bluuebunny/crossref_metadata_2025 huggingface dataset:
Ghrelin signaling regulates feeding behavior, metabolism, and memory through the vagus nerve
Authors: Davis Elizabeth A. , Wald Hallie S. , Suarez Andrea N. , Zubcevic Jasenka , Liu Clarissa M. , Cortella Alyssa M. , Kamitakahara Anna K. , Polson Jaimie W. , Arnold Myrtha , Grill Harvey J. , de Lartigue Guillaume , Kanoski Scott E.
Published: June 2020

Vagal afferent neuron (VAN) signaling sends information from the gut to the brain and is fundamental in the neural control of feeding behavior and metabolism. Recent findings reveal that VAN signaling also plays a critical role in cognitive processes, including hippocampus (HPC)-dependent memory. VANs, located in nodose ganglia, express receptors for various gut-derived endocrine signals, however, the function of these receptors with regards to feeding behavior, metabolism, and memory control is poorly understood. We hypothesized that VAN-mediated processes are influenced by ghrelin, a stomach-derived orexigenic hormone, via communication to its receptor (growth hormone secretagogue receptor [GHSR]) expressed on gut-innervating VANs. To examine this hypothesis, rats received nodose ganglia injections of an adeno-associated virus (AAV) expressing short hairpin RNAs targeting GHSR (or a control AAV) for RNA interference-mediated VAN-specific GHSR knockdown. Results reveal that VAN GHSR knockdown induced various feeding and metabolic disturbances, including increased meal frequency, impaired glucose tolerance, delayed gastric emptying, and increased body weight compared to controls. Additionally, VAN-specific GHSR knockdown impaired HPC-dependent episodic contextual memory and reduced HPC brain-derived neurotrophic factor expression, but did not affect anxiety-like behavior or levels of general activity. A functional role for endogenous VAN GHSR signaling was further confirmed by results revealing that VAN signaling is required for the hyperphagic effects of ghrelin administered at dark onset, and that gut-restricted ghrelin-induced increases in VAN firing rate require intact VAN GHSR expression. Collective results reveal that VAN GHSR signaling is required for both normal feeding and metabolic function as well as HPC-dependent memory.
Representation Learning of Resting State fMRI with Variational Autoencoder
Authors: Kim Jung-Hoon , Zhang Yizhen , Han Kuan , Wen Zheyu , Choi Minkyu , Liu Zhongming
Published: June 2020

Resting state functional magnetic resonance imaging (rsfMRI) data exhibits complex but structured patterns. However, the underlying origins are unclear and entangled in rsfMRI data. Here we establish a variational auto-encoder, as a generative model trainable with unsupervised learning, to disentangle the unknown sources of rsfMRI activity. After being trained with large data from the Human Connectome Project, the model has learned to represent and generate patterns of cortical activity and connectivity using latent variables. The latent representation and its trajectory represent the spatiotemporal characteristics of rsfMRI activity. The latent variables reflect the principal gradients of the latent trajectory and drive activity changes in cortical networks. Latent representations are clustered by both individuals and brain states. Representational geometry captured as covariance or correlation between latent variables, rather than cortical connectivity, can be used as a more reliable feature to accurately identify subjects from a large group, even if only a short period of data is available per subjects.
Characterisation of the role and regulation ofUltrabithoraxin sculpting fine-scale leg morphology
Authors: Buffry Alexandra D. , Kittelmann Sebastian , McGregor Alistair P.
Published: June 2020

Hox genes are expressed during embryogenesis and determine the regional identity of animal bodies along the antero-posterior axis. However, they also function post-embryonically to sculpt fine-scale morphology. To better understand how Hox genes are integrated into post-embryonic gene regulatory networks, we further analysed the role and regulation ofUltrabithorax(Ubx) during leg development inDrosophila melanogaster. Ubxregulates several aspects of bristle and trichome patterning on the femurs of the second (T2) and third (T3) leg pairs. We found that repression of trichomes in the proximal posterior region of the T2 femur by Ubx is likely mediated by activation of the expression ofmicroRNA-92aby this Hox protein. Furthermore, we identified a novel enhancer ofUbxthat recapitulates the temporal and regional activity of this gene in T2 and T3 legs. We then used transcription factor binding motif analysis in regions of accessible chromatin in T2 leg cells to predict and functionally test transcription factors that may regulate theUbxleg enhancer. We also tested the role of the Ubx co-factors Homothorax (Hth) and Extradenticle (Exd) in T2 and T3 femurs. We found several transcription factors that may act upstream or in concert with Ubx to modulate trichome patterning along the proximo-distal axis of developing femurs and that the repression of trichomes also requires Hth and Exd. Taken together our results provide insights into howUbxis integrated into a postembryonic gene regulatory network to determine fine-scale leg morphology.
A general theory of coherence between brain areas
Authors: Schneider Marius , Dann Benjamin , Sheshadri Swathi , Scherberger Hansjörg , Vinck Martin
Published: June 2020

