bluuebunny/crossref_metadata_2025 huggingface dataset:
A Hybrid of Light-Field and Light-Sheet Imaging to Decouple Myocardial Biomechanics from Intracardiac Flow Dynamics
Authors: Wang Zhaoqiang , Ding Yichen , Satta Sandro , Roustaei Mehrdad , Fei Peng , Hsiai Tzung K.
Published: September 2020

Biomechanical forces intimately contribute to cardiac morphogenesis. However, 4-D (3-D space + time) imaging is needed to investigate the developmental cardiac mechanics with high temporal and spatial resolution. We hereby integrated light-sheet fluorescence microscopy (LSFM) with light-field microscopy (LFM), to simultaneously visualize myocardial contractility and intracardiac blood flow in three dimensions at 200 volumes per second (vps). LSFM allows for reconstruction of the myocardial contraction in zebrafish embryo; and LFM enables simultaneous tracking of the blood cells entering and leaving the contracting heart. We herein established particle tracking velocimetry to interrogate the trajectories of intracardiac blood cells, and we demonstrated deformable image registration to reveal a decrease in the myocardial contractility from atrioventricular (AV) canal to the outflow tract (OFT). We imaged myocardium undergoing torsional contraction and blood flow undergoing regurgitation. Taken together, the integration of light-field and light-sheet microscopy, followed by an image-based analysis pipeline, provides the biomechanical insights into coupling myocardial kinetics with rotational contraction along with intracardiac flow dynamics during development.
Bimodality of gene expression in cancer patient tumors as interpretable biomarkers for drug sensitivity
Authors: Ba-Alawi Wail , Nair Sisira Kadambat , Li Bo , Mammoliti Anthony , Smirnov Petr , Mer Arvind Singh , Penn Linda , Haibe-Kains Benjamin
Published: September 2020

Identifying biomarkers predictive of cancer cells’ response to drug treatment constitutes one of the main challenges in precision oncology. Recent large-scale cancer pharmacogenomic studies have boosted the research for finding predictive biomarkers by profiling thousands of human cancer cell lines at the molecular level and screening them with hundreds of approved drugs and experimental chemical compounds. Many studies have leveraged these data to build predictive models of response using various statistical and machine learning methods. However, a common challenge in these methods is the lack of interpretability as to how they make the predictions and which features were the most associated with response, hindering the clinical translation of these models. To alleviate this issue, we develop a new machine learning pipeline based on the recent LOBICO approach that explores the space of bimodally expressed genes in multiple largein vitropharmacogenomic studies and builds multivariate, nonlinear, yet interpretable logic-based models predictive of drug response. Using our method, we used a compendium of three of the largest pharmacogenomic data sets to build robust and interpretable models for 101 drugs that span 17 drug classes with high validation rate in independent datasets.
Comparison between cultivation and sequencing based approaches for microbiota analysis in swabs and biopsies of chronic wounds
Authors: Mahnic Aleksander , Breznik Vesna , Ihan Maja Bombek , Rupnik Maja
Published: September 2020

Chronic wounds are a prominent health concern affecting 0.2% of individuals in the Western population. Microbial colonization and the consequent infection contribute significantly to the healing process of chronic wounds. We have compared cultivation and 16S amplicon sequencing (16S-AS) for the characterization of bacterial populations in swabs and biopsy tissues obtained from 45 chronic wounds and analysed metadata for wound-specific and clinical-outcome-associated correlations with bacterial community structure.

Using cultivation approach, we detected a total of 39 bacterial species, on average 2.89 per sample (SD=1.93). Comparison of cultivation results between swabs and biopsy samples showed no significant advantage of one sampling method over the other. 16S-AS was advantageous in comparison to the cultivation approach in case of highly diverse communities, where we could additionally detect numerous obligate and facultative anaerobic bacteria from generaAnaerococcus, Finegoldia, Porphyromonas, MorganellaandProvidencia. Based on the community diversity, chronic wound microbiota could be distributed into three groups, however, no correlation between groups and clinical outcome was observed. Clinically estimated presence of biofilm and a larger surface area at the initial visit were most significantly associated with unfavourable clinical outcomes after one-year follow-up visit.Corynebacteriumwas the single most predictive bacterial genus associated with unfavourable clinical outcomes in our study.
Discovery of divided RdRp sequences and a hitherto unknown genomic complexity in fungal viruses
Authors: Chiba Yuto , Yaguchi Takashi , Urayama Syun-ichi , Hagiwara Daisuke
Published: September 2020

By identifying variations in viral RNA genomes, cutting-edge metagenome technology has potential to reshape current concepts about the evolution of RNA viruses. This technology, however, cannot process low-homology genomic regions properly, leaving the true diversity of RNA viruses unappreciated. To overcome this technological limitation we applied an advanced method, Fragmented and Primer-Ligated Double-stranded (ds) RNA Sequencing (FLDS), to screen RNA viruses from 155 fungal isolates, which allowed us to obtain complete viral genomes in a homology-independent manner. We created a high-quality catalog of 19 RNA viruses (12 viral species) that infectAspergillusisolates. Among them, nine viruses were not detectable by the conventional methodology involving agarose gel electrophoresis of dsRNA, a hallmark of RNA virus infections. Segmented genome structures were determined in 42% of the viruses. Some RNA viruses had novel genome architectures; one contained a dual methyltransferase domain and another had a separated RNA-dependent RNA polymerase (RdRp) gene. A virus from a different fungal taxon (Pyricularia) had an RdRp sequence that was separated on different segments, suggesting that a divided RdRp is widely present among fungal viruses, despite the belief that all RNA viruses encode RdRp as a single gene. These findings illustrate the previously hidden diversity and evolution of RNA viruses, and prompt reconsideration of the structural plasticity of RdRp. By highlighting the limitations of conventional surveillance methods for RNA viruses, we showcase the potential of FLDS technology to broaden current knowledge about these viruses.

