bluuebunny/crossref_metadata_2025 huggingface dataset:
The SARS-CoV-2 antibody landscape is lower in magnitude for structural proteins, diversified for accessory proteins and stable long-term in children
Authors: Hachim Asmaa , Gu Haogao , Kavian Otared , Kwan Mike YW , Chan Wai-hung , Yau Yat Sun , Chiu Susan S , Tsang Owen TY , Hui David SC , Ma Fionn , Lau Eric HY , Cheng Samuel MS , Poon Leo LM , Peiris JS Malik , Valkenburg Sophie A , Kavian Niloufar
Published: January 2021

Background

Children are less clinically affected by SARS-CoV-2 infection than adults with the majority of cases being mild or asymptomatic and the differences in infection outcomes are poorly understood. The kinetics, magnitude and landscape of the antibody response may impact the clinical severity and serological diagnosis of COVID-19. Thus, a comprehensive investigation of the antibody landscape in children and adults is needed.

Methods

We tested 254 plasma from 122 children with symptomatic and asymptomatic SARS-CoV-2 infections in Hong Kong up to 206 days post symptom onset, including 146 longitudinal samples from 58 children. Adult COVID-19 patients and pre-pandemic controls were included for comparison. We assessed antibodies to a 14-wide panel of SARS-CoV-2 structural and accessory proteins by Luciferase Immunoprecipitation System (LIPS).

Findings

Children have lower levels of Spike and Nucleocapsid antibodies than adults, and their cumulative humoral response is more expanded to accessory proteins (NSP1 and Open Reading Frames (ORFs)). Sensitive serology using the three N, ORF3b, ORF8 antibodies can discriminate COVID-19 in children. Principal component analysis revealed distinct serological signatures in children and the highest contribution to variance were responses to non-structural proteins ORF3b, NSP1, ORF7a and ORF8. Longitudinal sampling revealed maintenance or increase of antibodies for at least 6 months, except for ORF7b antibodies which showed decline. It was interesting to note that children have higher antibody responses towards known IFN antagonists: ORF3b, ORF6 and ORF7a. The diversified SARS-CoV-2 antibody response in children may be an important factor in driving control of SARS-CoV-2 infection.
COVID-19 Vaccine Acceptance Among Health Care Workers in the United States
Authors: Shekhar Rahul , Sheikh Abu Baker , Upadhyay Shubhra , Singh Mriganka , Kottewar Saket , Mir Hamza , Barrett Eileen , Pal Suman
Published: January 2021

Background

Acceptance of the COVID-19 vaccine will play a major role in combating the pandemic. Healthcare workers (HCWs) are amongst the first group to receive vaccination, so it is important to consider their attitudes about COVID-19 vaccination to better address barriers to widespread vaccination acceptance.

Methods

We conducted a cross sectional study to assess the attitude of HCWs toward COVID-19 vaccination. Data was collected between October 7th and November 9th, 2020. We received 4080 responses out of which 3479 were complete responses and were included in final analysis.

Results

36% of respondents were willing to take the vaccine as soon as it became available while 56% were not sure or would wait to review more data. Vaccine acceptance increased with increasing age, education, and income level. Lower acceptance was noted in females (31%), Black (10%), Latinx (30%) and Conservative/Republican (21%) HCWs, and those working in a rural setting (26%). Direct medical care providers had higher vaccine acceptance (49%). Safety (69%), effectiveness (69%) and speed of development/approval (74%) were noted as the most common concerns regarding COVID-19 vaccination in our survey.

Conclusion

Immediate acceptance of a COVID-19 vaccine is low, with the majority of HCWs choosing to wait to review more data before deciding on personal vaccination. Overall attitudes toward vaccination were positive but specific concerns regarding COVID-19 vaccine are prevalent. Differences in vaccine acceptance were noted between individual and group characteristics which should be addressed to avoid exacerbating health inequities.
Colour Ambiguity in Real Scenes and the Role of Perceptual Organisation
Authors: Werner Annette , Schmidt Alisa , Hilmers Julian , Boborzi Lukas , Weigold Manuela
Published: January 2021

In this study we show a reproduction of the dress-ambiguity phenomenon in a real scene and we report quantitative measurements of the corresponding colour perceptions. The original, real dress, known from #thedress-illusion, was illuminated by combined short- and longwavelength broadband lights from two slide projectors. Test subjects viewing the dress reported to perceive the dress’ fabric and lace colours as blue & black, white & gold or light blue & brown; their corresponding perceptual matches were distributed along the blue/yellow cardinal axis, and exhibited a variability comparable to the ambiguity of the dress photograph. It is particularly noteworthy that the colour ambiguity emerged despite explicit knowledge of the observers about the direction of the light source. Manipulating the background of the real dress (change in chromaticity and luminance, or masking) revealed significant differences between the perceptual groups regarding lightness and colour of the dress. Our findings suggest that observer specific differences in the perceptual organisation of the visual scene are responsible for the colour ambiguity observed for the real dress; in particular, we conclude that colour computations of white & gold viewers focused onto the local region of the dress, whereas the colour processes of blue & black and light-blue & brown viewers were strongly influenced by contextual computations including the background. Our segmentation hypothesis extends existing explanations for the dress’ ambiguity and proposes image based (in the case of the real scene) and high level (in the case of the photograph) neural processes which control the spatial reach of contextual colour computations. The relation between the ambiguity in our real scene and the dress photograph is discussed.
Small mitochondrial protein NERCLIN regulates cardiolipin homeostasis and mitochondrial ultrastructure
Authors: Konovalova Svetlana , Torregrosa-Muñumer Rubén , Manjunath Pooja , Baral Sundar , Liu Xiaonan , Holopainen Minna , Kvist Jouni , Rajendran Jayasimman , Yang Yang , Varjosalo Markku , Käkelä Reijo , Somerharju Pentti , Tyynismaa Henna
Published: January 2021

