bluuebunny/crossref_metadata_2025 huggingface dataset:
The biophysical basis underlying the maintenance of early phase long-term potentiation
Authors: Becker Moritz F. P. , Tetzlaff Christian
Published: August 2020

The maintenance of synaptic changes resulting from long-term potentiation (LTP) is essential for brain function such as memory and learning. Different LTP phases have been associated with diverse molecular processes and pathways, and the molecular underpinnings of LTP on the short, as well as long time scales, are well established. However, the principles on the intermediate time scale of 1-6 hours that mediate the early phase of LTP (E-LTP) remain elusive. We hypothesize that the interplay between specific features of postsynaptic receptor trafficking is responsible for sustaining synaptic changes during this LTP phase. We test this hypothesis by formalizing a biophysical model that integrates several experimentally-motivated mechanisms. The model captures a wide range of experimental findings and predicts that synaptic changes are preserved for hours when the receptor dynamics are shaped by the interplay of structural changes of the spine in conjunction with increased trafficking from recycling endosomes and the cooperative binding of receptors. Furthermore, our model provides several predictions to verify our findings experimentally.

Author summary

The cognitive ability of learning is associated with plasticity-induced changes in synaptic transmission efficacy mediated by AMPA receptors. Synaptic changes depend on a multitude of molecular and physiological mechanisms, building complex interaction networks. By formalizing and employing a biophysical model of AMPAR trafficking, we unravel and evaluate the interplay between key mechanisms such as receptor binding, exocytosis, morphological changes, and cooperative receptor binding. Our findings indicate that cooperative receptor binding in conjunction with morphological changes of the spine and increased trafficking from recycling endosomes leads to the maintenance of synaptic changes on behaviorally relevant time spans. Characterizing the principles underlying synaptic changes will provide insight into the role of synaptic dynamics in neurodegenerative diseases.
Visualization of Phase-Amplitude Coupling Using Rhythmic High-Frequency Activity
Authors: Hashimoto Hiroaki , Khoo Hui Ming , Yanagisawa Takufumi , Tani Naoki , Oshino Satoru , Kishima Haruhiko , Hirata Masayuki
Published: August 2020

Objective

High-frequency activities (HFAs) and phase-amplitude coupling (PAC) are gaining attention as key neurophysiological biomarkers for studying human epilepsy. We aimed to clarify and visualize how HFAs are modulated by the phase of low-frequency bands during seizures.

Methods

We used intracranial electrodes to record seizures of symptomatic focal epilepsy (15 seizures in seven patients). Ripples (80–250 Hz), as representative of HFAs, were evaluated along with PAC. The synchronization index (SI), representing PAC, was used to analyze the coupling between the amplitude of ripples and the phase of lower frequencies. We created a video in which the intracranial electrode contacts were represented by circles that were scaled linearly to the power changes of ripple.

Results

The main low frequency band modulating ictal-ripple activities was the θ band (4–8 Hz), and after completion of ictal-ripple burst, δ (1–4 Hz)-ripple PAC occurred. The video showed that fluctuation of the diameter of these circles indicated the rhythmic changes during significant high values of θ-ripple PAC.

Conclusions

We inferred that ripple activities occurring during seizure evolution were modulated by θ rhythm. In addition, we concluded that rhythmic circles’ fluctuation presented in the video represents the PAC phenomenon. Our video is thus a useful tool for understanding how ripple activity is modulated by the low-frequency phase in relation with PAC.
Functional diagnostics using fresh uncultured lung tumor cells to guide personalized treatments
Authors: Talwelkar Sarang S. , Mäyränpää Mikko I. , Søraas Lars , Potdar Swapnil , Bao Jie , Hemmes Annabrita , Linnavirta Nora , Lømo Jon , Räsänen Jari , Knuuttila Aija , Wennerberg Krister , Verschuren Emmy W.
Published: August 2020

Functional profiling of a cancer patient’s tumor cells holds potential to tailor personalized cancer treatment. Here we report the utility of Fresh Uncultured Tumor-derived EpCAM+ epithelial Cells (FUTC) forex vivodrug response interrogation. Analysis of murineKrasmutant FUTCs demonstrated pharmacological and adaptive signaling profiles comparable to subtype-matched cultured cells. Applying FUTC profiling on non-small cell lung cancer patient samples, we generated robust drug response data in 18 of 19 cases, where the cells exhibited targeted drug sensitivities corresponding to their oncogenic drivers. In one of these cases, anEGFRmutant lung adenocarcinoma patient refractory to osimertinib, FUTC profiling was used to guide compassionate treatment. FUTC profiling identified selective sensitivity to disulfiram and the combination of carboplatin plus etoposide and the patient received substantial clinical benefit from the treatment with these agents. We conclude that FUTC profiling provides a robust, rapid, and actionable assessment of personalized cancer treatment options.
Quantitative yeast-yeast two hybrid for discovery and binding affinity estimation of protein-protein interactions
Authors: Bacon Kaitlyn , Blain Abigail , Bowen John , Burroughs Matthew , McArthur Nikki , Menegatti Stefano , Rao Balaji M.
Published: August 2020