Author Summary

The development of RNA-seq technology has facilitated the discovery of RNA viruses in all types of biological samples. However, it is technically difficult to detect highly novel viruses using RNA-seq. We successfully reconstructed the genomes of multiple novel fungal RNA viruses by screening host fungi using a new technology, FLDS. Surprisingly, we identified two viral species whose RNA-dependent RNA polymerase (RdRp) proteins were separately encoded on different genome segments, overturning the commonly accepted view of the positional unity of RdRp proteins in viral genomes. This new perspective on divided RdRp proteins should hasten the discovery of viruses with unique RdRp structures that have been overlooked, and further advance current knowledge and understanding of the diversity and evolution of RNA viruses.
Epidemiology and clinical outcome of COVID-19: A multi-centre cross sectional study from Bangladesh
Authors: Mannan Adnan , Hamidullah Mehedi H. M. , Chy Naim Uddin Hasan A , Qayum Md. Omar , Akter Farhana , Rob Abdur , Biswas Prasun , Hossain Sanjida , Ayub Mustak Ibn
Published: September 2020

Objectives

To investigate SARS-CoV-2 associated epidemiology and clinical outcomes in Bangladesh to understand the course of COVID-19 pandemic and suggest prevention measures.

Methods

A cross-sectional retrospective study was conducted among 1,021 RT-PCR confirmed but recovered COVID-19 cases from six participating hospitals in Bangladesh.

Results

Of the total sample, 111 (10.9%) cases were asymptomatic while the number of symptomatic cases were 910 (89.1%). Higher prevalence of COVID-19 persisted in the male population (75%) and for the 31-40 age group. More than 85% of the samples reported BCG vaccination mark. Common symptoms observed in our study samples were fever (72.4%), cough (55.9%), loss of taste (40.7%) and body ache (40%); whereas for the biochemical parameters, Neutrophil (46.4%), D-dimer (46.1%), Ferritin (37.9%) and SGPT (36.8%) levels were found elevated. Post-COVID complications including pain (31.8%), loss of concentration (24.4%) and anxiety or depression (23.1%) were found significantly prevalent.

Conclusion

Our study has shown that adult males aged between 31-40 in Bangladesh are more vulnerable to being infected with COVID-19. With an indication for the rising trend of the asymptomatic cases, deployment of interventions to curb further community spread is necessary to avoid the grave outcomes of COVID-19 in Bangladesh.
Robust SARS-COV-2 serological population screens via multi-antigen rules-based approach
Authors: Fotis Christos , Meimetis Nikolaos , Tsolakos Nikos , Politou Marianna , Akinosoglou Karolina , Pliaka Vicky , Minia Angeliki , Terpos Evangelos , Trougakos Ioannis P. , Mentis Andreas , Marangos Markos , Panayiotakopoulos George , Dimopoulos Meletios A. , Gogos Charalampos , Spyridonidis Alexandros , Alexopoulos Leonidas G.
Published: September 2020

More than 300 SARS-COV-2 serological tests have recently been developed using either the nucleocapsid phosphoprotein (N), the spike glycoprotein subunit (S1), and more recently the receptor binding domain (RBD). Most of the assays report very good clinical performance characteristics in well-controlled clinical settings. However, there is a growing belief that good performance characteristics that are obtained during clinical performance trials might not be sufficient to deliver good diagnostic results in population-wide screens that are usually characterized with low seroprevalence. In this paper, we developed a serological assay against N, S1 and RBD using a bead-based multiplex platform and a rules-based computational approach to assess the performance of single and multi-antigen readouts in well-defined clinical samples and in a population-wide serosurvey from blood donors. Even though assays based on single antigen readouts performed similarly well in the clinical samples, there was a striking difference between the antigens on the population-wide screen. Asymptomatic individuals with low antibody titers and sub-optimal assay specificity might contribute to the large discrepancies in population studies with low seroprevalence. A multi-antigen assay requiring partial agreement between RBD, N and S1 readouts exhibited enhanced specificity, less dependency on assay cut-off values and an overall more robust performance in both sample settings. Our data suggest that assays based on multiple antigen readouts combined with a rules-based computational consensus can provide a more robust platform for routine antibody screening.