Cardiolipin (CL) is an essential phospholipid for mitochondrial structure and function. Here we present a small mitochondrial protein, NERCLIN, as a negative regulator of CL homeostasis and mitochondrial ultrastructure. Primate-specific NERCLIN is expressed ubiquitously fromGRPEL2locus on a tightly regulated low level, but induced by heat stress. NERCLIN overexpression severely disrupts mitochondrial cristae structure and induces mitochondrial fragmentation. Proximity labeling suggested interactions of NERCLIN with CL synthesis and prohibitin complexes on the matrix side of the inner mitochondrial membrane. Lipid analysis indicated that NERCLIN regulates mitochondrial CL content. The regulation may occur directly through interaction with PTPMT1, a proximal partner on the CL synthesis pathway, as its product phosphatidylglycerol was also reduced by NERCLIN. We propose that NERCLIN contributes to stress-induced adaptation of mitochondrial dynamics and turnover by regulating the mitochondrial CL content. Our findings add NERCLIN to the group of recently identified small mitochondrial proteins with important regulatory functions.
A stochastic model of homeostasis: the roles of noise and nuclear positioning in deciding cell fate
Authors: Jangid Amit , Selvarajan Suriya , Ramaswamy Ram
Published: January 2021

We study a population based cellular model starting from a single stem cell which stochastically divides to give rise to either daughter stem cells or differentiated daughter cells. There are three main components in the model: nucleus position, gene-regulatory network, and stochastic segregation of transcription factors in daughter cells. We study the proportion of self-renewal and differentiated cell lines as a function of the nucleus position, which in turn decides the plane of cleavage. Both nuclear position and noise play an important role in determining the stem cell genealogies and these results can be compared with a Markov model that ignores nucleus position. We have observed long and short genealogies from model simulation which compares well with experimental results from neuroblast and B-cell division. Symmetric cellular divisions were observed when the nucleus is apical, while asymmetric division occurs when the nucleus is towards the base. The number of clones decreases as a function of time in this model, although the average clone size increases.
SERS uncovers the link between conformation of cytochromecheme and mitochondrial membrane potential
Authors: Brazhe Nadezda A. , Nikelshparg Evelina I. , Baizhumanov Adil A. , Grivennikova Vera G. , Semenova Anna A. , Novikov Sergey M. , Volkov Valentyn S. , Arsenin Aleksey V , Yakubovsky Dmitry I. , Evlyukhin Andrey B. , Bochkova Zhanna V. , Goodilin Eugene A. , Maksimov Georgy V. , Sosnovtseva Olga , Rubin Andrey B.
Published: January 2021

The balance between the mitochondrial respiratory chain activity and the cell’s needs in ATP ensures optimal cellular function. Cytochromecis an essential component of the electron transport chain (ETC), which regulates ETC activity, oxygen consumption, ATP synthesis and can initiate apoptosis. The impact of conformational changes in cytochromecon its function is not understood for lack of access to these changes in intact mitochondria. We have developed a novel sensor that uses unique properties of label-free surface-enhanced Raman spectroscopy (SERS) to identify conformational changes in heme of cytochromecand to elucidate their role in functioning mitochondria. We verify that molecule bond vibrations assessed by SERS is a reliable indicator of the heme conformation during changes in the inner mitochondrial membrane potential and ETC activity. We have found that cytochromecheme reversibly switches between planar and ruffled conformations in response to the inner mitochondrial membrane potential and H+concentration in the intermembrane space to regulate the efficiency of the mitochondrial respiratory chain, thus, adjusting the mitochondrial respiration to the cell’s consumption of ATP and the overall activity. The ability of the proposed SERS-based sensor to track mitochondrial function opens wide perspectives on cell bioenergetics.

