bluuebunny/crossref_metadata_2025 huggingface dataset:
Bleaching correction for DNA-measurements in highly diluted solutions using confocal microscopy
Authors: Sparrenberg Lorenz T. , Greiner Benjamin , Mathis Harald P.
Published: April 2020

Precise and reliable determination of the nucleic acid concentration in biological samples still remains a challenge. This is particularly since the established fluorescene-based methods provide insufficient results, when only minute sample quantitites are available for analysis. Among other effects, photobleaching is the main reason for this. Since large molecules diffuse more slowly than small molecules, they are exposed to more excitation cycles and therefore have a higher probability of permanently losing their fluorescence. Solutions with large molecules hence show a reduced fluorescence. In this paper we present a method to correct this effect and thus allow high-precision sample concentration determination in minute sample quantities (< 2 µl drops with concentrations < 20 pg/µl). For this purpose, we used confocal microscopy with single molecule sensitivity. In the first step, we derived calibration curves from DNA solutions with defined fragment length. We analyzed dilution series over a wide concentration range (1 pg/µl – 1000 pg/µl) and measured their specific diffusion coefficients by employing fluorescence correlation spectroscopy. Using this information, we correct the measured fluorescence intensity of the calibration solutions for photobleaching effects. Subsequently, we evaluated our method by analyzing a series of DNA mixtures of varying composition.
A mechanistic model of the BLADE platform predicts performance characteristics of 256 different synthetic DNA recombination circuits
Authors: Bowyer Jack E. , Ding Chloe , Weinberg Benjamin H. , Wong Wilson W. , Bates Declan G.
Published: April 2020

Boolean logic and arithmetic through DNA excision (BLADE) is a recently developed platform for implementing inducible and logical control over gene expression in mammalian cells, which has the potential to revolutionise cell engineering for therapeutic applications. This 2-input 2-output platform can implement 256 different logical circuits that exploit the specificity and stability of DNA recombination. Here, we develop the first mechanistic mathematical model of the 2-input BLADE platform based on Cre- and Flp-mediated DNA excision. After calibrating the model on experimental data from two circuits, we demonstrate close agreement between model outputs and data on the other 111 circuits that have so far been experimentally constructed using the 2-input BLADE platform. Model simulations of the remaining 143 circuits that have yet to be tested experimentally predict excellent performance of the 2-input BLADE platform across the range of possible circuits. Circuits from both the tested and untested subsets that perform less well consist of a disproportionally high number of STOP sequences. Model predictions suggested that circuit performance declines with a decrease in recombinase expression and new experimental data was generated that confirms this relationship.
Synaptic transmission induces site-specific changes in sialylation onN-linked glycoproteins in rat nerve terminals
Authors: Boll Inga , Jensen Pia , Schwämmle Veit , Larsen Martin R.
Published: April 2020

Synaptic transmission leading to release of neurotransmitters in the nervous system is a fast and highly dynamic process. Previously, protein interaction and phosphorylation have been thought to be the main regulators of synaptic transmission. Here we show a novel potential modulator of synaptic transmission, sialylation ofN-linked glycosylation. The negatively charged sialic acids can be modulated, similarly to phosphorylation, by the action of sialyltransferases and sialidases thereby changing local structure and function of membrane glycoproteins. We characterized site-specific alteration in sialylation onN-linked glycoproteins in isolated rat nerve terminals after brief depolarization using quantitative sialiomics. We identified 1965 formerly sialylatedN-linked glycosites in synaptic proteins and found that the abundances of 430 glycosites changed after five seconds depolarization. We observed changes on essential synaptic proteins such as synaptic vesicle proteins, ion channels and transporters, neurotransmitter receptors and cell adhesion molecules. This study is to our knowledge the first to describe ultra-fast site-specific modulation of the sialiome after brief stimulation of a biological system.
The dynamic Nexus: Gap junctions control protein localization and mobility in distinct and surprising ways
Authors: McCutcheon Sean , Stout Randy F. , Spray David C.
Published: April 2020

Gap junction (GJ) channels permit molecules, such as ions, metabolites and second messengers, to transfer between cells. Their function is critical for numerous cellular interactions. GJ channels are composed of Connexin (Cx) hexamers paired across extracellular space and typically form large rafts of clustered channels, called plaques, at cell appositions. Cxs together with molecules that interact with GJ channels make up a supramolecular structure known as the GJ Nexus. While the stability of connexin localization in GJ plaques has been studied, mobility of other Nexus components has yet to be addressed. Colocalization analysis of several nexus components and other membrane proteins reveal that certain molecules are excluded from the GJ plaque (Aquaporin 4, EAAT2b), while others are quite penetrant (lipophilic molecules, Cx30, ZO-1, Occludin). Fluorescence recovery after photobleaching (FRAP) of tagged Nexus-associated proteins showed that mobility in plaque domains is affected by mobility of the Cx proteins. These novel findings indicate that the GJ Nexus is a dynamic membrane organelle, with cytoplasmic and membrane-embedded proteins binding and diffusing according to distinct parameters.