Quantifying the binding affinity of protein-protein interactions is important for elucidating connections within biochemical signaling pathways, as well as characterization of binding proteins isolated from combinatorial libraries. We describe a quantitative yeast-yeast two hybrid (qYY2H) system that not only enables discovery of specific protein-protein interactions, but also efficient, quantitative estimation of their binding affinities (KD). In qYY2H, the bait and prey proteins are expressed as yeast cell surface fusions using yeast surface display. We developed a semi-empirical framework for estimating theKDof monovalent bait-prey interactions, using measurements of the apparentKDof yeast-yeast binding, which is mediated by multivalent interactions between yeast-displayed bait and prey. Using qYY2H, we identified interaction partners of SMAD3 and the tandem WW domains of YAP from a cDNA library and characterized their binding affinities. Finally, we showed that qYY2H could also quantitatively evaluate binding interactions mediated by post-translational modifications on the bait protein.
Freshwater sponge hosts and their green algae symbionts: a tractable model to understand intracellular symbiosis
Authors: Hall Chelsea , Camilli Sara , Dwaah Henry , Kornegay Benjamin , Lacy Christine A. , Hill Malcolm S. , Hill April L.
Published: August 2020

In many freshwater habitats, green algae form intracellular symbioses with a variety of heterotrophic host taxa including several species of freshwater sponge. These sponges perform important ecological roles in their habitats, and the poriferan:green algae partnerships offers unique opportunities to study the evolutionary origins and ecological persistence of endosymbioses. We examined the association betweenEphydatia muelleriand its chlorophyte partner to identify features of host cellular and genetic responses to the presence of intracellular algal partners.Chlorella-likegreen algal symbionts were isolated from field-collected adultE. muelleritissue harboring algae. The sponge-derived algae were successfully cultured and subsequently used to reinfect aposymbioticE. muelleritissue. We used confocal microscopy to follow the fate of the sponge-derived algae after inoculating algae-freeE. muellerigrown from gemmules to show temporal patterns of symbiont location within host tissue. We also infected aposymbioticE. muelleriwith sponge-derived algae, and performed RNASeq to study differential expression patterns in the host relative to symbiotic states. We compare and contrast our findings with work in other systems (e.g., endosymbioticHydra) to explore possible conserved evolutionary pathways that may lead to stable mutualistic endosymbioses. Our work demonstrates that freshwater sponges offer many tractable qualities to study features of intracellular occupancy and thus meet criteria desired for a model system.
Rational engineering ofKluyveromyces marxianusto create a chassis for the production of aromatic products
Authors: Rajkumar Arun S. , Morrissey John P.
Published: August 2020

The yeastKluyveromyces marxianusoffers unique potential for industrial biotechnology because of useful features like rapid growth, thermotolerance and a wide substrate range. As an emerging alternative platform,K. marxianusrequires the development and validation of metabolic engineering strategies to best utilize its metabolism as a basis for bio-based production. To illustrate the synthetic biology strategies to be followed and showcase its potential, we describe a comprehensive approach to rationally engineer a metabolic pathway inK. marxianus. We use the phenylalanine biosynthetic pathway both as a prototype and because phenylalanine is a precursor for commercially valuable secondary metabolites. First, we modify and overexpress the pathway to be resistant to feedback inhibition so as to overproduce phenylalaninede novofrom synthetic minimal medium. Second, we assess native and heterologous means to increase precursor supply to the biosynthetic pathway. Finally, we eliminate branch points and competing reactions in the pathway and rebalance precursors to redirect metabolic flux to a specific product, 2-phenylethanol (2-PE). As a result, we are able to construct robust strains capable of producing over 800 mg L−12-PE from minimal medium. The strains we constructed are a promising platform for the production of aromatic amino acid-based biochemicals, and our results illustrate challenges with attempting to combine individually beneficial modifications in an integrated platform.
Construction of a complete set ofNeisseria meningitidisdefined mutants – the NeMeSys 2.0 collection – and its use for the phenotypic profiling of the genome of an important human pathogen
Authors: Muir Alastair , Gurung Ishwori , Cehovin Ana , Bazin Adelme , Vallenet David , Pelicic Vladimir
Published: August 2020

One of the great challenges in biology is to determine the function of millions of genes of unknown function. Even in model bacterial species, there is a sizeable proportion of such genes, which has fundamental and practical consequences. Here, we constructed a complete collection of defined mutants in protein-coding genes – named NeMeSys 2.0 – in the human pathogenNeisseria meningitidis, consisting of individual mutants in 1,584 non-essential genes. This effort identified 391 essential genes – broadly conserved in other bacteria – leading to a full overview of the essential meningococcal genome, associated with just four underlying basic biological functions: 1) expression of genome information, 2) preservation of genome information, 3) cell membrane structure/function, and 4) cytosolic metabolism. Subsequently, we illustrated the utility of the NeMeSys 2.0 collection for determining gene function by identifying 1) a novel and conserved family of histidinol-phosphatase, 2) 20 genes, including three new ones, involved in the biology of type IV pili, a widespread virulence factor, and 3) several conditionally essential genes found in regions of genome plasticity encoding antitoxins and/or immunity proteins, which become dispensable when the gene encoding the cognate toxin is deleted. These findings have implications beyond the meningococcus. The NeMeSys 2.0 collection is an invaluable resource paving the way for a global phenotypic landscape in a major human bacterial pathogen.
Influence of multi-axial dynamic constraint on cell alignment and contractility in engineered tissues
Authors: Reynolds Noel H. , McEvoy Eoin , Panadero Pérez Juan Alberto , Coleman Ryan J. , McGarry Patrick
Published: August 2020