For Table of Contents Only
Glial activation in prion diseases is strictly nonautonomous and requires neuronal PrPSc
Authors: Lakkaraju Asvin KK , Sorce Silvia , Senatore Assunta , Nuvolone Mario , Guo Jingjing , Schwarz Petra , Moos Rita , Pelczar Pawel , Aguzzi Adriano
Published: January 2021

Although prion infections cause cognitive impairment and neuronal death, transcriptional and translational profiling shows progressive derangement within glia but surprisingly little changes within neurons. Here we expressed PrPCselectively in neurons, astrocytes or oligodendrocytes of mice. After prion infection, both astrocyte and neuron-restricted PrPCexpression led to copious brain accumulation of PrPSc. As expected, neuron-restricted expression was associated with typical prion disease. However, mice with astrocyte-restricted PrPCexpression experienced a normal life span, did not develop clinical disease, and did not show astro- or microgliosis. Besides confirming that PrPScis innocuous to PrPC-deficient neurons, these results show that astrocyte-born PrPScdoes not activate the extreme neuroinflammation that accompanies the onset of prion disease and precedes any molecular changes of neurons. This points to a nonautonomous mechanism by which prion-infected neurons instruct astrocytes and microglia to acquire a specific cellular state that, in turn, drives neural dysfunction.
In vitropectate lyase activity and carbon uptake assays and whole genome sequencing ofBacillus amyloliquefacienssubsp.plantarumstrains for a pectin defective pathway
Authors: Hassan Mohammad K.
Published: January 2021

The pectin lyase activity of 59Bacillus amyloliquefaciens subsp. plantarum (Bap)strains was testedin vitroon Pectate Agar (PA) and Tris-Spizizen Salts (TSS) medium. Bap strains were cultured on TSA medium and washed three times with sterile water before the inoculation on PA media. Higher and lower pectate lyase activity were observed in six (AP193, AP203, AP299, AP80, AP102, and AP52) and four (AP 194, AP214, AP215, and AP305)Bapstrains compared to other Bap strains. A total of 12 Bap strains (AP67, AP71, AP77, AP78, AP85, AP102, AP108, AP135, AP143, AP189, AP192, and AP193) grew vigorously on TSS medium. A total of sixBapstrains (AP194, AP204, AP214, AP216, AP219, and HD73) had lower growth compared to otherBapstrains. Pectin (1%) were used forin vitroPA and TSS medium. Pectate lyase and utilization activity were not found inBacillus thuringiensissubsp.kurstakistrain HD73 compared toBapstrains. A draft genome sequence for strains AP194 and AP214 that were negative for pectin utilization were generated using an Illumina MiSeq. RAST analysis revealed that the pectin-associated gene altronate hydrolase(uxaA)absent in AP 214 strain. Multiple amino acid alignments ofexuTanduxuBgene sequence showed dissimilarities among AP194, AP214, and referenceBapstrains.
Aberrant Dynamic Functional Connectivity of Default Mode Network in Schizophrenia and Links to Symptom Severity
Authors: Sendi Mohammad S.E. , Zendehrouh Elaheh , Ellis Charles A. , Liang Zhijia , Fu Zening , Mathalon Daniel H. , Ford Judith M. , Preda Adrian , van Erp Theo G. M. , Miller Robyn. L , Pearlson Godfrey D. , Turner Jessica A. , Calhoun Vince D.
Published: January 2021

Background

Schizophrenia affects around 1% of the global population. Functional connectivity extracted from resting-state functional magnetic resonance imaging (rs-fMRI) has previously been used to study schizophrenia and has great potential to provide novel insights into the disorder. Some studies have shown abnormal functional connectivity in the default mode network of individuals with schizophrenia, and more recent studies have shown abnormal dynamic functional connectivity (dFC) in individuals with schizophrenia. However, DMN dFC and the link between abnormal DMN dFC and symptom severity have not been well characterized.

Method

Resting-state fMRI data from subjects with schizophrenia (SZ) and healthy controls (HC) across two datasets were analyzed independently. We captured seven maximally independent subnodes in the DMN by applying group independent component analysis and estimated dFC between subnode time courses using a sliding window approach. A clustering method separated the dFCs into five reoccurring brain states. A feature selection method modeled the difference between SZs and HCs using the state-specific FC features. Finally, we used the transition probability of a hidden Markov model to characterize the link between symptom severity and dFC in SZ subjects.

Results

We found decreases in the connectivity of the anterior cingulate cortex (ACC) and increases in the connectivity between the precuneus (PCu) and the posterior cingulate cortex (PCC) (i.e., PCu/PCC) of SZ subjects. In SZ, the transition probability from a state with weaker PCu/PCC and stronger ACC connectivity to a state with stronger PCu/PCC and weaker ACC connectivity increased with symptom severity.

Conclusions

To our knowledge, this was the first study to investigate DMN dFC and its link to schizophrenia symptom severity. We identified reproducible neural states in a data-driven manner and demonstrated that the strength of connectivity within those states differed between SZs and HCs. Additionally, we identified a relationship between SZ symptom severity and the dynamics of DMN functional connectivity. We validated our results across two datasets. These results support the potential of dFC for use as a biomarker of schizophrenia and shed new light upon the relationship between schizophrenia and DMN dynamics.
6-gingerol interferes with amyloid-beta (Aβ) peptide aggregation
Authors: Berntsson Elina , Paul Suman , Sholts Sabrina B. , Jarvet Jüri , Barth Andreas , Gräslund Astrid , Wärmländer Sebastian K. T. S.
Published: January 2021