Summary Statement

Gap junctions are clustered membrane channels in plasma membrane of astrocytes and other cells. We report new information on how gap junctions control location and mobility of other astrocyte proteins.
CryoEM Structure of CtBP2 Confirms Tetrameric Architecture
Authors: Jecrois Anne M. , Dcona M. Michael , Deng Xiaovan , Bandyopadhyay Dipankar , Grossman Steven R. , Schiffer Celia A. , Royer William E.
Published: April 2020

C-terminal binding proteins 1 and 2 (CtBP1 and CtBP2) are transcriptional regulators that activate or repress many genes involved in cellular development, apoptosis and metastasis. CtBP proteins are activated under hypoxic conditions where NAD(H) levels tend to be higher. NADH-dependent activation of CtBP2 has direct implication in multiple types of cancers and poor patient prognosis. Previous studies have proposed dimeric CtBP as the relevant oligomeric state, however our studies with multi-angle light scattering have shown that the primary effect of NADH binding is to promote the assembly of two CtBP dimers into tetramers. Here, we present the cryoEM structures of two different constructs of CtBP2 corroborating that the native state of CtBP2 in the presence of NADH is indeed tetrameric. The physiological relevance of tetrameric CtBP2 was tested in HCT116; CtBP2 −/− cells transfected with tetramer destabilizing_mutants. Mutants that inhibit tetramer formation show a decrease in expression of the CtBP transcriptional target TIAM1 and exhibit a decrease in the ability to promote cell migration. Together with our cryoEM studies, these results highlight the tetramer as the functional oligomeric form of CtBP2.
Analysis of stress responses inAstyanaxlarvae reveals heterogeneity among different populations
Authors: Chin Jacqueline SR , Loomis Cody L. , Albert Lydia T. , Medina-Trenche Shirley , Kowalko Johanna , Keene Alex C. , Duboué Erik R.
Published: April 2020

Stress responses are conserved physiological and behavioral outcomes as a result of facing potentially harmful stimuli, yet in pathological states, stress becomes debilitating. Stress responses vary considerably throughout the animal kingdom, but how these responses are shaped evolutionarily is unknown. The Mexican cavefish has emerged as a powerful system for examining genetic principles underlying behavioral evolution. Here, we demonstrate that caveAstyanaxhave reduced behavioral and physiological measures of stress when examined at larval stages. We also find increased expression of the glucocorticoid receptor, a repressible element of the neuroendocrine stress pathway. Additionally, we examine stress in three different cave populations, and find that some, but not all, show reduced stress measures. Together, these results reveal a mechanistic system by which cave-dwelling fish reduced stress, presumably to compensate for a predator poor environment.

Research Highlight

Cavefish populations ofA. mexicanushave reduced stress relative to surface conspecific at larval stages

We show that a glucocorticoid receptor, a negative regulator of the neuroendocrine stress axis, is upregulated in stress-resistant cavefish

There exists much ontological heterogeneity between different cavefish populations.
Deep learning models for lipid-nanoparticle-based drug delivery
Authors: Harrison Philip J , Wieslander Håkan , Sabirsh Alan , Karlsson Johan , Malmsjö Victor , Hellander Andreas , Wählby Carolina , Spjuth Ola
Published: April 2020

Large-scale time-lapse microscopy experiments are useful to understand delivery and expression in RNA-based therapeutics. The resulting data has high dimensionality and high (but sparse) information content, making it challenging and costly to store and process. Early prediction of experimental outcome enables intelligent data management and decision making. We start from time-lapse data of HepG2 cells exposed to lipid-nanoparticles loaded with mRNA for expression of green fluorescent protein (GFP). We hypothesize that it is possible to predict if a cell will express GFP or not based on cell morphology at time-points prior to GFP expression. Here we present results on per-cell classification (GFP expression/no GFP expression) and regression (level of GFP expression) using three different approaches. In the first approach we use a convolutional neural network extracting per-cell features at each time point. We then utilize the same features combined with: a long-short-term memory (LSTM) network encoding temporal dynamics (approach 2); and time-series feature extraction using the python package tsfresh followed by principal component analysis and gradient boosting machines (approach 3), to reach a final classification or regression result. Application of the three approaches to a previously unanalyzed test set of cells showed good predictive performance of all three approaches but that accounting for the temporal dynamics via LSTMs or tsfresh led to significantly improved performance. The predictions made by the LSTM and tsfresh applications were not significantly different. The results highlight the benefit of accounting for temporal dynamics when studying drug delivery using high content imaging.
Insights into calcium signaling and gene expression in astrocytes uncovered with 129S4 Slc1a3-2A-CreERT2 knock-in mice
Authors: Kaczmarczyk Lech , Reichenbach Nicole , Blank Nelli , Jonson Maria , Dittrich Lars , Petzold Gabor C. , Jackson Walker
Published: April 2020