One Sentence Summary

Clinical and Population-level performance of single and multiplex SARS-CoV-2 serological assays.
Evolution of immunity to SARS-CoV-2
Authors: Wheatley Adam K. , Juno Jennifer A. , Wang Jing J. , Selva Kevin J. , Reynaldi Arnold , Tan Hyon-Xhi , Shi Lee Wen , Wragg Kathleen M. , Kelly Hannah G. , Esterbauer Robyn , Davis Samantha K. , Kent Helen E. , Mordant Francesca L. , Schlub Timothy E. , Gordon David L. , Khoury David S. , Subbarao Kanta , Cromer Deborah , Gordon Tom P. , Chung Amy W. , Davenport Miles P. , Kent Stephen J.
Published: September 2020

The durability of infection-induced SARS-CoV-2 immunity has major implications for public health mitigation and vaccine development. Animal studies1,2and the scarcity of confirmed re-infection3suggests immune protection is likely, although the durability of this protection is debated. Lasting immunity following acute viral infection requires maintenance of both serum antibody and antigen-specific memory B and T lymphocytes and is notoriously pathogen specific, ranging from life-long for smallpox or measles4, to highly transient for common cold coronaviruses (CCC)5. Neutralising antibody responses are a likely correlate of protective immunity and exclusively recognise the viral spike (S) protein, predominantly targeting the receptor binding domain (RBD) within the S1 sub-domain6. Multiple reports describe waning of S-specific antibodies in the first 2-3 months following infection7-12. However, extrapolation of early linear trends in decay might be overly pessimistic, with several groups reporting that serum neutralisation is stable over time in a proportion of convalescent subjects8,12-17. While SARS-CoV-2 specific B and T cell responses are readily induced by infection6,13,18-24, the longitudinal dynamics of these key memory populations remains poorly resolved. Here we comprehensively profiled antibody, B and T cell dynamics over time in a cohort recovered from mild-moderate COVID-19. We find that binding and neutralising antibody responses, together with individual serum clonotypes, decay over the first 4 months post-infection, as expected, with a similar decline in S-specific CD4+ and circulating T follicular helper (cTFH) frequencies. In contrast, S-specific IgG+ memory B cells (MBC) consistently accumulate over time, eventually comprising a significant fraction of circulating MBC. Modelling of the concomitant immune kinetics predicts maintenance of serological neutralising activity above a titre of 1:40 in 50% of convalescent subjects to 74 days, with probable additive protection from B and T cells. Overall, our study suggests SARS-CoV-2 immunity after infection is likely to be transiently protective at a population level. SARS-CoV-2 vaccines may require greater immunogenicity and durability than natural infection to drive long-term protection.
Live cell PNA labelling enables erasable fluorescence imaging of membrane proteins
Authors: Gavins Georgina C. , Gröger Katharina , Bartoschek Michael D. , Wolf Philipp , Beck-Sickinger Annette G. , Bultmann Sebastian , Seitz Oliver
Published: September 2020

DNA nanotechnology is an emerging field, which promises fascinating opportunities for the manipulation and imaging of proteins on a cell surface. The key to progress in the area is the ability to create the nucleic acid-protein junction in the context of living cells. Here we report a covalent labelling reaction, which installs a biostable peptide nucleic acid (PNA) tag. The reaction proceeds within minutes and is specific for proteins carrying a 2 kDa coiled coil peptide tag. Once installed the PNA label serves as a generic landing platform that enables the recruitment of fluorescent dyes via nucleic acid hybridization. We demonstrate the versatility of this approach by recruiting different fluorophores, assembling multiple fluorophores for increased brightness, and achieving reversible labelling by way of toehold mediated strand displacement. Additionally, we show that labelling can be carried out using two different coiled coil systems, with EGFR and ETBR, on both HEK293 and CHO cells. Finally, we apply the method to monitor internalization of EGFR on CHO cells.
Small molecules inhibit SARS-COV-2 induced aberrant inflammation and viral replication in mice by targeting S100A8/A9-TLR4 axis
Authors: Guo Qirui , Zhao Yingchi , Li Junhong , Liu Jiangning , Guo Xuefei , Zhang Zeming , Cao Lili , Luo Yujie , Bao Linlin , Wang Xiao , Wei Xuemei , Deng Wei , Chen Luoying , Zhu Hua , Gao Ran , Qin Chuan , Wang Xiangxi , You Fuping
Published: September 2020

The SARS-CoV-2 pandemic poses an unprecedented public health crisis. Accumulating evidences suggest that SARS-CoV-2 infection causes dysregulation of immune system. However, the unique signature of early immune responses remains elusive. We characterized the transcriptome of rhesus macaques and mice infected with SARS-CoV-2. Alarmin S100A8 was robustly induced by SARS-CoV-2 in animal models as well as in COVID-19 patients. Paquinimod, a specific inhibitor of S100A8/A9, could reduce inflammatory response and rescue the pneumonia with substantial reduction of viral titers in SASR-CoV-2 infected animals. Remarkably, Paquinimod treatment resulted in 100% survival of mice in a lethal model of mouse coronavirus (MHV) infection. A novel group of neutrophils that contributed to the uncontrolled inflammation and onset of COVID-19 were dramatically induced by coronavirus infections. Paquinimod treatment could reduce these neutrophils and regain antiviral responses, unveiling key roles of S100A8/A9 and noncanonical neutrophils in the pathogenesis of COVID-19, highlighting new opportunities for therapeutic intervention.
Geospatial HIV-1 subtype C gp120 sequence diversity and its predicted impact on broadly neutralizing antibody sensitivity
Authors: Sutar Jyoti , Deshpande Suprit , Mullick Ranajoy , Hingankar Nitin , Patel Vainav , Bhattacharya Jayanta
Published: September 2020

