bluuebunny/crossref_metadata_2025 huggingface dataset:
How to Extend the Capabilities of a Commercial Two-Photon Microscope to Perform Super-Resolution Imaging, Wavelength Mixing and Label-Free Microscopy
Authors: Peres Chiara , Nardin Chiara , Yang Guang , Mammano Fabio
Published: September 2021

Multimodal microscopy combines multiple non-linear techniques that take advantage of different optical processes to generate contrast and increase the amount of information that can be obtained from biological samples. However, the most advanced optical architectures are typically custom-made and require complex alignment procedures, as well as daily maintenance by properly trained personnel for optimal performance. Here, we describe a hybrid system we constructed to overcome these disadvantages by modifying a commercial upright microscope. We show that our multimodal imaging platform can be used to seamlessly perform two-photon STED, wavelength mixing and label-free microscopy in both ex vivo and in vivo samples. The system is highly stable and endowed with remote alignment hardware that ensures simplified operability for non-expert users. This optical architecture is an important step forward towards a wider practical applicability of non-linear optics to bioimaging.
Activation of the Zinc-sensing receptor GPR39 promotes T cell reconstitution after hematopoietic stem cell transplant
Authors: Iovino Lorenzo , Cooper Kirsten , deRoos Paul , Kinsella Sinéad , Evandy Cindy , Ugrai Tamas , Mazziotta Francesco , Ensbey Kathleen S , Granadier David , Hopwo Kayla , Smith Colton , Gagnon Alex , Galimberti Sara , Petrini Mario , Hill Geoffrey R. , Dudakov Jarrod A.
Published: September 2021

Prolonged lymphopenia represents a major clinical problem after cytoreductive therapies such as chemotherapy and the conditioning required for hematopoietic stem cell transplant (HCT), contributing toward the risk of infections and malignant relapse. Restoration of T cell immunity is dependent on tissue regeneration in the thymus, the primary site of T cell development; although the capacity of the thymus to repair itself diminishes over lifespan. However, although boosting thymic function and T cell reconstitution is of considerable clinical importance, there are currently no approved therapies for treating lymphopenia. Here we found that Zinc (Zn), is critically important for both normal T cell development as well as repair after acute damage. Accumulated Zn in thymocytes during development was released into the extracellular milieu after HCT conditioning, where it triggered regeneration by stimulating endothelial cell-production of BMP4 via the cell surface receptor GPR39. Dietary supplementation of Zn was sufficient to promote thymic function in a mouse model of allogeneic HCT, including enhancing the number of recent thymic emigrants in circulation; although direct targeting of GPR39 with a small molecule agonist enhanced thymic function without the need for prior Zn accumulation in thymocytes. Together, these findings not only define an important pathway underlying tissue regeneration, but also offer an innovative preclinical approach to treat lymphopenia in HCT recipients.

KEY POINTS

Thymocytes release zinc after HCT conditioning is sensed by GPR39 and promotes epithelial repair

Pharmacologic stimulation of GPR39 promotes T cell reconstitution after HCT
A MYB transcription factor, PlMYB308, plays an essential role in flower senescence of herbaceous peony
Authors: Ji Xiaotong , Xu Zhuangzhuang , Wang Meiling , Zhong Xuyang , Zeng Lingling , Sun Daoyang , Niu Lixin
Published: September 2021

Herbaceous peony is an important cut-flower plant cultivated across the world, but its short vase life substantially restricts the economic value of this crop. It is well established that endogenous hormones regulate the senescing process, but the molecular mechanism of them in flower senescence is still unclear. Here, we isolated a MYB transcription factor gene PlMYB308 from herbaceous peony flowers. Transcript abundance of PlMYB308 was strongly up-regulated in senescing petals. Silencing of PlMYB308 resulted in delayed peony flower senescence, and dramatically increased gibberellin (GA) but reduced ethylene and abscisic acid (ABA) levels in petals. Ectopic overexpression of PlMYB308 in tobacco accelerated flower senescence, and reduced GA but increased ethylene and ABA accumulation. Correspondingly, biosynthetic genes of ethylene, ABA, and GA showed variable expression levels in petals after silencing or overexpression of PlMYB308. A dual-luciferase assay showed that PlMYB308 specifically bound to the PlACO1 promoter. High expression levels of PlMYB308 were accompanied by low petal anthocyanin accumulation in senescing petals. A further bimolecular fluorescence complementation assay revealed an interaction between PlMYB308 and PlbHLH33, which was supposed to inhibit the anthocyanin biosynthesis. Taken together, our results suggest that the PlMYB308-PlACO1 and PlMYB308-PlbHLH33 regulatory checkpoints perhaps positively and negatively operate the production of ethylene and anthocyanin, respectively, and thus contribute to the senescence with impaired pigmentation in herbaceous peony flowers.
Neurodevelopmental processes in the prefrontal cortex derailed by chronic HIV-1 viral protein exposure
Authors: McLaurin Kristen A. , Li Hailong , Booze Rosemarie M. , Mactutus Charles F.
Published: September 2021