What does neuronal coherence tell us about neuronal communication? Does coherence between field potentials (e.g. LFP, EEG, MEG) reflect spiking entrainment or coupling between oscillators? Is it a mechanism for communication between brain areas, or a byproduct of interareal connectivity and spectral power? We hypothesized that interareal coherence is explained by the fact that outputs from one cortical area give rise to synaptic inputs in the same brain area, and correlated synaptic inputs in another area. Our mathematical analysis demonstrates that coherence between a sending and receiving area is precisely predicted from only two parameters: Interareal connectivity and oscillatory synchronization in the sending area. This model predicts narrow-band coherence even in case of a flat transfer function and in the absence of spiking entrainment in a downstream area, and reproduces frequency-specific Granger-causality patterns between brain areas (gamma feedforward, beta feedback). In general, we find that Granger-causality between field potentials is dominated by oscillatory synchronization in the sending area, whereas spiking entrainment is determined by the resonant properties of the receiver. Our model accurately reproduces LFP-LFP beta-coherence between macaque areas 7B and F5 in the absence of beta phase-locking within area F5. Together, these findings uncover a precise mechanistic model of interareal coherence as a (by)product of connectivity and power.
Urine proteome changes in a chronic unpredictable mild stress (CUMS) mouse model of major depressive disorder
Authors: Huan Yuhang , Wei Jing , Su Tong , Gao Youhe
Published: June 2020

Background

Major depressive disorder (MDD) is a prevalent complex psychiatric disorder with a high prevalence rate. Because MDD is a systemic multifactorial disorder involving complex interactions and disturbances of various molecular pathways, there are no effective biomarkers for clinical diagnosis. Urine is not subjected to homeostatic control, allowing it to reflect the sensitive and comprehensive changes that occur in various diseases. In this study, we examined the urine proteome changes in a CUMS mouse model of MDD.

Methods

Male C57BL/6 mice were subjected to chronic unpredictable mild stress for 5 weeks. The tail suspension test (TST) and sucrose consumption test (SCT) were then applied to evaluate depression-like behaviors. The urine proteomes on day 0 and day 36 in the CUMS group were profiled by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS).

Results

A total of 45 differential proteins were identified, 24 of which have been associated with the pathogenic mechanisms of MDD, while 10 proteins have been previously suggested as MDD biomarkers. There was an average of two differential proteins that were identified through 1048574 random combination statistical analyses, indicating that at least 95% of the differential proteins were reliable and not the result of random combination. The differential proteins were mainly associated with blood coagulation, inflammatory responses and central nervous system development.

Conclusions

Our preliminary results indicated that the urine proteome can reflect changes associated with MDD in the CUMS model, which provides potential clues for the diagnosis of clinical MDD patients.
Structural basis for distinct inflammasome complex assembly by human NLRP1 and CARD8
Authors: Qin Gong , Robinson Kim , Chenrui Xu , Jiawen Zhang , Zhi Boo Zhao , Thiam Teo Daniel Eng , Yaming Zhang , Yew Lim John Soon , Ing Goh Wah , Wright Graham , Zhong Franklin L. , Bin Wu , Reversade Bruno
Published: June 2020

Nod-like receptor (NLR) proteins activate pyroptotic cell death and IL-1 driven inflammation by assembling and activating the inflammasome complex. Closely related NLR proteins, NLRP1 and CARD8 undergo unique auto-proteolysis-dependent activation and are implicated in auto-inflammatory diseases; however, the molecular mechanisms of activation are not understood. Here we report the structural basis of how the activating domains (FIINDUPA-CARD) of NLRP1 and CARD8 self-oligomerize to trigger the assembly of distinct inflammasome complexes. Recombinant FIINDUPA-CARD of NLRP1 forms a two-layered filament, with an inner core composed of oligomerized CARD domains and the outer layer consisting of FIINDUPArings. Biochemically, oligomerized NLRP1-CARD is sufficient to drive ASC speck formation in cultured human cells via filament formation-a process that is greatly enhanced by NLRP1-FIINDUPA, which forms ring-like oligomersin vitro. In addition, we report the cryo-EM structures of NLRP1-CARD and CARD8-CARD filaments at 3.7 Å, which uncovers unique structural features that enable NLRP1 and CARD8 to discriminate between ASC and pro-caspase-1. In summary, our findings provide unique structural insight into the mechanisms of activation for human NLRP1 and CARD8, uncovering an unexpected level of specificity in inflammasome signaling mediated by heterotypic CARD domain interactions.
Mitochondrial dsRNAs activate PKR and TLR3 to promote chondrocyte degeneration in osteoarthritis
Authors: Kim Sujin , Lee Keonyong , Choi Yong Seok , Ku Jayoung , Lee Yun Jong , Kim Yoosik
Published: June 2020

Protein kinase R (PKR) is an immune response protein that becomes activated by long double-stranded RNAs (dsRNAs). Several studies reported the misactivation of PKR in patients of degenerative diseases including primary osteoarthritis (OA). However, the molecular identity of PKR-activating dsRNAs remains unknown. Here, we investigate the role of mitochondrial dsRNAs (mt-dsRNAs) in the development of OA. We find that in response to OA-mimicking stressors, cytosolic efflux of mt-dsRNAs is increased, leading to PKR activation and subsequent induction of inflammatory cytokines and apoptosis. Moreover, mt-dsRNAs are exported to the extracellular space where they activate toll-like receptor 3. Elevated expression of mt-dsRNAs in the synovial fluids of OA patients further supports our data. Lastly, we show that autophagy protects chondrocytes from mitochondrial dysfunction partly by removing cytosolic mt-dsRNAs. Together, these findings establish the PKR-mt-dsRNA as a critical regulatory axis in OA development and suggest mt-dsRNAs as a potential target in fighting OA.
Premature commitment to uncertain beliefs during human NMDA receptor hypofunction
Authors: Salvador Alexandre , Arnal Luc H. , Vinckier Fabien , Domenech Philippe , Gaillard Raphaël , Wyart Valentin
Published: June 2020