Alzheimer’s disease (AD) is the most prevalent age-related cause of dementia. AD affects millions of people worldwide, and to date there is no cure. The pathological hallmark of AD brains is deposition of amyloid plaques, which mainly consist of amyloid-β (Aβ) peptides, commonly 40 or 42 residues long, that have aggregated into amyloid fibrils. Intermediate aggregates in the form of soluble Aβ oligomers appear to be highly neurotoxic. Cell and animal studies have previously demonstrated positive effects of the molecule 6-gingerol on AD pathology. Gingerols are the main active constituents of the ginger root, which in many cultures is a traditional nutritional supplement for memory enhancement. Here, we use biophysical experiments to characterizein vitrointeractions between 6-gingerol and Aβ40peptides. Our experiments with atomic force microscopy imaging, and nuclear magnetic resonance and Thioflavin-T fluorescence spectroscopy, show that the hydrophobic 6-gingerol molecule interferes with formation of Aβ40aggregates, but does not interact with Aβ40monomers. Thus, together with its favourable toxicity profile, 6-gingerol appears to display many of the desired properties of an anti-AD compound.
Testosterone induces a conditioned place preference to the nest of a monogamous mouse under field conditions
Authors: Petric Radmila , Kalcounis-Rueppell Matina C. , Marler Catherine A.
Published: January 2021

Transient increases in testosterone (T-pulses) occur after social interactions in males of various vertebrate species, but the functions of T-pulses are poorly understood. Under laboratory conditions, the rewarding nature of T-pulses induces conditioned place preferences (CPPs), but what are the effects in a complex field environment? We present the first evidence that T-pulses administered to males at their nest site in the wild increased time spent at the nest regardless of pup presence in the monogamous, biparental, and territorial California mouse (Peromyscus californicus). Female partners of the T-males, in turn, spent less time at the nest. Independent of treatment, mice produced more ultrasonic vocalizations (USVs) when alone, but T-mice produced more USVs than controls. T-males produced USVs with a smaller bandwidth that likely traveled farther. Our combined results provide compelling evidence that T-pulses can significantly shift the behavioral focus and location of individuals in a complex field setting.
A field-wide assessment of differential expression profiling by high throughput sequencing reveals widespread bias
Authors: Päll Taavi , Luidalepp Hannes , Tenson Tanel , Maiväli Ülo
Published: January 2021

Here we assess inferential quality in the field of differential expression profiling by high throughput sequencing, based on analysis of datasets submitted 2008-2020 to the NCBI GEO data repository. We take advantage of the parallel differential expression testing over thousands of genes, whereby each experiment leads to a large set of p values, the distribution of which can indicate the validity of assumptions behind the test. Moreover, from a well-behaved p value setπ0, the fraction of genes that are not differentially expressed, can be estimated. We found that only 25% of experiments resulted in theoretically expected p value histogram shapes, although there is a marked improvement over time. Uniform p value histogram shapes, indicative of < 100 true effects, were extremely few. Furthermore, although many HT-seq workflows assume that most genes are not differentially expressed we found 37% of experiments to haveπ0-s of less than 0.5, as if most genes changed their expression level. Restricting our analysis to studies involving cancer or transcription factors, expected to lead to real changes in expression of many genes, did not result in meaningfully different distributions ofπ0-s. Both the fractions of different p value histogram types and theπ0values are strongly associated with the differential expression analysis program used by the original authors. While we could double the proportion of theoretically expected p value distributions by removing low-count features from analysis, this treatment did not remove the association with the analysis program. Taken together, our results indicate widespread bias in differential expression profiling field.
Positive and Neutral Updating Reconsolidate Aversive Episodic Memories via Different Routes
Authors: Wang Jingyi , Chen Boxuan , Sha Manqi , Gu Yiran , Wu Haitao , Forcato Cecilia , Qin Shaozheng
Published: January 2021

Aversive memories are long-lasting and prone to have adverse effects on our emotional wellbeing and mental health. Yet, how to remedy the maladaptive effects of aversive memories remains elusive. Using memory reactivation and emotional updating manipulations, we investigated how positive and neutral emotion updates aversive memories for reconsolidation in humans. We found that positive updating after reactivation was equivalent to neutral updating in altering true memories of the aversive story, but introduced more false memory. Moreover, an additional 12 hours of sleep reconsolidation did not further enlarge true memory differences, but attenuated the effect of reactivation and updating on false memory. Interestingly, the neutral rather than the positive updating reduced the emotional arousal of the aversive memory 24 hours later. Our findings provide novel insights into real-world therapeutic applications regarding how updating with positive and neutral emotion may reshape aversive memories, especially when taking wake- and sleep-filled reconsolidation into account.
DenovoProfiling: a webserver for de novo generated molecule library profiling
Authors: Liu Zhihong , Du Jiewen , Liu Bingdong , Cui Zongbin , Fang Jiansong , Xie Liwei
Published: January 2021

