bluuebunny/crossref_metadata_2025 huggingface dataset:
Insect asynchronous flight requires neural circuit de-synchronization by electrical synapses
Authors: Hürkey Silvan , Niemeyer Nelson , Schleimer Jan-Hendrik , Ryglewski Stefanie , Schreiber Susanne , Duch Carsten
Published: February 2022

Despite profound mechanistic insight into motor pattern generation, for asynchronous insect flight – the most prevalent form of flight employed by >600.000 species – architecture and function of the underlying central pattern generating (CPG) neural network remain elusive. Combining electro- and optophysiology, Drosophila genetics, and mathematical modelling, we uncover a miniaturized circuit solution of motoneurons interconnected by electrical synapses that, contrary to doctrine, serve to de-synchronize network activity. This minimal gap-junctional motoneuron network suffices to translate unpatterned premotor input into stereotyped firing sequences which are conserved across species and generate stable wingbeat power. Mechanistically, network de-synchronization requires weak electrical coupling in conjunction with specific postsynaptic excitability dynamics, revealing an unexpected, generic feature in the control of neural circuit dynamics by electrical synapses.

One Sentence Summary

Electrical synapses de-synchronize neural network firing to enable stable wingbeat power during insect flight.
RNase H-based analysis of synthetic mRNA 5’ cap incorporation
Authors: Chan Siu-Hong , Whipple Joseph M. , Dai Nan , Kelley Theresa M. , Withers Kathryn , Tzertzinis George , Corrêa Ivan R , Robb G. Brett
Published: February 2022

Advances in mRNA synthesis and lipid nanoparticles technologies have helped make mRNA therapeutics and vaccines a reality. The 5’ cap structure is a crucial modification required to functionalize synthetic mRNA for efficient protein translation in vivo and evasion of cellular innate immune responses. The extent of 5’ cap incorporation is one of the critical quality attributes in mRNA manufacturing. RNA cap analysis involves multiple steps: generation of pre-defined short fragments from the 5’ end of the kilobase-long synthetic mRNA molecules using RNase H, a ribozyme or a DNAzyme, enrichment of the 5’ cleavage products, and LC-MS intact mass analysis. In this communication, we describe 1) a framework to design site-specific RNA cleavage using RNase H; 2) a method to fluorescently label the RNase H cleavage fragments for more accessible readout methods such as gel electrophoresis or high-throughput capillary electrophoresis; 3) a simplified method for post-RNase H purification using desthiobiotinylated oligonucleotides and streptavidin magnetic beads followed by elution using water. By providing a design framework for RNase H-based RNA 5’ cap analysis using less resource-intensive analytical methods, we hope to make RNA cap analysis more accessible to the scientific community.
A natural fusion of flavodiiron, rubredoxin, and NADH:rubredoxin oxidoreductase domains is the highly efficient water-forming oxidase of T. vaginalis
Authors: Abdulaziz Evana N. , Bell Tristan A. , Rashid Bazlur , Heacock Mina L. , Skinner Owen S. , Yaseen Mohammad A. , Chao Luke H. , Mootha Vamsi K. , Pierik Antonio J. , Cracan Valentin
Published: February 2022

Microaerophilic pathogens such as Giardia lamblia and Trichomonas vaginalis have robust oxygen consumption systems to detoxify oxygen and maintain the intracellular redox balance. This oxygen consumption is a result of the H2O-forming NADH oxidase activity of two distinct flavin-containing systems: H2O-forming NADH oxidases (NOXes) and multicomponent flavodiiron proteins (FDPs). Both systems are not membrane-bound and recycle NADH into oxidized NAD+ while simultaneously removing O2 from the local environment, making them crucial for the survival of human microaerophilic pathogens. In this study, using bioinformatic and biochemical analysis, we show that T. vaginalis lacks a NOX-like enzyme, and instead harbors three proteins that are very close in their amino acid sequence and represent a natural fusion between N-terminal FDP, central rubredoxin and C-terminal NADH:rubredoxin oxidoreductase domains. We demonstrate that this natural fusion protein with fully populated flavin redox centers unlike a “stand-alone” FDP (also present in T. vaginalis), directly accepts reducing equivalents of NADH to catalyze the four-electron reduction of O2 to water within a single polypeptide and with an extremely high turnover. Using single particle electron cryo-microscopy (cryo-EM) we present structural insight into the spatial organization of the FDP core within this multidomain fusion protein. Our studies represent an important addition to our understanding of systems that allow human protozoan parasites to maintain their optimal redox balance and survive transient exposure to oxic conditions.
Chemically modified dsRNA induces RNAi effects in insects in vitro and in vivo: A potential new tool for improving RNA-based plant protection
Authors: Howard John D. , Beghyn Myriam , Dewulf Nathalie , De Vos Yves , Philips Annelies , Portwood David , Kilby Peter M. , Oliver Duncan , Maddelein Wendy , Brown Stephen , Dickman Mark J.
Published: February 2022