In uncertain environments, accurate decision-making requires integrating ambiguous or conflicting signals – a cognitive inference process thought to require n-methyl-d-aspartate (NMDA) synaptic receptors. Here we characterized the causal impact of human NMDA receptor hypofunction on cognitive inference using placebo-controlled infusions of ketamine in a visual cue combination task. Participants tested under ketamine showed elevated uncertainty, together with impaired cognitive inference despite intact visual processing. This behavioral effect of ketamine was associated in patterns of electrical brain activity with degraded and unbalanced coding of presented cues in associative cortex, followed by premature response preparation in motor cortex. Through quantitative simulations, we propose that these cognitive alterations reflect an urge to explain away the elevated uncertainty triggered by ketamine. This compensatory mechanism may cause the emergence of psychotic symptoms observed under chronic NMDA receptor dysfunction, but also forge unusually strong beliefs when confronted with uncertainty in everyday life.
Entelon®(vitis viniferaseed extract) reduces inflammation and calcification in a beagle dog model of intravascular bovine pericardium implantation
Authors: Choi Gab-Chol , Kim Sokho , Rahman Mahbubur , Oh Ji Hyun , Cho Yun Seok , Shin Hong Ju
Published: June 2020

Objective

Inflammation and calcification are major factors responsible for failure of bioprosthetic valve and other substitute heart valve implantations. The objective of this study was to evaluate the anti-inflammatory and anti-calcification effects of Entelon150®(consisting of grape-seed extract) in a beagle dog model of intravascular bovine pericardium implantation.

Methods

In total, 8 healthy male beagle dogs were implanted with a bovine pericardium bilaterally in the external jugular veins and divided into two groups. Animals in the Entelon150®group (n = 4) were treated with 150 mg of Entelon150®twice daily for six weeks after surgery. The negative control (NC) group (n = 4) was treated with 5 ml of saline using the same method. After six weeks, we measured the calcium content, performed histological examination, and performed molecular analysis.

Results

The calcium content of implanted tissue in the Entelon150®group (0.56±0.14 mg/g) was significantly lower than that in the NC group (1.48±0.57 mg/g) (p < 0.05). Histopathological examination showed that infiltration of chronic inflammatory cells, such as fibroblasts and macrophages, occurred around the graft in all groups; however, the inflammation level of the implanted tissue in the Entelon150®group was significantly lower than that in the NC group. Both immunohistochemical and western blot analyses revealed that bone morphogenetic protein 2 expression was significantly attenuated in the Entelon150®group.

Conclusions

Our results indicate that Entelon150®significantly attenuates post-implantation inflammation and degenerative calcification of the bovine pericardium in dogs. Therefore, Entelon150®may increase the longevity of the bovine pericardium after intravascular implantation.
Detecting new allies: Modifier screen identifies a genetic interaction betweenImaginal disc growth factor 3and a Rho-kinase substrate during dorsal appendage tube formation inDrosophila
Authors: Espinoza Claudia Y. , Berg Celeste A.
Published: June 2020

Biological tube formation underlies organ development, and when disrupted, can cause severe birth defects. To investigate the genetic basis of tubulogenesis, we study the formation ofDrosophila melanogastereggshell structures, called dorsal appendages, which are produced by epithelial tubes. Previously we found that precise levels ofDrosophilaChitinase-like proteins (CLPs), encoded by theImaginal disc growth factor (Idgf)gene family, are needed to regulate dorsal-appendage tube closure and tube migration. To identify factors that act in theIdgfpathway, we developed a genetic modifier screen based on the finding that overexpressingIdgf3causes dorsal appendage defects with ∼50% frequency. Using a library of partially overlapping heterozygous deficiencies, we scanned chromosome 3L and found regions that enhanced or suppressed theIdgf3-overexpression phenotype. Using smaller deletions, RNAi, and mutant alleles, we further mapped five regions and refined the interactions to 58 candidate genes. Importantly, mutant alleles identifiedcombover (cmb), a substrate of Rho-kinase (Rok) and a component of the Planar Cell Polarity (PCP) pathway, as anIdgf3-interacting gene: loss of function enhanced while gain of function suppressed the dorsal appendage defects. Since PCP drives cell intercalation in other systems, we asked ifcmb/+affected cell intercalation in our model, but we found no evidence of its involvement in this step. Instead, we found that loss ofcmbdominantly enhanced tube defects associated withIdgf3overexpression by expanding the apical area of dorsal appendage cells. Apical surface area determines tube volume and shape; in this way,Idgf3andcmbregulate tube morphology.
Mutation bias shapes gene evolution inArabidopsis thaliana
Authors: Monroe J. Grey , Srikant Thanvi , Carbonell-Bejerano Pablo , Exposito-Alonso Moises , Weng Mao-Lun , Rutter Matthew T. , Fenster Charles B. , Weigel Detlef
Published: June 2020