With the advances of deep learning techniques, various architectures for molecular generation have been proposed for de novo drug design. Successful cases from academia and industrial demonstrated that the deep learning based de novo molecular design could efficiently accelerate the drug discovery process. The flourish of the de novo molecular generation methods and applications created great demand for the visualization and functional profiling for the de novo generated molecules. The rising of publicly available chemogenomic databases lays good foundations and create good opportunities for comprehensive profiling of the de novo library. In this paper, we present DenovoProfiling, a web server dedicated for de novo library visualization and functional profiling. Currently, DenovoProfiling contains six modules: (1) identification & visualization, (2) chemical space, (3) scaffold analysis, (4) molecular alignment, (5) target & pathways, and (6) drugs mapping. DenovoProfiling could provide structural identification, chemical space exploration, drugs mapping, and targets & pathways. The comprehensive annotated information could give user a clear picture of their de novo library and could provide guidance in the further selection of candidates for synthesis and biological confirmation. DenovoProfiling is freely available athttp://denovoprofiling.xielab.net.
The engineered peptide construct NCAM1-Aβ inhibits aggregation of the human prion protein (PrP)
Authors: Gielnik Maciej , Zhukova Lilia , Zhukov Igor , Gräslund Astrid , Kozak Maciej , Wärmländer Sebastian K.T.S.
Published: January 2021

In prion diseases, the prion protein (PrP) becomes misfolded and forms fibrillar aggregates, which are resistant to proteinase degradation and become responsible for prion infectivity and pathology. So far, no drug or treatment procedures have been approved for prion disease treatment. We have previously shown that engineered cell-penetrating peptide constructs can reduce the amount of prion aggregates in infected cells. The molecular mechanisms underlying this effect are however unknown. Here, we use atomic force microscopy (AFM) imaging to show that the aggregation of the human PrP protein can be inhibited by equimolar amounts of the 25 residues long engineered peptide construct NCAM1-Aβ.
An autoregulatory negative feedback loop controls thermomorphogenesis in Arabidopsis
Authors: Lee Sanghwa , Zhu Ling , Huq Enamul
Published: January 2021

Plant growth and development are acutely sensitive to high ambient temperature ascribable in part to climate change. However, the mechanism of high ambient temperature signaling is not well defined. Here, we show that HECATEs (HEC1 and HEC2), two helix-loop-helix transcription factors, inhibit thermomorphogenesis. While the expression ofHEC1andHEC2is increased and HEC2 protein is stabilized at high ambient temperature,hec1hec2double mutant showed exaggerated thermomorphogenesis. Analyses of the four major PIF (PIF1, PIF3, PIF4 and PIF5) mutants and overexpression lines showed that they all contribute to promote thermomorphogenesis. Furthermore, genetic analysis showed thatpifQis epistatic tohec1hec2. HECs and PIFs oppositely control the expression of many genes in response to high ambient temperature. HEC2 interacts with PIF4 both in yeast andin vivo. In the absence of HECs, PIF4 binding to its own promoter as well as the target gene promoters was enhanced, indicating that HECs control PIF4 activity via heterodimerization. Overall, these data suggest that PIF4-HEC forms an autoregulatory composite negative feedback loop that controls growth genes to modulate thermomorphogenesis.
Quantifying the regulatory role of individual transcription factors inEscherichia coli
Authors: Guharajan Sunil , Chhabra Shivani , Parisutham Vinuselvi , Brewster Robert C.
Published: January 2021

Gene regulation often results from the action of multiple transcription factors (TFs) acting at a promoter, with a net regulation that depends on both the direct interactions of TFs with RNA polymerase (RNAP) and the indirect interactions with each other. Here we measure the fundamental regulatory interactions of TFs inE. coliby designing synthetic target genes that isolate the individual TFs regulatory effect. Using a thermodynamic model, the direct regulatory impact of the TF on RNAP is decoupled from TF occupancy and interpreted as acting through two mechanisms: (de)stabilization of RNAP and (de)acceleration of transcription initiation. We find the contributions of each mechanism depends on TF identity and binding location; for the set of TFs profiled, regulation immediately downstream of the promoter is insensitive to TF identity, yet these same TFs regulate by distinct mechanisms upstream of the promoter. Strikingly, we observe two fundamental regulatory paradigms with these two mechanisms acting coherently, to rein-force the observed regulatory role (activation or repression), or incoherently, where the TF regulates two distinct steps with opposing effect. This insight provides critical information on the scope of TF-RNAP regulation allowing for a stronger approach to characterize the endogenous regulatory function of TFs.
Diversification dynamics of hypermetamorphic blister beetles (Meloidae): Are homoplastic host shifts and phoresy key factors of a rushing forward strategy to escape extinction?
Authors: López-Estrada E.K. , Sanmartín I. , Uribe J.E. , Abalde S. , García-París M.
Published: January 2021