Due to the widespread access to, and implementation of, combination antiretroviral therapy, individuals perinatally infected with human immunodeficiency virus type 1 (HIV-1) are living into adolescence and adulthood. Perinatally infected adolescents living with HIV-1 (pALHIV) are plagued by progressive, chronic neurocognitive impairments; the pathophysiological mechanisms underlying these deficits, however, remains understudied. A longitudinal experimental design from postnatal day (PD) 30 to PD 180 was utilized to establish the development of pyramidal neurons, and associated dendritic spines, from layers II-III of the medial prefrontal cortex (mPFC). Three putative neuroinflammatory markers (i.e., IL-1β, IL-6, and TNF-α) were evaluated early in development (i.e., PD 30) as a potential mechanism underlying synaptic dysfunction in the mPFC. Constitutive expression of HIV-1 viral proteins induced prominent neurodevelopmental alterations, independent of biological sex, in pyramidal neurons from layers II-III of the mPFC. Specifically, HIV-1 transgenic rats exhibited prominent deficits in dendritic and synaptic pruning, a developmental decrease in synaptic connectivity, and an age-related decline in synaptic efficacy. Examination of dendritic spine morphology revealed an age-related population shift towards a more immature dendritic spine phenotype in HIV-1 transgenic animals. There was no compelling evidence for neuroinflammation in the mPFC during early development. Understanding the neural mechanisms underlying chronic neurocognitive impairments in pALHIV may afford a key target for innovative therapeutics and cure strategies; an urgent need given the growing population of pALHIV.
Contiguously-hydrophobic sequences are functionally significant throughout the human exome
Authors: Lohia Ruchi , Hansen Matthew E.B. , Brannigan Grace
Published: September 2021

Hydrophobic interactions have long been established as essential to stabilizing structured proteins as well as drivers of aggregation, but the impact of hydrophobicity on the functional significance of sequence variants has rarely been considered in a genome-wide context. Here we test the role of hydrophobicity on functional impact using a set of 70,000 disease and non-disease associated single nucleotide polymorphisms (SNPs), using enrichment of disease-association as an indicator of functionality. We find that functional impact is uncorrelated with hydrophobicity of the SNP itself, and only weakly correlated with the average local hydrophobicity, but is strongly correlated with both the size and minimum hydrophobicity of the contiguous hydrophobic domain that contains the SNP. Disease-association is found to vary by more than 6-fold as a function of contiguous hydrophobicity parameters, suggesting utility as a prior for identifying causal variation. We further find signatures of differential selective constraint on domain hydrophobicity, and that SNPs splitting a long hydrophobic region or joining two short regions of contiguous hydrophobicity are particularly likely to be disease-associated. Trends are preserved for both aggregating and non-aggregating proteins, indicating that the role of contiguous hydrophobicity extends well beyond aggregation risk.

Statement of Significance

Proteins rely on the hydrophobic effect to maintain structure and interactions with the environment. Surprisingly, no signs that amino acid hydrophobicity influences natural selection have been detected using modern genetic data. This may be because analyses that treat each amino acid separately do not reveal significant results, which we confirm here. However, because the hydrophobic effect becomes more powerful as more hydrophobic molecules are introduced, we tested whether unbroken stretches of hydrophobic amino acids are under selection. Using genetic variant data from across the human genome, we found evidence that selection pressure increases continually with the length of the unbroken hydrophobic sequence. These results could lead to improvements in a wide range of genomic tools as well as insights into disease and protein evolutionary history.
FOXO1 repressesSprouty2andSprouty4expression in endothelial cells to promote arterial specification and vascular remodeling in the mouse yolk sac
Authors: Li-Villarreal Nanbing , Wong Rebecca Lee Yean , Garcia Monica D. , Udan Ryan S. , Poché Ross A. , Rasmussen Tara L. , Rhyner Alexander M. , Wythe Joshua D. , Dickinson Mary E.
Published: September 2021

The establishment of a functional circulatory system is required for post-implantation development during murine embryogenesis. Previous studies in loss of function mouse models have shown that FOXO1, a Forkhead family transcription factor, is required for yolk sac vascular remodeling and survival beyond embryonic day (E) 11. Here, we demonstrate that loss ofFoxO1in E8.25 endothelial cells results in increasedSprouty2andSprouty4transcripts, reduced expression of arterial genes, and decreasedFlk1/Vegfr2mRNA levels without affecting overall endothelial cell identity, survival, or proliferation. Using aDll4-BAC-nlacZreporter line, we found that one of the earliest expressed arterial genes,Delta like 4(Dll4), is significantly reduced in the yolk sac ofFoxO1mutants without being substantially affected in the embryo proper. We show that in the yolk sac, FOXO1 not only binds directly to a subset of previously identifiedSprouty2gene regulatory elements (GREs), as well as newly identified, evolutionarily conservedSprouty4GREs, but can also repress their expression. Additionally, over expression ofSprouty4in transient transgenic embryos largely recapitulates reduced expression of arterial genes seen in endothelialFoxO1mutant mouse embryos. Together, these data reveal a novel role for FOXO1 as a key early transcriptional repressor controlling both pre-flow arterial specification and subsequent vessel remodeling within the murine yolk sac.
Distinct stress-dependent signatures of cellular and extracellular tRNA-derived small RNAs (tDRs)
Authors: Li Guoping , Manning Aidan , Bagi Alex , Yang Xinyu , Howard Jonathan , Chan Patricia P. , Sweeney Thadryan , Li Haobo , Laurent Brice D. , Kontaridis Maria I. , Laurent Louise C. , Van Keuren-Jensen Kendall , Aranki Sary F. , Muehlschlegel Jochen , Kitchen Robert , Lowe Todd M. , Das Saumya
Published: September 2021

