bluuebunny/crossref_metadata_2025 huggingface dataset:
The tumor microenvironment drives transcriptional phenotypes and their plasticity in metastatic pancreatic cancer
Authors: Raghavan Srivatsan , Winter Peter S. , Navia Andrew W. , Williams Hannah L. , DenAdel Alan , Kalekar Radha L. , Galvez-Reyes Jennyfer , Lowder Kristen E. , Mulugeta Nolawit , Raghavan Manisha S. , Borah Ashir A. , Kapner Kevin S. , Väyrynen Sara A. , Costa Andressa Dias , Ng Raymond W.S. , Wang Junning , Reilly Emma , Ragon Dorisanne Y. , Brais Lauren K. , Jaeger Alex M. , Spurr Liam F. , Li Yvonne Y. , Cherniack Andrew D. , Wakiro Isaac , Rotem Asaf , Johnson Bruce E. , McFarland James M. , Sicinska Ewa T. , Jacks Tyler E. , Clancy Thomas E. , Perez Kimberly , Rubinson Douglas A. , Ng Kimmie , Cleary James M. , Crawford Lorin , Manalis Scott R. , Nowak Jonathan A. , Wolpin Brian M. , Hahn William C. , Aguirre Andrew J. , Shalek Alex K.
Published: August 2020

Bulk transcriptomic studies have defined classical and basal-like gene expression subtypes in pancreatic ductal adenocarcinoma (PDAC) that correlate with survival and response to chemotherapy; however, the underlying mechanisms that govern these subtypes and their heterogeneity remain elusive. Here, we performed single-cell RNA-sequencing of 23 metastatic PDAC needle biopsies and matched organoid models to understand how tumor cell-intrinsic features and extrinsic factors in the tumor microenvironment (TME) shape PDAC cancer cell phenotypes. We identify a novel cancer cell state that co-expresses basal-like and classical signatures, demonstrates upregulation of developmental and KRAS-driven gene expression programs, and represents a transitional intermediate between the basal-like and classical poles. Further, we observe structure to the metastatic TME supporting a model whereby reciprocal intercellular signaling shapes the local microenvironment and influences cancer cell transcriptional subtypes. In organoid culture, we find that transcriptional phenotypes are plastic and strongly skew toward the classical expression state, irrespective of genotype. Moreover, we show that patient-relevant transcriptional heterogeneity can be rescued by supplementing organoid media with factors found in the TME in a subtype-specific manner. Collectively, our study demonstrates that distinct microenvironmental signals are critical regulators of clinically relevant PDAC transcriptional states and their plasticity, identifies the necessity for considering the TME in cancer modeling efforts, and provides a generalizable approach for delineating the cell-intrinsic versus -extrinsic factors that govern tumor cell phenotypes.
In Vitro Inactivation of Human Coronavirus by Titania Nanoparticle Coatings and UVC Radiation: Throwing Light on SARS-CoV-2
Authors: Khaiboullina Svetlana , Uppal Timsy , Dhabarde Nikhil , Subramanian Vaidyanathan Ravi , Verma Subhash C.
Published: August 2020

The newly identified pathogenic human coronavirus, SARS-CoV-2, led to an atypical pneumonia-like severe acute respiratory syndrome (SARS) outbreak calledcoronavirusdisease 2019 (COVID-19). Currently, nearly 23 million cases have been confirmed worldwide with the highest COVID-19 cases been confirmed in the United States. As there is no vaccine or any effective interventions, massive efforts to create a postential vaccine to combat COVID-19 is underway. In the meantime, safety precautions and effective disease control strategies appear to be vital for preventing the virus spread in the public places. Due to the longevity of the virus on smooth surfaces, photocatalytic properties of self-disinfecting/cleaning surfaces appear to be a promising tool to help guide disinfection policies to control infectious SAR-CoV-2 spread in high-traffic areas such as hospitals, grocery stores, airports, schools, and stadiums. Here, we explored the photocatalytic properties of nanosized TiO2(TNPs) as induced by the UV radiation, towards virus deactivation. Our preliminary results using close genetic relative of SAR-CoV-2, HCoV-NL63, showed the virucidal efficacy of photoactive TNPs deposited on glass coverslips, as examined by quantitative RT-PCR and virus culture assays. Efforts to extrapolate the underlying concepts described in this study to SARS-CoV-2 are currently underway.
Phenotype prediction from genome-wide genotyping data: a crowdsourcing experiment
Authors: Naret Olivier , Baranger David AA , Mohanty Sharada Prasanna , Tzovaras Bastian Greshake , Salathé Marcel , Fellay Jacques ,   with the openSNP and crowdAI community
Published: August 2020

Background

The increasing statistical power of genome-wide association studies is fostering the development of precision medicine through genomic predictions of complex traits. Nevertheless, it has been shown that the results remain relatively modest. A reason might be the nature of the methods typically used to construct genomic predictions. Recent machine learning techniques have properties that could help to capture the architecture of complex traits better and improve genomic prediction accuracy.