In this study an experimental rig is developed to investigate the influence of tissue constraint and cyclic loading on cell alignment and active cell force generation in uniaxial and biaxial engineered tissues constructs. Addition of contractile cells to collagen hydrogels dramatically increases the measured forces in uniaxial and biaxial constructs under dynamic loading. This increase in measured force is due to active cell contractility, as is evident from the decreased force after treatment with cytochalasin-D. Prior to dynamic loading, cells are highly aligned in uniaxially constrained tissues but are uniformly distributed in biaxially constrained tissues, demonstrating the importance of tissue constraints on cell alignment. Dynamic uniaxial stretching resulted in a slight increase in cell alignment in the centre of the tissue, whereas dynamic biaxial stretching had no significant effect on cell alignment. Our active modelling framework accurately predicts our experimental trends and suggests that a slightly higher (3%) total SF formation occurs at the centre of a biaxial tissue compared to the uniaxial tissue. However, high alignment of SFs and lateral compaction in the case of the uniaxially constrained tissue results in a significantly higher (75%) actively generated cell contractile stress, compared to the biaxially constrained tissue. These findings have significant implications for engineering of contractile tissue constructs.
Bimodal evolution of Src and Abl kinase substrate specificity revealed using mammalian cell extract as substrate pool
Authors: Finneran Patrick , Soucheray Margaret , Wilson Christopher , Otten Renee , Buosi Vanessa , Krogan Nevan J. , Swaney Danielle L. , Theobald Douglas L. , Kern Dorothee
Published: August 2020

The specificity of phosphorylation by protein kinases is essential to the integrity of biological signal transduction. While peptide sequence specificity for individual kinases has been examined previously, here we explore the evolutionary progression that has led to the modern substrate specificity of two non-receptor tyrosine kinases, Abl and Src. To efficiently determine the substrate specificity of modern and reconstructed ancestral kinases, we developed a method using mammalian cell lysate as the substrate pool, thereby representing the naturally occurring substrate proteins. We find that the oldest tyrosine kinase ancestor was a promiscuous enzyme that evolved through a more specific last common ancestor into a specific human Abl. In contrast, the parallel pathway to human Src involved a loss of substrate specificity, leading to general promiscuity. These results add a new facet to our understanding of the evolution of signaling pathways, with both subfunctionalization and neofunctionalization along the evolutionary trajectories.
Deletion of the voltage-gated calcium channel, CaV1.3, causes deficits in motor performance and associative learning
Authors: Lauffer Marisol , Wen Hsiang , Myers Bryn , Plumb Ashley , Parker Krystal , Williams Aislinn
Published: August 2020

L-type voltage-gated calcium channels are important regulators of neuronal activity and are widely expressed throughout the brain. One of the major L-type voltage-gated calcium channel isoforms in the brain is CaV1.3. Mice lacking CaV1.3 are reported to have impairments in fear conditioning and depressive-like behaviors, which have been linked to CaV1.3 function in the hippocampus and amygdala. Genetic variation in CaV1.3 has been linked to a variety of psychiatric disorders, including autism and schizophrenia, which are associated with altered motor learning, associative learning, and social function. Here, we explored whether CaV1.3 plays a role in these behaviors. We found that CaV1.3 knockout mice have deficits in rotarod learning despite normal locomotor function. Deletion of CaV1.3 is also associated with impaired gait adaptation and associative learning on the Erasmus Ladder. We did not observe any impairments in CaV1.3 knockout mice on assays of anxiety-like, depression-like, or social preference behaviors. Our results suggest an important role for CaV1.3 in neural circuits involved in motor learning and concur with previous data showing its involvement in associative learning.
The Posterior Insular Cortex is Necessary for the Consolidation of Tone Fear Conditioning
Authors: de Paiva J.P.Q. , Bueno A.P.A. , Dos Santos Corrêa M. , Oliveira M.G.M. , Ferreira T.L , Fornari R.V.
Published: August 2020

The insular cortex (IC) is notably implicated in emotional and cognitive processing; however, little is known regarding to what extent its two main subregions play functionally distinct roles on memory consolidation of conditioned fear tasks. Here we verified the effects of temporary functional inactivation of the anterior (aIC) and posterior IC (pIC) on contextual and tone fear memory. Rats received post-training bilateral infusions of the GABAAreceptor agonist muscimol into either the aIC or pIC and were tested 48 and 72 hours after the conditioning session to assess contextual (CFC) and tone (TFC) fear conditioning, respectively. Inactivation of the aIC during memory consolidation did not affect fear memory for CFC or TFC. On the other hand, post-training inactivation of the pIC impaired TFC but not CFC. Our findings indicate that the pIC is a necessary part of the neural circuitry related to the consolidation of cued-fear memories.

