, we report a structure-guided investigation of the stand-alone aryl adenylation enzyme FbsH. We report on structures bound to its native substrate 2,3-dihydroxybenzoic acid (DHB) as well as an inhibitor that mimics the adenylate intermediate. We produced enzyme variants with an expanded binding pocket that are more tolerant for analogs containing a DHB C4 modification. Wild-type and mutant enzymes were then used in anin vitroreconstitution analysis to assess the production of analogs of the final product as well as several early-stage intermediates. This analysis shows that some altered substrates progress down the fimsbactin assembly line to the downstream domains. However, analogs from alternate building blocks are produced at lower levels, indicating that selectivity exists in the downstream catalytic domains. These findings expand the substrate scope of producing condensation products between serine and aryl acids and identify the bottlenecks for chemoenzymatic production of fimsbactin analogs.
Structured flexibility in recurrent neural networks via neuromodulation
Authors: Costacurta Julia C. , Bhandarkar Shaunak , Zoltowski David M. , Linderman Scott W.
Published: July 2024

The goal of theoretical neuroscience is to develop models that help us better understand biological intelligence. Such models range broadly in complexity and biological detail. For example, task-optimized recurrent neural networks (RNNs) have generated hypotheses about how the brain may perform various computations, but these models typically assume a fixed weight matrix representing the synaptic connectivity between neurons. From decades of neuroscience research, we know that synaptic weights are constantly changing, controlled in part by chemicals such as neuromodulators. In this work we explore the computational implications of synaptic gain scaling, a form of neuromodulation, using task-optimized low-rank RNNs. In our neuromodulated RNN (NM-RNN) model, a neuromodulatory subnetwork outputs a low-dimensional neuromodulatory signal that dynamically scales the low-rank recurrent weights of an output-generating RNN. In empirical experiments, we find that the structured flexibility in the NM-RNN allows it to both train and generalize with a higher degree of accuracy than low-rank RNNs on a set of canonical tasks. Additionally, via theoretical analyses we show how neuromodulatory gain scaling endows networks with gating mechanisms commonly found in artificial RNNs. We end by analyzing the low-rank dynamics of trai ned NM-RNNs, to show how task computations are distributed.
Rab5 Overcomes CAR T Cell Dysfunction Induced by Tumor-Mediated CAR Capture
Authors: Gu Meidi , Carvalho Edmund J. , Read Kaitlin A. , Nardo David Padron , Riley James L.
Published: July 2024

Continuous interaction between chimeric antigen receptor (CAR) T cell (CART) and tumors often result in CART dysfunction and tumor escape. We observed that tumors can take up CAR molecules, leaving CARTs without surface-expressed CARs and thus unable to kill tumors after prolonged exposure. Overexpression of Rab5 resulted in augmented clathrin-independent endocytosis, preventing loss of surface-expressed CARs, and enhanced CART activity. Interestingly, we observed membrane protrusions on the CART cell surface which disappeared after multiple tumor challenges. Rab5 maintained these protrusions after repeated tumor engagements and their presence correlated with effective tumor clearance, suggesting a link between endocytosis, membrane protrusions, and cytolytic activity.In vivo, Rab5-expressing CARTs demonstrated improved activity and were able to clear an otherwise refractory mesothelin-expressing solid cancer in humanized mice by maintaining CAR surface expression within the tumor. Thus, pairing Rab5 with CAR expression could improve the clinical efficacy of CART therapy.

Highlights

“CAR-jacking” occurs when surface CAR is internalized by target tumor cells.

Rab5 overexpression prevents “CAR-jacking” and enhances CART function.

Rab5 promotes CAR endocytic recycling and maintains membrane protrusions.