Classical evolutionary theory maintains that mutation rate variation between genes should be random with respect to fitness1–4and evolutionary optimization of genic mutation rates remains controversial3,5. However, it has now become known that cytogenetic (DNA sequence + epigenomic) features influence local mutation probabilities6, which is predicted by more recent theory to be a prerequisite for beneficial mutation rates between different classes of genes to readily evolve7. To test this possibility, we used de novo mutations in Arabidopsis thaliana to create a high resolution predictive model of mutation rates as a function of cytogenetic features across the genome. As expected, mutation rates are significantly predicted by features such as GC content, histone modifications, and chromatin accessibility. Deeper analyses of predicted mutation rates reveal effects of introns and untranslated exon regions in distancing coding sequences from mutational hotspots at the start and end of transcribed regions in A. thaliana. Finally, predicted coding region mutation rates are significantly lower in genes where mutations are more likely to be deleterious, supported by numerous estimates of evolutionary and functional constraint. These findings contradict neutral expectations that mutation probabilities are independent of fitness consequences. Instead they are consistent with the evolution of lower mutation rates in functionally constrained loci due to cytogenetic features, with important implications for evolutionary biology8.
Trophic cooperation promotes bacterial survival ofStaphylococcus aureusandPseudomonas aeruginosa
Authors: Camus Laura , Briaud Paul , Bastien Sylvère , Elsen Sylvie , Doléans-Jordheim Anne , Vandenesch François , Moreau Karen
Published: June 2020

In the context of infection,Pseudomonas aeruginosaandStaphylococcus aureusare frequently co-isolated, particularly in cystic fibrosis (CF) patients. Within lungs, the two pathogens exhibit a range of competitive and coexisting interactions. In the present study, we explored the impact ofS. aureuson the physiology ofP. aeruginosain the context of coexistence. Transcriptomic analyses showed thatS. aureussignificantly and specifically affects the expression of numerous genes involved inP. aeruginosacarbon and amino acid metabolism. In particular, 65% of the strains presented considerable overexpression of the genes involved in the acetoin catabolic (aco) pathway. We demonstrated that acetoin is (i) produced by clinicalS. aureusstrains, (ii) detected in sputa from CF patients, and (iii) involved inP. aeruginosa’s acosystem induction. Furthermore, acetoin is catabolized byP. aeruginosa, a metabolic process that improves the survival of both pathogens by providing a new carbon source forP. aeruginosaand avoiding the toxic accumulation of acetoin onS. aureus. Due to its beneficial effects on both bacteria, acetoin catabolism could testify to the establishment of trophic cooperation betweenS. aureusandP. aeruginosain the CF lung environment, thus promoting their persistence.
CRISPR-Cas-amplified urine biomarkers for multiplexed and portable cancer diagnostics
Authors: Hao Liangliang , Zhao Renee T. , Ngambenjawong Chayanon , Fleming Heather E. , Bhatia Sangeeta N.
Published: June 2020

Synthetic biomarkers, exogenous probes that generate molecular reporters, represent an emerging paradigm in precision diagnostics with applications across infectious and noncommunicable diseases. In order to achieve their promise, these methods reply on multiplexing strategies to provide tools that are both sensitive and specific. However, the field of synthetic biomarkers has not benefited from molecular strategies such as DNA-barcoding due to the susceptibility of nucleic acidsin vivo. Herein, we exploit chemically-stabilized DNAs to tag synthetic biomarkers and produce diagnostic signalsviaCRISPR nucleases. Our strategy capitalizes on disease-associated, protease-activated release of nucleic acid barcodes and polymerase-amplification-free, CRISPR-Cas-mediated barcode detection in unprocessed biofluids. In murine cancer models, we show that the DNA-encoded urine biomarkers can noninvasively detect and monitor disease progression, and demonstrate that nuclease amplification can be harnessed to convert the readout to a point-of-care tool. This technique combines specificity with ease of use to offer a new platform to study human disease and guide therapeutic decisions.
A pathway for error-free non-homologous end joining of resected meiotic double-strand breaks
Authors: Hatkevich Talia , Miller Danny E. , Turcotte Carolyn A. , Miller Margaret C. , Sekelsky Jeff
Published: June 2020

Programmed DNA double-strand breaks (DSBs) made during meiosis are repaired by recombination with the homologous chromosome to generate, at selected sites, reciprocal crossovers that are critical for the proper separation of homologs in the first meiotic divisions. Backup repair processes can compensate when the normal meiotic recombination processes are non-functional. We describe a novel backup repair mechanism that occurs when the homologous chromosome is not available inDrosophila melanogastermeiosis. In the presence of a previously described mutation (Mcm5A7) that disrupts chromosome pairing, DSB repair is initiated by homologous recombination but is completed by non-homologous end joining (NHEJ). Remarkably, this process yields precise repair products. Our results provide support for a recombination intermediate recently discovered in mouse meiosis, in which an oligonucleotide bound to the Spo11 protein that catalyzes DSB formation remains bound after resection. We propose that this oligonucleotide functions as a primer for fill-in synthesis to allow scarless repair by NHEJ.
Embryonic stem cells commit to differentiation by symmetric divisions following a variable lag period
Authors: Strawbridge Stanley E , Blanchard Guy B , Smith Austin , Kugler Hillel , Martello Graziano
Published: June 2020