Evolving diversity in globally circulating HIV-1 subtypes presents formidable challenge in defining and developing neutralizing antibodies for prevention and treatment. HIV-1 subtype C is responsible for majority of global HIV-1 infections. Broadly neutralizing antibodies (bnAbs) capable of neutralizing distinct HIV-1 subtypes by targeting conserved vulnerable epitopes on viral envelope protein (Env) are being considered as promising antiviral agents for prevention and treatment. In the present study, we examined the diversity in genetic signatures and attributes that differentiate region-specific global HIV-1 subtype Cgp120sequences associated with virus neutralization outcomes to key bnAbs having distinct epitope specificities. A total of 1814 full length HIV-1 subtype C gp120 sequence from 37 countries were retrieved from Los Alamos National Laboratory HIV database (www.hiv.lanl.gov). The amino acid sequences were assessed for their phylogenetic association, variable loop lengths and prevalence of potential N-linked glycosylation sites (pNLGS). Responses of these sequences to bnAbs were predicted with a machine learning algorithm ‘bNAb-ReP’ and compared with those reported in the CATNAP database. Phylogenetically, sequences from Asian countries including India clustered together however differed significantly when compared with pan African subtype C sequences. Variable loop lengths within Indian and African clusters were distinct from each other, specifically V1, V2 and V4 loops. Furthermore, V1V2 and V2 alone sequences were also found to vary significantly in their charges. Pairwise analyses at each of the 25 pNLG sites indicated distinct country specific profiles. Highly significant differences (p<0.001***) were observed in prevalence of four pNLGS (N130, N295, N392 and N448) between South Africa and India, having most disease burden associated with subtype C. Our findings highlight that the distinctly evolving clusters within global intra-subtype Cgp120sequences are likely to influence the disparate region-specific sensitivity of circulating HIV-1 subtype C to bnAbs.
Benefits of Deep Learning Classification of Continuous Noninvasive Brain-Computer Interface Control
Authors: Stieger James R. , Engel Stephen A. , Suma Daniel , He Bin
Published: September 2020

Noninvasive brain-computer interfaces (BCIs) assist paralyzed patients by providing access to the world without requiring surgical intervention. While the performance of noninvasive BCI is hindered by long training times and variable user proficiency, it may be improved by deep learning methods, such as convolutional neural networks (CovNets). Prior work has suggested that the application of deep learning to EEG signals collected over the motor cortex during motor imagery based BCI increases classification accuracy in standard sensorimotor rhythm (SMR) BCI datasets. It remains to be seen whether these improvements can generalize to practical scenarios such as continuous control tasks (as opposed to prior work reporting one classification per trial), or whether valuable information remains latent outside of the motor cortex (as no prior work has compared full scalp coverage to motor only electrode montages). Here we report that deep learning methods significantly increase offline classification accuracy on an independent, large, and longitudinal online motor imagery BCI dataset with up to 4-classes and continuous 2-dimensional feedback. Improvements in classification accuracy were found to negatively correlate with initial online BCI performance, suggesting deep learning methods preferentially benefit BCI participants who need it most. The CovNets also significantly increased the information transfer rate (ITR) of the BCI system: They produced a two-fold increase in ITR without loss in classification accuracy when comparing CovNet models trained with full scalp EEG coverage to the traditional motor cortex specific decoding. Our results suggest that a variety of neural biomarkers useful for BCI, including those outside the motor cortex, can be detected through deep learning methods.
Transcriptomic dysregulations associated with SARS-CoV-2 infection in human nasopharyngeal and peripheral blood mononuclear cells
Authors: de Melo Caroline Vilas Boas , Bhuiyan Maruf Ahmed , Gatua Winfred Nyoroka , Kanyerezi Stephen , Uzairue Leonard , Abechi Priscilla , Kumar Karan , Rahmat Jabale , Giwa Abdulazeez , Mwandira Gracious , Olamilekan Abisogun Mujib , George Tiffany Ezinne , Adejinmi Oluwapelumi John , Ibironke Monsurat Ademidun , Rotimi Olayemi David , Abo-Elenein Dina Aly Mahmoud Aly , Abubakar Ridwanullah Abiodun , Usman Mahmood , Adewunmi Ifeoluwa , Akinpelu Oyewumi , Emmanuel Olajide , Reang Khatendra , Olalekan Akadiri , Carl Sarah H.
Published: September 2020

Introduction

Over 24 million people have been infected globally with the novel coronavirus, SARS-CoV-2, with more than 820,000 succumbing to the resulting COVID-19 disease as of the end of August 2020. The molecular mechanisms underlying the pathogenesis of the disease are not completely elucidated. Thus, we aim to understand host response to SARS-CoV-2 infection by comparing samples collected from two distinct compartments (infection site and blood), obtained from COVID-19 subjects and healthy controls.

Methods

We used two publicly available gene expression datasets generated via RNA sequencing in two different samples; nasopharyngeal swabs and peripheral blood mononuclear cells (PBMCs). We performed a differential gene expression analysis between COVID-19 subjects and healthy controls in the two datasets and then functionally profiled their differentially expressed genes (DEGs). The genes involved in innate immunity were also determined.