Rab5-expressing CARTs exhibit enhanced therapeutic efficacy against solid tumors.
In vivoanalysis of the relationship between CP26 and qE-type NPQ via higher-orderArabidopsis cp26mutants
Authors: Walter Julia , Patel-Tupper Dhruv , Lam Lam , Ma Alexa , Taylor Georgia , Fleming Graham R. , Niyogi Krishna K. , Kromdijk Johannes
Published: July 2024

CP26 is a monomeric minor light-harvesting complex of PSII (LHCII) protein that connects major LHCII trimers to the PSII core in photosynthetic thylakoid membranes. Previous studies have proposed that CP26 is not only involved in light harvesting but could also be involved in non-photochemical quenching (NPQ). Here, we analyzed higher-orderArabidopsis cp26mutants using biophysical and pharmacological approaches to investigate the nature of NPQ and its relationship to known NPQ regulators (PSII subunit S (PsbS), the xanthophyll-converting enzyme VDE and the pH gradient across the thylakoid membrane). Maximum PSII quantum efficiencies (Fv/Fm) and chlorophyll fluorescence lifetimes in the dark were significantly lower incp26mutants, confirming that CP26 deficiency leads to a sustained quenched state even in the absence of light. Destabilized PSII-LHCII supercomplexes as observed with native PAGE analysis are the likely cause for this pre-quenched state, without other antenna proteins being able to rescue this phenotype. Further analyses revealed thatcp26mutants exhibit modest (single mutant) to highly significant (double mutants) reductions in overall NPQ capacity, which do not directly rely on PsbS and VDE (although the effect is more pronounced when these qE components are altered) but depend on thylakoid lumen acidification and protonation of protein residues. Together, these results show that the NPQ component lacking incp26mutants acts independently of qE and qZ and is induced in a slower phase of NPQ induction that most likely relies on pH-dependent conformational changes.
Environmental context sculpts spatial and temporal visual processing in thalamus
Authors: Peelman Kayla , Haider Bilal
Published: July 2024

Behavioral state modulates neural activity throughout the visual system1–3. This is largely due to changes in arousal that alter internal brain state4–10. Much is known about how these internal factors influence visual processing7–11, but comparatively less is known about the role of external environmental contexts12. Environmental contexts can promote or prevent certain actions13, and it remains unclear if and how this affects visual processing. Here, we addressed this question in the thalamus of awake head-fixed mice while they viewed stimuli but remained stationary in two different environmental contexts: either a cylindrical tube, or a circular running wheel that enabled locomotion. We made silicon probe recordings in the dorsal lateral geniculate nucleus (dLGN) while simultaneously measuring multiple metrics of arousal changes, so that we could control for them across contexts. We found surprising differences in spatial and temporal processing in dLGN across contexts. The wheel context (versus tube) showed elevated baseline activity, and faster but less spatially selective visual responses; however, these visual processing differences disappeared if the wheel no longer enabled locomotion. Our results reveal an unexpected influence of the physical environmental context on fundamental aspects of early visual processing, even in otherwise identical states of alertness and stillness.
Expansion of the genomic and functional diversity of global ocean giant viruses
Authors: Minch Benjamin , Moniruzzaman Mohammad
Published: July 2024

Giant viruses (GVs) play crucial roles in the global ocean microbial food web and biogeochemistry by infecting protists. Traditionally, insights into GV ecology and functions have been limited to culture-based studies. However, recent metagenomic advances have uncovered over 1,800 new GV genomes from the world’s oceans. While this rapid increase in genomic information marks an impressive advance for the field, it is nowhere close to the extensive genomic information available for other marine entities - e.g., prokaryotes and their ‘virome’. Addressing this gap, we present 230 novel, high-quality GV genomes and 398 partial genomes from nine global ocean datasets using an open-source bioinformatic workflow we developed. Notably, we identified numerous GV genomes from the Baltic Sea, offering insights into their phylogenomics, metabolic potential, and environmental drivers in one of the largest brackish water ecosystems. We discovered new GV functions, including photosynthetic proteins, and identified a significant functional divide between the Imitervirales and Algavirales orders. Additionally, we evaluated best practices for GV genome recovery from metagenomic datasets through a case study on the Baltic Sea dataset. Our study significantly expands the marine GV genomic and functional diversity, broadening our understanding of their roles in the food web and biogeochemistry.
Ligand induced receptor multimerization achieves the specificity enhancement of kinetic proofreading without associated costs
Authors: Kirby Duncan , Zilman Anton
Published: July 2024