The cellular response to stress is an important determinant of disease pathogenesis. Uncovering the molecular fingerprints of distinct stress responses may yield novel biomarkers for different diseases, and potentially identify key signaling pathways important for disease progression. tRNAs and tRNA-derived small RNAs (tDRs) comprise one of the most abundant RNA species in cells and have been associated with cellular stress responses. The presence of RNA modifications on tDRs has been an obstacle for accurately identifying tDRs with conventional small RNA sequencing. Here, we use AlkB-facilitated methylation sequencing (ARM-seq) to uncover a comprehensive landscape of cellular and extracellular tDR expression in a variety of human and rat cells during common stress responses, including nutritional deprivation, hypoxia, and oxidative stress. We found that extracellular tDRs have a distinct fragmentation signature with a predominant length of 31-33 nts and a highly specific termination position when compared with intracellular tDRs. Importantly, we found these signatures are better discriminators of different cellular stress responses compared to extracellular miRNAs. Distinct extracellular tDR signatures for each profiled stressor are elucidated in four different types of cells. This distinct extracellular tDR fragmentation pattern is also noted in plasma extracellular RNAs from patients on cardiopulmonary bypass. The observed overlap of these patient tDR signatures with the signatures of nutritional deprivation and oxidative stress in our cellular models provides preliminary in vivo corroboration of our findings and demonstrates the potential to establish novel extracellular tDR biomarkers in human disease models.
The human disease geneCLEC16Aencodes an intrinsically disordered protein region required for mitochondrial quality control
Authors: Gingerich Morgan A. , Liu Xueying , Chai Biaoxin , Pearson Gemma L. , Vincent Michael P. , Stromer Tracy , Zhu Jie , Sidarala Vaibhav , Renberg Aaron , Sahu Debashish , Klionsky Daniel J. , Schnell Santiago , Soleimanpour Scott A.
Published: September 2021

CLEC16A regulates mitochondrial health through mitophagy and is associated with over 20 human diseases. While CLEC16A has ubiquitin ligase activity, the key structural and functional regions of CLEC16A, and their relevance for human disease, remain unknown. Here, we report that a disease-associated CLEC16A variant lacks a C-terminal intrinsically disordered protein region (IDPR) that is critical for mitochondrial quality control. Using carbon detect NMR, we find that the CLEC16A C terminus lacks secondary structure, validating the presence of an IDPR. Loss of the CLEC16A C-terminal IDPRin vivoimpairs pancreatic β-cell mitophagy, mitochondrial function, and glucose-stimulated insulin secretion, ultimately causing glucose intolerance. Deletion of the CLEC16A C-terminal IDPR increases its self-ubiquitination and destabilizes CLEC16A, thus impairing formation of a critical CLEC16A-dependent mitophagy complex. Importantly, CLEC16A stability is dependent on proline bias within the C-terminal IDPR, but not amino acid sequence order or charge. Together, we clarify how an IDPR in CLEC16A prevents diabetes, thus implicating the disruption of IDPRs as novel pathological contributors to diabetes and other CLEC16A-associated diseases.
Transposon Screen of Surface Accessibility inS. aureus
Authors: Ferraro Noel J. , Pires Marcos M.
Published: September 2021

Bacterial cell walls represent one of the most prominent targets of antibacterial agents. These agents include natural products (e.g., vancomycin) and proteins stemming from the innate immune system (e.g., peptidoglycan-recognition proteins and lysostaphin). Among bacterial pathogens that infect humans,Staphylococcus aureus(S. aureus) continues to impose a tremendous healthcare burden across the globe.S. aureushas evolved countermeasures that can directly restrict the accessibility of innate immune proteins, effectively protecting itself from threats that target key cell well components. We recently described a novel assay that directly reports on the accessibility of molecules to the peptidoglycan layer within the bacterial cell wall ofS. aureus. The assay relies on site-specific chemical remodeling of the peptidoglycan with a biorthogonal handle. Here, we disclose the application of our assay to a screen of a nonredundant transposon mutant library for susceptibility of the peptidoglycan layer with the goal of identifying genes that contribute to the control of cell surface accessibility. We discovered several genes that resulted in higher accessibility levels to the peptidoglycan layer and showed that these genes modulate sensitivity to lysostaphin. These results indicate that this assay platform can be leveraged to gain further insight into the biology of bacterial cell surfaces.