Mouse embryonic stem (ES) cells are derived from the epiblast of the preimplantation embryo and retain the capacity to give rise to all embryo lineages. ES cells can be released into differentiation from a near-homogeneous maintenance condition. Exit from the ES cell state can be accurately monitored using the Rex1-GFPd2 transgenic reporter, providing a powerful system for examining a mammalian cell fate transition. Here, we performed live-cell imaging and tracking of ES cells during entry into differentiation for 48 hours in defined conditions. We observed a greater cell surface area and a modest shortening of the cell cycle prior to exit and subsequently a reduction in cell size and increase in motility. We did not see any instance of cells regaining ES cell identity, consistent with unidirectional developmental progression. Transition occurred asynchronously across the population but genealogical tracking revealed a high correlation in cell-cycle length and Rex1-GFPd2 expression between daughter cells. A population dynamics model was consistent with symmetric divisions during exit from naive pluripotency. Collapse of ES cell identity occurred acutely in individual cells but after a variable delay. The variation in lag period can extend up to three generations, creating marked population asynchrony.
The effect of hybridization on transposable element accumulation in an undomesticated fungal species
Authors: Hénault Mathieu , Marsit Souhir , Charron Guillaume , Landry Christian R.
Published: June 2020

Transposable elements (TEs) are mobile genetic elements that can profoundly impact the evolution of genomes and species. A long-standing hypothesis suggests that hybridization could deregulate TEs and trigger their accumulation, although it received mixed support from studies in plants and animals. Here, we tested this hypothesis in fungi using incipient species of the undomesticated yeastSaccharomyces paradoxus. Population genomic data revealed no signature of higher transposition in natural hybrids. As we could not rule out the elimination of past transposition increase signatures by natural selection, we performed a laboratory evolution experiment on a panel of artificial hybrids to measure TE accumulation in the near absence of selection. Changes in TE copy numbers were not predicted by the level of evolutionary divergence between the parents of a hybrid genotype. Rather, they were highly dependent on the individual hybrid genotypes, showing that strong genotype-specific deterministic factors govern TE accumulation in yeast hybrids.
Deep mutational scanning of SARS-CoV-2 receptor binding domain reveals constraints on folding and ACE2 binding
Authors: Starr Tyler N. , Greaney Allison J. , Hilton Sarah K. , Crawford Katharine H.D. , Navarro Mary Jane , Bowen John E. , Tortorici M. Alejandra , Walls Alexandra C. , Veesler David , Bloom Jesse D.
Published: June 2020

The receptor binding domain (RBD) of the SARS-CoV-2 spike glycoprotein mediates viral attachment to ACE2 receptor, and is a major determinant of host range and a dominant target of neutralizing antibodies. Here we experimentally measure how all amino-acid mutations to the RBD affect expression of folded protein and its affinity for ACE2. Most mutations are deleterious for RBD expression and ACE2 binding, and we identify constrained regions on the RBD’s surface that may be desirable targets for vaccines and antibody-based therapeutics. But a substantial number of mutations are well tolerated or even enhance ACE2 binding, including at ACE2 interface residues that vary across SARS-related coronaviruses. However, we find no evidence that these ACE2-affinity enhancing mutations have been selected in current SARS-CoV-2 pandemic isolates. We present an interactive visualization and open analysis pipeline to facilitate use of our dataset for vaccine design and functional annotation of mutations observed during viral surveillance.
The quaternion-based spatial-coordinate and orientation-frame alignment problems
Authors: Hanson Andrew J.
Published: June 2020

The general problem of finding a global rotation that transforms a given set of spatial coordinates and/or orientation frames (the `test' data) into the best possible alignment with a corresponding set (the `reference' data) is reviewed. For 3D point data, this `orthogonal Procrustes problem' is often phrased in terms of minimizing a root-mean-square deviation (RMSD) corresponding to a Euclidean distance measure relating the two sets of matched coordinates. This article focuses on quaternion eigensystem methods that have been exploited to solve this problem for at least five decades in several different bodies of scientific literature, where they were discovered independently. While numerical methods for the eigenvalue solutions dominate much of this literature, it has long been realized that the quaternion-based RMSD optimization problem can also be solved using exact algebraic expressions based on the form of the quartic equation solution published by Cardano in 1545; focusing on these exact solutions exposes the structure of the entire eigensystem for the traditional 3D spatial-alignment problem. The structure of the less-studied orientation-data context is then explored, investigating how quaternion methods can be extended to solve the corresponding 3D quaternion orientation-frame alignment (QFA) problem, noting the interesting equivalence of this problem to the rotation-averaging problem, which also has been the subject of independent literature threads. The article concludes with a brief discussion of the combined 3D translation–orientation data alignment problem. Appendices are devoted to a tutorial on quaternion frames, a related quaternion technique for extracting quaternions from rotation matrices and a review of quaternion rotation-averaging methods relevant to the orientation-frame alignment problem. The supporting information covers novel extensions of quaternion methods to the 4D Euclidean spatial-coordinate alignment and 4D orientation-frame alignment problems, some miscellaneous topics, and additional details of the quartic algebraic eigenvalue problem.
The costs of networking in nonwork domains: a resource-based perspective
Authors: Wolff Hans-Georg , Kim Sowon
Published: June 2020