Kinetic proofreading (KPR) is a commonly invoked mechanism for specificity enhancement of receptor signaling. However, specificity enhancement comes at a cost of non-equilibrium energy input and signal attenuation. We show that ligand induced multimeric receptor assembly can enhance receptor specificity to the same degree as KPR, yet without the need for out-of-equilibrium energy expenditure and signal loss. We show how multimeric receptor specificity enhancement arises from the amplification of affinity differences via sequential progression down a free energy landscape. We also show that multimeric receptor ligand recognition is more robust to stochastic fluctuations and molecular noise than KPR receptors. Finally, we show that multimeric receptors perform signaling tasks beyond specificity enhancement like absolute discrimination and aspects of ligand antagonism. Our results suggest that multimeric receptors may serve as a potent mechanism of ligand discrimination comparable to and potentially with more advantages than traditional proofreading.
Reference-informed prediction of alternative splicing and splicing-altering mutations from sequences
Authors: Xu Chencheng , Bao Suying , Wang Ye , Li Wenxing , Chen Hao , Shen Yufeng , Jiang Tao , Zhang Chaolin
Published: July 2024

Alternative splicing plays a crucial role in protein diversity and gene expression regulation in higher eukaryotes, and mutations causing dysregulated splicing underlie a range of genetic diseases. Computational prediction of alternative splicing from genomic sequences not only provides insight into gene-regulatory mechanisms but also helps identify disease-causing mutations and drug targets. However, the current methods for the quantitative prediction of splice site usage still have limited accuracy. Here, we present DeltaSplice, a deep neural network model optimized to learn the impact of mutations on quantitative changes in alternative splicing from the comparative analysis of homologous genes. The model architecture enables DeltaSplice to perform “reference-informed prediction” by incorporating the known splice site usage of a reference gene sequence to improve its prediction on splicing-altering mutations. We benchmarked DeltaSplice and several other state-of-the-art methods on various prediction tasks, including evolutionary sequence divergence on lineage-specific splicing and splicing-altering mutations in human populations and neurodevelopmental disorders, and demonstrated that DeltaSplice outperformed consistently. DeltaSplice predicted ∼15% of splicing quantitative trait loci (sQTLs) in the human brain as causal splicing-altering variants. It also predicted splicing-altering de novo mutations outside the splice sites in a subset of patients affected by autism and other neurodevelopmental disorders (NDDs), including 19 genes with recurrent splicing-altering mutations. Integration of splicing-altering mutations with other types of de novo mutation burdens allowed the prediction of eight novel NDD-risk genes. Our work expanded the capacity of in silico splicing models with potential applications in genetic diagnosis and the development of splicing-based precision medicine.
Spectrum of molecular hexaquarks
Authors: Wang Bo , Chen Kan , Meng Lu , Zhu Shi-Lin
Published: July 2024

We investigate the mass spectra of molecular-type hexaquark states in the dibaryon systems. These systems are composed of the charmed baryons [Σc(*),Ξc(′,*)], doubly charmed baryons [Ξcc(*)], and hyperons [Σ(*),Ξ(*)]. We consider all possible combinations of particle-particle and particle-antiparticle pairs, including the S-wave spin multiplets in each combination. We establish the underlying connections among the molecular tetraquarks, pentaquarks, and hexaquarks with the effective quark-level interactions. We find that the existence of molecular states in DD*, DD¯*, and ΣcD¯(*) systems leads to the emergence of a large number of deuteronlike hexaquarks in the heavy flavor sectors. Currently, there have been several experimental candidates for molecular tetraquarks and pentaquarks. The experimental search for near-threshold hexaquarks will further advance the establishment of the underlying dynamical picture of hadronic molecules and deepen our understanding of the role of spin-flavor symmetry in near-threshold residual strong interactions.