Table of Contents Figure
Adaptation and phenotypic diversification ofBacillus thuringiensis407 biofilm are accompanied by a fuzzy spreader morphotype
Authors: Lin Yicen , Maróti Gergely , Strube Mikael Lenz , Kovács Ákos T.
Published: September 2021

Bacillus cereusgroup (Bacillus cereus sensu lato) has a diverse ecology, including various species that produce biofilms on abiotic and biotic surfaces. While genetic and morphological diversification enable the adaptation of multicellular communities, this area remains largely unknown in theBacillus cereusgroup. In this work, we dissected the experimental evolution ofBacillus thuringiensis407 Cry-during continuous recolonization of plastic beads. We observed the evolution of a distinct colony morphotype that we named fuzzy spreader (FS) variant. Most multicellular traits of the FS variant displayed higher competitive ability versus the ancestral strain, suggesting an important role for diversification in the adaptation ofB. thuringiensisto the biofilm lifestyle. Further genetic characterization of FS variant revealed the disruption of a guanylyltransferase gene by an insertion sequence (IS) element, which could be similarly observed in the genome of a natural isolate. The evolved FS and the deletion mutant in the guanylyltransferase gene (Bt407ΔrfbM) displayed similarly altered aggregation and hydrophobicity compared to the ancestor strain, suggesting that adaptation process highly depends on the physical adhesive forces.
Assessing the effectiveness of honey bee pollinators for cultivated blueberries in South Africa
Authors: Martin Keanu , Anderson Bruce , Minnaar Corneile , de Jager Marinus L
Published: September 2021

Globally, agricultural crops are often dependent on insect pollination. Blueberries are an example of such a crop and owing to their proposed health benefits they are grown around the world, including locations where their native bumble bee pollinators do not occur. In the absence of bumble bees, blueberry pollination in South Africa and many other parts of the non-native, commercial range is performed primarily by honey bees. Despite this, the effectiveness of honey bee pollination on blueberries remains understudied. This study determined the effect of honey bee pollination on components of fruit yield (fruit set and mass) of five blueberry varieties that are extensively planted in South Africa. For each variety, two metrics were calculated: 1) the benefit of bees — a comparison of fruit yields after exposure to honey bees and fruit yields after honey bee exclusion, 2) the pollination deficit — the difference in yield between hand pollination (maximum yield potential) and yields after exposure to honey bee pollinators. Honey bee pollination consistently resulted in improved yields, although the magnitude of this improvement (i.e., the benefit of bees) was dependent on the variety considered. Similarly, the pollination deficit also varied considerably across varieties and while some varieties appeared to perform close to maximum potential (small pollination deficit), others yielded well below their maximum potential under honey bee pollination. This study demonstrates that honey bees are functional pollinators of blueberries in areas where native blueberry pollinators are absent. However, in such areas, it is important that special focus be given to selecting blueberry varieties that perform well with honey bees as their sole pollinator. Further research is necessary to determine how the pollination deficit of blueberry varieties can be decreased as well as how to increase the effectiveness of honey bee pollination.
A cytoplasmic protein kinase in Chlamydomonas couples engagement of ciliary receptors to rapid cellular responses
Authors: Awasthi Mayanka , Ranjan Peeyush , Kelterborn Simon , Hegemann Peter , Snell William J.
Published: September 2021

The principal function of the primary cilium is to convert cues from the extracellular milieu into changes in cyclic nucleotide concentration and cytoplasmic responses, but fundamental questions remain about the mechanisms of transmission of cilium-to-cytoplasm signals. During fertilization in Chlamydomonas reinhardtii, ciliary adhesion between plus and minus gametes triggers an immediate ∼10-fold increase in cellular cAMP and activation for cell fusion. Here, we identify Gamete-Specific Protein Kinase (GSPK) as an essential link between cilary receptor engagement and gamete activation. The ciiary adhesion-induced increase in cAMP and cell fusion are severely impaired in gspk mutants but fusion is rescued by a cell-permeable form of cAMP, indicating that GSPK functions upstream of the cAMP increase. GSPK is cytoplasmic, and, remarkably, the entire cellular complement is phosphorylated in less than 60 seconds after ciliary contact. Thus, a cytoplasmic protein kinase rapidly converts a ciliary membrane cue into a global cellular response.
The m6A reader YTHDC2 is essential for escape from KSHV SOX-induced RNA decay
Authors: Macveigh-Fierro Daniel , Cicerchia Angelina , Cadorette Ashley , Sharma Vasudha , Muller Mandy
Published: September 2021

The role m6A modifications have increasingly been associated with diverse set of roles in modulating viruses and influencing the outcomes of viral infection. Here we report that the landscape of m6A deposition is drastically shifted during KSHV (Kaposi Sarcoma Associated herpesvirus) lytic infection for both viral and host transcripts. In line with previous reports, we also saw an overall decrease in host methylation in favor of viral mRNA along with 5’ hypomethylation and 3’ hypermethylation. During KSHV lytic infection, a major shift in overall mRNA abundance is driven by the viral endoribonuclease SOX, which induces the decay of greater than 70% of transcripts. Here, we reveal that Interlukin-6 (IL-6) mRNA, a well-characterized SOX-resistant transcript, is m6A modified during lytic infection. Furthermore, we show that this modification falls within the IL-6 SOX Resistance Element (SRE), an RNA element in IL-6 3’ UTR that was previously shown to be sufficient for protection from SOX cleavage. We show that the presence of this m6A modification is essential to confer SOX resistance to the IL-6 mRNA. We next show that this modification recruits the m6A reader YTHDC2 and found that YTHDC2 is necessary for the escape of the IL-6 transcript. These results shed light on how the host cell has evolved to use RNA modifications to circumvent viral manipulation of RNA fate during KSHV infection.
MAR1 links membrane adhesion to membrane merger during cell-cell fusion in Chlamydomonas
Authors: Pinello Jennifer F. , Liu Yanjie , Snell William J.
Published: September 2021

