bluuebunny/crossref_metadata_2025 huggingface dataset:
Healing potential of wild type and recombinant S100A8 to attenuate skin wound inflammation
Authors: Olaitan Akinshipo Abdul Warith , Chen Lin , DiPietro Luisa A.
Published: September 2020

Background

Wounds represent a major health burden in our society and poorly healing wounds are a significant clinical problem worldwide, During the acute inflammatory, neutrophils which are normal wound scavengers seems to create additional tissue destruction and promote scar formation. This project examined the utility of using pluronic gel to deliver ala42S100A8, a peptide that repels neutrophils, to wounds, allowing more regenerative repair.

Method

Excisional wound models on female BALB/c mice were made and 4 treatments including pluronic gel only group, Wild type S100A8 (1, 2, and 4μg) with Pluronic gel, and ala42S100A8 (1, 2, and 4μg) with Pluronic gel were applied to the wounds. Wounds were harvested at day 1 and day 3. Myeloperoxidase (MPO) protein level was examined using an ELISA kit and cytokine protein expression of CXCL1 (GRO-1), CXCL2 (MIP-2). IL-6, and TNF-α was determined using a multiplex ELISA kit.

Results

MPO level in Pluronic gel treated wounds at day 1 was significantly higher than that in control, suggesting that the Pluronic gel itself causes increased inflammation in wounds, while treatment with 1μg of s100A8 or 1 and 4μg of ala42S100A8 seemed to decrease MPO at day 1 compared to the Pluronic gel treated wounds. Treatment with 1μg of s100A8 also led to a decrease IL-6 and TNF-α production at day 1 when compared to the Pluronic gel group, although no statistical difference was observed

Conclusions

Our findings strongly suggest that wound inflammation is reduced by treatment with 1ug of S100A8. As such, this study provides proof-of-principal for further investigations of S100A8/ala42S100A8 as a wound therapeutic. Additional studies with lower doses and increased sample size, along with the use of alternative delivery systems, will provide important information about the utility of this approach.
Orientation of Directional Deep Brain Stimulation Leads on CT: Resolving the Ambiguity
Authors: Kurtev-Rittstieg Rebecca , Achatz Stefan , Nourinia Amir , Mittermeyer Stephan
Published: September 2020

While directional deep brain stimulation (DBS) shows promising clinical effects by providing a new degree of freedom in programming, precise knowledge of the lead position and orientation is necessary to mitigate the resulting increased complexity. Two methods for orientation assessment based on postoperative CT imaging have become available, but neither of them is currently able to resolve the respective 180° artifact symmetry. Both rely on information about the intended orientation and assume that a deviation of more than ± 90° is very unlikely. Our aim was to develop an enhanced algorithm capable of detecting asymmetries in the CT data and to thus eliminate the need for user interaction. Two different approaches are presented: one based on the lead marker’s center of mass (COM) and one based on asymmetric sampling of the marker’s intensity profile (ASM). Both were tested on a total of 98 scans of 2 lead phantoms, resulting in 165 measurements with a large variety of lead implantation and orientation angles. The 180° ambiguity was correctly resolved in 99.4% of cases by COM and in 96.4% of cases by ASM. These results demonstrate the substantial and currently unused asymmetry in CT and the potential for a truly automated workflow.
A sleep epidemic or enlightenment? A Bayesian approach to test the sleep epidemic hypothesis shows foragers have short and fragmented sleep compared to large scale societies
Authors: Samson David R.
Published: September 2020

Human sleep is linked with nearly every aspect of our health and wellbeing. The question whether and to what extent human sleep is in a state of evolutionary mismatch has gained recent attention from both clinical and biological science researchers. Here, I use a comparative Bayesian approach aimed at testing the sleep epidemic hypothesis – the idea that, due to labor demands and technological disruption, sleep-wake activity is negatively impacted in post-industrial, economically developed societies. In contrast to the expectations of the sleep epidemic hypothesis, when compared to both large and small-scale subsistence societies that rely on agriculture for subsistence, foragers were the shortest, least efficient sleeping group. Coupled with previous work demonstrating that foragers have stronger circadian rhythms compared to those sleeping in buffered environments, I present the sleep-rhythm trade-off hypothesis – that sleep duration, quality, and synchrony is driven by trade-offs between sleep security and comfort versus sleep site environmental exposure. One strategy to improve wellbeing of modern sleepers would be to focus on behavioral interventions that reduce desynchronizations of circadian rhythms, while holding the positive ground of safe, secure, and regulated sleep environments typical of economically developed societies.
MiMSI - a deep multiple instance learning framework improves microsatellite instability detection from tumor next-generation sequencing
Authors: Ziegler John , Hechtman Jaclyn F. , Ptashkin Ryan , Jayakumaran Gowtham , Middha Sumit , Chavan Shweta S. , Vanderbilt Chad , DeLair Deborah , Casanova Jacklyn , Shia Jinru , DeGroat Nicole , Benayed Ryma , Ladanyi Marc , Berger Michael F. , Fuchs Thomas J. , Zehir Ahmet
Published: September 2020