Abstract

Genetic variation is a primary determinant of phenotypic diversity within populations. In laboratory mice, genetic variation has often been regarded as a serious experimental confounder, and thus minimized through inbreeding. However, generalizations of results obtained with inbred strains need to be made with caution. Effects of genetic background on traits need to be controlled, especially when working with complex phenotypes and disease models. Here we compared behavioral parameters of C57Bl/6 – the mouse strain most widely used for biomedical research - with those of 129S4. Our data demonstrate high within-strain and intra-litter behavioral hyperactivity in C57Bl/6. In contrast, 129S4 had relatively consistent activity levels throughout life. This consistency would be advantageous for studying neurodegeneration and aging, when mice need to be analyzed for long periods. However, the majority of mouse models and transgenic tools are on a C57Bl/6 background. We recently established six popular Cre driver lines and two Cre effector lines in 129S4. To augment this collection, we genetically engineered a Cre mouse line to study astrocytes directly in 129S4, which we describe here. For functional validation, it was crossed with two Cre effector lines, each in a different genomic locus, and showed in both cases that it was functional and astrocyte-specific. Calcium currents studied with gCaMP5g-tdTomato were more heterogenous, lasted longer and had a higher amplitude in cortical compared to hippocampal astrocytes. Translatomes studied with RiboTag revealed that some genes thought to mark neurons are also expressed in astrocytes, that genes linked to a single neurodegenerative disease have highly divergent expression patterns, and that ribosome proteins are non-uniformly expressed across brain regions and cell types.
Larger active site in an ancestral hydroxynitrile lyase increases catalytically promiscuous esterase activity
Authors: Jones Bryan J. , Evans Robert L. , Mylrea Nathan J. , Chaudhury Debayan , Luo Christine , Guan Bo , Pierce Colin T. , Gordon Wendy R. , Wilmot Carrie M. , Kazlauskas Romas J.
Published: April 2020

Hydroxynitrile lyases (HNL’s) belonging to the α/β-hydrolase-fold superfamily evolved from esterases approximately 100 million years ago. Reconstruction of an ancestral hydroxynitrile lyase in the α/β-hydrolase fold superfamily yielded a catalytically active hydroxynitrile lyase, HNL1. Several properties of HNL1 differ from the modern HNL from rubber tree (HbHNL). HNL1 favors larger substrates as compared toHbHNL, is two-fold more catalytically promiscuous for ester hydrolysis (p-nitrophenyl acetate) as compared to mandelonitrile cleavage, and resists irreversible heat inactivation to 35 °C higher than forHbHNL. We hypothesized that the x-ray crystal structure of HNL1 may reveal the molecular basis for the differences in these properties. The x-ray crystal structure solved to 1.96-Å resolution shows the expected α/β-hydrolase fold, but a 60% larger active site as compared toHbHNL. This larger active site echoes its evolution from esterases since related esterase SABP2 from tobacco also has a 38% larger active site thanHbHNL. The larger active site in HNL1 likely accounts for its ability to accept larger hydroxynitrile substrates. Site-directed mutagenesis ofHbHNL to expand the active site increased its promiscuous esterase activity 50-fold, consistent with the larger active site in HNL1 being the primary cause of its promiscuous esterase activity. Urea-induced unfolding of HNL1 indicates that it unfolds less completely thanHbHNL (m-value = 0.63 for HNL1 vs 0.93 kcal/ mol·M forHbHNL), which may account for the ability of HNL1 to better resist irreversible inactivation upon heating. The structure of HNL1 shows changes in hydrogen bond networks that may stabilize regions of the folded structure.
Mitochondrial Aurora kinase A induces mitophagy by interacting with MAP1LC3 and Prohibitin 2
Authors: Bertolin Giulia , Alves-Guerra Marie-Clotilde , Cheron Angélique , Burel Agnès , Prigent Claude , Borgne Roland Le , Tramier Marc
Published: April 2020

Epithelial and haematologic tumours often show the overexpression of the serine/threonine kinase AURKA. Recently, AURKA was shown to localise at mitochondria, where it regulates mitochondrial dynamics and ATP production. Here we define the molecular mechanisms of AURKA in regulating mitochondrial turnover by mitophagy. When overexpressed, AURKA induces the disappearance of Outer Mitochondrial Membrane proteins by the proteasome. Then, AURKA triggers the degradation of Inner Mitochondrial Membrane (IMM)/matrix proteins by interacting with core components of the autophagy pathway. On the IMM, the kinase forms a tripartite complex with MAP1LC3 and the mitophagy receptor PHB2. This complex is necessary to trigger mitophagy in a PARK2/Parkin-independent manner. The formation of the tripartite complex is induced by the phosphorylation of PHB2 on Ser39, which is required for MAP1LC3 to interact with PHB2. Last, treatment with the PHB2 ligand Xanthohumol blocks AURKA-induced mitophagy by destabilising the tripartite complex. This treatment also restores normal ATP production levels. Altogether, these data provide evidence for a previously undetected role of AURKA in promoting mitophagy through the interaction with PHB2 and MAP1LC3. This work paves the way to the use of function-specific pharmacological inhibitors to counteract the effects of the overexpression of AURKA in cancer.
Broad geographical and ecological diversity from similar genomic toolkits in the ascomycete genusTetracladium
Authors: Anderson Jennifer L. , Marvanová Ludmila
Published: April 2020