Results

We found a clear difference in the host response to SARS-CoV-2 infection between the two sample groups. In COVID-19 subjects, the nasopharyngeal sample group indicated upregulation of genes involved in cytokine activity and interferon signalling pathway, as well as downregulation of genes involved in oxidative phosphorylation and viral transcription. Host response in COVID-19 subjects for the PBMC group, involved upregulation of genes involved in the complement system and immunoglobulin mediated immune response.CXCL13, GABRE, IFITM3were upregulated andHSPA1Bwas downregulated in COVID-19 subjects in both sample groups.

Conclusion

Our results indicate the host response to SARS-CoV-2 is compartmentalized and suggests potential biomarkers of response to SARS-CoV-2 infection.

Highlights

Transcriptomic profiling from publicly available RNA-seq count data revealed a site-specific immune response in COVID-19.

Host response was found cellular-mediated in nasopharyngeal samples and humoral-mediated in PBMCs samples.

CXCL13, GABREandIFITM3commonly upregulated andHSPA1Bdownregulated in both sample groups highlights the potential of these molecules as markers of response to SARS-CoV-2 infection.
Phase separation of tunable biomolecular condensates predicted by an interacting particle model
Authors: Muñoz-Gil Gorka , Romero-Aristizabal Catalina , Mateos Nicolas , de Llobet Cucalon Lara Isabel , Beato Miguel , Lewenstein Maciej , Garcia-Parajo Maria F. , Torreno-Pina Juan A.
Published: September 2020

Phase separation is emerging as key principle in the spatiotemporal organization of living cells. Given its relevance in the regulation of numerous biological functions, including gene transcription and chromatin architecture, modeling biomolecular condensation is gaining interest. Yet, most models developed so far rely on specific descriptions and/or experimentally inaccessible properties. Here we propose a theoretical model, where phase separation is explained by means of interaction probabilities between particles. With minimum model requirements, particle condensates emerge above a critical interaction probability. We tested the model predictions with single molecule experiments of tunable transcription factor condensates in the nucleus of living cells. Phase separation, condensate sizes, diffusion behavior, and mobility parameters, quantified by data analysis and machine learning, are fully recapitulated by our model. Our combined theoretical and experimental approach provides a general framework to investigate the biophysical parameters controlling phase separation in living cells and in other soft matter-based interacting systems.
Unprotected Peptide Macrocyclization and Stapling via A Fluorine-Thiol Displacement Reaction
Authors: Islam Md Shafiqul , Junod Samuel L. , Zhang Si , Buuh Zakey Yusuf , Guan Yifu , Kaneria Kishan H , Lyu Zhigang , Voelz Vincent , Yang Weidong , Wang Rongsheng E.
Published: September 2020

Stapled peptides serve as a powerful tool for probing protein-protein interactions, but its application has been largely impeded by the limited cellular uptake. Here we report the discovery of a facile peptide macrocyclization and stapling strategy based on a fluorine thiol displacement reaction (FTDR), which renders a class of peptide analogues with enhanced stability, affinity, and cell permeability. This new approach enabled selective modification of the orthogonal fluoroacetamide side chains in unprotected peptides, with the identified 1,3-benzenedimethanethiol linker promoting alpha helicity of a variety of peptide substrates, as corroborated by molecular dynamics simulations. The cellular uptake of these stapled peptides was universally enhanced compared to the classic ring-closing metathesis (RCM) stapled peptides. Pilot mechanism studies suggested that the uptake of FTDR-stapled peptides may involve multiple endocytosis pathways. Consistent with the improved cell permeability, the FTDR-stapled lead Axin analogues demonstrated better inhibition of cancer cell growth than the RCM-stapled analogues.

Graphical Abstract
Theta rhythmic attentional enhancement of alpha rhythmic perceptual sampling
Authors: Michel René , Dugué Laura , Busch Niko A.
Published: September 2020

Accumulating evidence suggests that visual perception operates in an oscillatory fashion at an alpha frequency (around 10 Hz). Moreover, visual attention also seems to operate rhythmically, albeit at a theta frequency (around 5 Hz). Both rhythms are often associated to “perceptual snapshots” taken at the favorable phases of these rhythms. However, less is known about the unfavorable phases: do they constitute “blind gaps,” requiring the observer to guess, or is information sampled with reduced precision insufficient for the task demands? As simple detection or discrimination tasks cannot distinguish these options, we applied a continuous report task by asking for the exact orientation of a Landolt ring’s gap to estimate separate model parameters for precision and the amount of guessing. We embedded this task in a well-established psychophysical protocol by densely sampling such reports across 20 cue-target stimulus onset asynchronies in a Posner-like cueing paradigm manipulating involuntary spatial attention. Testing the resulting time courses of the guessing and precision parameters for rhythmicities using a fast Fourier transform, we found an alpha rhythm (9.6 Hz) in the precision parameter and a theta rhythm (4.8 Hz) in the guess rate for invalidly cued trials. These results indicate that the perceptual alpha rhythm reflects fluctuations in spatial resolution, while the attentional theta rhythm provides periodic enhancement of this resolution. We propose a tentative model for this interplay and argue that both rhythms result in an environmental sampling characterized by fluctuating spatial resolution, speaking against a strict succession of blind gaps and perceptual snapshots.
Nickel(II) complexes based on L-amino-acid-derived ligands: synthesis, characterization and study of the role of the supramolecular structure in carbon dioxide capture
Authors: Rivas Marquina Andrea , Movilla Federico , Sánchez Montilva Olga Carolina , Rentschler Eva , Carrella Luca , Albores Pablo , Di Salvo Florencia
Published: September 2020