Union of two gametes to form a zygote is a defining event in the life of sexual eukaryotes, yet the mechanisms that underlie cell-cell fusion during fertilization remain poorly characterized. Here, in studies of fertilization in the green alga, Chlamydomonas, we report identification of a membrane protein on minus gametes, Minus Adhesion Receptor 1 (MAR1), that is essential for the membrane attachment with plus gametes that immediately precedes lipid bilayer merger. We show that MAR1 forms a receptor pair with previously identified receptor FUS1 on plus gametes, whose ectodomain architecture we find is identical to a sperm adhesion protein conserved throughout plant lineages. Strikingly, before fusion, MAR1 is biochemically and functionally associated with the ancient, evolutionarily conserved eukaryotic class II fusion protein HAP2 on minus gametes. Thus, the integral membrane protein MAR1 provides a molecular link between membrane adhesion and bilayer merger during fertilization in Chlamydomonas.
Network analysis outlines strengths and weaknesses of emerging SARS-CoV-2 Spike variants
Authors: Manrique P.D. , Chakraborty S. , Nguyen K. , Mansbach R. , Korber B. , Gnanakaran S.
Published: September 2021

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has triggered myriad efforts to dissect and understand the structure and dynamics of this complex pathogen. The Spike glycoprotein of SARS-CoV-2 has received special attention as it is the means by which the virus enters the human host cells. The N-terminal domain (NTD) is one of the targeted regions of the Spike protein for therapeutics and neutralizing antibodies against COVID-19. Though its function is not well-understood, the NTD is reported to acquire mutations and deletions that can accelerate the evolutionary adaptation of the virus driving antibody escape. Cellular processes are known to be regulated by complex interactions at the molecular level, which can be characterized by means of a graph representation facilitating the identification of key residues and critical communication pathways within the molecular complex. From extensive all-atom molecular dynamics simulations of the entire Spike for the wild-type and the dominant variant, we derive a weighted graph representation of the protein in two dominant conformations of the receptor-binding-domain; all-down and one-up. We implement graph theory techniques to characterize the relevance of specific residues at facilitating roles of communication and control, while uncovering key implications for fitness and adaptation. We find that many of the reported high-frequency mutations tend to occur away from the critical residues highlighted by our graph theory analysis, implying that these mutations tend to avoid targeting residues that are most critical for protein allosteric communication. We propose that these critical residues could be candidate targets for novel antibody therapeutics. In addition, our analysis provides quantitative insights of the critical role of the NTD and furin cleavage site and their wide-reaching influence over the protein at large. Many of our conclusions are supported by empirical evidence while others point the way towards crucial simulation-guided experiments.
Genomic evidence for divergent co-infections of SARS-CoV-2 lineages
Authors: Zhou Hang-Yu , Cheng Ye-Xiao , Xu Lin , Li Jia-Ying , Tao Chen-Yue , Ji Cheng-Yang , Han Na , Yang Rong , Li Yaling , Wu Aiping
Published: September 2021

Recently, patients co-infected by two SARS-CoV-2 lineages have been sporadically reported. Concerns are raised because previous studies have demonstrated co-infection may contribute to the recombination of RNA viruses and cause severe clinic symptoms. In this study, we have estimated the compositional lineage(s), tendentiousness, and frequency of co-infection events in population from a large-scale genomic analysis for SARS-CoV-2 patients. SARS-CoV-2 lineage(s) infected in each sample have been recognized from the assignment of within-host site variations into lineage-defined feature variations by introducing a hypergeometric distribution method. Of all the 29,993 samples, 53 (~0.18%) co-infection events have been identified. Apart from 52 co-infections with two SARS-CoV-2 lineages, one sample with co-infections of three SARS-CoV-2 lineages was firstly identified. As expected, the co-infection events mainly happened in the regions where have co-existed more than two dominant SARS-CoV-2 lineages. However, co-infection of two sub-lineages in Delta lineage were detected as well. Our results provide a useful reference framework for the high throughput detecting of SARS-CoV-2 co-infection events in the Next Generation Sequencing (NGS) data. Although low in average rate, the co-infection events showed an increasing tendency with the increased diversity of SARS-CoV-2. And considering the large base of SARS-CoV-2 infections globally, co-infected patients would be a nonnegligible population. Thus, more clinical research is urgently needed on these patients.
Lateral deformations of a crystal of potassium acid phthalate in an external electric field
Authors: Petrenko Arsen , Novikova Nataliya , Blagov Alexander , Kulikov Anton , Pisarevskii Yury , Verin Igor , Kovalchuk Michail
Published: September 2021