The ascomycete genusTetracladiumis best known for containing aquatic hyphomycetes, which are important decomposers in stream food webs. However, some species ofTetracladiumare thought to be multifunctional and are also endobionts in plants. Suprisingly,Tetracladiumsequences are increasingly being reported from metagenomics and metabarcoding studies of both plants and soils world-wide. It is not clear how these sequences are related to the described species and little is known about the non-aquatic biology of these fungi. Here, the genomes of 24Tetracladiumstrains, including all described species, were sequenced and used to resolve relationships among taxa and to improve our understanding of ecological and genomic diversity in this group. All genome-sequencedTetracladiumfungi form a monophyletic group. Conspecific strains ofT. furcatumfrom both aquatic saprotrophic and endobiont lifestyles and a putative cold-adapted clade are identified. Analysis of ITS sequences from water, soil, and plants from around the world reveals that multifunctionality may be widespread through the genus. Further, frequent reports of these fungi from extreme environments suggest they may have important but unknown roles in those ecosystems. Patterns of predicted carbohydrate active enzymes (CAZyme) and secondary metabolites in theTetracladiumgenomes are more similar to each other than to other ascomycetes, regardless of ecology, suggesting a strong role for phylogeny shaping genome content in the genus.Tetracladiumgenomes are enriched for pectate lyase domains (including PL3-2), GH71α-1,3-glucanase domains and CBM24α-1,3-glucan/mutan binding modules, and both GH32 and CBM38, inulinase and inulin binding modules. These results indicate that these fungi are well-suited to digesting pectate and pectin in leaves when living as aquatic hyphomycetes, and inulin when living as root endobionts. Enrichment forα-1,3-glucanase domains may be associated with interactions with biofilm forming microorganisms in root and submerged leaf environments.
Distance-based metrics for comparing conformational ensembles of intrinsically disordered proteins
Authors: Lazar Tamas , Guharoy Mainak , Vranken Wim , Rauscher Sarah , Wodak Shoshana J. , Tompa Peter
Published: April 2020

Intrinsically disordered proteins (IDPs) are proteins whose native functional states represent ensembles of highly diverse conformations. Such ensembles are a challenge for quantitative structure comparisons as their conformational diversity precludes optimal superimposition of the atomic coordinates, necessary for deriving common similarity measures such as the root-mean-square deviation (RMSD) of these coordinates. Here we introduce superimposition-free metrics, which are based on computing matrices of Cα-Cα distance distributions within ensembles and comparing these matrices between ensembles. Differences between two matrices yield information on the similarity between specific regions of the polypeptide, whereas the global structural similarity is captured by the ens_dRMS, defined as the root-mean-square difference between the medians of the Cα-Cαdistance distributions of two ensembles. Together, our metrics enable rigorous investigations of structure-function relationships in conformational ensembles of IDPs derived using experimental restraints or by molecular simulations, and for proteins containing both structured and disordered regions.

Statement of Significance

Important biological insight is obtained from comparing the high-resolution structures of proteins. Such comparisons commonly involve superimposing two protein structures and computing the residual root-mean-square deviation of the atomic positions. This approach cannot be applied to intrinsically disordered proteins (IDPs) because IDPs do not adopt well-defined 3D structures, rather, their native functional state is defined by ensembles of heterogeneous conformations that cannot be meaningfully superimposed. We report new measures that quantify the local and global similarity between different conformational ensembles by evaluating differences between the distributions of residue-residue distances and their statistical significance. Applying these measures to IDP ensembles and to a protein containing both structured and intrinsically disordered domains provides deeper insights into how structural features relate to function.
Testing the Effect of the Toba Volcanic Eruption on Population Sizes in Worldwide Mammal Species
Authors: Torosin Nicole S. , Raff Jennifer A. , Hayes M. Geoffrey
Published: April 2020

The volcanic eruption of Toba in northern Sumatra at 71 kyBP (±5 kyBP) emitted sulfur gas and deposited thick layers of dust throughout the surrounding region. It is thought to have had a significant and dramatic cooling impact on the paleoclimate worldwide. Ambrose [1] conjectured this to be the cause of the contemporaneous (50-100 kyBP) population bottleneck observed in humans. We hypothesize that a volcanic winter of sufficient magnitude to cause a population bottleneck in humans would similarly affect other mammals. To test this hypothesis, we estimated pairwise mismatch distributions using mtDNA control region sequences of 28 mammal species archived on NCBI to assess whether each species underwent a population bottleneck. For any species fitting the sudden expansion model, we estimated the timing of the bottleneck and compared it to the date range of the Toba eruption. Only 3 of the 28 species show evidence of rapid population expansion overlapping in time with the Toba eruption. Therefore, the hypothesis that the volcanic winter triggered by the Toba eruption caused a significant bottleneck impacting mammal species worldwide is not supported by mitochondrial evidence. Our results question the hypothesis that the Toba eruption contributed to the bottleneck observed in humans at this time.
A Non-Destructive Method for Quantifying Tissue Vascularity Using Quantitative Deep Learning Image Processing
Authors: Veith Austin , Baker Aaron B.
Published: April 2020