Highlights

We studied the role of the anterior (aIC) and posterior (pIC) insula in fear memory

Post-training inactivation of aIC and pIC did not impact contextual fear conditioning

The pIC but not aIC is necessary for the consolidation of tone fear conditioning
Murine GFP-Mx1 forms phase-separated nuclear condensates and associates with cytoplasmic intermediate filaments: novel antiviral activity against vesicular stomatitis virus
Authors: Sehgal Pravin B. , Yuan Hujuan , Scott Mia F. , Deng Yan , Liang Feng-Xia , Mackiewicz Andrzej
Published: August 2020

Type I and III interferons (IFNs) induce expression of the “myxovirus resistance proteins” MxA in human cells and its ortholog Mx1 in murine cells. Human MxA formscytoplasmicstructures, some tethered to intermediate filaments. In contrast, murine Mx1 mainly formsnuclearbodies. Both HuMxA and MuMx1 are antiviral towards influenza A virus (FLUAV) (an orthomyxovirus). However, it has long been considered that HuMxA, butnotMuMx1, was antiviral towards vesicular stomatitis virus (VSV) (a rhabdovirus). We previously reported that the cytoplasmic human GFP-MxA structures in Huh7 hepatoma cells were phase-separated membraneless organelles (MLOs) (“biomolecular condensates”). In the present study we investigated whether nuclear murine Mx1 structures might also represent phase-separated biomolecular condensates. The transient expression of murine GFP-Mx1 in Huh7 hepatoma and Mich-2H6 melanoma cells led to the appearance of Mx1 nuclear bodies. These GFP-MuMx1 nuclear bodies were rapidly disassembled by exposing cells to 1, 6-hexanediol (5% w/v), or to hypotonic buffer (40-50 mosM), consistent with properties of membraneless phase-separated condensates. FRAP assays revealed that the GFP-MuMx1 nuclear bodies upon photobleaching showed a slow partial recovery (mobile fraction: ∼18%) suggestive of a gel-like consistency. Surprisingly, expression of GFP-MuMx1 in Huh7 cells also led to the appearance of MuMx1 in a novel cytoplasmic giantin-based intermediate filament meshwork and in cytoplasmic structures in 20-30% of transiently transfected Huh7 cells. Remarkably, Huh7 cells with cytoplasmic murine GFP-MuMx1 filaments, but not those with only nuclear bodies, showed antiviral activity towards VSV. Thus, murine GFP-Mx1 nuclear bodies comprised phase-separated condensates. Unexpectedly, GFP-MuMx1 associated with cytoplasmic giantin-based intermediate filaments in a subset of Huh7 cells, and, such cells showed antiviral activity towards VSV.
RNA Editing Signatures Predict Response to Immunotherapies in Melanoma Patients
Authors: Siddiqui Jalal , Miles Wayne O.
Published: August 2020

Summary Paragraph

Immunotherapy has improved the prognosis for half of the melanoma patients, prompting a need to understand differences between responding and non-responding patients. Gene expression profiling of tumors has focused on deriving primarily immune-related signatures, however these have shown limited predictive power. Recent studies have highlighted the role of RNA editing in modulating resistance to immunotherapy. This has led us to test whether RNA editing activity can be predictive of response in publicly available datasets of immunotherapy-treated melanoma patients. Here, we identified RNA editing signatures that were able to predict with very high accuracy and confidence patient responses and outcomes. Our analysis, however, demonstrates that RNA editing by itself is sufficient as a strong predictive tool for examining sensitivity of melanoma patients to immunotherapy.
APC/CFZR-1Controls ZYG-1 Levels to Regulate Centrosome Assembly
Authors: Medley Jeffrey C. , DiPanni Joseph R. , Schira Luke , Shaffou Blake M. , Sebou Brandon M. , Song Mi Hye
Published: August 2020

Aberrant centrosome numbers are associated with human cancers. The levels of centrosome regulators positively correlate with centrosome number. Thus, tight control of centrosome protein levels is critical. InCaenorhabditis elegans, the anaphase-promoting complex/cyclosome and co-activator FZR-1 (APC/CFZR-1) ubiquitin ligase negatively regulates centrosome assembly through SAS-5 degradation. In this study, we identify theC. elegansZYG-1 (Plk4 in human) as a new substrate of APC/CFZR-1. Inhibiting APC/CFZR-1or mutating a ZYG-1 destruction (D)-box leads to elevated ZYG-1 levels at centrosomes, restoring bipolar spindles and embryonic viability tozyg-1mutants, suggesting that APC/CFZR-1targets ZYG-1 for proteasomal degradation via D-box motif. We also show the Slimb/βTrCP-binding (SB) motif is critical for ZYG-1 degradation, substantiating a conserved mechanism by which ZYG-1/Plk4 stability is regulated by SCFSlimb/βTrCP-dependent proteolysis via the conserved SB motif inC. elegans. Furthermore, inhibiting both APC/CFZR-1and SCFSlimb/βTrCP, by co-mutating ZYG-1 SB and D-box motifs, stabilizes ZYG-1 in an additive manner, conveying that APC/CFZR-1and SCFSlimb/βTrCPubiquitin ligases function cooperatively for timely ZYG-1 destruction inC. elegansembryos where ZYG-1 activity remains at threshold level to ensure normal centrosome number.
Postembryonic screen for mutations affecting spine development in zebrafish
Authors: Gray Ryan S. , Gonzalez Roberto , Ackerman Sarah D. , Minowa Ryoko , Griest Johanna F. , Bayrak Melisa N. , Troutwine Benjamin , Canter Stephen , Monk Kelly R. , Sepich Diane S. , Solnica-Krezel Lilianna
Published: August 2020