Changes in life history traits, including reproductive strategies or host shifts, are often considered triggers of speciation, affecting diversification rates. Subsequently, these shifts can have dramatic effects on the evolutionary history of a lineage. In this study, we examine the consequences of changes in life history traits, in particular host-type and phoresy, within the hypermetamorphic clade of blister beetles (Meloidae). This clade exhibits a complex life cycle involving multiple metamorphoses and parasitoidism. Most tribes within the clade are bee-parasitoids, phoretic or non-phoretic, while two tribes feed on grasshopper eggs. Species richness differs greatly between bee and grasshopper specialist clades, and between phoretic and non-phoretic genera. We generated a mitogenomic phylogeny of the hypermetamorphic clade of Meloidae, including 21 newly generated complete mitogenomes. The phylogeny and estimated lineage divergence times were used to explore the association between diversification rates and changes in host specificity and phoresy, using State-Dependent Speciation and Extinction (SSE) models, while accounting for hidden factors and phylogenetic uncertainty within a Bayesian framework. The ancestor of the hypermetamorphic Meloidae was a non-phoretic bee-parasitoid, and independent transitions towards phoretic bee-parasitoidism or grasshopper specialization occurred multiple times. Bee-parasitoid lineages that are non-phoretic have significantly higher relative extinction rates and lower diversification rates than grasshopper specialists or phoretic bee-parasitoids, while no significant differences were found between the latter two strategies. This suggests that these two life strategies contributed independently to the evolutionary success of Nemognathinae and Meloinae, allowing them to escape from the evolutionary constraints imposed by their hypermetamorphic life-cycle, and that the “bee-by-crawling” strategy may be an evolutionary “dead end”. We show how SSE models can be used not only for testing diversification dependence in relation to the focal character but to identify hidden traits contributing to the diversification dynamics. The ability of blister beetles to explore new evolutionary scenarios including the development of homoplastic life strategies, are extraordinary outcomes along the evolution of a single lineage: the hypermetamorphic Meloidae.
The spindle assembly checkpoint and the spatial activation of Polo kinase determine the duration of cell division and prevent neural stem cells tumor formation
Authors: Gallaud Emmanuel , Richard-Parpaillon Laurent , Pascal Aude , Métivier Mathieu , Archambault Vincent , Giet Régis
Published: January 2021

The maintenance of a restricted pool of asymmetrically dividing stem cells is essential for tissue homeostasis. This process requires the control of mitotic progression that ensures the accurate chromosome segregation. In addition, this event is coupled to the asymmetric distribution of cell fate determinants in order to prevent stem cell amplification. How this coupling is regulated remains poorly described. Here, using asymmetrically dividingDrosophilaneural stem cells (NSCs), we show that Polo kinase activity levels determine the length of cell division, independent of the spindle assembly checkpoint (SAC). This event is mediated by the direct phosphorylation of Polo kinase by Aurora A at spindle poles and Aurora B kinases at centromeres. Furthermore, we show that Aurora A-dependent activation of Polo is the major event that promotes NSC polarization and together with the SAC prevents brain tumor growth. Altogether, our results show that an Aurora/Polo kinase module couples NSC mitotic progression and polarization for tissue homeostasis.
Nonlinear collision between anisotropic propagating waves in mouse somatosensory cortex
Authors: Di Volo M. , Férézou I.
Published: January 2021

How does cellular organization shape the spatio-temporal patterns of activity in the cortex while processing sensory information? After measuring the propagation of activity in the mouse primary somatosensory cortex (S1) in response to single whisker deflections with Voltage Sensitive Dye (VSD) imaging, we developed a two dimensional mean field model of S1. We observed that, for strong enough excitatory cortical interactions, whisker deflections generate a propagating wave in S1. We developed an inversion method that reconstructs model parameters from VSD data, revealing that a spatially heterogeneous organization of synaptic strengths between pyramidal neurons in S1 is likely to be responsible for the anisotropic spatio-temporal patterns of activity measured experimentally. Finally, we report that two consecutive stimuli activating different spatial locations in S1 generate two waves which collide sub-linearly. In the model, such sub-linear interaction is explained by a lower sensitivity to external perturbations of neural networks during activated states.
Crystal structures and dielectric properties of 4,4′-dimethyl-6,6′-dichlorothioindigo (Pigment Red 181)
Authors: Sakthidharan C. P. , Niewa R. , Zherebtsov D. A. , Podgornov F. V. , Matveychuk Y. V. , Bartashevich E. V. , Nayfert S. A. , Adonin S. A. , Gavrilyak M. V. , Boronin V. A. , Polozov M. A. , Karthikeyan S. , Sarojadevi M. , Rajakumar K. , Prabunathan P.
Published: January 2021

The structures of the red polymorph (space group P
1) and the black polymorph (space group P21/c) of 4,4′-dimethyl-6,6′-dichlorothioindigo were solved from single-crystal samples. For both polymorphs, the spatial stacking of the flat molecules is driven by π-stacking and noncovalent interactions within the layers. Spectroscopic (UV–vis, IR and photoluminescence) and thermal properties of the red polymorph were investigated experimentally. The bandgap of this polymorph was estimated as 2.08 eV at room temperature. It is demonstrated that the electric conductivity of the red polymorph follows the hopping mechanism.
HGHA: task allocation and path planning for warehouse agents
Authors: Liu Yandong , Han Dong , Wang Lujia , Xu Cheng-Zhong
Published: January 2021

Purpose

With the rapid development of e-commerce, logistics demand is increasing day by day. The modern warehousing with a multi-agent system as the core comes into being. This paper aims to study the task allocation and path-planning (TAPP) problem as required by the multi-agent warehouse system.