Global agriculture loses over $100 billion of produce annually to crop pests such as insects. Many of these crop pests either have no current means of control or have developed resistance against chemical pesticides. Long dsRNAs are capable of inducing RNA interference (RNAi) in insects and are emerging as novel highly selective alternatives for sustainable insect management strategies. However, there are significant challenges associated with RNAi efficacy in insects. In this study, we synthesised a range of chemically modified long dsRNA in an approach to improve nuclease resistance and RNAi efficacy in insects. The results showed that dsRNA containing phosphorothioate modifications demonstrated increased resistance to southern green stink bug saliva nucleases. Phosphorothioate and 2’-fluoro modified dsRNA also demonstrated increased resistance to degradation by soil nucleases and increased RNAi efficacy in Drosophila melanogaster cell cultures. In live insects, chemically modified long dsRNA successfully resulted in mortality in both stink bug and corn rootworm. The results provide further mechanistic insight of RNAi efficacy dependence on modifications in the sense or antisense strand of the dsRNA in insects and demonstrate for the first time that RNAi can successfully be triggered by chemically modified long dsRNA in insect cells or live insects.
SRSF1 as a novel interacting partner for IFITM1/3 unravels the emergent role of IFITM1/3 mediating protein expression
Authors: Gómez-Herranz Maria , Faktor Jakub , Mayordomo Marcos Yébenes , Pilch Magdalena , Hernychova Lenka , Ball Kathryn L. , Vojtesek Borivoj , Hupp Ted R. , Kote Sachin
Published: February 2022

IFITM proteins play a role in cancer cell progression through undefined mechanisms. Here, we propose an emergent role of IFITM1/3 regulating protein synthesis. SBP-tagged IFITM1 protein was used to identify an association of IFITM1 protein with the cytosolic isoform of SRSF1 that transports mRNA to the ribosome. This cytosolic association was confirmed in situ using proximity ligation assays for SRSF1 and IFITM1/3, suggesting a role associated with translation. Accordingly, IFITM1/3 were shown to interact with HLA-B mRNA in response to IFNγ stimulation using RNA-protein proximity ligation assays. In addition, shotgun RNA sequencing in IFITM1/IFITM3 null cells and wt-SiHa cells indicated that reduced HLA-B gene expression does not account for lowered HLA-B protein synthesis in response to IFNγ. Furthermore, ribosome profiling using sucrose gradient sedimentation identified a reduction in 80S ribosomal fraction an IFITM1/IFITM3 null cells compared to their wild-type counterpart, partially reverted by IFITM1/3 complementation. Our data all together link the binding of IFITM1/3 proteins to HLA-B mRNA and SRSF1 as a mechanism to catalyze the synthesis of target proteins, suggesting an RNA chaperonin role for IFITM1/3 proteins.

Significance

IFITMs are widely studied for their role in inhibiting viruses, and multiple studies have associated IFITMs with cancer progression. However, mechanistic insights are not well understood. Our study proposes that IFITMs have a role regulating protein synthesis, a pivotal function highly relevant for viral infection and cancer progression. Our results suggest that IFITM1/3 is present in the ribosomal fraction and regulates particular protein expression; among them, we identified HLA-B. Changes in HLA-B expression could impact the presentation and recognition of oncogenic antigens on the cell surface by cytotoxic T cells and, ultimately, limit tumor cell eradication. In addition, the role of IFITMs mediating protein translation is relevant, as has the potential of regulating the expression of viral and oncogenic proteins.
Effects of calorie restriction on reactive oxygen species production by mitochondrial reverse electron transport, mitochondrial permeability transition pore, and beta-adrenergic stimulation during cardiac hypertrophy
Authors: Lucas Aline Maria Brito , Palacio Plinio Bezerra , Cunha Pedro Lourenzo Oliveira , Facundo Heberty Tarso
Published: February 2022

Calorie restriction is a nutritional intervention that reproducibly protects against the maladaptive consequences of cardiovascular diseases. Pathological cardiac hypertrophy leads to cellular growth, dysfunction (with mitochondrial dysregulation), and oxidative stress. The mechanisms behind the cardiovascular protective effects of calorie restriction are still under investigation. In this study, we addressed the impact of calorie restriction on mitochondria, oxidative stress markers, and β-adrenergic signaling during cardiac hypertrophy. This dietetic intervention prevented cardiac protein elevation, decreased atrial natriuretic peptide levels, and blocked the increase in heart weight per tibia length index seen in isoproterenol-induced cardiac hypertrophy. Our data suggest that inhibition of cardiac pathological growth by calorie restriction is accompanied by a lower mitochondrial reactive oxygen species formation and improved mitochondrial content. We also found that superoxide dismutase and glutathione peroxidase activities negatively correlate with cardiac hypertrophy. Calorie restriction also attenuated the opening of the Ca2+-induced mitochondrial permeability transition pore in mitochondria isolated from isoproterenol-treated mice. Isoproterenol (a β-agonist) increases cardiac rate (chronotropic response) and force of contraction (inotropic response). Given the nature of cardiac hypertrophy induction by isoproterenol, we tested whether calorie restriction could change the cardiac β-adrenergic sensitivity. Using isolated rat hearts in a langendorff system, we found that calorie restriction mice (similar to controls) have preserved β-adrenergic signaling. On the flipside, hypertrophic hearts (treated for seven days with isoproterenol) were insensitive to β-adrenergic activation using isoproterenol (50 nM). Despite protecting against cardiac hypertrophy, calorie restriction did not alter the lack of responsiveness to isoproterenol of isolated hearts harvested from isoproterenol-treated rats. These results suggest (through a series of mitochondrial, oxidative stress, and cardiac hemodynamic studies) that calorie restriction possesses beneficial effects against hypertrophic cardiomyopathy. However, it may lack effects on some of the hypertrophic consequences, such as β-adrenergic signaling repression.
AlphaFold accurately predicts distinct conformations based on oligomeric state of a de novo designed protein
Authors: Cummins Matthew C. , Jacobs Tim M. , Teets Frank D. , DiMaio Frank , Tripathy Ashutosh , Kuhlman Brian
Published: February 2022