The spinal vertebral column gives structural support for the adult body plan, protects the spinal cord, and provides muscle attachment and stability, which allows the animal to move within its environment. The development and maturation of the spine and its physiology involve the integration of multiple musculoskeletal tissues including bone, cartilage, and fibrocartilaginous joints, as well as innervation and control by the nervous system. One of the most common disorders of the spine in human is adolescent idiopathic scoliosis (AIS), which is characterized by the onset of an abnormal lateral curvature of the spine of <10° around adolescence, in otherwise healthy children. The genetic basis of AIS is largely unknown. Systematic genome-wide mutagenesis screens for embryonic phenotypes in zebrafish have been instrumental in the understanding of early patterning of embryonic tissues necessary to build and pattern the embryonic spine. However, the mechanisms required for postembryonic maturation and homeostasis of the spine remain poorly understood. Here we report the results from a small-scale forward genetic screen for adult-viable recessive and dominant mutant zebrafish, displaying overt morphological abnormalities of the adult spine. Germline mutations induced withN-ethylN-nitrosourea (ENU) were transmitted and screened for dominant phenotypes in 1,229 F1 animals, and subsequently bred to homozygosity in F3 families, from these, 314 haploid genomes were screened for recessive phenotypes. We cumulatively found 39 adult-viable (3 dominant and 36 recessive) mutations each leading to a defect in the morphogenesis of the spine. The largest phenotypic group displayed larval onset axial curvatures, leading to whole-body scoliosis without vertebral dysplasia in adult fish. Pairwise complementation testing within this phenotypic group revealed at least 16 independent mutant loci. Using massively-parallel whole genome or whole exome sequencing and meiotic mapping we defined the molecular identity of several loci for larval onset whole-body scoliosis in zebrafish. We identified a new mutation in theskolios/kinesin family member 6(kif6) gene, causing neurodevelopmental and ependymal cilia defects in mouse and zebrafish. We also report several recessive alleles of thescospondinanda disintegrin and metalloproteinase with thrombospondin motifs 9(adamts9) genes, which all display defects in spine morphogenesis. Many of the alleles characterized thus far are non-synonymous mutations in known essentialscospondinandadamts9genes. Our results provide evidence of monogenic traits that are critical for normal spine development in zebrafish, that may help to establish new candidate risk loci for spine disorders in humans.
Efferent feedback enforces bilateral coupling of spontaneous activity in the developing auditory system
Authors: Wang Yixiang , Sanghvi Maya , Gribizis Alexandra , Zhang Yueyi , Song Lei , Morley Barbara , Barson Daniel G. , Santos-Sacchi Joseph , Navaratnam Dhasakumar , Crair Michael
Published: August 2020

In the developing auditory system, spontaneous activity generated in the cochleae propagates into the central nervous system to promote circuit formation before hearing onset. Effects of the evolving peripheral firing pattern on spontaneous activity in the central auditory system are not well understood. Here, we describe the wide-spread bilateral coupling of spontaneous activity that coincides with the period of transient efferent modulation of inner hair cells from the medial olivochlear (MOC) system. Knocking out the α9/α10 nicotinic acetylcholine receptor, a requisite part of the efferent cholinergic pathway, abolishes these bilateral correlations. Pharmacological and chemogenetic experiments confirm that the MOC system is necessary and sufficient to produce the bilateral coupling. Moreover, auditory sensitivity at hearing onset is reduced in the absence of pre-hearing efferent modulation. Together, our results demonstrate how ascending and descending pathways collectively shape spontaneous activity patterns in the auditory system and reveal the essential role of the MOC efferent system in linking otherwise independent streams of bilateral spontaneous activity during the prehearing period.
A Novel Machine Learning Strategy for Prediction of Antihypertensive Peptides Derived from Food with High Efficiency
Authors: Wang Liyang , Niu Dantong , Wang Xiaoya , Shen Qun , Xue Yong
Published: August 2020

Strategies to screen antihypertensive peptides with high throughput and rapid speed will be doubtlessly contributed to the treatment of hypertension. The food-derived antihypertensive peptides can reduce blood pressure without side effects. In present study, a novel model based on Extreme Gradient Boosting (XGBoost) algorithm was developed using the primary structural features of the food-derived peptides, and its performance in the prediction of antihypertensive peptides was compared with the dominating machine learning models. To further reflect the reliability of the method in real situation, the optimized XGBoost model was utilized to predict the antihypertensive degree of k-mer peptides cutting from 6 key proteins in bovine milk and the peptide-protein docking technology was introduced to verify the findings. The results showed that the XGBoost model achieved outstanding performance with the accuracy of 0.9841 and the area under the receiver operating characteristic curve of 0.9428, which were better than the other models. Using the XGBoost model, the prediction of antihypertensive peptides derived from milk protein was consistent with the peptide-protein docking results, and was more efficient. Our results indicate that using XGBoost algorithm as a novel auxiliary tool is feasible for screening antihypertensive peptide derived from food with high throughput and high efficiency.
4-Styrylquinolines from cyclocondensation reactions between (2-aminophenyl)chalcones and 1,3-diketones: crystal structures and regiochemistry
Authors: Rodríguez Diego , Guerrero Sergio Andrés , Palma Alirio , Cobo Justo , Glidewell Christopher
Published: August 2020