Microsatellite instability (MSI) is a critical phenotype of cancer genomes and an FDA-recognized biomarker that can guide treatment with immune checkpoint inhibitors. Recent work has demonstrated that next-generation sequencing data can be used to identify samples with MSI-high phenotype. However, low tumor purity, as frequently observed in routine clinical samples, poses a challenge to the sensitivity of existing algorithms. To overcome this critical issue, we developed MiMSI, an MSI classifier based on deep neural networks and trained using a dataset that included low tumor purity MSI cases in a multiple instance learning framework. On a challenging yet representative set of cases, MiMSI showed higher sensitivity (0.940) and auROC (0.988) than MSISensor(sensitivity: 0.57; auROC: 0.911), an open-source software previously validated for clinical use at our institution using MSK-IMPACT large panel targeted NGS data.
Evidences for a nutritional role of iodine in plants
Authors: Kiferle Claudia , Martinelli Marco , Salzano Anna Maria , Gonzali Silvia , Beltrami Sara , Salvadori Piero Antonio , Hora Katja , Holwerda Harmen Tjalling , Scaloni Andrea , Perata Pierdomenico
Published: September 2020

Little is known about the role of iodine in plant physiology. We evaluated the impact of low concentrations of iodine on the phenotype, transcriptome and proteome ofArabidopsis thaliana. Our experiments showed that removal of iodine from the nutrition solution compromises plant growth, and restoring it in micromolar concentrations is beneficial for biomass accumulation and leads to early flowering. In addition, iodine treatments specifically regulate the expression of several genes, mostly involved in the plant defence response, suggesting that iodine may protect against both biotic and abiotic stress. Finally, we demonstrated iodine organification in proteins. Our bioinformatic analysis of proteomic data revealed that iodinated proteins identified in the shoots are mainly associated with the chloroplast and are functionally involved in photosynthetic processes, whereas those in the roots mostly belong and/or are related to the action of various peroxidases. These results suggest that iodine should be considered as a plant nutrient.
Electro-optical mechanically flexible coaxial microprobes for minimally invasive interfacing with intrinsic neural circuits
Authors: Ward Spencer , Riley Conor , Carey Erin M. , Nguyen Jenny , Esener Sadik , Nimmerjahn Axel , Sirbuly Donald J.
Published: September 2020

Central to advancing our understanding of neural circuits is the development of minimally invasive, multi-modal interfaces capable of simultaneously recording and modulating neural activity. Recent devices have focused on matching the mechanical compliance of tissue to reduce inflammatory responses1,2. However, reductions in the size of multi-modal interfaces are needed to further improve biocompatibility and long-term recording capabilities1. Here we demonstrate a multi-modal coaxial microprobe design with a minimally invasive footprint (8-12 μm diameter over millimeter lengths) that enables efficient electrical and optical interrogation of neural networks. In the brain, the probes allowed robust electrical measurement and optogenetic stimulation. Scalable fabrication strategies can be used with various electrical and optical materials, making the probes highly customizable to experimental requirements, including length, diameter, and mechanical properties. Given their negligible inflammatory response, these probes promise to enable a new generation of readily tunable multi-modal devices for minimally invasive interfacing with neural circuits.
A soluble ACE2 microbody protein fused to a single immunoglobulin Fc domain is a potent inhibitor of SARS-CoV-2 infection in cell culture
Authors: Tada Takuya , Fan Chen , Kaur Ramanjit , Stapleford Kenneth A. , Gristick Harry , Nimigean Crina , Landau Nathaniel R.
Published: September 2020

Soluble forms of ACE2 have recently been shown to inhibit SARS-CoV-2 infection. We report on an improved soluble ACE2, termed a “microbody” in which the ACE2 ectodomain is fused to Fc domain 3 of the immunoglobulin heavy chain. The protein is smaller than previously described ACE2-Ig Fc fusion proteins and contains an H345A mutation in the ACE2 catalytic active site that inactivates the enzyme without reducing its affinity for the SARS-CoV-2 spike. The disulfide-bonded ACE2 microbody protein inhibited entry of lentiviral SARS-CoV-2 spike protein pseudotyped virus and live SARS-CoV-2 with a potency 10-fold higher than unmodified soluble ACE2 and was active after initial virus binding to the cell. The ACE2 microbody inhibited the entry of ACE2-specific β coronaviruses and viruses with the high infectivity variant D614G spike. The ACE2 microbody may be a valuable therapeutic for COVID-19 that is active against SARS-CoV-2 variants and future coronaviruses that may arise.
Actin-binding compounds that affect the kinetics of the interaction of cardiac myosin with actin
Authors: Roopnarine Osha , Thomas David D.
Published: September 2020