The anisotropy of deformations in potassium acid phthalate crystals arising under the action of an external electric field up to 1 kV mm−1 applied along the [001] polar axis was studied using X-ray diffraction methods at room temperature. Electrical conductivity was measured and rocking curves for reflections 400, 070 and 004 were obtained by time-resolved X-ray diffractometry in Laue and Bragg geometries. Two saturation processes were observed from the time dependences of the electrical conductivity. A shift in the diffraction peaks and a change in their intensity were found, which indicated a deformation of the crystal structure. Rapid piezoelectric deformation and reversible relaxation-like deformation, kinetically similar to the electrical conductivity of a crystal, were revealed. The deformation depended on the polarity and strength of the applied field. The deformation was more noticeable in the [100] direction and was practically absent in the [001] direction of the applied field. X-ray diffraction analysis revealed a disordered arrangement of potassium atoms, i.e. additional positions and vacancies. The heights of potential barriers between the positions of K+ ions and the paths of their possible migration in the crystal structure of potassium acid phthalate were determined. The data obtained by time-resolved X-ray diffractometry and X-ray structure analysis, along with additional electrophysical measurements, allow the conclusion that the migration of charge carriers (potassium cations) leads to lateral deformation of the crystal structure of potassium phthalate in an external electric field.
In situ growth of an ethyl p-hydroxybenzoate single crystal by the vertical Bridgman technique: a potential nonlinear optical material for third-harmonic generation
Authors: Nayak Debabrata , Vijayan N. , Kumari Manju , Kiran  , Vashistha Nikita , Kumar Mahesh , Pant R. P.
Published: September 2021

Optically transparent single crystals of ethyl p-hydroxybenzoate (EPHB) were successfully grown by the vertical Bridgman technique. The crystalline phase and unit-cell dimensions were obtained from powder X-ray diffraction using Rietveld analysis. The presence of defects and grain boundaries was investigated by high-resolution X-ray diffraction. The optical quality of the grown single crystal was assessed by UV–Vis and photoluminescent spectroscopies. A blue emission, with a bi-exponential decay time, was obtained from time-resolved photoluminescence upon laser excitation at 266 nm. The mechanical strength of the EPHB single crystal was studied by Vickers hardness testing. A decrease in the laser-damage threshold was observed with a nanosecond Nd:YAG laser source for increased pulse repetition rates. The third-order nonlinearity, nonlinear absorption coefficient and nonlinear refractive index were measured using the Z-scan technique with a femtosecond Ti:sapphire laser. The third-order nonlinear coefficient values for the grown crystal were compared with those of a potassium dihydrogen phosphate single crystal.
Why won’t people speak up? Unpacking silence at work
Authors: Workman-Stark Angela
Published: September 2021

Purpose

This paper examines employee silence, namely, the causes of silence and how it might be overcome.

Design/methodology/approach

Drawing from academic research and work with organizations, the author explains that workplace diversity is insufficient to guarantee the contributions of diverse voices. The author then provides an overview of why individuals choose to remain silent and explores aspects of organizational culture and climate that contribute to silencing behaviors. Finally, the author offers suggestions on how organizational leaders can overcome silence.

Findings

The findings suggest that employee voice can be activated through a psychologically safe working environment in which leaders adopt a learning mindset, practice humility, create opportunities for all team members to contribute, treat people with fairness and respect, and hold others accountable to do the same. The findings also indicate that leaders can support safe and inclusive working environments by challenging basic assumptions and accepting vulnerability.

Originality/value

This paper makes an important contribution to the field of organization development and change by providing suggestions for how organizations can address workplace concerns and enhance performance by removing the inhibitors of “employee voice”.
Sociotechnical factors and Industry 4.0: an integrative perspective for the adoption of smart manufacturing technologies
Authors: Marcon Érico , Soliman Marlon , Gerstlberger Wolfgang , Frank Alejandro G.
Published: September 2021

Purpose

As the level of implementation of Industry 4.0 increases, misalignments between adopted technologies and organizational factors may result in benefits below expected. This paper aims to analyze how organizational factors can contribute to a higher level of adoption of Industry 4.0 technologies. The paper uses a sociotechnical perspective lens to achieve this aim.

Design/methodology/approach

Using a sample of 231 manufacturing companies in Denmark, a leading country in Industry 4.0 readiness, the paper analyzes through cluster analysis and logistic regression whether the development of four sociotechnical dimensions – that is, Social, Technical, Work Organization and Environmental factors – in these companies can benefit the achievement of higher levels of Industry 4.0 technology adoption.

Findings

The results show that companies focused on the development of sociotechnical aspects generally present higher Industry 4.0 adoption levels. However, some sociotechnical factors are less supportive than others.

Originality/value

Based on these results, practitioners can plan the adoption of advanced technologies, using a systemic organizational view. This study provides evidence on a growing field with few empirical studies available. The paper contributes by providing an analysis of a leading country in Industry 4.0 implementation, presenting a systemic view on technology adoption in the Industry 4.0 context.
The impact of Covid-19 on customer journeys: implications for interactive marketing
Authors: Kannan P.K. , Kulkarni Gauri
Published: September 2021

Purpose

The Covid-19 pandemic and the related closures and lockdowns have changed how consumers shop for products and how they consume them. In this paper, the authors focus on how customers' journeys from the awareness stage down to purchase and loyalty stages have been impacted by the pandemic across different product categories and markets and how they affect the same post-pandemic. The authors propose directions for future research based on our analysis.