Published by the American Physical Society
2024
Communicating multiverses in a holographic de Sitter braneworld
Authors: Yadav Gopal
Published: July 2024

In this paper, we construct the wedge holography for the de Sitter space as a bulk theory. First, we discuss a more general mathematical construction of wedge holography in parallel with wedge holography construction for the AdS bulk, and then we construct the wedge holography in the extended static patch. In the first case, we prove that one can construct wedge holography for the de Sitter bulk for the static patch as well as the global coordinate metric on end-of-the-world branes. Extended static patch wedge holography is constructed by joining the two copies of double holography in DS/dS correspondence. We find that wedge holography with extended static patch metric leads to the emergence of communicating universes. Further, we propose a model which provides the theoretical evidence of communicating multiverses.

Published by the American Physical Society
2024
Thermal quenching of classical and semiclassical scrambling
Authors: Sadhasivam Vijay Ganesh , Hunt Andrew C. , Meuser Lars , Litman Yair , Althorpe Stuart C.
Published: July 2024

Quantum scrambling often gives rise to short-time exponential growth in out-of-time-ordered correlators. The scrambling rate over an isolated saddle point at finite temperature is shown here to be reduced by a hierarchy of quenching processes. Two of these appear in the classical limit, where escape from the neighborhood of the saddle reduces the rate by a factor of two, and thermal fluctuations around the saddle reduce it further; a third process can be explained semiclassically as arising from quantum thermal fluctuations around the saddle, which are also responsible for imposing the Maldacena-Shenker-Stanford bound.

Published by the American Physical Society
2024
Pyrazine-bridged polymetallic copper–iridium clusters
Authors: Tickner Ben. J. , Gammons Richard , Whitwood Adrian C. , Duckett Simon B.
Published: July 2024

Single crystals of the molecular compound, {Cu20Ir6Cl8(C21H24N2)6(C4H4N2)3]·3.18CH3OH or [({Cu10Ir3}Cl4(IMes)3(pyrazine))2(pyrazine)]·3.18CH3OH [where IMes is 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene], with a unique heterometallic cluster have been prepared and the structure revealed using single-crystal X-ray diffraction. The molecule is centrosymmetric with two {Cu10Ir3} cores bridged by a pyrazine ligand. The polymetallic cluster contains three stabilizing N-heterocyclic carbenes, four Cl ligands, and a non-bridging pyrazine ligand. Notably, the Cu—Ir core is arranged in an unusual shape containing 13 vertices, 22 faces, and 32 sides. The atoms within the tridecametallic cluster are arranged in four planes, with 2, 4, 4, 3 metals in each plane. Ir atoms are present in alternate planes with an Ir atom featuring in the peripheral bimetallic plane, and two Ir atoms featuring on opposite sides of the non-adjacent tetrametallic plane. The crystal contains two disordered methanol solvent molecules with an additional region of non-modelled electron density corrected for using the SQUEEZE routine in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. The given chemical formula and other crystal data do not take into account the unmodelled methanol solvent molecule(s).
Protonation of histidine rings using quantum-mechanical methods
Authors: Moriarty Nigel W. , Moussa Jonathan , Adams Paul D.
Published: July 2024

Histidine can be protonated on either or both of the two N atoms of the imidazole moiety. Each of the three possible forms occurs as a result of the stereochemical environment of the histidine side chain. In an atomic model, comparing the possible protonation states in situ, looking at possible hydrogen bonding and metal coordination, it is possible to predict which is most likely to be correct. A more direct method is described that uses quantum-mechanical methods to calculate, also in situ, the minimum geometry and energy for comparison, and therefore to more accurately identify the most likely protonation state.
From greenwashing to greenbleaching: green communication and mitigating moral outrage in the context of revisited situational crisis communication theory
Authors: Selaković Marko , Ljepava Nikolina , Bagheri Noushin , Al Chami Riad
Published: July 2024