Using the molecular modeling program Rosetta, we designed a de novo protein, called SEWN0.1, that binds the heterotrimeric G protein Gαq. The design is helical, well-folded, and primarily monomeric in solution at a concentration of 10 uM. However, when we solved the crystal structure of SEWN0.1, we observed a dimer in a conformation incompatible with binding Gαq. Unintentionally, we had designed a protein that adopts alternate conformations depending on its oligomeric state. Recently, there has been tremendous progress in the field of protein structure prediction as new methods in artificial intelligence have been used to predict structures with high accuracy. We were curious if the structure prediction method AlphaFold could predict the structure of SEWN0.1 and if the prediction depended on oligomeric state. When AlphaFold was used to predict the structure of monomeric SEWN0.1, it produced a model that resembles the Rosetta design model and is compatible with binding Gαq, but when used to predict the structure of a dimer, it predicted a conformation that closely resembles the SEWN0.1 crystal structure. AlphaFold’s ability to predict multiple conformations for a single protein sequence should be useful for engineering protein switches.
Nutrient gradients mediate creation of highly resistant layers in structured microbial populations during antibiotic exposures
Authors: Stevanovic Mirjana , Boukéké-Lesplulier Thomas , Hupe Lukas , Hasty Jeff , Bittihn Philip , Schultz Daniel
Published: February 2022

Antibiotic treatments often fail to eliminate bacterial populations due to heterogeneity in how individual cells respond to the drug. In structured bacterial populations such as biofilms, bacterial metabolism and environmental transport processes lead to an emergent phenotypic structure and self-generated nutrient gradients towards the interior of the colony, which can affect cell growth, gene expression and susceptibility to the drug. Even in single cells, survival depends on a dynamic interplay between the drug’s action and the expression of resistance genes. How expression of resistance is coordinated across populations in the presence of such spatiotemporal environmental coupling remains elusive. Using a custom microfluidic device, we observe the response of spatially extended microcolonies of tetracycline-resistant E. coli to precisely defined dynamic drug regimens. We find an intricate interplay between drug-induced changes in cell growth and growth-dependent expression of resistance genes, resulting in the redistribution of nutrients and the reorganization of growth patterns. This dynamic environmental feedback affects the regulation of drug resistance differently across the colony, generating dynamic phenotypic structures that maintain colony growth during exposure to high drug concentrations and increase population-level resistance to subsequent exposures. A mathematical model linking metabolism and the regulation of gene expression is able to capture the main features of spatiotemporal colony dynamics. Uncovering the fundamental principles that govern collective mechanisms of antibiotic resistance in spatially extended populations will allow the design of optimal drug regimens to counteract them.
Regulation of adult neurogenesis and neuronal differentiation by Neural Cell Adhesion Molecule 2 (NCAM2)
Authors: Ortega-Gasco Alba , Parcerisas Antoni , Hino Keiko , Herranz-Perez Vicente , Ulloa Fausto , Elias-Tersa Alba , Bosch Miquel , Garcia-Verdugo Jose Manuel , Simo Sergi , Pujadas Lluis , Soriano Eduardo
Published: February 2022

Adult neurogenesis persists in mammals in the neurogenic zones where newborn neurons are incorporated into existing neuronal circuits. Relevant molecular elements of the neurogenic niches include the family of Cell Adhesion Molecules (CAM), which participate in signal transduction and regulate radial glial progenitor's (RGPs) survival, division and differentiation. The Neural Cell Adhesion Molecule 2 (NCAM2) is expressed in brain development and in adult stages, and controls dendrite arborisation and synaptic formation and maintenance during development. Nevertheless, the role of NCAM2 in neurogenesis and lineage progression is not well understood. Here we analyse the functions of NCAM2 in the regulation of RGPs in adult neurogenesis in the dentate gyrus and during corticogenesis, by using different lentiviral-mediated genetic approaches to modulate its expression, both in vivo and in vitro. First, we characterized the expression of NCAM2 among the main actors of the neurogenic process revealing different levels of NCAM2 amid the progression of RGPs and the formation of juvenile neurons. Further, we show that overexpression of NCAM2 arrest infected cells in a RGP-like state, with characteristic morphological, immunocytochemical and electron microscopy features. In contrast, NCAM2 overexpression in embryonic cortical progenitors does not seems to alter cell fate, but causes transient migration deficits. These results reveal a differential role of NCAM2 in the regulation of adult and embryonic RGPs, and specifically, a significant implication of NCAM2 in the regulation and progression of RGPs during adult neurogenesis in the hippocampus.
Phase separating RNA binding proteins form heterogeneous distributions of clusters in subsaturated solutions
Authors: Kar Mrityunjoy , Dar Furqan , Welsh Timothy J. , Vogel Laura , Kühnemuth Ralf , Majumdar Anupa , Krainer Georg , Franzmann Titus M. , Alberti Simon , Seidel Claus A. M. , Knowles Tuomas P.J. , Hyman Anthony A. , Pappu Rohit V.
Published: February 2022