The formation of the symmetrical μ3-carbonate-bridged self-assembled trinuclear NiII complex Na2{[Ni(LO)2(H2O)]3(μ3-CO3)} (LO is the carboxylate anion of a L-tyrosine derivative), involves atmospheric CO2 uptake. The asymmetric unit of the complex comprises an octahedral coordination for the NiII with two L-tyrosine-based ligands, a water molecule and one O atom of the carbonate bridge. The Ni3–μ3-CO3 core in this compound is the first reported of this kind according to the Cambridge Structural Database (CSD). The supramolecular structure is mainly sustained by hydrogen bonds developed by the phenolic functionality of the L-tyrosine moiety of one ligand and the carboxylate group of a neighbouring ligand. The crystal packing is then characterized by three interpenetrated supramolecular helices associated with a diastereoisomer of the type R-sup
P, which is essential for the assembly process. Magnetic susceptibility and magnetization data support weak ferromagnetic exchange interactions within the novel Ni3–μ3-CO3 core. The NiII complex obtained under the same synthetic conditions but using the analogous ligand derived from the amino acid L-phenylalanine instead of L-tyrosine gives rise to to a mononuclear octahedral system. The results obtained for the different complexes demonstrate the role of the supramolecular structure regarding the CO2 uptake property for these NiII–amino-acid-based systems.
Five concomitant polymorphs of a green fluorescent protein chromophore (GFPc) analogue: understanding variations in photoluminescence with π-stacking interactions
Authors: Mali Bhupendra P. , Dash Soumya Ranjan , Nikam Shrikant B. , Puthuvakkal Anisha , Vanka Kumar , Manoj Kochunnoonny , Gonnade Rajesh G.
Published: September 2020

The synthetically modified green fluorescent protein chromophore analogue 3,4,5-trimethoxybenzylidene imidazolinone (1) yielded five polymorphs (I, II, III, IV, V) concomitantly irrespective of the solvent used for crystallization. The pentamorphic modification of 1 is solely due to the interplay of iso-energetic weak intermolecular interactions in molecular associations as well as the conformational flexibility offered by a C—C single bond, which connects the electron-deficient moiety imidazolinone with the electron-rich trimethoxybenzylidene group. A common structural feature observed in all the polymorphs is the formation of a `zero-dimensional' centrosymmetric dimeric unit through a short and linear C—H...O hydrogen bond engaging phenyl C—H and imidazolinone carbonyl oxygen. However, the networking of these dimeric units showed a subtle difference in all the polymorphs. The 2D isostructurality was observed between polymorphs I, II and III, while the other two polymorphs IV and V revealed only `zero-dimensional' isostructurality. The different fluorescence emissions of Form I (blue) and Forms II to V (yellow) were attributed to the differences in π-stacking interactions. It shows that one can modulate the photophysical properties of these smart materials by slightly altering their crystal structure. Such an approach will aid in developing new multi-colour organic fluorescent materials of varying crystal structures for live-cell imaging and fluorescent sensing applications.
A new Tl4.86Fe0.82Hf1.18(MoO4)6ternary molybdate: crystal structure and properties
Authors: Novikova Nataliya E. , Grossman Victoria G. , Bazarov Bair G. , Verin Igor A. , Dudka Alexander P. , Stefanovich Sergei Yu. , Bazarova Jibzema G.
Published: September 2020

Single crystals of Tl4.86Fe0.82Hf1.18(MoO4)6[a=b= 10.5550 (3),c= 37.7824 (9) Å, γ = 120°] are obtained by the self-flux method in the Tl2MoO4–Fe2(MoO4)3–Hf(MoO4)2system. On the differential scanning calorimetry curve in the temperature range 320–350 K and atT∼ 690 K, endothermic peaks are observed. The second harmonic generation test shows an excess of the signal of the quartz standard by almost three times at room temperature. In the range 320–340 K its intensity decreases by almost three times and atT∼ 700 K it drops to zero. In the same interval, the temperature dependences of the unit-cell parameters and volume show stepwise changes. According to the X-ray diffraction data, the crystal structure consists of nonpolar and polar domains with different local symmetries. The structure is a three-dimensional framework consisting of alternating (Hf,Fe)O6octahedra connected by MoO4tetrahedra. Hf and Fe atoms occupy mixed Hf/Fe positions with different probabilities: 0.77:0.23, 0.50:0.50 and 0.32:0.68. Tl cations are located inside the framework in zigzag channels extended along theaandbaxes. The thallium arrangement is disordered,i.e.it involves additional positions and vacancies. The complex crystal structure has been solved using the nonstandard space groupR1, taking into account the local symmetryR3cfor the Mo atoms and mixed Hf/Fe positions mainly occupied by Hf atoms. The possible paths of ion transport are analyzed. The energy required to overcome the potential barrier between sites of Tl cations to migrate, which corresponds to the activation energy of conductivity, is estimated. The ion current is shown to be most probable in theabplane.
Why are Chinese and North American guests satisfied or dissatisfied with hotels? An application of big data analysis
Authors: Ying Shun , Chan Jin Hooi , Qi Xiaoguang
Published: September 2020

Purpose

The paper aims to identify the emergent themes of hotel guests’ satisfaction, to compare the distribution of the attributes of the themes between Chinese and North American guests and to compare the importance of the themes for different satisfaction levels between Chinese and North American guests from a cross-cultural perspective.