Design/methodology/approach

The TAPP problem targets to minimize the makespan by allocating tasks to the agents and planning collision-free paths for the agents. This paper presents the Hierarchical Genetic Highways Algorithm (HGHA), a hierarchical algorithm combining optimization and multi-agent path-finding (MAPF). The top-level is the genetic algorithm (GA), allocating tasks to agents in an optimized way. The lower level is the so-called highways local repair (HLR) process, avoiding the collisions by local repairment if and only if conflicts arise.

Findings

Experiments demonstrate that HGHA performs faster and more efficient for the warehouse scenario than max multi-flow. This paper also applies HGHA to TAPP instances with a hundred agents and a thousand storage locations in a customized warehouse simulation platform with MultiBots.

Originality/value

This paper formulates the multi-agent warehousing distribution problem, TAPP. The HGHA based on hierarchical architecture solves the TAPP accurately and quickly. Verifying the HGHA by the large-scale multi-agent simulation platform MultiBots.
A capsule-based collision detection approach of irregular objects in virtual maintenance
Authors: Jin Yuxue , Geng Jie , He Zhiyi , Lv Chuan , Zhao Tingdi
Published: January 2021

Purpose

Virtual maintenance simulation is of great importance to help designers find and avoid design problems. During its simulation phase, besides the high precision requirement, collision detection must be suitable for all irregular objects in a virtual maintenance environment. Therefore, in this paper, a collision detection approach is proposed based on encapsulation for irregular objects in the virtual maintenance environment.

Design/methodology/approach

First, virtual maintenance simulation characteristics and several commonly used bounding boxes methods are analyzed, which motivates the application of encapsulation theory. Based on these, three different encapsulation methods are oriented to the needs of simulation, including encapsulation of rigid maintenance objects, flexible maintenance objects and maintenance personnel. In addition, to detecting collisions accurately, this paper divides the detection process into two stages. That is, in the first stage, a rough detection is carried out and then a tiny slice space is constructed to generate corresponding capsule groups, which will be redetected in the secondary stage. At last, several case studies are applied to illustrate the performance of the methodology.

Findings

The automatic construction algorithm for bounding boxes can be adapted to all forms of objects. The number of detection primitives are greatly reduced. It introduces the reachable space of the human body in maintainability as the collision search area.

Originality/value

The advantages of virtual maintenance simulation could also be advantageous in the industry with further studies. The paper believes this study is of particular interest to the readers of your journal.
Financial market efficiency: global and regional financial market perspective
Authors: Abaidoo Rexford
Published: January 2021

Purpose

This study examines dynamics of global and regional financial market efficiency; and how specific features of the market and other conditions influence variability in such efficiency.

Design/methodology/approach

The study employs fixed effects statistical approach in its examination of how specific features of financial markets influence variability in its efficiency.

Findings

This study finds that individual IMF defined economic regions tend to exhibits significantly different financial market efficiency characteristics given specific market features and conditions. In regional level comparative analysis (e.g. Europe, Africa, Asia–Pacific etc.) this study finds that incidence of financial market uncertainty is the dominant condition with significant effect on financial market efficiency across all the IMF regions. In the global level analysis, empirical estimates presented suggest that financial market uncertainty, financial institutional depth and financial institutional efficiency tend to have significant positive influence on global financial market efficiency all things being equal. In the same analysis however, this study finds that financial market and financial institutional access growth has significant negative impact on financial market efficiency.

Originality/value

The uniqueness of this study compared to related ones found in the literature stems from its focus on financial market efficiency at the global, and IMF defined regional block level instead of on a specific economy as often found in the literature. Additionally, in contrast to other related studies, this study further examines the role of global financial market uncertainty in its financial market efficiency analysis. Financial market uncertainty variable may be unique to this study because the variable is derived through an econometric process from a base variable.
Government spending and economic growth: a trivariate causality testing
Authors: Olaoye Olumide , Afolabi Olatunji
Published: January 2021

Purpose

This paper investigates whether institutional environment influences the relationship government spending and economic growth in ECOWAS over the period 2008–2017.

Design/methodology/approach

The study adopts the recently developed panel vector autoregressive (PVAR) by Abrigo and Love (2015) and a two-step system generalised method of moment (GMM).

Findings

The results from the study show no evidence of either unidirectional or bidirectional causal relationship between government spending and economic growth in ECOWAS. Our findings reveal that government spending when associated with high level of corruption, oversized government and a waste of public resources will not cause economic growth.