The quantitative analysis of blood vessel networks is an important component in the understanding and analysis of vascular disease, ischemia, cancer and many other disease states. However, many imaging techniques used for imaging vascular networks are time consuming, prevent further analyses or are technically challenging. Here, we describe a nondestructive technique for imaging the vessels in harvested tissue samples that relatively rapid and effective visualization ofin situvasculature. Furthermore, this technique allows for further analysis of the sample using histochemical staining, immunostaining and other techniques that can be performed on fixed tissue. The method uses ex vivo permeation of the tissue with an iodine solution and micro CT imaging to visualize the vascular network. Using a deep learning algorithm, we trained a convolutional neural network to automatically segment blood vessels from the surrounding tissue for analysis and create a map of the vasculature. While this method cannot achieve the resolution obtainable through destructive techniques, it is a simple and quick method for visualizing and quantifying vascular networks in three dimensions prior to analysis with conventional histological techniques. The global visualization of the three-dimensional vascular network provided by this method gives additional insights into complex changes in the vascular structure and can guide further histological analyses to specific regions of the vascular network. Overall, this method is a simple technique that can be added to most conventional tissue analyses to enhance the quantification and information derived from animal models with vascular network remodeling.
Phylotranscriptomics of the Pentapetalae Reveals Frequent Regulatory Variation in Plant Local Responses to the Fungal Pathogen Sclerotinia sclerotiorum
Authors: Sucher Justine , Mbengue Malick , Dresen Axel , Barascud Marielle , Didelon Marie , Barbacci Adelin , Raffaele Sylvain
Published: April 2020

Quantitative disease resistance (QDR) is a conserved form of plant immunity that limits infections caused by a broad range of pathogens. QDR has a complex genetic determinism. The extent to which molecular components of the QDR response vary across plant species remains elusive. The fungal pathogen Sclerotinia sclerotiorum, causal agent of white mold diseases on hundreds of plant species, triggers QDR in host populations. To document the diversity of local responses to S. sclerotiorum at the molecular level, we analyzed the complete transcriptomes of six species spanning the Pentapetalae (Phaseolus vulgaris, Ricinus communis, Arabidopsis [Arabidopsis thaliana], Helianthus annuus, Solanum lycopersicum, and Beta vulgaris) inoculated with the same strain of S. sclerotiorum. About one-third of plant transcriptomes responded locally to S. sclerotiorum, including a high proportion of broadly conserved genes showing frequent regulatory divergence at the interspecific level. Evolutionary inferences suggested a trend toward the acquisition of gene induction relatively recently in several lineages. Focusing on a group of ABCG transporters, we propose that exaptation by regulatory divergence contributed to the evolution of QDR. This evolutionary scenario has implications for understanding the QDR spectrum and durability. Our work provides resources for functional studies of gene regulation and QDR molecular mechanisms across the Pentapetalae.
2,2,3,3,4,4,5,5-Octafluorohexane-1,6-diol
Authors: Feightner Kylie , Powell Douglas R. , Burba Christopher M.
Published: April 2020

In the crystal of the title compound, C6H6F8O4, O—H...O hydrogen bonds involving the hydroxy groups connect the molecules, forming a two-dimensional network parallel to (100). These hydrogen-bonding interactions appear to drive the O—C—C—O torsion angles into a gauche–trans–trans series of conformations along the backbone of the molecule.
Diaquatetrakis(μ-3-methoxybenzoato-κ2
O
1:O
1′)dicopper(II)
Authors: Srinivasan Bikshandarkoil R. , Bhargao Pooja H. , Sudhadevi P. K.
Published: April 2020

The asymmetric unit of the binuclear title compound, [Cu2(C8H7O3)4(H2O)2], comprises two halves of diaquatetrakis(μ-3-methoxybenzoato-κ2
O
1:O
1′)dicopper(II) units. The paddle-wheel structure of each complex is completed by application of inversion symmetry, with the inversion centre situated at the midpoint between two CuII atoms in each dimer. The two CuII atoms of each centrosymmetric dimer are bridged by four 3-methoxybenzoate anions resulting in Cu...Cu separations of 2.5961 (11) and 2.6060 (12) Å, respectively. The square-pyramidal coordination sphere of each CuII atom is completed by an apical water molecule. Intermolecular O—H...O hydrogen bonds of weak nature link the complexes into layers parallel to (100). The three-dimensional network structure is accomplished by C—H...O hydrogen bonds interlinking adjacent layers.
Poly[[μ4-3,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b:6′,7′-e]pyrazine]di-μ-iodido-dicopper(I)]: a two-dimensional copper(I) coordination polymer
Authors: Assoumatine Tokouré , Stoeckli-Evans Helen
Published: April 2020