Methods

We relied on crowd-sourcing to efficiently compare multiple genomic prediction methods. This represents an innovative approach in the genomic field because of the privacy concerns linked to human genetic data. There are two crowd-sourcing elements building our study. First, we constructed a dataset from openSNP (opensnp.org), an open repository where people voluntarily share their genotyping data and phenotypic information in an effort to participate in open science. To leverage this resource we release the ‘openSNP Cohort Maker’, a tool that builds a homogeneous and up-to-date cohort based on the data available on opensnp.org. Second, we organized an open online challenge on the CrowdAI platform (crowdai.org) aiming at predicting height from genome-wide genotyping data.

Results

The ‘openSNP Height Prediction’ challenge lasted for three months. A total of 138 challengers contributed to 1275 submissions. The winner computed a polygenic risk score using the publicly available summary statistics of the GIANT study to achieve the best result (r2= 0.53 versusr2= 0.49 for the second-best).

Conclusion

We report here the first crowd-sourced challenge on publicly available genome-wide genotyping data. We also deliver the ‘openSNP Cohort Maker’ that will allow people to make use of the data available on opensnp.org.
Predicting drug sensitivity of cancer cells based on DNA methylation levels
Authors: Miranda Sofia P. , Baião Fernanda A. , Maçaira Paula M. , Fleck Julia L. , Piccolo Stephen R.
Published: August 2020

Cancer cell lines, which are cell cultures developed from tumor samples, represent one of the least expensive and most studied preclinical models for drug development. Accurately predicting drug response for a given cell line based on molecular features may help to optimize drug-development pipelines and explain mechanisms behind treatment responses. In this study, we focus on DNA methylation profiles as one type of molecular feature that is known to drive tumorigenesis and modulate treatment responses. Using genome-wide, DNA methylation profiles from 987 cell lines from the Genomics of Drug Sensitivity in Cancer database, we applied machine-learning algorithms to evaluate the potential to predict cytotoxic responses for eight anti-cancer drugs. We compared the performance of five classification algorithms and four regression algorithms that use diverse methodologies, including tree-, probability-, kernel-, ensemble-, and distance-based approaches. For both types of algorithm, we artificially subsampled the data to varying degrees, aiming to understand whether training models based on relatively extreme outcomes would yield improved performance. We also performed an information-gain analysis to examine which genes were most predictive of drug responses. Finally, we used tumor data from The Cancer Genome Atlas to evaluate the feasibility of predicting clinical responses in humans based on models derived from cell lines. When using classification or regression algorithms to predict discrete or continuous responses, respectively, we consistently observed excellent predictive performance when the training and test sets both consisted of cell-line data. However, classification models derived from cell-line data failed to generalize effectively for tumors.
Comprehensive annotation and characterization of planarian tRNA and tRNA-derived fragments (tRFs)
Authors: Lakshmanan Vairavan , Bansal Dhiru , T N Sujith , Shivaprasad P.V. , Palakodeti Dasaradhi , Gopinath Srikar Krishna
Published: August 2020

tRNA-derived fragments (tRFs) have recently gained a lot of scientific interest due to their diverse regulatory roles in several cellular processes. However, their function in dynamic biological process such as development and regeneration remains unexplored. Here, we identify and characterise a role for tRFs in planarian regeneration. We first annotated 457 tRNA loci in S.mediterranea combining two tRNA prediction programs. Annotation of tRNAs facilitated the identification of three main species of tRFs in planarians; the shorter tRF-5s and itRFs, and the abundantly expressed 5-tsRNAs. Spatial profiling of tRFs in sequential transverse sections of planarians revealed diverse expression patterns of these small RNAs, including those that are enriched in the head and pharyngeal regions. Expression analysis of these tRF species revealed dynamic expression of these small RNAs over the course of regeneration suggesting an important role in planarian anterior and posterior regeneration. Finally, we show that 5-tsRNA in planaria interact with all three SMEDWI proteins while sequence analysis revealed a possible involvement of Dicers in the processing of itRFs. In summary, our findings implicate a novel role for tRFs in planarian regeneration, highlighting their importance in regulating complex systemic processes. Our study adds to the catalogue of post-transcriptional regulatory systems in planarian, providing valuable insights on the biogenesis and the function of tRFs in neoblasts and planarian regeneration.
Medial prefrontal activity at encoding determines enhanced recognition of threatening faces after 1.5 years
Authors: Liu Xiqin , Zhou Xinqi , Zeng Yixu , Li Jialin , Zhao Weihua , Xu Lei , Zheng Xiaoxiao , Fu Meina , Yao Shuxia , Cannistraci Carlo V. , Kendrick Keith M. , Becker Benjamin
Published: August 2020