Purpose

The purpose of the study is to examine the relevance and application of green communication in management of the risks associated with moral outrage inducing crises. The study aims to identify how green communication mitigates both crisis risks and moral outrage. Additionally, the research discusses ethical and unethical green communication practices in the context of their impact on relationships between organizations and stakeholders during the crisis.

Design/methodology/approach

The study is designed as exploratory research. Available English-language journal articles and conference proceedings have been examined to investigate the role of green communications in crisis response contexts. The application of the search criteria and initial filtering yielded a total of 139 publications for further analysis. Following a detailed review and subsequent filtering, the final sample of 66 unique cases has been selected and analyzed in the context of Situational Crisis Communication Theory.

Findings

The systematic review and document analysis indicated multitude of significances of green communications in the context of the updated Situational Crisis Communication Theory. Moreover, a novel phenomenon has been identified: greenbleaching is exaggerated or fabricated usage of green communication to mitigate risks in the organizational crises caused by ESG-unrelated factors or events.

Originality/value

This study offers greenbleaching as a novel concept. Moreover, this is the first research that examines unethical green communication in the context of moral outrage inducing crises. Insights for researchers and practitioners regarding sustainability communication, green communication, and crisis communication ethics are also incorporated.
Institutional ownership and cost of equity of Chinese firms
Authors: Huang Min , Jiang Hai , Ning Zhiyuan , Tu Jun
Published: July 2024

Purpose

The purpose of this paper is to investigate the role of institutional investors in the cost of equity for Chinese firms, especially state-owned enterprises (SOEs).

Design/methodology/approach

By using data from Chinese firms with a unique state ownership structure, we provide empirical evidence on whether institutional investors can help reduce the cost of equity for SOEs and non-SOEs, respectively, and if so, identify the underlying channels.

Findings

We find that an increase in the shareholdings of institutions, especially independent institutions, can lead to a reduction in the cost of equity. This effect is particularly prominent in SOEs compared to non-SOEs. Moreover, institutional investors promote corporate social responsibility activities and innovation activities of invested firms, thereby reducing the cost of equity.

Originality/value

This paper contributes to a comprehensive understanding of the effects of institutional shareholdings with heterogeneity on the cost of equity and their influential mechanisms in the process of mixed ownership reform.
Investigation of a novel hydraulic tunnel composite lining with polyurea coating interlayer
Authors: Li Bingqi , Zhang Jilei , Liu Xiaonan , Meng Tianyi
Published: July 2024

Purpose

Multilayer composite liner structures are the primary structural form of hydraulic tunnels. However, the bearing mechanism of multilayer composite liners has not been investigated thoroughly. Many existing design schemes do not properly achieve a balance between structural safety, anti-seepage capacity, and cost effectiveness. Thus, a new composite liner structure type and its theoretical model was proposed.

Design/methodology/approach

A novel hydraulic tunnel composite liner structure with a polyurea spray coating interlayer was proposed in this study. A theoretical model based on the state-space method was developed and verified using FEM models and existing theoretical models. Parametric analysis was conducted based on the theoretical model to investigate the influence of various variables, including interfacial shear stiffness, inner liner thickness, and outer liner elastic modulus.

Findings

It was concluded that the proposed theoretical model can be used successfully to calculate multilayer composite liner structures with high calculation efficiency. The overall deformation stiffness of the composite liner system increased with the interfacial shear stiffness. The sprayed coating interlayer significantly affects the residual force distribution between the outer and inner liners, which can also be affected by the adjustment of the thickness of the outer and inner liners. Thus, attention should be paid to these factors in the rational design of the proposed composite liner system.