We measured the effects of ten actin-binding compounds on the interaction of cardiac myosin subfragment 1 (S1) with pyrene labeled F-actin (PFA). These compounds, previously identified from a small-molecule high-throughput screen (HTS), perturb the microsecond structural dynamics of actin and the steady-state activity of actin-activated myosin ATPase. In the present study, we have further characterized their mechanisms of action by measuring their effects on PFA fluorescence, which is decreased specifically by the strong binding of myosin to actin, and is restored upon release of S1 by MgATP. We measured the effects of compounds under equilibrium and steady-state conditions, as affected by S1 and ATP, and also under transient conditions, in stopped-flow experiments following rapid addition of ATP to S1-bound PFA. We observe that these compounds affect the early steps of the myosin ATPase cycle to different extents (mild, moderate, and severe). The compounds decrease the equilibrium constant for the formation of the collision complex and the rate constant for subsequent isomerization to the ternary complex, indicating increased ATP affinity and trapping of ATP in the myosin active site. These compound effects on actin structure inhibit the kinetics of the actin-myosin interaction in ways that may be desirable for possible treatment of hypercontractile forms of hypertrophic cardiomyopathy (HCM). This work helps to elucidate the mechanisms of action of these compounds, several of which are currently used therapeutically, and it sets the stage for future HTS campaigns on a larger scale, to discover new drugs for treatment of heart failure.
VAPYRIN attenuates defence by repressing PR gene induction and localized lignin accumulation during arbuscular mycorrhizal symbiosis ofPetunia hybrida
Authors: Chen Min , Bruisson Sébastien , Bapaume Laure , Darbon Geoffrey , Glauser Gaëtan , Schorderet Martine , Reinhardt Didier
Published: September 2020

The intimate association of host and fungus in arbuscular mycorrhizal (AM) symbiosis can potentially trigger induction of host defence mechanisms against the fungus, implying that successful symbiosis requires suppression of defence.

We addressed this phenomenon by using AM-defectivevapyrin(vpy) mutants inPetunia hybrida, including a new allele (vpy-3) with a transposon insertion close to the ATG start codon. We explore whether abortion of fungal infection invpymutants is associated with the induction of defence markers such as cell wall alterations, accumulation of reactive oxygen species (ROS), defence hormones, and induction of pathogenesis-related (PR) genes.

We show thatvpymutants exhibit a strong resistance against intracellular colonization, which is associated with the generation of thick cell wall appositions (papillae) with lignin impregnation at fungal entry sites, while no accumulation of defence hormones, ROS, or callose was observed. Systematic analysis of PR gene expression revealed that several PR genes are induced in mycorrhizal roots of the wild type, and even more invpyplants. Some PR genes are induced exclusively invpymutants.

Taken together, these results suggest thatVPYis involved in avoiding or suppressing the induction of a cellular defence syndrome that involves localized lignin deposition and PR gene induction.
Fixation and effective size in a haploid-diploid population with asexual reproduction
Authors: Bessho Kazuhiro , Otto Sarah P.
Published: September 2020

The majority of population genetic theory assumes fully haploid or diploid organisms with obligate sexuality, despite complex life cycles with alternating generations being commonly observed. To reveal how natural selection and genetic drift shape the evolution of haploid-diploid populations, we analyze a stochastic genetic model for populations that consist of a mixture of haploid and diploid individuals, allowing for asexual reproduction and niche separation between haploid and diploid stages. Applying a diffusion approximation, we derive the fixation probability and describe its dependence on the reproductive values of haploid and diploid stages, which depend strongly on the extent of asexual reproduction in each phase and on the ecological differences between them.

Highlight

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Classical models consider fully haploid or diploid populations

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We model haploid-diploid life cycles allowing for asexual reproduction

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We obtain the fixation probability of alleles subject to selection and drift

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Reproductive values of haploid and diploid stages shape their evolution
Contrasting tempos of sex chromosome degeneration in sticklebacks
Authors: Sardell Jason M. , Josephson Matthew P. , Dalziel Anne C. , Peichel Catherine L. , Kirkpatrick Mark
Published: September 2020

The steps of sex chromosome evolution are often thought to follow a predictable pattern and tempo, but few studies have examined how the outcomes of this process differ between closely related species with homologous sex chromosomes. The sex chromosomes of the threespine stickleback (Gasterosteus aculeatus) and Japan Sea stickleback (G. nipponicus) have been well characterized. Little is known, however, about the sex chromosomes in their distantly related congener, the blackspotted stickleback (G. wheatlandi). We used pedigrees of interspecific crosses to obtain the first phased X and Y genomic sequences from blackspotted sticklebacks. Using novel statistical methods, we demonstrate that the oldest stratum of theGasterosteussex chromosomes evolved on Chromosome 19 in the ancestor of all three species. Despite this shared ancestry, the sex chromosomes of the blackspotted stickleback have experienced much more extensive recombination suppression, XY differentiation, and Y degeneration than those of the other two species. The ancestral blackspotted stickleback Y chromosome fused with Chromosome 12 less than 1.4 million years ago, which may have been favored by the very small size of the recombining region on the ancestral sex chromosome. Recombination is also suppressed between the X and Y over the bulk of Chromosome 12, although it has experienced little degeneration. These results demonstrate that sex chromosome evolution does not always follow a predictable tempo.
Histone acetylation at the sulfotransferase 1a1 gene is associated with its hepatic expression in normal aging
Authors: Kronfol Mohamad M. , Dozmorov Mikhail G. , Jahr Fay M. , Halquist Matthew S. , McRae MaryPeace , Wijesinghe Dayanjan S. , Price Elvin T. , Slattum Patricia W. , McClay Joseph L.
Published: September 2020