Design/methodology/approach

By adopting Python (a computer language), the word-frequency method was used to identify emergent themes of hotel guests’ satisfaction. Topic modeling was adopted to compare the attributes distribution of each theme and the features of satisfaction between Chinese and North American guests.

Findings

First, three themes were identified including functionality, staff and price. Functionality can be further categorized into five subthemes, namely, room, travel, food, environment and hotel facility. Second, the distribution of the attributes of the themes between Chinese and North American guests was compared from a cross-cultural perspective. Chinese guests tend to mention both lifestyles- and social norms–related attributes and expect personalized service, while North American guests mainly prefer to describe lifestyle-related attributes and prefer standardized service. Third, the study compared the changing importance of the themes (functionality, staff and price) for different satisfaction levels between Chinese and North American guests. As the satisfaction level decreases, the importance of functionality decreases, that of staff increases and that of price remain stable for Chinese guests. In contrast, the importance of each theme has fluctuated mildly from the high to the low satisfaction level for North American guests.

Practical implications

Proposed managerial implications are to highlight lifestyle- and social norms-related attributes, as well as personalized service for Chinese guests. However, lifestyle-related attributes and standardized service should be facilitated for North American guests. Specific suggestions were made to help improve hotel performance such as the good performance of functional-related attributes, which could enhance satisfaction and better staff performance, which would reduce dissatisfaction.

Originality/value

By mining big data, this study investigated hotel guests’ satisfaction from a dynamic instead of a static perspective. This study provides some rare insights into differences in key attributes influencing satisfaction levels of Chinese versus North American guests staying in luxury hotels in China. This study also takes a novel approach to examine the dynamics of the importance of the various themes at different satisfaction levels, and contrast these dynamics between Chinese and North American guests. The findings offer valuable insight into market segmentation and management in the hospitality industry.
Cultural influences on normative reactions to incivility: comparing individuals from South Korea and Spain
Authors: Moon Chanki , Sánchez‐Rodríguez Ángel
Published: September 2020

Purpose

Antecedents and influences of workplace incivility have recently been studied in many areas of research but there is still a lack of consideration for the impact of culture. Theoretical considerations for the present research are based on the cultural dimensions of power distance and tightness/looseness because the collective levels of power distance are similar between Korea and Spain, but the collective levels of tightness/looseness are different between the two countries. The purpose of this paper is to examine whether individuals’ occupational position affects their normative reactions to incivility differently.

Design/methodology/approach

Participant (victim)’s (those who react to uncivil behaviors) social power (low vs high) and perpetrator’s (those who exhibit uncivil behaviors) social power (low vs high) were experimentally manipulated; all participants were randomly assigned to one of four perpetrator × victim conditions in relation to hierarchical positions (Ntot = 467).

Findings

The results suggest that the level of social and personal acceptability was greater either among Koreans than Spanish at a collective level or among people who endorsed higher power distance and tightness values. All in all, the findings highlight cultural influences on the importance of social hierarchy as a factor that can impact the people’s normative reactions to incivility.

Originality/value

The findings broaden our understanding of the psychology of employees in relation to incivility, by simultaneously considering the influences of culture (power distance and tightness/looseness) and social power.
Sustainability-oriented innovation (SOI) in the cultural village: an actor-network perspective in the case of Laweyan Batik Village
Authors: Harsanto Budi , Permana Chrisna T.
Published: September 2020

Purpose

This study aims to explore the development of sustainability-oriented innovation (SOI) in the cultural village. SOI has recently generated widespread interest, both academically and practically, by factoring in environmental and social impacts in addition to economic aspects. However, previous works have mostly been performed at profit organisations, with few discussed at the non-profit, and likewise, in the cultural village.

Design/methodology/approach

This study uses a qualitative approach by focusing on a unique case, Laweyan Batik Village in Surakarta, Indonesia. Founded in the 15th century, Laweyan Batik Village remains the oldest batik village in Indonesia. Batik is the traditional fabric of Indonesia, influenced by Arabian, Chinese and European patterns, that was recognised in 2009 by UNESCO as part of the World's Intangible Cultural Heritage. The actor-network theory (ANT) is used as an analytical framework to understand the process of SOI development through the role of actors in developing innovations.

Findings

The findings suggest that, it is not only in mainstream business sectors and formal settings, as already evidenced by existing literature, that SOI can be promoted, but also in community sectors and within informal settings. This paper has found that the development of sustainability innovation in these settings is challenged by the dynamics of the actors and the institutional settings. The overall development process of sustainability innovation has been undertaken through so-called “collaborative practices”, emphasising the involvement of government actors and non-government actors, highlighting community leaders, academics and NGOs as the “in-between” actors who provide knowledge sharing and maintain communications to ensure the promotion of the SOI concepts and programmes.