Macromolecular phase separation is thought to be one of the processes that drives the formation of membraneless biomolecular condensates in cells. The dynamics of phase separation, especially at low endogenous concentrations found in cells, are thought to follow the tenets of classical nucleation theory describing a sharp transition between a dense phase and a dilute phase characterized by dispersed monomers. Here, we usedin vitrobiophysical studies to study subsaturated solutions of phase separating RNA binding proteins with intrinsically disordered prion like domains (PLDs) and RNA binding domains (RBDs). Surprisingly, we find that subsaturated solutions are characterized by heterogeneous distributions of clusters comprising tens to hundreds of molecules. These clusters also include low abundance mesoscale species that are several hundreds of nanometers in diameter. Our results show that cluster formation in subsaturated solutions and phase separation in supersaturated solutions are strongly coupled via sequence-encoded interactions. Interestingly, however, cluster formation and phase separation can be decoupled from one another using solutes that impact the solubilities of phase separating proteins. They can also be decoupled by specific types of mutations. Overall, our findings implicate the presence of distinct, sequence-specific energy scales that contribute to the overall phase behaviors of RNA binding proteins. We discuss our findings in the context of theories of associative polymers.

Significance Statement

Membraneless biomolecular condensates are molecular communities with distinct compositional preferences and functions. Considerable attention has focused on phase separation as the process that gives rise to condensates. Here, we show that subsaturated solutions of RNA binding proteins form heterogeneous distributions of clusters in subsaturated solutions. The formation of clusters in subsaturated solutions and condensates in supersaturated solution are coupled through sequence-specific interactions. Given the low endogenous concentrations of phase separating proteins, our findings suggest that clusters in subsaturated conditions might be of functional relevance in cells.
BMAL1 drives muscle repair through control of hypoxic NAD+ regeneration in satellite cells
Authors: Zhu Pei , Hamlish Noah X. , Thakkar Abhishek Vijay , Steffeck Adam W.T. , Rendleman Emily J. , Khan Nabiha H. , Waldeck Nathan J. , DeVilbiss Andrew W. , Martin-Sandoval Misty S. , Mathews Thomas P. , Chandel Navdeep S. , Peek Clara B.
Published: February 2022

The process of tissue regeneration occurs in a developmentally timed manner, yet the role of circadian timing is not understood. Here, we identify a role for the adult muscle stem cell (MuSC)-autonomous clock in the control of muscle regeneration following acute ischemic injury. We observed greater muscle repair capacity following injury during the active/wake period as compared with the inactive/rest period in mice, and loss of Bmal1 within MuSCs leads to impaired muscle regeneration. We demonstrate that Bmal1 loss in MuSCs leads to reduced activated MuSC number at day 3 postinjury, indicating a failure to properly expand the myogenic precursor pool. In cultured primary myoblasts, we observed that loss of Bmal1 impairs cell proliferation in hypoxia (a condition that occurs in the first 1–3 d following tissue injury in vivo), as well as subsequent myofiber differentiation. Loss of Bmal1 in both cultured myoblasts and in vivo activated MuSCs leads to reduced glycolysis and premature activation of prodifferentiation gene transcription and epigenetic remodeling. Finally, hypoxic cell proliferation and myofiber formation in Bmal1-deficient myoblasts are restored by increasing cytosolic NAD+. Together, we identify the MuSC clock as a pivotal regulator of oxygen-dependent myoblast cell fate and muscle repair through the control of the NAD+-driven response to injury.
Crystal structures of two Co(NCS)2 urotropine coordination compounds with different Co coordinations
Authors: Krebs Christoph , Jess Inke , Näther Christian
Published: February 2022

The reaction of Co(NCS)2 with urotropine in ethanol leads to the formation of two different compounds, namely, bis(ethanol-κO)bis(hexamethylenetetramine-κN)bis(thiocyanato-κN)cobalt(II)–diaqua-κ
2O-bis(hexamethylenetetramine-κN)bis(thiocyanato-κN)cobalt(II)–ethanol–hexamethylenetetramine (1.2/0.8/1.6/4), [Co(NCS)2(C6H12N4)2(C2H6O)2]1.2·[Co(NCS)2(C6H12N4)2(H2O)2]0.8·1.6C2H6O·4C6H12N4, 1, and tris(ethanol-κO)(hexamethylenetetramine-κN)bis(thiocyanato-κN)cobalt(II), [Co(NCS)2(C6H12N4)(C2H6O)3], 2. In the crystal structure of compound 1, two crystallographically independent discrete complexes are observed that are located on centres of inversion. In one of them, the Co cation is octahedrally coordinated to two terminal N-bonded thiocyanate anions, two urotropine ligands and two ethanol molecules, whereas in the second complex 80% of the coordinating ethanol is exchanged by water. Formally, compound 1 is a mixture of two different complexes, i.e. diaquadithiocyanatobis(urotropine)cobalt(II) and diethanoldithiocyanatobis(urotropine)cobalt(II), that contain additional ethanol and urotropine solvate molecules leading to an overall composition of [Co(NCS)2(urotropine)2(ethanol)1.2(H2O)0.8·0.8ethanol·4urotropine. Both discrete complexes are linked by intermolecular O—H...O and O—H...N hydrogen bonding and additional urotropine solvate molecules into chains, which are further connected into layers. These layers combine into a three-dimensional network by pairs of centrosymmetric intermolecular C—H...S hydrogen bonds. In the crystal structure of compound 2, dithiocyanato(urotropine)triethanolcobalt(II), the cobalt cation is octahedrally coordinated to two terminal N-bonded thiocyanate anions, one urotropine ligand and three ethanol molecules into discrete complexes, which are located in general positions. These complexes are linked by intermolecular O—H...N hydrogen bonding into layers, which are further connected into a three-dimensional network by intermolecular C—H...S hydrogen bonding.
Crystal structure of 1,1′,2,2′,4,4′-hexaisopropylmagnesocene
Authors: Bachmann Nico , Wirtz Lisa , Morgenstern Bernd , Müller Carsten , Schäfer André
Published: February 2022