Phase II drug metabolism is poorly studied in advanced age and older adults may exhibit significant variability in their expression of phase II enzymes. We hypothesized that age-related changes to epigenetic regulation of genes involved in phase II drug metabolism may contribute to these effects. We examined published epigenome-wide studies of human blood and identified theSULT1A1andUGT1A6genes as the top loci showing epigenetic changes with age. To assess possible functional alterations with age in the liver, we assayed DNA methylation (5mC) and histone acetylation changes around the mouse homologsSult1a1andUgt1a6in liver tissue from mice aged 4-32 months obtained from the National Institute on Aging rodent tissue bank. Our sample shows significant loss of 5mC atSult1a1, mirroring the loss of 5mC with age observed in human blood DNA at the same locus. We also detected increased histone 3 lysine 9 acetylation (H3K9ac) with age atSult1a1, but no change to histone 3 lysine 27 acetylation (H3K27ac).Sult1a1gene expression is significantly positively associated with H3K9ac levels, accounting for 23% of the variation in expression. We did not detect any significant changes atUgt1a6. We conclude thatSult1a1expression is under epigenetic influence in normal aging and that this influence is more pronounced for H3K9ac than DNA methylation or H3K27ac in this study. More generally, our findings support the relevance of epigenetics in regulating key drug metabolizing pathways. In future, epigenetic biomarkers could prove useful to inform dosing in older adults.
Microbiome-related aspects of locust density-dependent phase transition
Authors: Lavy Omer , Lewin-Epstein Ohad , Bendett Yonatan , Gophna Uri , Gefen Eran , Hadany Lilach , Ayali Amir
Published: September 2020

Locust plagues are an ancient phenomenon, with references going back to the Old Testament. These swarming pests are notorious for their tendency to aggregate and perform long migrations, consuming vast amounts of vegetation and decimating the cultivated fields on their path. However, when population density is low, locusts will express a solitary, cryptic, non-aggregating phenotype that is not considered as an agricultural pest. Although transition of locusts from the solitary to the gregarious phase has been well studied, the shifts in the locust microbiome composition associated with this phase-transition have yet to be addressed. Here, using 16S rRNA amplicon sequencing, we compared the bacterial composition of solitary desert locusts before and after a crowding-induced phase-transition. Our findings reveal that the microbiome is altered during the phase transition. We also show that this significant change in bacterial composition includes the acquisition of a specific bacterial species -Weissella cibaria(Firmicutes), which has been previously shown to induce aggregation in cockroaches. Our findings led us to hypothesize that the locust microbiome may play a role in inducing aggregation behavior, contributing to the formation and maintenance of a swarm. Employing a mathematical model, we demonstrate the potential evolutionary advantage of inducing aggregation under various environmental conditions; and specifically, when the aggregation-inducing microbe exhibits a relatively high horizontal transmission rate. This is a first description of a previously unknown and important aspect of locust phase transition, demonstrating that the phase shift includes a shift in the gut and integument bacterial composition.
Struct2Graph: A graph attention network for structure based predictions of protein-protein interactions
Authors: Baranwal Mayank , Magner Abram , Saldinger Jacob , Turali-Emre Emine S. , Elvati Paolo , Kozarekar Shivani , VanEpps J. Scott , Kotov Nicholas A. , Violi Angela , Hero Alfred O.
Published: September 2020

Background

Development of new methods for analysis of protein-protein interactions (PPIs) at molecular and nanometer scales gives insights into intracellular signaling pathways and will improve understanding of protein functions, as well as other nanoscale structures of biological and abiological origins. Recent advances in computational tools, particularly the ones involving modern deep learning algorithms, have been shown to complement experimental approaches for describing and rationalizing PPIs. However, most of the existing works on PPI predictions use protein-sequence information, and thus have difficulties in accounting for the three-dimensional organization of the protein chains.

Results

In this study, we address this problem and describe a PPI analysis based on a graph attention network, namedStruct2Graph, for identifying PPIs directly from the structural data of folded protein globules. Our method is capable of predicting the PPI with an accuracy of 98.89% on the balanced set consisting of an equal number of positive and negative pairs. On the unbalanced set with the ratio of 1:10 between positive and negative pairs, Struct2Graph achieves a five-fold cross validation average accuracy of 99.42%. Moreover, Struct2Graph can potentially identify residues that likely contribute to the formation of the protein-protein complex. The identification of important residues is tested for two different interaction types: (a) Proteins with multiple ligands competing for the same binding area, (b) Dynamic protein-protein adhesion interaction. Struct2Graph identifies interacting residues with 30% sensitivity, 89% specificity, and 87% accuracy.