Structures are reported for two matched sets of substituted 4-styrylquinolines which were prepared by the formation of the heterocyclic ring in cyclocondensation reactions between 1-(2-aminophenyl)-3-arylprop-2-en-1-ones with 1,3-dicarbonyl compounds. (E)-3-Acetyl-4-[2-(4-methoxyphenyl)ethenyl]-2-methylquinoline, C21H19NO2, (I), (E)-3-acetyl-4-[2-(4-bromophenyl)ethenyl]-2-methylquinoline, C20H16BrNO, (II), and (E)-3-acetyl-2-methyl-4-{2-[4-(trifluoromethyl)phenyl]ethenyl}quinoline, C21H16F3NO, (III), are isomorphous and in each structure the molecules are linked by a single C—H...O hydrogen bond to form C(6) chains. In (I), but not in (II) or (III), this is augmented by a C—H...π(arene) hydrogen bond to form a chain of rings; hence, (I)–(III) are not strictly isostructural. By contrast with (I)–(III), no two of ethyl (E)-4-[2-(4-methoxyphenyl)ethenyl]-2-methylquinoline-3-carboxylate, C22H21NO3, (IV), ethyl (E)-4-[2-(4-bromophenyl)ethenyl]-2-methylquinoline-3-carboxylate, C21H18BrNO2, (V), and ethyl (E)-2-methyl-4-{2-[4-(trifluoromethyl)phenyl]ethenyl}quinoline-3-carboxylate, C22H18F3NO2, (VI), are isomorphous. The molecules of (IV) are linked by a single C—H...O hydrogen bond to form C(13) chains, but cyclic centrosymmetric dimers are formed in both (V) and (VI). The dimer in (V) contains a C—H...π(pyridyl) hydrogen bond, while that in (VI) contains two independent C—H...O hydrogen bonds. Comparisons are made with some related structures, and both the regiochemistry and the mechanism of the heterocyclic ring formation are discussed.
Does the gender quota law affect bank performances? Evidence from Italy
Authors: Mazzotta Romilda , Ferraro Olga
Published: August 2020

Purpose

This study aims to examine the impact of an increasing board diversity on the performance of Italian listed banks for the period 2008–2014, taking into account the effects of the implementation of gender quota laws in Italy. The study also investigates the effects of this potential relationship during the crisis that Italy had to cope with since 2011, as well as the potential impact of female directors and their roles on bank boards.

Design/methodology/approach

To verify this relationship, the study uses a panel sample of 22 listed banks and applies fixed effects with the Driscoll-Kraay error. Considering the shareholders’ perspective, bank performance (BP) is measured by return on average equity. The robustness of results is verified through return on average assets, Tobin’s Q (a market measure from investors/stakeholders’ perspective) and an alternate estimation model, i.e. GMM.

Findings

The findings highlight a positive relationship between the performance accounting measures and gender diversity, a non-neutral impact of the presence of female directors on boards and a significant and negative effect on market measures.

Research limitations/implications

The results of the study, as far as accounting measures are concerned, support managerial and legislative efforts toward more gender-balanced boards and the appointment of female directors in executive or independent roles. As per market measures, the results suggest that the presence of women on boards should be considered advantageous in terms of value, so that the market can finally appreciate diverse bank boards.

Originality/value

First, previous studies did not provide exhaustive results to document the proposed relationship and did not examine this relationship during a financial crisis. Second, the role of female directors on boards is also taken into account. Third, the study highlighted that BP is a multi-dimensional construct, with accounting and market metrics being its distinct dimensions.
Balancing value and risk within a city's event portfolio: an explorative study of DMO professionals' assessments
Authors: Andersson Tommy D. , Getz Don , Jutbring Henrik
Published: August 2020

Purpose

This study aims to advance both theory and praxis for event portfolio management in cities and destinations. An experiment has been conducted with professional event practitioners in a city to determine their opinions and strategies for balancing value and risk within their event portfolio. The first objective is to rank 14 of the city's recurring events in terms of both value and risk. Second, the events are plotted in a two-dimensional chart of value versus risk with the objective to differentiate between the 14 events. The third objective is to describe the event characteristics that event professionals associate with value and risk.

Design/methodology/approach

Results derive from an experiment involving the forced Q-sort procedure and professional event managers from a city renowned as an “event capital”. Empirical evidence is analysed by the constant comparative method of how events are being evaluated by ten professionals working for a DMO.

Findings

Economic impact and image effects are characteristics of high-value events as is an opportunity to create relations with event owners for future collaboration. Local community involvement is important for all events. The issue of portfolio fit was a common argument for weak-value events.

Research limitations/implications

Results are based on the opinions of ten DMO employees in one large city. Conclusions help build event portfolio theory.