The title compound, 3Cp2Mg or [Mg(C14H23)2], was synthesized from the corresponding triisopropylcyclopentadiene by treatment with n-butyl-sec-butylmagnesium. The structural characterization by single-crystal X-ray diffraction revealed that the compound crystallizes in the triclinic space group P\overline{1} with half a molecule per asymmetric unit and a staggered arrangement of the cyclopentadienide ligands.
Effects of Big Five personality traits and market mavenship on consumers' intention to spread word-of-mouth in the art context
Authors: Chieffi Verdiana , Pichierri Marco , Peluso Alessandro M. , Collu Cristiana , Guido Gianluigi
Published: February 2022

Purpose

This study investigates the transmission of art-related aspects (i.e. art products or services and people's experiences at museums) via word-of-mouth (WOM) from a personality perspective. Specifically, the study explores the effects of the Big Five personality traits (based on the five-factor model) and market mavenship (i.e. the propensity to provide general marketplace and shopping information) on intention to spread WOM in the art context.

Design/methodology/approach

Data were gathered through two field surveys, conducted via a structured questionnaire and analyzed using multiple regression analysis.

Findings

Results indicate that extraversion is the only Big Five personality trait that increases WOM intention (e.g. by talking to others about a visit to a museum). Market mavenship also increases such an intention (e.g. by talking to others about art services).

Practical implications

The study's findings could motivate arts managers to formulate and/or refine segmentation strategies around their consumers' personality traits, since these variables may differently motivate them to spread art-related WOM. The findings may also help companies and institutions operating in the art industry to design communication strategies oriented around their consumers' personality type to appropriately connect with different groups of customers based on their innate human drives.

Originality/value

This is the first study to assess the effects of Big Five personality traits and market mavenship on WOM intention in the art context, thus expanding scholarly understanding of psychological drivers behind arts-related WOM.
Sustainability teaching using case-based debates
Authors: Georgallis Panikos , Bruijn Kayleigh
Published: February 2022

Purpose

Given today’s pressing societal challenges, business schools are increasingly expected to incorporate sustainability in their curricula. Yet, while research on corporate sustainability is on the rise, there is less innovation in teaching methods as most institutions rely on traditional methods to teach sustainability in the classroom. This paper aims to present the case-based debate as an appropriate teaching method for exposing students to the complexity of business sustainability issues.

Design/methodology/approach

The pedagogical background of the traditional case method and the debate method have been analyzed to provide an integrated understanding of the benefits of combining the two in the case-based debate. Building on the authors’ experiences from using case-based debates in the classroom, the paper describes what a case-debate is and how it can be implemented.

Findings

The paper offers a practical tool that can be used to teach sustainability in business schools and other educational institutions. Case-based debates can elicit active participation, support the development of students’ critical thinking skills and improve reflexivity by compelling students to seriously and actively engage with opposing viewpoints on a given issue.

Originality/value

This paper presents a hybrid approach for sustainability teaching that combines the benefits of the traditional case method with those of an in-class debate. The case-based debate method has received little attention in educational research and business sustainability teaching practice but can serve multiple teaching objectives relevant to sustainability teaching.
The demand-side dynamics of firms' within-industry geographic scope
Authors: Manral Lalit
Published: February 2022

Purpose

The author invokes the concept of strategic adaptation to first specify the evolutionary as well as the strategic character of the causal mechanism (“intra-industry exit”), and second to explain its effect on the evolution of firms' within-industry geographic scope. The author reconciles the two competing logics for firm behavior – strategic choice and environmental selection – that underpin alternate explanations for the relationship between intra-industry exit and the evolution of geographic scope. This paper contributes to both theory and empirics concerning the dynamics of firms' competitive scope, in general, and within-industry geographic scope, in particular.

Design/methodology/approach

The US long-distance telecom services industry during the period 1984–1996, which satisfies the empirical requirements of a geographically fragmented industry characterized by demand-side heterogeneity across the submarkets, provides the research setting and panel data to test the empirical hypotheses.

Findings

The author finds that while the firms' overall performance influences their intra-industry exit decisions, it is the firm-in-market performance that influences their decision to exit a specific submarket. The author also finds that intra-industry exit decision, when influenced by firm performance, does lead to reduction in geographic scope.