Conclusions

In this manuscript, we address the problem of prediction of PPIs using a first of its kind, 3D-structure-based graph attention network (code available athttps://github.com/baranwa2/Struct2Graph). Furthermore, the novel mutual attention mechanism provides insights into likely interaction sites through its unsupervised knowledge selection process. This study demonstrates that a relatively low-dimensional feature embedding learned from graph structures of individual proteins outperforms other modern machine learning classifiers based on global protein features. In addition, through the analysis of single amino acid variations, the attention mechanism shows preference for disease-causing residue variations over benign polymorphisms, demonstrating that it is not limited to interface residues.
Role of Mcpip1 in obesity-induced hepatic steatosis as determined by myeloid and liver-specific conditional knockouts
Authors: Pydyn Natalia , Żurawek Dariusz , Kozieł Joanna , Kuś Edyta , Wojnar-Lason Kamila , Jasztal Agnieszka , Fu Mingui , Jura Jolanta , Kotlinowski Jerzy
Published: September 2020

Monocyte chemoattractant protein-induced protein 1 (MCPIP1,aliasRegnase1) is a negative regulator of inflammation, acting through cleavage of transcripts coding for proinflammatory cytokines and by inhibition of NFκB activity. Moreover, it was demonstrated, that MCPIP1 regulates lipid metabolism both in adipose tissue and hepatocytes. In this study, we investigated the effects of tissue-specific Mcpip1 deletion on the regulation of hepatic metabolism and development of non-alcoholic fatty liver disease (NAFLD).

We used knock-in control Mcpip1fl/flmice and animals with deletion of Mcpip1 in myeloid leukocytes (Mcpip1fl/flLysMCre) and in hepatocytes (Mcpip1fl/flAlbCre), which were fed chow or a high-fat diet (HFD) for 12 weeks. Mcpip1fl/flLysMCremice were fed a chow diet were characterized by a significantly reduced hepatic expression of genes regulating lipid and glucose metabolism, which subsequently resulted in hypoglycemia and dyslipidemia. These animals also displayed systemic inflammation, demonstrated by increased concentrations of cytokines in the plasma. On the other hand, there were no significant changes in phenotype in Mcpip1fl/flAlbCremice. Although we detected a reduced hepatic expression of genes regulating glucose metabolism and β-oxidation in these mice, they remained asymptomatic. Upon feeding them a HFD, Mcpip1fl/flLysMCremice did not develop obesity, glucose intolerance, nor hepatic steatosis, but were characterized by hypoglycemia and dyslipidemia, along with proinflammatory phenotype with symptoms of cachexia. Mcpip1fl/flAlbCreanimals, following a HFD, became hypercholesterolemic, but accumulated lipids in the liver at the same level as Mcpip1fl/flmice, and no changes in the level of soluble factors tested in the plasma were detected.

In conclusion, we have demonstrated that Mcpip1 protein plays an important role in the liver homeostasis. Depletion of Mcpip1 in myeloid leukocytes, followed by systemic inflammation, has a more pronounced effect on controlling liver metabolism and homeostasis than the depletion of Mcpip1 in hepatocytes.
Discovery of human ACE2 variants with altered recognition by the SARS-CoV-2 spike protein
Authors: Heinzelman Pete , Romero Philip A.
Published: September 2020

Understanding how human ACE2 genetic variants differ in their recognition by SARS-CoV-2 can have a major impact in leveraging ACE2 as an axis for treating and preventing COVID-19. In this work, we experimentally interrogate thousands of ACE2 mutants to identify over one hundred human single-nucleotide variants (SNVs) that are likely to have altered recognition by the virus, and make the complementary discovery that ACE2 residues distant from the spike interface can have a strong influence upon the ACE2-spike interaction. These findings illuminate new links between ACE2 sequence and spike recognition, and will find wide-ranging utility in SARS-CoV-2 fundamental research, epidemiological analyses, and clinical trial design.
The organization and developmental establishment of cortical interneuron presynaptic circuits
Authors: Pouchelon Gabrielle , Bollmann Yannick , Fisher Elaine , Agba Chimuanya K , Xu Qing , Ritola Kimberly D , Mirow Andrea MC , Kim Sehyun , Cossart Rosa , Fishell Gord
Published: September 2020

Sensory and cognitive functions are processed in discrete cortical areas and depend upon the integration of long range cortical and subcortical inputs. PV and SST inhibitory interneurons (cINs) gate these inputs and failure to do so properly is implicated in many neurodevelopmental disorders. The logic by which these interneuron populations are integrated into cortical circuits and how these vary across sensory versus associative cortical areas is unknown. To answer this question, we began by surveying the breadth of afferents impinging upon PV and SST cINs within distinct cortical areas. We found that presynaptic inputs to both cIN populations are similar and primarily dictated by their areal location. By contrast, the timing of when they receive these afferents is cell-type specific. In sensory regions, both SST and PV cINs initially receive thalamocortical first order inputs. While by adulthood PV cINs remain heavily skewed towards first order inputs, SST cINs receive an equal balance of first and higher order thalamic afferents. Remarkably, while perturbations to sensory experience affect PV cIN thalamocortical connectivity, SST cIN connectivity is disrupted in a model of fragile X syndrome (Fmr1 loss of function) but not a model of ASD (Shank3B loss of function). Altogether, these data provide a comprehensive map of cIN afferents within different functional cortical areas and reveal the region-specific logic by which PV and SST cIN circuits are established.
An automated platform for in situ serial crystallography at room temperature
Authors: Ren Zhong , Wang Cong , Shin Heewhan , Bandara Sepalika , Kumarapperuma Indika , Ren Michael Y. , Kang Weijia , Yang Xiaojing
Published: September 2020