The reaction of ligand 3,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b:6′,7′-e]pyrazine (L) with CuI led to the formation of a two-dimensional coordination polymer, incorporating a [Cu2I2] motif. These units are linked via the four S atoms of the ligand to form the title two-dimensional coordination polymer, poly[[μ4-3,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b:6′,7′-e]pyrazine]di-μ-iodido-dicopper(I)], [Cu2I2(C12H16N2S4)]
n
, (I). The asymmetric unit is composed of a ligand molecule, two copper(I) atoms and two I− ions. Both copper(I) atoms are fourfold S2I2 coordinate with almost regular trigonal-pyramidal environments. In the crystal, the layers, lying parallel to (102), are linked by C—H...I hydrogen bonds, forming a supramolecular framework.
Institutional Contradictions of the French state as Shareholder
Authors: Girard Carine , Gates Stephen
Published: April 2020

Purpose

This paper aims to demonstrate that state shareholders are confronted with contradictory logics leading to institutional contradictions that activist shareholders can exploit. The competing logics of the state as shareholder and their impact on corporate governance and shareholder activism offer fertile grounds for research advances in Coordinated Market Economies (CMEs).

Design/methodology/approach

Through an extensive literature review of state ownership, institutional contradictions and shareholder activism, this paper analyzes two case studies involving the French State as shareholder.

Findings

In the French context, these two cases illustrate how institutional contradictions result in opportunities for shareholder activism. By focusing on the institutional contradictions of the state shareholder, this investigation suggests a need for experimental research to observe how shareholder activists adapt to each institutional change in CMEs. This experimentation can help policymakers to avoid creating additional conditions that shareholder activists can exploit.

Research limitations/implications

This focuses only on France and its state shareholdings. To generalize results, studies of other CMEs and state shareholders are needed.

Practical implications

Policymakers should consider all legislative proposals for their potential to deviate from corporate governance practice by experimenting with them in a laboratory setting. Shareholder activists can compare state shareholders’ actions against the state’s legislation to emphasize institutional contradictions that counter minority shareholders’ rights.

Originality/value

This research is the first to analyze how the state as shareholder can exploit its competing logics to resist against shareholder activism and support management or to become itself a shareholder activist.
A fuzzy approach to identify fish red spot disease
Authors: Bhoi Sourav Kumar , Panda Sanjaya Kumar , Jena Kalyan Kumar , Mallick Chittaranjan , Khan Akhtar
Published: April 2020

Purpose

Fish are considered as one of the important aquatic animals in the planet. They play a vital role in the nutrient cycle. They can be considered as one of the healthy food for human beings. They can also act as a solution for some of the human health problems. If fish are affected by several diseases, they in turn provide an adverse effect on human health. Therefore, it is very much essential to protect fish from being affected by any diseases.

Design/methodology/approach

This paper is mainly focused on the identification of the red spot diseased area in fish. In this work, a fuzzy rule based method (FRBAM) and triangular membership function (TMFN) is used to identify the red spot disease (RSD) in the fish by analyzing several red spot diseased fish (RSDF) images. The canny edge detector is used for intermediate processing of RSDF images.

Findings

The proposed method is able to identify the red pixels over the fish by marking the affected area with red color by using a standard RGB model.

Originality/value

The proposed method follows FRBAM and TMFN in order to detect the RSD and canny edge detector for processing of RSDF images. Finally, it is tested using ten different image sizes and the results show its better performance in terms of detection of RSD affected regions of fish and execution time.
Street-level collaboration: perception, power, and politics on the frontlines of collaboration
Authors: Jagannath Harish P.
Published: April 2020

Purpose

To examine the implementation processes and outcomes of collaborative governance initiatives through the lens of bureaucratic politics.

Design/methodology/approach

An in-depth single case study research design with 28 embedded cases to study the implementation of a collaborative governance initiative. This paper uses the analytical technique of process tracing to explicate necessary and sufficient conditions to uncover causal mechanisms and confirm descriptive and causal inferences.

Findings

This study finds that when street-level bureaucrats perceived the collaborative initiative as a health intervention (and not as a collaborative initiative), it resulted in low levels of stakeholder participation and made the collaborative initiative unsuccessful. This paper finds that bureaucratic politics is the causal mechanism that further legitimized this perception resulting in each stakeholder group avoiding participation and sticking to their departmental siloes.

Research limitations/implications

This is a single case study about a revelatory case of collaborative governance implementation in India, and findings are analytically generalizable to similar administrative contexts. Further research is needed through a multiple case study design in a comparative context to examine bureaucratic politics in implementing collaborative initiatives.