Research limitations/implications

This context-specific theory, which conceptualizes the dynamics of firms' geographic scope as an evolutionary process, explains the temporal change in the geographic scope of firms during the latter part of the demand growth stage of a geographically fragmented industry.

Originality/value

This analysis of the demand-side dynamics of firms' within-industry geographic scope focuses on the hypothetical causal effect of intra-industry exit, a pervasive business phenomenon. First, the demand-side analysis of the evolution of geographic scope is grounded in a theoretical framework that melds firm dynamics with submarket dynamics and industry dynamics. Second, this analysis explicates the demand-side underpinnings of the strategic adaptive mechanism.
Acoustic signature reveals blue whales tune life‐history transitions to oceanographic conditions
Authors: Oestreich William K. , Abrahms Briana , McKenna Megan F. , Goldbogen Jeremy A. , Crowder Larry B. , Ryan John P.
Published: February 2022

Matching the timing of life‐history transitions with ecosystem phenology is critical for the survival of many species, especially those undertaking long‐distance migrations. As a result, whether and how migratory populations adjust timing of life‐history transitions in response to environmental variability are important questions in ecology and conservation. Yet the flexibility and drivers of life‐history transitions remain largely untested for migratory marine populations, which contend with the unique spatiotemporal dynamics and sensory conditions found in marine ecosystems.

Here, using an acoustic signature of blue whales’ regional population‐level transition from foraging to breeding migration, we document significant interannual flexibility in the timing of this life‐history transition (spanning roughly 4 months) over a continuous 6‐year study period.

We further show that variability in the timing of this transition follows the oceanographic phenology of blue whales’ foraging habitat, with a later transition from foraging to breeding migration occurring in years with an earlier onset, later peak and greater accumulation of biological productivity.

These findings indicate that blue whales delay the transition from foraging to southward migration in years of the highest and most persistent biological productivity, consistent with the hypothesis that this population maximizes energy intake on foraging grounds rather than departing towards breeding grounds as soon as sufficient energy reserves are accumulated.

The use of flexible cues (e.g. foraging conditions and long‐distance acoustic signals) in timing a major life‐history transition may be key to the persistence of this endangered population facing the pressures of rapid environmental change. Furthermore, these results extend theoretical understanding of the flexibility and drivers of population‐level migration to a relatively solitary marine migrant.

Read the free Plain Language Summary for this article on the Journal blog.
Short Interest and Corporate Investment: Evidence from Supply Chain Partners†
Authors: Chen Xia , Gong Guojin , Luo Shuqing
Published: February 2022

We investigate whether short interest affects supply chain partners' investments. This investigation is important for understanding the real effect of short sellers in facilitating stakeholders' investment decisions. Prior research suggests that short interest conveys negative news in a timely manner, which predicts future deterioration in firm fundamentals. We predict and find that a supplier's future investments decrease with its major customers' short interest. Consistent with predictions, this result is more pronounced when customers' short interest is more informative about their future performance, when customers have a more opaque information environment, and when suppliers incur lower customer switching costs. The results are robust when we use various approaches to address endogeneity concerns and establish causality. Our findings suggest that short sellers provide valuable information to supply chain partners when making investment decisions.
Limitation of standard pseudoisochromatic plates in identifying colour vision deficiencies when compared with genetic testing
Authors: Arnegard Solveig , Baraas Rigmor C. , Neitz Jay , Hagen Lene A. , Neitz Maureen
Published: February 2022

Purpose

The Ishihara pseudoisochromatic (PIC) plate test is the most used test for identifying red‐green colour‐deficient individuals, but it is not known how the Ishihara results compare with that of genetics testing. Here, the outcome of genotype analysis of OPN1LW and OPN1MW was compared with that of the Ishihara (24‐plate ed., 1964) and the Hardy‐Rand‐Rittler (4th ed. 2002) PIC plate tests.

Methods

Healthy participants with normal habitual visual acuity (n = 454, 16–24 years; 193 males; logMAR ≤ 0.00) gave saliva samples for opsin gene analysis and performed the two PIC plate tests as part of a cross‐sectional study. The criteria for failing the PIC tests were according to manufacturers' instructions. DNA was extracted and used in genotyping assays of OPN1LW and OPN1MW genes from each participant using the Agena MassArray genotyping system.

Results

Ten male (5.2%) and 3 (1.1%) female participants were identified as red‐green colour deficient based on PIC tests alone. The combination of MassArray and PIC test results identified 10.4% of male and 0.8% of female participants to be colour deficient (males: 0.5% protan and 9.9% deutan; females: 0.8% deutan). Hardy–Weinberg calculations based on male frequencies from combining the MassArray and the PIC test results gave female frequency estimates of colour deficiency and carriers closely matching measured frequencies.