Direct observation of functional motions in protein structures is highly desirable for understanding how these nanomachineries of life operate at the molecular level. Because cryogenic temperatures are non-physiological and may prohibit or even alter protein structural dynamics, it is necessary to develop robust X-ray diffraction methods that enable routine data collection at room temperature. We recently reported a crystal-on-crystal device to facilitate in situ diffraction of protein crystals at room temperature devoid of any sample manipulation. Here an automated serial crystallography platform based on this crystal-on-crystal technology is presented. A hardware and software prototype has been implemented, and protocols have been established that allow users to image, recognize and rank hundreds to thousands of protein crystals grown on a chip in optical scanning mode prior to serial introduction of these crystals to an X-ray beam in a programmable and high-throughput manner. This platform has been tested extensively using fragile protein crystals. We demonstrate that with affordable sample consumption, this in situ serial crystallography technology could give rise to room-temperature protein structures of higher resolution and superior map quality for those protein crystals that encounter difficulties during freezing. This serial data collection platform is compatible with both monochromatic oscillation and Laue methods for X-ray diffraction and presents a widely applicable approach for static and dynamic crystallographic studies at room temperature.
Crystal structure of tris[4-(naphthalen-1-yl)phenyl]amine
Authors: Yano Masafumi , Kashiwagi Yukiyasu , Inada Yoshinori , Hayashi Yuki , Mitsudo Koichi , Kubono Koji
Published: September 2020

In the title molecule, C48H33N, the central N atom shows no pyramidalization, so that the N atom and the three C atoms bound to the N atom lie almost in the same plane. The three para-phenylene rings bonded to the N atom are in a propeller form. All of the naphthalene ring systems are slightly bent. In the crystal, molecules form an inversion dimer, through two pairs of C—H...π interactions, which further interacts with the adjacent dimer via another two pairs of C—H...π interactions, forming a column structure along the a axis. There are no significant interactions between these column structures.
Drivers of financial and operational efficiency of MFIs: empirical evidences from Eastern Europe and Central Asia
Authors: Khan Asif , Shireen Saba
Published: September 2020

Purpose

The study attempts to examine the bias-adjusted financial and operational efficiency estimates of microfinance institutions (MFIs) operating in the Eastern Europe and Central Asia (ECA) region during the financial year 2017–2018. In addition, the study also identifies the responsible factors determining the financial and operational performances of MFIs operating in the ECA region.

Design/methodology/approach

The study employs two-stage bootstrap data envelopment analysis (DEA). In the first stage, the authors incorporate the bootstrap procedure in the DEA framework as suggested by Simar and Wilson (2000) to estimate the bias-corrected efficiency scores of 67 sample MFIs. In order to identify the drivers of efficiency level, the study deploys the bootstrap truncated regression model following the Simar and Wilson (2007) guidelines in the second stage of analysis.

Findings

The authors note from the empirical results that MFIs operating in the ECA region are relatively more financially efficient (0.588) than socially efficient (0.496). However, none of the MFIs were found to be operating at best-practice frontier while considering the bias-adjusted efficiency estimates. Further, the results of second stage of analysis confirm that corporate governance, that is, board size has positive and statistically significant impact on MFIs’ performances. In addition, the bad credit quality deteriorates both financial revenue and operational efficiency. Moreover, the MFIs’ size, profit status and debt-to-equity ratio were also found to be statistically significant to determine the operational and financial efficiency of MFIs in the ECA region.

Practical implications

The study provides the robust efficiency estimates and factors responsible to determine the financial and operational efficiency of MFIs operating in the ECA region. Further, the empirical results of the study provide the inputs and further direction to the policymakers, regulators, practitioners and managers in framing the policy and optimal operating strategies for ECA MFIs industry.

Originality/value

The study extends the DEA analysis by incorporating the bootstrap procedure in DEA model to estimate the bias-adjusted efficiency scores which are more reliable and robust. In addition, bootstrap truncated regression has been applied to identify the drivers of efficiency. Moreover, in the literature there is no single study which has deployed the double bootstrap DEA framework to examine the financial and operational efficiency estimates and its drivers.
The risk management role of nonexecutive directors: from capital expenditure perspective
Authors: To Tho Anh , Suzuki Yoshihisa , Ho Hong Thu Thi , Tran Siem Thi , Tran Tuan Quoc
Published: September 2020

Purpose

This study investigates the impact of board independence on firm risk of Vietnamese listed firms and the moderating effect of capital expenditure on this relationship.

Design/methodology/approach

This paper applies fixed effects and dynamic generalized method of moments (GMM) models to examine hypothesized associations between the proportion of nonexecutive directors and stock return volatility, as well as the moderating effect of capital expenditure. The robustness tests are implemented by applying alternative measures of overinvestment and firm risk.

Findings

The results show that the presence of nonexecutive directors on board increases firm risk. However, the combination of nonexecutive ratio and capital expenditure ratio has a significant negative impact on firm risk. The result is also confirmed by the difference between the monitoring role of nonexecutive directors in overinvesting and underinvesting firms.