Design/methodology/approach

Analyzing the components of customer utility, the authors provide the basis for the rapid shift towards online and digital touchpoints and the nature of emerging interactions between firms and consumers. The authors highlight those areas where changes could be permanent.

Findings

The authors show why some of the changes due to the Covid-19 pandemic could be permanent and irrevocable and what this implies for firms' strategies to acquire, retain, and grow their business with their customers.

Originality/value

The authors highlight why omnichannel strategies are the way for firms to thrive in the post-pandemic marketplace, and outline areas for future research that will allow researchers to examine how customer journeys will evolve post-pandemic.
Profiting from innovation in the aftermath of an economic crisis
Authors: Lichtenthaler Ulrich
Published: September 2021

Purpose

The aim of this paper is to present systematically a variety of benefits from innovating in response to an economic crisis.

Design/methodology/approach

This is a conceptual paper that draws on prior conceptual and empirical studies, especially the innovation-based view of firm performance.

Findings

Many firms have cut their innovation expenditures in response to the COVID-19 crisis. However, the financial crisis in 2008/2009 has shown that these short-term cost savings may have severely negative consequences on competitiveness. Several innovation examples from the crisis due to the COVID-19 pandemic further indicate that companies may benefit from a variety of first-order innovations, which go considerably beyond product development. Consequently, researchers and executives need to consider the variety of innovation types beyond product development, and they further need to emphasize second-order innovations, which describe the dynamic transformation of innovation management.

Originality/value

Academics and practitioners need to put specific attention to the transformation of innovation processes at the beginning of a crisis because firms may have to redesign their innovation processes. This dynamic reconfiguration and realignment of innovation processes further is essential again if a crisis continues for a longer period, such as the crisis due to the coronavirus pandemic. For example, if a company currently does not respond to relevant trends, its competitive position will deteriorate because other companies will enter the market. If firms can afford to continue or strengthen the innovation activities, they may profit substantially after the crisis.
Reallocation of nitrogen and phosphorus from roots drives regrowth of grasses and sedges after defoliation under deficit irrigation and nitrogen enrichment
Authors: Wang Ruzhen , Cresswell Tom , Johansen Mathew P. , Harrison Jennifer J. , Jiang Yong , Keitel Claudia , Cavagnaro Timothy R. , Dijkstra Feike A.
Published: September 2021

Reallocation of nutrients from roots to shoots is essential for plant regrowth in grasslands, particularly in nutrient‐poor conditions. However, the response of root nutrient reallocation to changes in nitrogen (N) and water availability remains largely unknown.

Using a novel 15N and 32P labelling technique, we quantified the contribution of N and phosphorus (P) to shoot regrowth from either root reallocation or direct soil uptake for perennial grasses exposed to high‐frequency deficit irrigation (HFDI) and N addition.

Without N addition, HFDI showed no impact on uptake and reallocation of N and P, likely due to unaffected soil N availability and a greater diffusion barrier offsetting increased accumulation in plant‐available soil P. With N addition, HFDI increased plant N rather than P uptake, because of increasing soil N availability instead of P under combined HFDI and N addition. The HFDI decreased both N and P reallocation with N addition, possibly due to exhaustion of nutrient reserves in roots that were re‐allocated above‐ground. Reallocation contributed 48%–97% of N and 58%–79% of P required during the first 2 weeks of shoot regrowth.

Synthesis. Our results highlight the importance of N and P reallocation from roots to buffer against changes in soil N and P availability and to maintain N:P ratio in shoot regrowth.
Rental equivalence, owner‐occupied housing, and inflation measurement: Microlevel evidence from Ireland
Authors: Coffey Cathal , McQuinn Kieran , O'Toole Conor
Published: September 2021

We use unique supervisory property‐level rental data to estimate a rental equivalence (RE) measure for owner‐occupied housing (OOH) for Ireland. Our data from the official, domestic rental regulator allow us to simultaneously address three issues that have arisen in the empirical application of rental equivalent measures. First, we can differentiate between new and existing rent levels in the analysis; second, we can control for other utility costs; and finally, we are able to estimate an RE measure in the absence of rent controls. To better approximate the OOH structure of the Irish residential market, we estimate 32 separate regional hedonic rent models and use the results to reweight the RE index. We find that our subsequent estimate of RE results in a reduction in the Irish headline rate of consumer price inflation by 0.4 percentage points. Furthermore, we show that there are considerable differences in the inflation rate if new relative to existing rents are used in the RE measures with measures based purely on existing rents biasing downward both the RE measure and the overall consumer price index. This suggests that considerable care is required for policymakers in using RE methods in the presence of data gaps.
A predictive risk‐scoring model for multiple synchronous early gastric cancers or gastric dysplasia before initial endoscopic resection
Authors: Xu Shan Shan , Chai Ning Li , Tang Xiao Wei , Linghu En Qiang , Wang Sha Sha , Feng Xiu Xue , Li Bao
Published: September 2021

Objective

To establish a new and easy‐to‐use risk‐scoring predictive model to help identify high‐risk patients with multiple synchronous gastric neoplasms (MSGN), including early gastric cancer (EGC) and gastric dysplasia (GD), before initial endoscopic resection (ER).