Purpose

While studies have established that networking is an investment in an individual's career that pays off, recent research has begun to examine the potential costs of networking. This study suggests that prior research is limited in scope, as it remains focused on the work domain. Drawing upon the work home resources model (Ten Brummelhuis and Bakker, 2012), the authors broaden this perspective and develop a framework of negative consequences in nonwork domains. The paper proposes that networking generates costs in nonwork domains, because it requires the investment of finite energy resources in the work domain, and people lack these resources in other domains.

Design/methodology/approach

This study uses structural equation modeling of multisource data from N = 306 individuals and their partners to examine how networking affects two distinct nonwork outcomes: work–family conflict and work–life balance.

Findings

Analyses support the general framework: networking is related to time- and strain-based work–family conflict, and work time mediates the relationship between networking and these forms of conflict. Moreover, networking exhibits an inverted U-shaped relationship with work–life balance, indicating that excessive networking as well as a lack of networking decrease work–life balance.

Originality/value

This study adds to the emergent literature on the negative consequences of networking. The findings suggest that employees and organizations should adopt a broader and more balanced perspective on networking: one that takes the well-known benefits – but also potential costs in work and nonwork domains – into account.
Impact of product innovativeness on technology switching in global market
Authors: AL-Kwifi Osama Sam , Ongsakul Viput , Abu Farha Allam K. , Zafar Ahmed U. , Karasneh Mahmoud
Published: June 2020

Purpose

The purpose of this paper is to explore the relationship between product innovativeness and the process of technology switching. This issue is important for two reasons: (1) in mature markets, the only way to increase market share is through consumers' switching from competitor firms and (2) it is essential to determine whether the product innovation strategy can meet users' needs in high-technology markets.

Design/methodology/approach

Research centers (university hospitals) specializing in magnetic resonance imaging (MRI) are the lead users of the MRI market. In this market, the technology switching process was tracked using an annual conference database. Interviews with industry experts and lead users were conducted in order to determine the relationship between product innovativeness and technology switching.

Findings

The findings reveal that in the lead users' segment, technology switching is occurring at a significant level. The interviews emphasized the influence of product innovativeness on technology switching in the global MRI market, as well as the importance of adopting an open innovation process as a strategy to enhance product innovativeness.

Practical implications

The results can be generalized to industries with similar characteristics, such as high rates of technological change and technology heterogeneity. In high-technology markets, managers should monitor switching behavior. They should also study the influence of product innovativeness on such behavior in order to determine the correct product innovation strategy and meet users' preferences effectively.

Originality/value

The literature reports considerable research that investigates switching behavior, but most publications use data from a short time period and cover a limited geographical region. This is the first study that uses data to track the switching behavior of high-technology products on a global scale over a 22-year period.
Understanding nascent women entrepreneurs: an exploratory investigation into their entrepreneurial intentions
Authors: Wannamakok Wisuwat , Chang Yu-Yu
Published: June 2020

Purpose

Women entrepreneurs are having increasingly profound impacts on the global economic landscape, although little is known about what supports or restricts women’s entrepreneurial attempts. The purpose of this paper is to explore the perceptual (i.e. presence of role models and fear of failure) and cognitive (i.e. opportunity recognition and entrepreneurial knowledge) mechanisms that influence a women’s choice of an entrepreneurial career.

Design/methodology/approach

A transnational sample of 9,716 women participating in global entrepreneurship monitor (GEM) survey was examined using logistical regression analysis.

Findings

The results indicate that role models, opportunity discovery and entrepreneurial knowledge have a significant and positive influence on female respondents’ entrepreneurial intentions. Interestingly, fear of failure is not related to their entrepreneurial intention, which challenges the prevailing assumption that the worries about new venture outcomes are the primary suppressor of women’s entrepreneurship.

Originality/value

This study sheds new light on the intention of becoming women entrepreneurs, which has multiple implications for originality/value. This study sheds new light on the intention of becoming women entrepreneurs, which has many implications for policymakers. Moreover, theoretical contributions and directions for future research are discussed.
An examination of the e-government service value chain
Authors: Kumar Rajiv , Kumar Ritu , Sachan Amit , Gupta Piyush
Published: June 2020

Purpose

E-government quality (e-GovQual) and e-government user value (e-GUV) are multidimensional concepts. While previous studies have identified apparent factors influencing e-government satisfaction (e-GovSat) and e-government adoption intention (e-GovAI), such as e-GovQual and e-GUV, but they have neglected to explain the influence of the dimensions of these two concepts. The purpose of this research is to study e-government service value chain (e-GSVC) one-GovQual dimensions, e-GUV dimensions, e-GovSat and e-GovAI.