Originality/value

With the development of China’s water conservancy projects, complex geological conditions, high surrounding rock stress, high internal and external water pressures, and other unique application scenarios have gradually increased. This places higher requirements on the bearing performance and impermeability of hydraulic tunnel lining structures. On the other hand, conventional hydraulic tunnel lining structures can hardly achieve a satisfactory balance between economy, structural safety, and impermeability. Thus, the proposed structure has the potential to be used in a wide range of applications.
Identifying and prioritizing the barriers to TQM implementation in food industries using group best-worst method (a real-world case study)
Authors: Mohammadpour Mona , Afrasiabi Ahmadreza , Yazdani Morteza
Published: July 2024

Purpose

In today’s age of globalization, every industry puts well-determined efforts toward surviving in the market. Industries are well aware of the fact that offering quality products and improving customer satisfaction is the strategic decision toward successful outcomes. During the recent years, food companies have undergone remarkable growth and development worldwide. In the Middle East, with a wide variety of demand and range of cultures, Iran is leading the food industries and possessed a top position of paramount importance. The present research aims to identify and prioritize barriers to implementing total quality management (TQM) in the Solico Food and Beverage Production Group (SFBPG) as a case study.

Design/methodology/approach

Firstly, an initial list of barriers is prepared based on a literature review. The identified barriers are then classified into four groups namely behavioral, technical-structural, human and cultural and strategic barriers based on the viewpoint of an expert team at a well-known food company. Secondly, the barriers are prioritized by adopting a special approach to multi-criteria decision-making (MCDM) called the Group Best-Worst Method (GBWM).

Findings

The obtained results reveal that the most substantial barriers prohibiting the successful implementation of TQM are lack of top management commitment and participation (0.334), high organizational burnout rate (0.128), instability and frequent changes of senior managers (0.123).

Originality/value

In general, this research has ranked the barriers from the most important one to the least significant instance. Additionally, this can enable managers and practitioners in the food industry to make worthy decisions and suggest multiple solutions to cope with obstacles to the successful implementation of TQM.
Analysis of barriers for adopting blockchain in agri-food supply chain management: a decision support framework
Authors: Virmani Naveen , Singh Rajesh Kumar
Published: July 2024

Purpose

Integrating digital technologies such as artificial intelligence and blockchain make the agri-food supply chain (ASCM) transparent, resilient and flexible. However, its adoption is quite complex due to various anticipated barriers. So, the presented research purposes to explore and investigate the barriers.

Design/methodology/approach

This study employs hybrid approach including Best-Worst Method (BWM) and Graph Theoretic Approach (GTA). Data were collected from industry experts employed in the agri-food sector and analyzed by means of standard operating procedures.

Findings

GTA results show that Technological barriers have the highest barrier intensity. Moreover, BWM results show that “Increased operational complexity” is the topmost barrier to adopting blockchain in ASCM. “Lack of interoperability” ranks second among the identified barriers.

Research limitations/implications

The results benefit the managers, practitioners and researchers to understand the anticipated barriers so that necessary strategies can be developed, and organizations can become more resilient, agile, transparent and traceable.

Originality/value

The presented work is the first to develop a mathematical model and assess the industry’s eagerness to adopt blockchain in ASCM. The proposed framework will greatly benefit the stakeholders working in agri-food sector.
Demonstrating and communicating artificial intelligence brand capabilities: Amazon Web Services sponsorship with the National Football League
Authors: Fortunato John A. , Kosterich Allie
Published: July 2024

Purpose

As artificial intelligence (AI) continues to influence sports league and team operations, the brands providing these services are sponsoring sports properties to demonstrate and communicate their performance capabilities. This article examines Amazon Web Services (AWS) sponsorship with the National Football League (NFL). This sponsorship features functional congruence, which is when a sponsor has a participatory role in performing services for the property.