Research limitations/implications

The results imply that Vietnamese listed firms take stock return volatility into consideration before nominating and appointing nonexecutive directors into their board, especially in overinvesting firms. From another perspective, the shift toward having a majority of nonexecutive directors on boards can play a significant role in pursuing a stable or risky business strategy.

Originality/value

This paper investigates the influences of nonexecutive directors on firm risk in the context of Vietnam.
Identifying export markets for Indian medical devices
Authors: Siddiqui Areej Aftab , Singh Parul
Published: September 2020

Purpose

Medical device industry in India is a niche sector with few key players but it possesses huge potential for both domestic and international trade. In recent years, a number of regulatory relaxations have been provided to medical device manufacturers in India to enhance production and further trade especially exports. Though the industry is highly dependent on imports, the purpose of this paper is to identify key medical devices using the revealed comparative advantage, which can be exported from India by identifying new markets.

Design/methodology/approach

For the selected medical devices, India’s exports to the world and the newly identified markets are forecasted using the autoregressive integrated moving average model of regression.

Findings

It is seen that three major medical devices emerge to be the ones where India has the capacity and potential to manufacture and export. These medical devices are electro-cardiographs, magnetic resonance imaging apparatus and oscilloscopes and oscillographs being exported to the USA, Australia; China and the USA, respectively, which is rising in recent years.

Research limitations/implications

As the forecasted values indicate that there is an increasing potential in exports from India to the world of the selected medical devices, there is an urgent need to develop this industry and enhance exports from India. Very few studies have been carried out to examine and forecast exports from specific sectors or industries which is the need of the hour now.

Originality/value

The paper also provides suggestions to exporters and policymakers on leveraging the future export potential of selected medical devices.
Optimisation of a chuck for cardboard can seaming – part 2: numerical modelling and statistical analyses
Authors: Velkavrh Igor , Ausserer Florian , Klien Stefan , Voyer Joel , Vorlaufer Georg , Abbrederis Alexander
Published: September 2020

Purpose

In the cardboard package production process, the cardboard roll and the cardboard bottom are joined in the seaming process. During the process, the cardboard is plastically deformed and damage to the cardboard surface can occur. The purpose of this study was to optimise the macro-geometrical parameters of the seaming chuck in order to minimise the cardboard damage during the seaming process.

Design/methodology/approach

The influences of geometrical properties of the seaming chuck on the seaming force were investigated using numerical investigations and statistical analysis.

Findings

A force-displacement model was established, which enabled the optimisation of the seaming chuck geometry for a reduction of the seaming force.

Research limitations/implications

Results from the present study imply that for tribological optimisation, not only the surface properties such as roughness and frictional response but also the macro-geometrical features of the actual mechanical components should be considered, as these can considerably affect the contacting forces and consequently the friction within the tribosystem.

Practical implications

Based on the performed analyses, a new seaming chuck was manufactured, which is currently undergoing testing in the real production process and is providing improved performance in terms of seam quality as compared to the benchmark.

Originality/value

In the present work, a systematic approach towards the use of statistical methods in tribological optimisation projects is provided for a use case applying a combination of numerically calculated and experimentally measured values.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0065/
Continuous e-learning at the workplace: the passport for the future of knowledge
Authors: Kapo Amra , Mujkic Alisa , Turulja Lejla , Kovačević Jasna
Published: September 2020

Purpose

Conceptual model in this paper combines existing scientific knowledge grounded in theories of planned behavior, diffusion of innovation and a unified theory of acceptance and use of technology, while aiming to identify relevant determinants of continuous use of e-learning by employees who used e-learning in the past year at their workplace.

Design/methodology/approach

The authors developed and empirically tested the positive impact of professional, personal, IT and environmental factors on the continued use of e-learning among 672 employees across different sectors using the structural equation modeling technique.

Findings

Research results suggest that the most powerful determinant of continuous use of e-learning are personal factors. Environmental influences and technological aspects also exhibit a positive and significant impact on the continuous use of e-learning. Research hypothesis related to the positive influence of professional factors on the continuous use of e-learning has not been empirically confirmed. Also, results demonstrated that continued use of e-learning contributes to better individual business performance.

Practical implications

The practical contribution is threefold: to companies, education institutions and human resource managers. For companies, identification of key determinants will lead to a better understanding of employees needs regarding continuous job improvements. The findings can be used by educational institutions to design e-learning programs according to results and real value to employees. On the other hand, human resource managers can benefit from this study in terms of getting concrete factors that motivate employees for continuous job improvement.

Originality/value

The research sheds light on the proposed integrated model that tests the post-adoption of the continuous use of e-learning within an organizational context.
An Empirical Study on Volatility Spillover Effect among KOSPI200, Futures, ETFs Markets
Authors: Kang Seok-Kyu , Byun Youngtae , Park Jonghae
Published: September 2020

In this study we compared the effectiveness of different ETFs. For this purpose, we analyzed the volatility spillover effect (process) among KOSPI200, KOSPI200 futures and KOSPI200 ETFs such as KODEX200, KOSEF200, KINDEX200, TIGER200 using multi-variate GARCH model. The sample was generated from high frequency data set over the period from 05/24/2009 to 12/29/2011 (669 days). The volatility spillover effect was examined at 1, 5, 10, 30 minute' intervals for each market and the main results are as follows;

First, KODEX200 has the highest correlations with KOSPI200 and KOSPI200 futures in four ETFs.