Design/methodology/approach

The study employs a quantitative method to test the hypotheses and validate the proposed model. Data are collected from 378 e-government users across different parts of India comprising of different demographic characteristics. The model is analyzed using structural equation modeling.

Findings

The findings highlight the impact of the dimensions of e-GovQual (efficiency, trust, reliability and citizen support) on the dimensions of e-GUV (functional, economic, social and emotional value) as e-GUV dimensions affect e-GovSat, which in turn influences e-GovAI. The results validate the e-GSVC and also stress the partial mediating role of the dimensions of e-GUV on the relationship between the dimensions of e-GovQual and e-GovSat.

Research limitations/implications

The sample size of 378 may not be a proper representation of a country like India, which has huge diversity within its vast population.

Practical implications

The study offers practitioners a clear picture and a useful guide to better understand the drivers of value, satisfaction and adoption in the case of e-government users.

Originality/value

This study is probably the first attempt toward demonstrating the process influencing e-GovSat via e-GUV dimensions originating from excellent e-GovQual dimensions to ultimately trigger e-GovAI.
The effects of self-reflection on individual intellectual capital
Authors: Wang Zhining , Cai Shaohan , Liu Mengli , liu Dandan , Meng Lijun
Published: June 2020

Purpose

The aim of this paper is to develop a tool measuring individual intellectual capital (IIC) and investigate the relationship between self-reflection and IIC.

Design/methodology/approach

This study developed a theoretical model based on social cognitive theory and the literature of self-reflection and intellectual capital (IC). This research collected responses from 502 dyads of employees and their direct supervisors in 150 firms in China, and the study tested the research model using structural equation modeling (SEM).

Findings

The results indicate that three components of self-reflection, namely, need for self-reflection, engagement in self-reflection and insight, significantly contribute to all the three components of IIC, such as individual human capital, individual structural capital and individual relational capital. The findings suggest that need for self-reflection is the weakest component to impact individual human capital and individual relationship capital, while insight is the one that mostly enhances individual structural capital.

Practical implications

This paper suggests that managers can enhance employees' IIC by facilitating their self-reflection. Managers can develop appropriate strategies based on findings of this study, to achieve their specific goals.

Originality/value

First, this study develops a tool for measuring IIC. Second, this study provides an enriched theoretical explanation on the relationship between self-reflection and IIC – by showing that the three subdimensions of self-reflection, such as need, engagement and insight, influence the three subdimensions of IIC, such as individual human capital, individual structural capital and individual relational capital.
Analysis on the operation mechanism of the ecosystem of crowd innovation space based on grounded theory
Authors: Wei Wu , Ni Hui
Published: June 2020

Purpose

The purpose of this paper is to study the operation mechanism of the ecosystem of crowd innovation space. Though the crowd innovation space is a new product of China's innovation-driven strategy, there are some barriers in operation. So, this problem is worthy of study.

Design/methodology/approach

In this study, data were obtained through four-month field investigation and semistructured interview, then classified and analyzed through grounded theory, because grounded theory is conducive to the exploration and discovery of new theories.

Findings

This study finds that the relationship between makerspace and entrepreneurs is strong social relational embeddedness. The relationship between crowd innovation space and governments and investment institutions is economic relational embeddedness. Under these social network ties, entrepreneurs, crowd innovation space, social investment institutions and so on can interact directly with each other to different degrees, carry out value cocreation activities and improve the benefits of all elements in the ecosystem and the ecosystem itself.

Originality/value

This study researches the operation mechanism of crowd innovation space ecosystem and identifies the ties between various elements in the ecosystem on the perspective of social network, which is conducive to improve the self-generating capacity of crowd innovation space and enhance the success rate of entrepreneurship.
Customer journey analyses in digital media: exploring the impact of cross-media exposure on customers' purchase decisions
Authors: Klein Jan F. , Zhang Yuchi , Falk Tomas , Aspara Jaakko , Luo Xueming
Published: June 2020

Purpose

In the age of digital media, customers have access to vast digital information sources, within and outside a company's direct control. Yet managers lack a metric to capture customers' cross-media exposure and its ramifications for individual customer journeys. To solve this issue, this article introduces media entropy as a new metric for assessing cross-media exposure on the individual customer level and illustrates its effect on consumers' purchase decisions.

Design/methodology/approach

Building on information and signalling theory, this study proposes the entropy of company-controlled and peer-driven media sources as a measure of cross-media exposure. A probit model analyses individual-level customer journey data across more than 25,000 digital and traditional media touchpoints.

Findings

Cross-media exposure, measured as the entropy of information sources in a customer journey, drives purchase decisions. The positive effect is particularly pronounced for (1) digital (online) versus traditional (offline) media environments, (2) customers who currently do not own the brand and (3) brands that customers perceive as weak.

Practical implications

The proposed metric of cross-media exposure can help managers understand customers' information structures in pre-purchase phases. Assessing the consequences of customers' cross-media exposure is especially relevant for service companies that seek to support customers' information search efforts. Marketing agencies, consultancies and platform providers also need actionable customer journey metrics, particularly in early stages of the journey.