Originality/value

Unlike previous studies, we resolve the inherent problems of endogeneity and persistence in economic data. Likewise, we depart from existing studies that examined the causal relationship in a bivariate framework and adopt a trivariate causality testing.
The effectiveness of effectuation: a meta-analysis on contextual factors
Authors: Chen Jiawen , Liu Linlin , Chen Qingxin
Published: January 2021

Purpose

Empirical data on the impacts of entrepreneurial effectuation on firm performance are scattered and controversial. This study conducts a meta-analysis to obtain evidence on whether and under what conditions effectuation is valuable. A contextual framework is proposed that highlights the boundary condition of the performance impact of effectuation.

Design/methodology/approach

Both the traditional approach of meta-analysis and advanced techniques of Bayesian meta-analytic tests are used to combine numerous studies from varied research contexts.

Findings

Meta-analytic results show that effectuation generally has a positive impact on firm performance, and is context-dependent, leading to stronger performance for older firms and firms in high-tech industries and emerging countries.

Originality/value

The findings provide important implications for entrepreneurs who are considering applying effectuation. This study highlights that effectuation is context-dependent and the performance implications of effectuation are contingent on contextual factors at organizational, industrial and institutional levels. This study extends the contextual understanding of the effectuation–performance relationship.
Enriching management learning with differentiated instruction
Authors: Alstete Jeffrey W. , Meyer John P. , Beutell Nicholas J.
Published: January 2021

Purpose

The purpose of this study is to utilize an exploratory multiple-case design research method using three undergraduate management courses at a medium-sized private comprehensive college near a large metropolitan area in the USA.

Design/methodology/approach

This paper explores differentiated instruction in relation to experiential learning in management education by examining three teaching applications from different management courses to illustrate these concepts.

Findings

The use of differentiated instruction in management education is supported through varied approaches such as individual student and team-based scaffolding that demonstrate the applicability of differentiation. In addition to improving student learning, other benefits include improved student retention and faculty autonomy in course creation and delivery. The implementation involves a proactive response to learner needs informed by a faculty perspective that recognizes student diversity yet retains quality assurance standards with mindful assessment and planning.

Research limitations/implications

The comparatively small number of courses and instructional methods may make the specific findings and examples more relevant to the type of institution examined. Yet, the general conclusions and methods identified have potential implications for learners in a wide variety of colleges and universities.

Practical implications

Differentiated instruction may be a useful approach for enhancing learning in heterogenous groups of students by recognizing student readiness and making appropriate modifications.

Originality/value

This paper offers an exploratory overview of differentiated instruction with guidance for management faculty members in designing and implementing these approaches in their courses.
Adverse obstetric outcomes in two Brazilian maternity hospitals
Authors: Andrade Alessa Leila , Gama Zenewton André da Silva , Freitas Marise Reis de , Medeiros Wilton Rodrigues , Sousa Kelienny de Meneses , Silva Edna Marta Mendes da , Rosendo Tatyana Souza
Published: January 2021

Purpose

Obstetric adverse outcomes (AOs) are an important topic and the use of composite measures may favor the understanding of their impact on patient safety. The aim of the present study was to estimate AO frequency and obstetric care quality in low and high-risk maternity hospitals.

Design/methodology/approach

A one-year longitudinal follow-up study in two public Brazilian maternity hospitals. The frequency of AOs was measured in 2,880 randomly selected subjects, 1,440 in each institution, consisting of women and their newborn babies. The frequency of 14 AOs was estimated every two weeks for one year, as well as three obstetric care quality indices based on their frequency and severity as follows: the Adverse Outcome Index (AOI), the Weighted Adverse Outcome Score and the Severity Index.

Findings

A significant number of mothers and newborns exhibited AOs. The most prevalent maternal AOs were admission to the ICU and postpartum hysterectomy. Regarding newborns, hospitalization for > seven days and neonatal infection were the most common complications. Adverse outcomes were more frequent at the high-risk maternity, however, they were more severe at the low-risk facility. The AOI was stable at the high-risk center but declined after interventions during the follow-up year.

Originality/value

High AO frequency was identified in both mothers and newborns. The results demonstrate the need for public patient safety policies for low-risk maternity hospitals, where AOs were less frequent but more severe.
Students as change agents for campus sustainability in Malaysian universities
Authors: Mohamad Zeeda Fatimah , Mamat Mohd Zufri , Muhamad Noor Muhamad Faisal
Published: January 2021

Purpose

The notion of students as change agents have widely been used in the campus sustainability literature, but very little has been done to unpack what it really means in practice. This paper aims to critically investigate university students’ perspectives on their role as a change agent for campus sustainability in the context of Malaysian universities.

Design/methodology/approach

In-depth interviews were carried out with 21 students that have been categorized as change agents through selection criteria at three leading universities in the area of campus sustainability in Malaysia. The data collected from the interviews were analysed through content-based and thematic analysis.

Findings

Findings demonstrate that students are the backbone behind the implementation of campus sustainability activities. They play the multi-faceted role of leaders, supporters and ambassadors in initiating and driving campus sustainability. The results further suggest that support and freedom to act are the empowering factors that have driven these change agents in carrying out their initiatives. However, without a position, the students’ voices are not significant.

Originality/value

This study provides deeper evidence-based insights on the notion of students as change agents and how it can be operationalized in the context of campus sustainability.