Design/methodology/approach

The AWS sponsorship with the NFL is captured by examining specially created websites, in-game sponsored elements, and television commercials aired during the broadcast of NFL games. The AWS website focuses on the services profiled in this article.

Findings

AWS provides the NFL with performance-based (on-the-field) and business-based (off-the-field) services. Of particular note, AWS capabilities help the NFL create the game schedule and address the issue of player health and safety. Demonstrating functional congruence appears to be especially valuable in business-to-business marketing where purchase decisions are more focused on brand reliability. AWS television commercials feature the tagline, “if AWS can do this for the NFL, imagine what it can do for your business.”

Originality/value

With the role of AI in sports in its relative infancy, it is imperative to document what services AI brands are performing for a professional sports league. Examining AWS sponsorship with the NFL provides a timely, practical example of how an AI brand communicates and positions itself using sponsorship as a marketing strategy.
Investigating in-service teachers’ views on ChatGPT integration
Authors: Hojeij Zeina , Kuhail Mohammad Amin , ElSayary Areej
Published: July 2024

Purpose

This study aims investigate in-service teachers’ perspectives on the integration of ChatGPT, an artificial intelligence (AI)-driven chatbot, into United Arab Emirates (UAE) private schools. As the UAE progresses towards a knowledge-based economy, aligning with the goals of the UAE 2030 vision, this research assesses the capacity of ChatGPT to enhance the educational experience within the framework of technological pedagogical content knowledge.

Design/methodology/approach

A mixed-methods approach is used, combining a survey assessing teachers’ attitudes and a thematic analysis of open-ended responses, to explore the effectiveness, challenges and pedagogical implications of ChatGPT’s use in the classroom.

Findings

Findings reveal that teachers value ChatGPT for its potential to individualize learning and streamline the creation of educational materials, aligning with the shift towards student-centred approaches and the demands of 21st-century skills. However, significant challenges are noted, including ethical concerns, the need for reliable content and a necessity for extensive professional development to fully realize ChatGPT’s benefits.

Practical implications

While ChatGPT transforms teaching and learning practices, realizing this potential requires addressing critical issues through adaptive policy-making, continuous educator training and thoughtful integration into the curriculum.

Originality/value

The study highlights the importance of a collaborative approach to dealing with the details of AI in education, ensuring that advancements like ChatGPT align with the evolving educational paradigms of the UAE.
Visualising accountability: nurturing care and trust
Authors: Oliveira Lídia , Caria Ana , Nunes Diogo
Published: July 2024

Purpose

Based on the comprehensive definition of accounting of Carnegie et al. (2021a, 2021b), this study examines how visual imagery can expand and enhance accountability to stakeholders and create room for more human-centric accounts. This study aims to understand how this use can elucidate and prompt interpretations of rhetorical features aimed at envisioning legitimacy and being perceived as accountable.

Design/methodology/approach

Following a methodological interpretative approach, this paper draws on a qualitative case study based on a Portuguese charity, the Santa Casa da Misericordia do Porto, from 2019 to 2021, including the COVID-19 crisis period, analysing visual rhetoric in annual and sustainability reports.

Findings

The study illuminates how the visual images interact and evoke shared cultural understandings, shaping meanings that can symbolically foster organisational legitimacy and envisions accountability. These symbolic and emotive elements capture and make visible social impacts and reflect broader societal concerns.

Originality/value

The study of visual images within the accounting context can enrich the understanding of accounting as a technical, social and moral practice, while expanding the scope of accountability and promoting a more human-centred approach to accounting. It also adds to the literature on the persuasiveness and rhetoric of accounting and reporting visualisations and on charities’ accountability in crisis period.
Product market competition, debt rollover risk and financial default risk: evidence from Indian corporates
Authors: Chaturvedi Anurag , Singh Archana
Published: July 2024

Purpose

The study investigates the impact of the interaction effect of product market competition and rollover risk on the default risk of the firms.