Originality/value

Service managers and marketers can integrate the media entropy metric into their marketing dashboards and use it to steer their investments in different media types. Researchers can include the metric in empirical models to explore customers' omni-channel journeys.
Uncertain risk: assessing open data signals
Authors: Washington Anne L.
Published: June 2020

Purpose

Open data resources contain few signals for assessing their suitability for data analytics. The purpose of this paper is to characterize the uncertainty experienced by open data consumers with a framework based on economic theory.

Design/methodology/approach

Drawing on information asymmetry theory about market exchanges, this paper investigates the practical challenges faced by data consumers seeking to reuse open data. An inductive qualitative analysis of over 2,900 questions asked between 2013 and 2018 on an internet forum identified how a community of 15,000 open data consumers expressed uncertainty about data sources.

Findings

Open data consumers asked direct questions that expressed uncertainty about the availability, interoperability and interpretation of data resources. Questions focused on future value and some requests were devoted to seeking data that matched known sources. The study proposes a data signal framework that explains uncertainty about open data within the context of control and visibility.

Originality/value

The proposed framework bridges digital government practice to information signaling theory. The empirical evidence substantiates market aspects of open data portals. This paper provided a needed case study of how data consumers experience uncertainty. The study integrates established theories about risk to improve the reuse of open data.
Insecticidal activity of Origanum majorana L. essential oil as anti‐cholinergic agent
Authors: Prabu Sivaprasath , Jing Dapeng , Chandran Viswanathan , Mathew Preethy
Published: June 2020

The present study was focused on exploring the presence of active compounds in Origanum majorana essential oil (OmEO), and its various knock‐down effects against the rice moth, Corcyra cephalonica. GC–MS analysis detected the existence of major compounds such as monoterpenes, cis‐β‐terpineol and terpinen‐4‐ol with the total proportion of 52.16%. Fumigant toxicity against adult and larvae was calculated with an LC50 value of 11.31 and 49.83 μL/L air, respectively. The contact toxicity against adult, pupa, larvae and eggs was observed with LC50 value 2.54, 0.95, 2.78, and 0.49 μL/L, respectively. Furthermore, the influential repellent behavior against adults has been observed. Acetylesterase (AChE) inhibition activity of OmEO was observed against adult and larvae of C. cephalonica with an IC50 value of 35.89 and 118.54 μL/mL, respectively. Moreover, computational docking study revealed the binding affinity of Cis‐β‐terpineol and terpinen‐4‐ol towards the active binding sites of AChE. On the other hand, Fluorescence‐assisted cytometry and comet assay confirmed the cytotoxic and genotoxic effect of OmEO at various concentrations on C. cephalonica. Altogether, the results showed the knock‐down effect of OmEO against C. cephalonica, and it could be a potential biocontrol measure against the stored product pest.
Wild bee (Apiformes) communities in contrasting habitats within agricultural and wooded landscapes: implications for conservation management
Authors: Twerd Lucyna , Sobieraj‐Betlińska Anna
Published: June 2020

Semi‐natural habitats are characterized by a high diversity of wildlife. However, other areas, e.g. old fields, can also play an important role in biodiversity conservation.

We assessed the species richness, abundance, and diversity of wild bees (Apiformes), including species of various functional groups in two contrasting and differently managed landscape types. For this study, we selected 15 xerothermic or sandy grasslands or extensively managed fresh meadows located in agricultural landscapes as well as 15 old fields located in wooded landscapes. The study sites differed in area, stage of succession, and management regime.

We did not detect any significant differences in total species richness, abundance, and diversity of Apiformes between the two landscape types, which suggests that both semi‐natural habitats and old fields are highly attractive to bees. The two habitat types, however, differed in species composition and proportions of functional groups. We found that in wooded landscapes, eusocial, hive‐nesting, and large‐sized species increased in abundance.

The collected information on the preferences of Apiformes in respect of various habitats and landscapes makes it possible to protect and restore valuable habitats through the implementation of suitable methods of management, both locally and on the scale of landscapes.
A systematic review and trial sequential analysis of intravenous vs. oral peri‐operative paracetamol
Authors: Mallama M. , Valencia A. , Rijs K. , Rietdijk W. J. R. , Klimek M. , Calvache J. A.
Published: June 2020

Postoperative pain might be different after intravenous vs. oral paracetamol. We systematically reviewed randomised controlled trials in patients >15 years that compared intravenous with oral paracetamol for postoperative pain. We identified 14 trials with 1695 participants. There was inconclusive evidence for an effect of route of paracetamol administration on postoperative pain at 0–2 h (734 participants), 2–6 h (766 participants), 6–24 h (1115 participants) and >24 h (248 participants), with differences in standardised mean (95%CI) pain scores for intravenous vs. oral of −0.17 (−0.45 to 0.10), −0.09 (−0.24 to 0.06), 0.06 (−0.12 to 0.23) and 0.03 (−0.22 to 0.28), respectively. Trial sequential analyses suggested that a total of 3948 participants would be needed to demonstrate a meaningful difference in pain or its absence at 0–2 h. There were no differences in secondary outcomes. Intravenous paracetamol is more expensive than oral paracetamol. Substitution of oral paracetamol in half the patients given intravenous paracetamol in our hospital would save around £ 38,711 (€ 43,960 or US$ 47,498) per annum.