Second, all ETFs have a cointegrated relationship with its underlying asset KOSPI200 as KOSPI200 and KOSPI200 futures do.

Third, in the daily data the volatility spillover among ETFs, KOPSI200 and KOSPI200 futures was investigated in part but it was not consistent.

The fourth, according to the result derived from high-frequency data analysis the volatility spillover effect from KODEX200 to KOSPI200 (KOSPI200 futures) is bigger than that from KOSPI200 (KOSPI200 futures) to KODEX200 while other ETFs are not.

The overall results indicate that KODEX200 which is the biggest ETF in volume performs very important roles in finding the price of underlying asset and further researches can be expected.
Did healthcare professional perspectives on the quality and safety environment in New Zealand public hospitals change from 2012 to 2017?
Authors: Gauld Robin , Horsburgh Simon
Published: September 2020

Purpose

The work environment is known to influence professional attitudes toward quality and safety. This study sought to measure these attitudes amongst health professionals working in New Zealand District Health Boards (DHBs), initially in 2012 and again in 2017.

Design/methodology/approach

Three questions were included in a national New Zealand health professional workforce survey conducted in 2012 and again in 2017. All registered health professionals employed with DHBs were invited to participate in an online survey. Areas of interest included teamwork amongst professionals; involvement of patients and families in efforts to improve patient care and ease of speaking up when a problem with patient care is perceived.

Findings

In 2012, 57% of respondents (58% in 2017) agreed health professionals worked as a team; 71% respondents (73% in 2017) agreed health professionals involved patients and families in efforts to improve patient care and 69% (65% in 2017) agreed it was easy to speak up in their clinical area, with none of these changes being statistically significant. There were some response differences by respondent characteristics.

Practical implications

With no change over time, there is a demand for improvement. Also for leadership in policy, management and amongst health professionals if goals of improving quality and safety are to be delivered upon.

Originality/value

This study provides a simple three-question method of probing perceptions of quality and safety and an important set of insights into progress in New Zealand DHBs.
Hospitality as differentiated services in Brazilian private hospitals
Authors: Quinan Christiano , Costa Filho Bento Alves
Published: September 2020

Purpose

The objective of this study is to assess the role of differentiated hospitality services considering the perspective of Brazilian accredited private hospitals.

Design/methodology/approach

In-depth interviews were applied to 10 hospitals top management executives (C-Suite level) having as support unstructured data collection routine exploring the issues: main client of the hospital, differentiated hospitality services (DS), hospital board expectation about DS, brand building, service charging policies and nonfinancial results.

Findings

Results indicate the interviewed institutions are adopting gradually a new business model in healthcare, in which an empowered patient and his/her needs and satisfaction is gaining relevance. This new conception having hospitality services as a base is transforming a former medical focused sector into a competitive business-oriented approach.

Research limitations/implications

The nonprobabilistic nature of the sample does not permit statistical inference of results to the population; they are valid only for healthcare management exploratory insights.

Practical implications

Coming from the hotel sector, hospitality amenities are turning into strategic instrument and provoking competition in a segment of hospitals targeting upper-middle-class clients, able to afford higher healthcare insurance premiums.

Social implications

In the new business approach, the patient that in recent past was passive is increasingly getting attention and bargaining power.

Originality/value

The main contribution is centered on the comprehension of an international dynamic in Brazil of a new business model that is changing a traditional sector, once focused in medicine and healing into a market-oriented business.
Lean simulations in production and operations management – a systematic literature review and bibliometric analysis
Authors: Abideen Ahmed Zainul , Mohamad Fazeeda Binti , Fernando Yudi
Published: September 2020

Purpose

Recently, much research about the effects of simulation on an organization’s operational performance and efficiency has been carried out. But still, there is a need for lean-based simulations rather than just modelling the system. However, these studies still lack systematization. Consequently, the purpose of this paper is to systematize the literature on lean simulations in the area of production and operations management.

Design/methodology/approach

A systematic analysis was performed on 93 articles extracted from the Clarivate Analytics Web of Science (WoS) Core Collection database. The analysis was limited to only articles that come under the “Engineering industrial,” “Engineering Manufacturing” and “Operations Research and Management” subject category in WoS Core Collection database. Later, a bibliometric analysis was integrated with the literature review for deeper literature categorization.

Findings

A bibliometric analysis displayed the relevance of selected literature (keywords, authors and sources). The systematic literature review helped to clarify each clusters’ content and purpose.

Research limitations/implications

This study portrays the gaps in the lean simulation integration methods and techniques through a detailed systematic and bibliometric review.

Practical implications

Lean managers can get various insights and ideas on implementing lean and simulation integration methods in real-time process improvement scenarios.

Social implications

This study demonstrates the best future recommendations for lean based modelling for both consumers and organizations that shall address the social and economic issues.

Originality/value

To the best of the authors’ knowledge, minimal attention has been paid to systematizing the literature on lean simulation in industrial, manufacturing and operations management. This study contributes to close this gap.