Methods

We retrospectively enrolled 1361 patients with EGC or GD who had undergone ER from November 2006 to September 2019. The patients were randomly divided into the training (n = 681) and validation cohorts (n = 680). In the training phase a prediction score was constructed to assess the independent predictors of MSGN based on multivariate logistic regression analysis. The performance of the prediction model was evaluated using the receiver operating characteristic (ROC) curve and the Hosmer‐Lemeshow test.

Results

Of the 1361 patients, 122 (9.0%) had MSGN. Three predictors for MSGN were scored and weighted, as follows: elderly male (≥65 y; three points), a family history of gastric cancer (two points) and surface redness (two points). Accordingly, patients were divided into the low (risk score, 0‐3 points) or high‐risk groups (risk score, 4‐7 points). In the validation cohort, the incidence of MSGN in the low‐risk and high‐risk groups were 6.1% and 32.0%, respectively (P < 0.001). Our predictive risk‐scoring model showed good discrimination (the area under the ROC curve [AUROC] 0.719, 95% confidence interval [CI] 0.634‐0.794, P < 0.001) and calibration ability (Hosmer‐Lemeshow test, χ2 = 6.539, P = 0.587) in the validation group.

Conclusion

This risk‐scoring model has a good performance in predicting MSGN before the initial ER.
The use of computed tomography in the management of injury in tertiary emergency departments in Western Australia: Evidence of overtesting?
Authors: Ha Ninh T. , Abdullah Lana , Bulsara Max , Celenza Antonio , Doust Jenny , Fatovich Daniel , McRobbie Donald , Mountain David , O’Leary Peter , Slavotinek John , Wright Cameron , Youens David , Moorin Rachael
Published: September 2021

Background

This study investigated trends in computed tomography (CT) utilization across different triage categories of injury presentations to tertiary emergency departments (EDs) and associations with diagnostic yield measured by injury severity, hospitalization and length of stay (LOS), and mortality.

Methods

A total of 411,155 injury‐related ED presentations extracted from linked records from Western Australia from 2004 to 2015 were included in the retrospective study. The use of CT scanning and diagnostic yield measured by rate of diagnosis with severe injury, hospitalizations and LOS, and mortality were captured annually for injury‐related ED presentations. Multivariable regression models were used to calculate the annual adjusted rate of CT scanning for injury presentations and hospitalizations across triage categories, diagnosis with severe injury, LOS, and mortality. The significance of changes observed was compared among patients with CT imaging relative to those without CT.

Results

While the number of ED presentations with injury increased by 65% from 2004 to 2015, the use of CT scanning in these presentations increased by 176%. The largest increase in CT use was among ED presentations triaged as semi‐/nonurgent (+256%). Injury presentations with CT, compared to those without, had a higher rate of diagnosis with moderate/severe injury and hospitalization but no difference in LOS and mortality. The probability/rate observed in the outcomes of interest had a greater decrease over time in those with CT scanning compared with those without CT scanning across triage categories.

Conclusions

The reduction in diagnostic yield in terms of injury severity and hospitalization found in our study might indicate a shift toward overtesting using CT in ED for injury or a higher use of CT to assist in the management of injuries. This helps health care policymakers consider whether the current increase in CT use meets the desired levels of quality and efficient care.
Burning for grassland pollination: Recently burned patches promote plant flowering and insect pollinators
Authors: Goldas Camila da Silva , Podgaiski Luciana Regina , da Silva Carolina Veronese Corrêa , Mendonça Milton de Souza
Published: September 2021

Grasslands are historically and evolutionarily associated with disturbances, such as fire, that drive biodiversity assembly patterns and biotic interactions. Disturbance suppression in fire‐prone ecosystems usually leads to a decline in forb diversity and flowering due to biomass accumulation, which could jeopardise pollinator diversity. In this study, we investigated patterns and drivers of plant flowering and flower insect visitor communities in a chronosequence of patches from different time‐since‐fire categories in Southern Brazilian grasslands. Old‐burnt patches (more than 2 years since fire) had taller vegetation, more biomass and grass cover than intermediate (about 1 year after fire) and freshly‐burnt patches (less than 6 months since fire), which had increased bare soil cover. Forb flower abundance was much higher in freshly burnt patches, directly predicted by the degree of habitat openness. Pollinator insects were then benefited by floral resource aggregation in freshly burnt patches, increasing in abundance (bees and butterflies) and species richness (bees). Beetle communities were positively influenced by vegetation height. Furthermore, plant species flowering and bee species composition varied between freshly and old‐burnt grasslands, with indicator species found for all recovery stages but mainly freshly‐burnt patches. Altogether, these results indicate the importance of maintaining freshly‐burnt patches in the grassland landscape: it helps to sustain flower diversity, pollination services and flowering plant reproduction. Our findings support the idea that a mosaic of grasslands from different times‐since‐fire should be considered for grassland conservation.