Conclusions

MassArray identified twice as many colour‐deficient males as identified from PIC tests alone. Combining results from MassArray and the PIC tests proves to be more reliable than any single test at correctly identifying red‐green colour‐deficient individuals and carriers.
How does workplace ostracism hurt employee creativity? Thriving at work as a mediator and organization‐based self‐esteem as a moderator
Authors: Zhang Rui , Kang Haiying , Jiang Zhou , Niu Xiongying
Published: February 2022

Drawing on the socially embedded model of thriving and conservation of resources theory, we explore the negative effect of workplace ostracism on employee thriving. We model organization‐based self‐esteem (OBSE) as a moderator and extend our examination to the downstream implications of thriving for employee creativity. Using a scenario‐based experiment (Study 1) with 387 working adults, we find that workplace ostracism is more likely to prevent workers with higher levels of OBSE from thriving at work. This finding is verified in Study 2, in which we use multiwave, multisource data collected from 207 employees and their supervisors to test the proposed model. The results further show that for employees with higher levels of OBSE, thriving at work is more likely to mediate the relationship between workplace ostracism and employee creativity. These findings provide important practical implications for fostering employee thriving and promoting creativity in the workplace by managing workplace ostracism.
Social gaze in preterm infants may act as an early indicator of atypical lateralization
Authors: Davis Rachael , Donati Georgina , Finnegan Kier , Boardman James P. , Dean Bethan , Fletcher‐Watson Sue , Forrester Gillian S.
Published: February 2022

Visual field biases have been identified as markers of atypical lateralization in children with developmental conditions, but this is the first investigation to consider early lateralized gaze behaviors for social stimuli in preterm infants. Eye‐tracking methods with 51 preterm (33 male, 92.1% White) and 61 term‐born (31 male, 90.1% White) infants aged 8–10 months from Edinburgh, UK, captured the development of visual field biases, comparing gaze behavior to social and non‐social stimuli on the left versus right of the screen. Preterm infants showed a significantly reduced interest to social stimuli on the left versus right compared to term children (d = .58). Preterm children exhibit early differential orienting preferences that may be an early indicator of atypical lateralized function.
Guidelines for Colorectal Cold Polypectomy (supplement to “Guidelines for Colorectal Endoscopic Submucosal Dissection/Endoscopic Mucosal Resection”)
Authors: Uraoka Toshio , Takizawa Kohei , Tanaka Shinji , Kashida Hiroshi , Saito Yutaka , Yahagi Naohisa , Yamano Hiro‐o , Saito Shoichi , Hisabe Takashi , Yao Takashi , Watanabe Masahiko , Yoshida Masahiro , Saitoh Yusuke , Tsuruta Osamu , Igarashi Masahiro , Toyonaga Takashi , Ajioka Yoichi , Fujimoto Kazuma , Inoue Haruhiro
Published: February 2022

The Japan Gastroenterological Endoscopy Society published the second edition of the “Guidelines for Colorectal Endoscopic Submucosal Dissection/Endoscopic Mucosal Resection” in 2019 to clarify the indications for colorectal endoscopic mucosal resection (EMR) and endoscopic submucosal dissection and to ensure appropriate preoperative diagnoses as well as effective and safe endoscopic treatment in front‐line clinical settings. Endoscopic resection with electrocautery, including polypectomy and EMR, is indicated for colorectal polyps. Recently, the number of facilities introducing and implementing cold polypectomy without electrocautery has increased. Herein, we establish supplementary guidelines for cold polypectomy. Considering that the level of evidence for each statement is limited, these supplementary guidelines must be verified in clinical practice.
Can a virtual learning module foster empathy in dental undergraduate students?
Authors: Anishchuk Sviatlana , Kubacki Angela , Howell Yvonne , van Harten Maria T. , Yarascavitch Carilynne , MacGiolla Phadraig Caoimhin
Published: February 2022

Background

Empathy is an essential part of patient‐centred health care, which positively benefits both patients and clinicians. There is little agreement regarding how best to design and deliver training for healthcare trainees to impart the skills and behaviours of clinical empathy. The study aimed to inform the field by sharing an educational intervention where we aimed to improve empathy amongst dental undergraduate students in Trinity College Dublin using a virtual learning module.

Methods

Adopting pre–post‐repeat pre‐experimental design, dental professional students completed the Jefferson Scale of Empathy (JSE) for Health Professional Students immediately prior to and after a three‐week virtual programme designed to increase clinical empathy. Using a three‐factor model described for the JSE in the literature, scores were evaluated for internal consistency and paired tests were performed on scores appropriate to their distributions. Seven‐point Likert scales were scored to record student experience of training and technology, which are reported descriptively.

Results

Most of the 37 participants were female (76%) and represented dental science (N = 27) and dental hygiene roles (N = 7). Results revealed a mean JSE‐HPS scale score rise from 110.0 (SD = 10.4) to 116.4 (SD = 11.1), which represented a rise of 5.8% (t (36) = 3.6, p = 0.001). The three factors associated with cognitive empathy, namely perspective‐taking (T(36) = 3.931, p < 0.001; walking in the patient's shoes T(36) = 2.093, p = 0.043); and compassionate care (Z = 2.469, p = 0.014) were all found to have increased after the intervention. Students reported a positive experience of discipline‐specific and generic videos as part of the module.