Originality/value

This research contributes in two main ways: first, an understanding of the process of sustainability innovation in a cultural village that has not been deeply explored by current literature; and second, the use of the actor network theory as an analytical framework from which to map the process of SOI collaborative development through networking dimensions.
The effects of resilience and familiarity on the relationship between CSR and consumer attitudes
Authors: Rew Dongjun , Cha Wonsuk
Published: September 2020

Purpose

This study aims to explore the effects of consumer resilience and brand familiarity on the relationship between corporate social responsibility (CSR) and consumer attitudes toward the company conducting CSR in places that have suffered from traumatic events such as natural or anthropogenic disasters and uncertainty of public health issue.

Design/methodology/approach

This study collected survey-based data from 194 participants who suffered from natural and anthropogenic disasters in the state of Texas. Path analysis was used to test each structural relationship among variables after verifying the reliability and validity of each variable. Analysis of variance was used to investigate the difference in resilience between the two groups.

Findings

This study verified that there is a positive relationship between CSR and consumer attitude. More importantly, the results show that both resilience and familiarity play an important role as a mediator in the relationship between CSR and attitudes. In particular, it tells us that a group with high resilience shows a higher possibility of having positive attitudes toward the company than another group having low resilience.

Originality/value

This study empirically tested the impacts of CSR, resilience and brand familiarity on building consumer attitudes. Furthermore, this study explored the effects of resilience and brand familiarity on the relationship between CSR and attitudes. Thus, this study was able to contribute to understanding the effects of CSR, resilience and familiarity on building a positive attitude in the specific settings, in terms of traumatic events, theoretically and practically.
3D Surface Scanning for Smart Repair Manufacturing Application
Authors: Chuang Ho-Yu , Chang Jen-Yuan (James)
Published: September 2020

At present, automatic machines have gradually replaced human labor for improving both the stability and effectiveness of manufacturing operations. Five-axis CNC machine tools are commonly used for traditional surface milling machining. However, it is still necessary to manually reposition the work-piece for the CNC machine tools that enviably lowers position accuracy. As such, it is essential to develop an integrated fusion system that can scan any objects and conduct repair operations automatically. The primary purpose of this research is to integrate the stereo vision system into an existing industrial manipulator. With the proposed method and system, the position error can be reduced by avoiding moving the work-pieces during operations. Also, reconstructing the scan results from multiple views avoids the common blocking problem in vision. Finally, the distance of the manipulator path is optimized by the Hill Climbing algorithm, allowing to create a trajectory of the manipulator end-effector to reprocess the work-piece. In the future, this system can be implemented for automated optical inspection (AOI), such as pipeline maintenance, turbine engine maintenance, and automatic classification of defects.
Robot Manipulator Vibration Resistance Control Based on Physical Model
Authors: Chen Ting-Sheng , Chang Jen-Yuan (James)
Published: September 2020

The overwhelming manufacturing process with robotic arm has replaced human labors in handling and manufacturing work-pieces in factories. In these years, higher accuracy and repeatability are required for robotic manipulators to perform processes such as welding, deburring and grinding in factories. In these path-following processes, the manipulator’s end-effector often encounter position error caused by its vibrating structures. Therefore, the quality of machining accuracy and surface roughness becomes unstable and unsatisfied. For the purpose of avoiding the vibrations to occur in the robotic manipulator, this study aims to design a control method to reduce vibrations which is divided into two parts, namely (1) dynamic modeling the robot arm by applying modified mass-spring-damper model to each joints and links of the robot arm, and (2) realizing the control of the robot arm’s vibration resistance with predicated dynamics to compensate for the undesired dynamics, respectively. Through the proposed model, the response of each joints in different postures and different payloads applied at the end effector can be fully analyzed and the vibrations can be predicted and compensated. Results with the proposed vibration resistance control method indicate improvement of the model robot arm’s dynamic position error.
System Identification With Particle Swarm Optimization Method for Nonlinear Dynamic Systems
Authors: Fernández Manuel A. , Chang Jen-Yuan (James)
Published: September 2020

This paper presents a comparison between different system identification techniques, namely Least Squared Estimation, Total Least Squares, Linear Sequential Estimation, the Gauss-Newton method, and Particle Swarm Optimization. A DC motor model was simulated in Simulink, with arbitrarily selected parameters, and the input and output values were used to test the effectiveness of these system identification techniques.
An Investigation on Steering Sensor Fault Reconstruction of Autonomous Driving for Functional Safety Using Sliding Mode Observer
Authors: Oh Kwang-Seok , Yi Kyong-Su
Published: September 2020

This paper investigates on sensor fault reconstruction of sensors used for steering control of autonomous vehicle for functional safety. Sensor information such as steering angle and longitudinal velocity is generally needed for the design of steering feedback control system. If there exists unexpected fault signals in sensors, fatal accident can occur during autonomous driving because controller cannot compute the accurate control input. In this study, the sliding mode observer has been designed for fault reconstruction of steering angle and velocity sensors. In order to design the observer, the bicycle model that represents dynamic relationship between steering angle and velocities such as lateral velocity and yaw rate of vehicle has been used. The stability analysis has been conducted in accordance with velocity of the vehicle. The fault signals in sensors have been reconstructed using the injection term in sliding mode observer with the sliding mode gains designed for the stability. The performance evaluation has been conducted in Matlab/Simulink environment under the curved path tracking scenario.