Practical implications

Policymakers and managers need to carefully consider the implications of engaging organizations with competing institutional histories when formulating and implementing collaborative governance initiatives.

Originality/value

This study's uniqueness is that it examines implementation of collaborative governance through a bureaucratic politics lens. Specifically, the study applies Western-centric scholarship on collaborative governance and street-level bureaucracy to a non-Western developing country context to push the theoretical and empirical boundaries of key concepts in public administration.
The mediating role of board size, philanthropy and working capital management between basic corporate governance factors and firm's performance
Authors: Shahid Muhammad Naeem , Abbas Aamir , Latif Khalid , Attique Ayesha , Khalid Safwan
Published: April 2020

Purpose

This study aims to identify the impact of corporate governance on performance of sugar mills. In order to study this relation, a model is constructed in which ownership structure and independent directors are taken as independent variables. Whereas firm performance is analyzed by using proxy variables such as return on asset (ROA), return on equity (ROE) and sales growth. Moreover, size of board, working capital management (WCM) and philanthropy are taken as mediating variables between governance variables and firm performance.

Design/methodology/approach

The data of 32 sugar mills listed at Pakistan Stock Exchange for the period of four years (i.e. 2014–2017) is used for this research. Moreover, to investigate the model, generalized least squares statistical method is used to measure the relationship between variables.

Findings

The results revealed that there is significant but positive relationship between independent directors and ROA while ownership structure and ROE have significant but negative relationship. Thus, the board of directors should make it sure that all stakeholders and organizations should increase the nonfamily ownership in firms for better corporate performance. Moreover, philanthropy and WCM mediate the relationship between corporate governance and firms' performance.

Practical/implications

This research work will be helpful in the corporate governance, and further researchers can conduct their study by considering executive/nonexecutive director and institutional owners as governance variables.

Originality/value

This paper fulfills an identified need to study how Corporate Governance effect the performance of firm.
Art to enhance consumer engagement in the luxury fashion domain
Authors: Grassi Alessia
Published: April 2020

Purpose

This paper explores an opportunity for luxury fashion brands to strengthen their engagement with consumers through the arts and without undermining the exclusivity of the luxury product.

Design/methodology/approach

This paper is based on an interpretive qualitative approach aiming to specifically investigate Fondazione Prada – a contemporary art gallery owned and managed by the fashion brand Prada. Data were collected through semi-structured interviews and a focus group implemented with the “mystery shopper” technique. Template analysis was used to analyse the data.

Findings

Fondazione Prada has the potential for a deep engagement, but specific lack of dialogue and interaction needs to be addressed. Learning from and sharing values with the public through a two-way peer conversation elicited by contemporary art will benefit both the foundation and the fashion brand, in generating value as the result of a spillover effect. Thus, a significant competitive advantage might be gained.

Originality/value

This paper extends work on consumer brand engagement in physical and non-commercial “brand's places”, by evaluating the engagement provided by contemporary art foundations owned by luxury fashion brands. By leveraging the engaging nature of contemporary art, luxury fashion brands could provide an inclusive and engaging experience without undermining the characteristic of exclusivity of the luxury product and hence, gain a significant competitive advantage for the brand.
Halal six sigma framework for defects reduction
Authors: Vanany Iwan , Hua Tan Kim , Siswanto Nurhadi , Arvitrida Niniet Indah , Pahlawan Firman Mega
Published: April 2020

Purpose

In recent years, halal food industries are facing a high level of competition. The growing demand for halal food means firms are working hard to improve quality and reduce halal food defects. The purpose of this study is to propose a halal-based six sigma (SS) framework that could be used to reduce halal food defects and improve compliance.

Design/methodology/approach

The proposed halal six sigma (HSS) framework has five phases based on the define-measure-analyse-improve-control (DMAIC) approach. The proposed framework also integrates halal assurance system requirements into HSS to ensure compliance. Tools used in the proposed model include SIPOC tools, Pareto diagram, root cause analysis and the improvement process flows. A case study in a chicken meat company is used to test and validate the proposed framework. In case of study research, brainstorming was used to review an initial proposed framework and focus group discussions were used to determine feasible improvement actions.

Findings

The results showed that the proposed HSS framework could be effective to detect and reduce the halal defects and lower the halal defect costs. By adopting the framework, the case firm was able to lower halal defect costs significantly and increase the SS level.

Practical implications

SS approach can be designed and adapted to specific food industry. HSS framework could provide a systematic approach to reduce halal food defects and sustain the improvement efforts. The proposed HSS framework is also easy to use to understand halal critical points and improve halal compliance.

Originality/value

This study proposed a HSS framework that can be adopted to reduce halal food defects and costs. This proposed framework will benefit the halal food industry intending to realize zero halal food defects and lower production costs. The limited number of publications in the research theme of halal food defects show that there is a significant gap in the existing body of knowledge.
Legitimizing black businesses: three examples from the Civil War to civil rights
Authors: Hollingsworth Keith
Published: April 2020

Purpose

In “Reinventing Entrepreneurial History,” Wadhwani and Lubinski (2017) encourage the study of legitimacy, the sense that a new organization or venture “belongs” to, or fits within, the social construct of its time.