Conclusion

The study demonstrated that a virtual educational module was associated with an increase in empathy amongst dental undergraduate students. The design of a blended module incorporating the Massive Open Online Course (MOOC) and virtual learning are beneficial and have a promising future.
Detecting patterns of vertebrate biodiversity across the multidimensional urban landscape
Authors: Alberti Marina , Wang Tianzhe
Published: February 2022

Explicit characterisation of the complexity of urban landscapes is critical for understanding patterns of biodiversity and for detecting the underlying social and ecological processes that shape them. Urban environments exhibit variable heterogeneity and connectivity, influenced by different historical contingencies, that affect community assembly across scales. The multidimensional nature of urban disturbance and co‐occurrence of multiple stressors can cause synergistic effects leading to nonlinear responses in populations and communities. Yet, current research design of urban ecology and evolutionary studies typically relies on simple representation of the parameter space that can be observed. Sampling approaches apply simple urban gradients such as linear transects in space or comparisons of urban sites across the urban mosaic accounting for a few variables. This rarely considers multiple dimensions and scales of biodiversity, and proves to be inadequate to explain observed patterns. We apply a multidimensional approach that integrates distinctive social, ecological and built characteristics of urban landscapes, representing variations along dimensions of heterogeneity, connectivity and historical contingency. Measuring species richness and beta diversity across 100 US metropolitan areas at the city and 1‐km scales, we show that distinctive signatures of urban biodiversity can result from interactions between socioecological heterogeneity and connectivity, mediated by historical contingency.
Dynamic organization of the bone marrow plasma cell niche
Authors: Aaron Tonya S. , Fooksman David R.
Published: February 2022

Prophylactic, serological memory relies on maintaining stable reservoirs of plasma cells, capable of constitutively‐secreting high‐affinity, anti‐pathogen antibody for a lifetime. Although antibody titers generated by some vaccines (e.g. measles) can last a lifetime, other vaccinations (e.g. tetanus) need repeated boosting because long‐lived plasma cells are not produced or maintained. Moreover, in old age, the ability to generate long‐lived humoral responses diminishes. Despite their importance to health, it is unknown how long‐lived plasma cells survive over years, whereas most antibody secreting cells die off within weeks after vaccination. In this review, we focus on how known factors regulate the longevity of plasma cell fitness and survival, and how that landscape is shaped by environmental influences, such as inflammation, infection and aging. In addition, we highlight newly discovered cellular dynamics in the bone marrow that may reframe the mechanisms supporting long‐lived plasma cell survival and function.
Modifications to rapid response team (medical emergency team) activation criteria and its impact on patient safety
Authors: Chinthamuneedi Raja M. , Phaltane Sandeep , Chinthamuneedi Meher P. , Kondalsamy‐Chennakesavan Srinivas , K. Cheung Benjamin
Published: February 2022

Background

Modifications to rapid response team (RRT) activation criteria occur commonly in Australian hospitals without evidence to define their use.

Aims

To evaluate the effectiveness of RRT activation criteria modifications in preventing RRT activation and differences in adverse events associated with treatment delays caused by modifications.

Methods

A prospective chart audit of hospital patients with RRT activation criteria modifications admitted during a 12‐month period in a large regional hospital in Toowoomba, Australia. The incidence of RRT activation criteria modifications, RRT activations and rates of adverse events following criteria modifications were investigated. Adverse events were defined as a delayed treatment on the ward, unplanned intensive care unit admission, cardiac arrest and unexpected death. Differences in patient outcomes among medical and surgical patients were also investigated.

Results

A total of 271 patients out of 4009 admitted patients had modifications to their RRT activation criteria. There was no difference in rates of RRT activation in patients with modified criteria compared with patients with unmodified criteria (P = 0.37). In patients with RRT activation criteria modifications, rates of adverse events were higher in patients who met their modified RRT criteria (93.3%) compared with those who did not meet modified RRT criteria (3.8%; P < 0.001). Additionally, in patients with modifications, rates of adverse events were higher in medical patients (27.6%; n = 50) compared with surgical patients (15.6%; n = 14; P = 0.03).

Conclusions

The results strongly suggest that RRT criteria modification is associated with no difference in rates of RRT activation and with detrimental impacts on patient safety, particularly in medical patients.
Patient‐reported experience measures in deprescribing for hospitalised older patients: a prospective, multicentre, observational study
Authors: Ngui Keat , Lam Patrick , Materne Mishael , Hilmer Sarah N.
Published: February 2022

Background

Hospitalisation provides an opportunity for medication review and deprescribing. Patient‐reported experience measures (PREM) for deprescribing in older patients in hospital are not well described.

Aims

To pilot test and describe PREM for deprescribing in older patients, compare PREM by patient characteristics and investigate patients’ awareness of medication changes on hospital discharge.

Methods

This prospective, multicentre, observational cohort study at two tertiary hospitals in Sydney, Australia, evaluated the PREM questionnaire developed by the NSW Therapeutic Advisory Group. It was completed by patients (or their next of kin) recruited from acute geriatric medicine and orthogeriatric services. Association with nine patient characteristics was analysed using the Chi‐squared test and multivariable regression. Awareness of medication changes and test–retest reliability were analysed using descriptive statistics.

Results

Overall, 201 participants completed the questionnaire, with 170 eligible for analysis; 34 (20%) of 170 were aware of reduction or cessation of their usual medications on discharge and reported involvement in decision‐making and receiving enough information to reduce or stop one or more of their usual medications (positive PREM). Independent predictors of positive PREM included respondent (next of kin), hospital (Hospital 1), language (English) and specialty (acute geriatric medicine). Overall, 92 (59.4%) of 155 patients with medication changes were aware of those changes on hospital discharge.

Conclusions

These PREM are a feasible tool to examine older patients’ experiences of deprescribing in hospital and might be applied to evaluate interventions to improve awareness, shared decision‐making and provision of information when deprescribing for older patients.