Practical implications

The results and methods are useful for event strategists and evaluators. In particular, the management of event portfolios and policies covering events in cities and destinations can benefit from the documented method for explicitly balancing risks with perceived value.

Social implications

A portfolio perspective is also suggested as an approach to analyse the total tourist attractions portfolio of a destination.

Originality/value

Opinions regarding public value and risk by civil servants who work with events have not been studied before. The constant comparative method produces results that can be applied to policies governing events. In terms of theory development, concepts from financial portfolio management, product portfolio management and risk management are used to develop event portfolio design and management, and insights are gained on trade-offs in the process. The plot of the events in a two-dimensional chart of value versus risk clearly differentiated the 14 events and is an original contribution.
Segmentation of music festival visitors by values of hedonia, life satisfaction and eudaimonia
Authors: Saragih Harriman Samuel , Amelia Novi
Published: August 2020

Purpose

With the growing interest in eudaimonia in the past years and the need to better understand festival visitors' motivation in the context of music festivals, this study aims to propose visitor segmentation based on the values of hedonia, life satisfaction and eudaimonia.

Design/methodology/approach

The analysis in this study employs a case research method that follows the abductive paradigm. The authors begin their conceptual foundation with a review of the literature on hedonia, life satisfaction and eudaimonia. The authors then use the preliminary conceptual foundation as the basis of rival analysis through a focus group and interviews with senior executives, government officials, communities and other related stakeholders. The authors also carry out an exploratory factor analysis to determine the building blocks of eudaimonic festival experiences. Last, using cluster analysis, the authors support their conceptual proposition from the initial qualitative inquiries.

Findings

From the three studies that the authors performed, their findings suggest that, based on hedonia and eudaimonia, festival attendees can be divided into three distinct segments: (1) pleasure seekers (i.e. visitors who look for personal pleasure, enjoyment and affection), (2) playful learners (i.e. visitors who not only seek pleasure, but also consider the urgency to think about the need to grow as a person) and (3) transcendentalists (i.e. visitors who seek a balance of pleasure, escapism, self-reflection, personal meaning and impact through attending festival activities).

Research limitations/implications

This study argues that the ideas of hedonia and eudaimonia are present in the context of the music festival. Theoretically, this paper suggests that festival-goers can be divided into three clusters based on the values of hedonia and eudaimonia: pleasure seekers, playful learners and transcendentalists. Practically, this study suggests that festival organisers should consider developing music concert events by taking into account the eudaimonic and hedonistic desires, intrinsically possessed by the festival-goers, which is expected to add value to the produced musical event.

Originality/value

This study is the first to present visitor segmentation in a music festival setting based on the values of eudaimonia, life satisfaction and hedonia.
The medical university-governing board: an investigation of critical factors in the board performance in Iran
Authors: Sajadi Haniye Sadat , Maleki Mohammadreza , Michael Steve
Published: August 2020

Purpose

A university of medical sciences (UMS) is governed by a board that serves analogously as a board of trustees or a governing board in the western countries. In Iran, however, such boards operate under the broad leadership of the Ministry of Health and Medical Education (MoHME) but still wield enormous power over their universities. Given the influence boards have in the affairs of an UMS, the question remains how the medical university board can be improved so as to improve the overall effectiveness of these institutions. The purpose of this article is a response to this question by focusing on criteria necessary for reviewing board performance.

Design/methodology/approach

Using a qualitative approach, the study solicited data from 37 key informants that were purposefully chosen from 52 medical science universities across Iran. Semi-structured face-to-face and phone interviews as well as a review of relevant document were the main means of the data gathering. We performed the framework analysis using software ATLAS-ti (version 5).

Findings

The analysis identified 32 overlapping indicators that must be considered in a board performance. These indicators were reclassified and summarized into six categories, including trustees, trustees' leadership, board structure, board process, board output (short-length results) and board outcomes (long-length results).

Originality/value

Our study findings confirmed the role of the context and its relationship with the effective board performance. Here, the governing arrangement of all institutions including UMS is shadowed by the social, economic, cultural, political and technological status of the country. So, special attention is recommended to identify what should be considered to evaluate the performance of the board given the context.
Membership negotiation in the first workplace – Newcomers' experiences
Authors: Rajamäki Sari , Mikkola Leena
Published: August 2020

Purpose

This qualitative study aims to understand young professional newcomers' experiences of communication processes in membership negotiation in their first workplace after graduation.

Design/methodology/approach

Instead of a one-time interview, the participants were contacted five to ten times during the three to ten months, beginning when they entered the workplace. The data were analyzed using a constant comparative method.

Findings

Three communication processes during membership negotiation were identified: developing reciprocity, seeking and perceiving acceptance and becoming an active member. To experience membership, newcomers need to achieve acceptance and engage in reciprocal communication in early interaction situations with managers and coworkers.

Research limitations/implications

Only the experiences of newly graduated newcomers were studied. This study illustrates the communication processes and social interaction evolving in membership negotiation during newcomers' entry.

Practical implications

Organizations need to re-evaluate their short orientation programs to support membership negotiations in workplace communication.

Social implications

By recognizing the communication processes during membership negotiation, the practices of newcomers' entry can be developed to support the membership development.