Design/methodology/approach

To this end, this query will consider methods used in the period between the Civil War and the Civil Rights Movement to show legitimacy in black economic endeavors. Three Atlanta entrepreneurs’ efforts will be used as demonstrative examples.

Findings

The overarching aim of this investigation of economic legitimization is to give practical examples of three distinct strategies in play: endorsement, authorization and storytelling. In addition, a fourth external actor, social organizations, that exists outside of the realms of media, government and law as noted by Bitektine and Haack (2015) is illustrated to grant validity within the black community. Also, the storytelling strategy is used to illustrate promoters, actors pushing legitimacy to benefit the community at large.

Originality/value

Arguably the search for economic and collective legitimacy within black businesses is not confined to the past. Stated in another way, black businesses still fight for legitimacy, and future research should be undertaken to show the similarities and differences in the two aforementioned periods.
An artificial-intelligence-based method for assessing service quality: insights from the prosthodontics sector
Authors: Martins Sara M. , Ferreira Fernando A.F. , Ferreira João J. M. , Marques Carla S.E.
Published: April 2020

Purpose

The prosthodontics sector is facing major challenges because of scientific and technological advances that imply a clearer definition of lines of action and decision making processes. Measuring quality of service in this sector is a complex decision problem since the perceptions of three main players need to be considered: patients, dentists and dental technicians. This study sought to develop an artificial-intelligence-based (AI-based) method for assessing service quality in the dental prosthesis sector.

Design/methodology/approach

Using strategic options development and analysis (SODA), which is grounded on cognitive mapping, and the measuring attractiveness by a categorical based evaluation technique (MACBETH), a constructivist decision support system was designed to facilitate the assessment of service quality in the dental prosthesis sector. The system was tested, and the results were validated both by the members of an expert panel and by the vice-president of the Portuguese association of dental prosthesis technicians.

Findings

The methodological process developed in this study is extremely versatile and its practical application facilitated the development of an empirically robust evaluation model in this study context. Specifically, the profile analyses carried out in actual clinics allowed the cases in which improvements are needed to be identified.

Originality/value

Although already applied in the fields of AI and decision making, no prior work reporting the use of SODA and MACBETH for assessing service quality in the prosthodontics sector has been found.
Brand hate: a multidimensional construct
Authors: Zhang Chun , Laroche Michel
Published: April 2020

Purpose

This study aims to examine the emotional components of brand hate and the variation of emotions across different levels of brand hate.

Design/methodology/approach

Study 1 uses in-depth interviews and data triangulation. Studies 2-5 make use of quantitative methods to test and validate the multidimensional structure of brand hate and the variation of its composing emotions.

Findings

Study 1 suggests that brand hate is a multidimensional construct comprised of anger-, sadness- and fear-related emotions; possible antecedents and consequences are discussed. The quantitative results from Studies 2-5 confirm the findings in Study 1. A three-factor scale consisting of nine items is developed. The proposed model is tested among different samples and is compared with the currently available brand hate models. In addition, the findings show that emotions weigh differently for different brand hate levels.

Research limitations/implications

This study contributes to the brand hate literature and provides a structure to understand brand hate more thoroughly.

Practical implications

Companies can benefit from the research through a better knowledge of brand hate. Managers can use the multidimensional measurement to detect brand hate and better cope with it.

Originality/value

This study is among the first few attempts to examine the multidimensionality of brand hate and to investigate the variation of emotions in different brand hate levels. This study contributes to a more precise description of the brand hate construct and improves understanding of consumer-brand relationships.
Evaluation of a participatory approach to improve healthy eating and physical activity in a secure mental health setting
Authors: Mateo-Urdiales Alberto , Michael Margaret , Simpson Charlotte , Beenstock Jane
Published: April 2020

Purpose

The prevalence of obesity in secure mental health units is higher than in the general population, having a negative impact on the physical health and mental well-being of people with severe mental health illness (SMI). The purpose of this study was to describe the feasibility of a programme aimed to help people with SMI to eat healthily and be physically active.

Design/methodology/approach

A mixed-methods approach was used. A questionnaire administered to patients in both wards measured acceptability, demand, implementation and practicality of the project. Individual semi-structured interviews and focus groups were used to explore staff and patients’ perceptions of the project; as well as the barriers and enablers towards an effective implementation and participation in the project’s activities.

Findings

Patients were, overall, satisfied with the activities implemented. Successful activities were easy to implement, had staff actively engaged and did not require logistic or administrative planning beforehand. Barriers included unawareness around funding mechanisms of activities, staff capacity issues or lack of patients’ permission to leave the ward.

Originality/value

Few studies have assessed the feasibility of real-life interventions aimed to improve healthy eating and physical activity in secure mental health units. The results of this study can inform commissioners and providers of mental health services to design and implement new interventions and programmes.