Design/methodology/approach

The study used the sample of unbalanced panel data from Indian corporates without any survivability bias over the period from 2009 to 2020 consisting of 30,396 firm-year observations of 6,718 firms spread across 143 industry groups. The panel data regression tests the interaction effect in the context of the asset substitution problem, predation threat theory, competitive shock, and competitive risk.

Findings

The empirical results highlighted the dominance of the predatory effect of competition over the disciplinary advantage of short-term debts. The competitive shock to the industry results in a higher credit spread for refinancing short-term debt and significantly increases rollover risk for firms. Smaller firms have higher default risk from rollover losses than larger firms in the face of competition due to asset-substitution problems and strong rivalry. For firms with weaker fundamentals, the interaction effect of rollover risk and competition exacerbates the flight-to-quality problem, resulting in a systemic event.

Practical implications

The investors can benefit by factoring ex-ante the interdependence of competition, debt market illiquidity, and default premia while calculating the credit risk. The shareholders of competitive firms can reduce the moral hazard of refinancing the rollover losses and defaulting at a higher fundamental default threshold, by reducing sub-optimal utilization of funds by managers and agency costs.

Originality/value

As per the best of author knowledge, the present study is the first to study the moderating effect of product market competition in exacerbating default risk through the rollover channel.
Efficacy and safety of risankizumab by baseline corticosteroid use and achievement of corticosteroid‐free clinical and endoscopic outcomes in patients with moderately to severely active Crohn's disease
Authors: Schreiber Stefan , Cross Raymond K. , Panaccione Remo , D'Haens Geert , Bossuyt Peter , Dotan Iris , Colombel Jean‐Frederic , Louis Edouard , Dubinsky Marla C. , Kligys Kristina , Neimark Ezequiel , Song Alexandra , Zambrano Javier , Kalabic Jasmina , Cheng Erica , Zhang Yafei , Ferrante Marc
Published: July 2024

Background

Risankizumab is efficacious and well tolerated in adults with moderately to severely active Crohn's disease (CD).

Aim

To evaluate the corticosteroid‐sparing effect of risankizumab in CD.

Methods

During the 12‐week induction period, patients maintained stable baseline corticosteroid doses, up to 20 mg/day prednisone or equivalent. At week 0 of maintenance, a mandatory corticosteroid taper was started. This post hoc analysis evaluated corticosteroid‐free clinical and endoscopic outcomes at week 52 of maintenance; safety was also assessed.

Results

Of 889 patients randomised to induction with risankizumab 600 mg or placebo, 285 (32.1%) were taking baseline concomitant corticosteroids. Week 12 clinical remission and endoscopic response rates were greater for risankizumab 600 mg versus placebo, regardless of concomitant corticosteroid use. At week 52, 66.7%, 50.0% and 41.2% of patients taking risankizumab 180 mg, risankizumab 360 mg and (withdrawal) placebo, respectively, discontinued corticosteroids. Week 52 corticosteroid‐free clinical remission per stool frequency/abdominal pain score (risankizumab 180 mg [42.7%] or 360 mg [49.8%]; [withdrawal] placebo [39.0%]), corticosteroid‐free clinical remission per Crohn's Disease Activity Index (risankizumab 180 mg [51.0%] or 360 mg [49.5%]; [withdrawal] placebo [40.2%]), and corticosteroid‐free endoscopic response (risankizumab 180 mg [44.6%] or 360 mg [44.7%]; [withdrawal] placebo [20.7%]) rates were greater for risankizumab than placebo. Adverse event rates were generally similar, regardless of baseline corticosteroid use.

Conclusions

Efficacy of risankizumab 600 mg induction therapy was independent of concomitant corticosteroid use. Risankizumab 180 and 360 mg maintenance therapy yielded high rates of corticosteroid‐free clinical and endoscopic outcomes at week 52.