Originality/value

This study contributes to membership negotiation by showing how newcomers join the flow of membership negotiation through the processes of developing reciprocity, seeking and perceiving acceptance and becoming an active member.
In control we trust!? Exploring formal control configurations for municipally owned corporations
Authors: Krause Tobias Alexander , Swiatczak Martyna Daria
Published: August 2020

Purpose

This study examines the interplay of formal types of control (input, behavior and outcome) exercised on municipally owned corporations (MOCs). It further investigates whether particular informal contingencies (trust and interdependence) predict affiliation to the derived municipal control configurations.

Design/methodology/approach

The paper applies an exploratory cluster analysis based on survey data from 243 top-level managers of German MOCs. It then investigates the clustered municipal control configurations using binomial logistic regression.

Findings

The exploratory analysis reveals four municipal control configurations: (1) input-dominated control, (2) outcome-dominated control, (3) mixed input/outcome control and (4) “neglect of formal control”. As expected, both of the informal contingencies demonstrate strong predictive power. More precisely, trust increases the likelihood of belonging to the dominant outcome control cluster and interdependence increases the likelihood of belonging to the mixed input/outcome control cluster. Surprisingly, the neglect of formal control cluster is characterized by low trust and low interdependence.

Originality/value

The study sheds light on the widely assumed but understudied interplay of different formal controls in hybrid governance settings. Furthermore, the analysis stresses the importance of trust and interdependence when explaining hybrid control configurations.
Does CEO power matter for the performance of retrenchment strategy?
Authors: Brahmana Rayenda Khresna , You Hui Wei , Kontesa Maria
Published: August 2020

Purpose

This research aims to examine the moderating role of CEO power on the relationship between retrenchment strategy and firm performance by framing the relationship under an agency theory, and power circulation theory.

Design/methodology/approach

This study focuses on a sample of 319 non-financial public listed companies in Malaysia from the year 2011–2016 and estimates the model under two-step GMM panel regression to eliminate the endogeneity issue.

Findings

The results show that the retrenchment strategy increased firm performance. Meanwhile, greater CEO power changes that retrenchment effect into increased performance. This study also indicates the CEO power strengthens the relationship between firm performance and retrenchment. However, CEO power does not have any effect on the performance of low retrenchment, and the performance of big firm size.

Research limitations/implications

The findings show that the higher CEO power cause higher firm performance and higher retrenchment. This research suggests that CEO power can make retrenchment strategy works and the decision made can affect the firm performance significantly.

Originality/value

This study examines the effect of CEO power on the performance of retrenchment strategy implementation by contesting agency theory, power circulation theory, and resource-based view theory within the emerging country context.
Organizational support and employee thriving at work: exploring the underlying mechanisms
Authors: Guan Xiaoyu , Frenkel Stephen
Published: August 2020

Purpose

The purpose of this paper is to investigate whether perceived organizational support for strength use (POSSU) predicts employee thriving at work and the underlying mechanisms that explain this relationship.

Design/methodology/approach

The analysis is based on data from an online, time-lagged survey of 209 employees. Latent moderated structural equations (LMS) method was used to test the mediating role of job crafting and meaningfulness and the moderating role of core self-evaluation (CSE) in the organizational support-employee thriving relationship.

Findings

POSSU has a direct, positive relationship with employee thriving at work. Moreover, this relationship is fully mediated by employees' job crafting (as an agentic work behavior) and meaningfulness (as a resource produced at work). In addition, contextual factor of POSSU synergistically interacts with individual characteristic of CSE to foster thriving at work.

Research limitations/implications

Based on a time-lagged survey, causal relationships cannot be drawn from this study. Results point to future research that can incorporate specific types of work climate and organizational practices in a multilevel design to investigate how context at team, unit and organizational levels impact employee thriving.

Practical implications

The study results highlight the importance of fostering employee thriving at work by implementing organizational practices that create supportive, innovative and meaningful workplaces. Management needs to pay close attention to develop a supportive organizational climate geared to identifying, developing and utilizing employees' strengths.

Originality/value

This study provides theoretical explanations and empirical tests on the mechanisms linking organization support and employee thriving based on the socially embedded model of thriving.
The Finnish Think Tank Landscape – A Mixture of Consensualism and Adversity?
Authors: Lounasmeri Lotta I.
Published: August 2020

As a common feature of Nordic countries, the Finnish landscape of thinks tanks has been populated by large corporatist interest organisations and government‐funded research organisations. In addition to this, since 2005, party‐affiliated think tanks form a notable part of the picture. Recently, several small think tanks that are oriented towards specific themes, such as international relations, the environment and feminism, have been founded. This article examines Finnish developments in the field of think tanks with two objectives. First, it gives a general overview of the Finnish think tank landscape. Second, by using interview data and public mission statements of the most prominent think tanks, it explores how these organisations see their role in Finnish society. What is their relationship with media and the political machinery, and how does this relate to their position and activities as either consensual or adversarial actors? It is concluded that redeeming the place of think tanks in the Finnish polity is a continuing challenge, and resorting to adversarial tactics is not a favourable way to do so. This approach has mostly been attempted by neoliberal think tanks that, in the past, have also profited from corporatist structures to enhance their objectives.