Studies demonstrated that faces with threatening emotional expressions are better remembered than non-threatening faces. However, whether this memory advantage persists over years and which neural systems underlie such an effect remains unknown. Here, we investigated recognition of incidentally encoded faces with angry, fearful, happy, sad and neutral expressions over >1.5 years (N= 89). Univariate analyses showed that threatening faces (angry, fearful) were better recognized than happy and neutral faces after >1.5 years, and that the threat-related memory enhancement was driven by forgetting of non-threatening faces. Multivariate principal component analysis (PCA) confirmed the discriminative performance between threatening and non-threatening faces. With an innovative Behavioral Pattern Similarity Analysis (BPSA) approach and functional magnetic resonance imaging (fMRI) acquisition during encoding, we further found that the long-term memory advantage for threatening faces were underpinned by differential neural encoding in the left inferior occipital gyrus (IOG) and right ventromedial prefrontal/orbitofrontal cortex (vmPFC/OFC). Our study provides the first evidence that threatening facial expressions lead to persistent face recognition over periods of >1.5 years and differential encoding-related activity in the visual cortex and medial prefrontal cortex may underlie this effect.
piRNA-mediated gene regulation and adaptation to sex-specific transposon expression inD. melanogastermale germline
Authors: Chen Peiwei , Kotov Alexei A. , Godneeva Baira K. , Bazylev Sergei S. , Olenina Ludmila V. , Aravin Alexei A.
Published: August 2020

Small non-coding piRNAs act as sequence-specific guides to repress complementary targets in Metazoa. Prior studies inDrosophilaovaries have demonstrated the function of piRNA pathway in transposon silencing and therefore genome defense. However, the ability of piRNA program to respond to different transposon landscape and the role of piRNAs in regulating host gene expression remain poorly understood. Here, we comprehensively analyzed piRNA expression and defined the repertoire of their targets inDrosophila melanogastertestes. Comparison of piRNA programs between sexes revealed sexual dimorphism in piRNA programs that parallel sex-specific transposon expression. Using a novel bioinformatic pipeline, we identified new piRNA clusters and established complex satellites as dual-strand piRNA clusters. While sharing most piRNA clusters, two sexes employ them differentially to combat sex-specific transposon landscape. We found several host genes targeted by piRNAs in testis, includingCG12717/pita, a SUMO protease gene. piRNAs encoded on Y chromosome silencepita, but not its paralog, to exert sex- and paralog-specific gene regulation. Interestingly,pitais targeted by endogenous siRNAs in a sibling species,Drosophila mauritiana, suggesting distinct but related silencing strategies invented in recent evolution to regulate a conserved protein-encoding gene.
Decontextualized learning for interpretable hierarchical representations of visual patterns
Authors: Etheredge R. Ian , Schartl Manfred , Jordan Alex
Published: August 2020

Summary

Apart from discriminative models for classification and object detection tasks, the application of deep convolutional neural networks to basic research utilizing natural imaging data has been somewhat limited; particularly in cases where a set of interpretable features for downstream analysis is needed, a key requirement for many scientific investigations. We present an algorithm and training paradigm designed specifically to address this: decontextualized hierarchical representation learning (DHRL). By combining a generative model chaining procedure with a ladder network architecture and latent space regularization for inference, DHRL address the limitations of small datasets and encourages a disentangled set of hierarchically organized features. In addition to providing a tractable path for analyzing complex hierarchal patterns using variation inference, this approach is generative and can be directly combined with empirical and theoretical approaches. To highlight the extensibility and usefulness of DHRL, we demonstrate this method in application to a question from evolutionary biology.
Individual bitter-sensing neurons inDrosophilaexhibit both ON and OFF responses that influence synaptic plasticity
Authors: Devineni Anita V. , Deere Julia U. , Sun Bei , Axel Richard
Published: August 2020

The brain creates internal representations that translate sensory stimuli into appropriate behavior. Most studies of sensory processing focus on which subsets of neurons are activated by a stimulus, but the temporal features of the neural response are also important for behavior. In the taste system, the timing of peripheral sensory responses has rarely been examined. We investigated the temporal properties of taste responses inDrosophila melanogasterand discovered that different types of taste sensory neurons show striking differences in their response dynamics. Strong responses to stimulus onset (ON responses) and offset (OFF responses) were observed in bitter-sensing neurons in the labellum, whereas bitter neurons in the leg and other classes of labellar taste neurons showed only an ON response. Individual bitter labellar neurons generate both the ON and OFF responses through a cell-intrinsic mechanism that requires canonical bitter receptors. The bitter ON and OFF responses at the periphery are propagated to dopaminergic neurons that innervate the mushroom body and mediate aversive learning. When bitter is used as a reinforcement cue, the bitter ON and OFF responses can drive opposing types of synaptic plasticity and the effect of the OFF response dominates, likely due to the rapid and preferential habituation of the ON response. Together, these studies characterize novel features of neural responses in the taste system and reveal their importance for neural circuit function.
Transport Mechanism of Class-3 P4 ATPase Lipid Flippases
Authors: Bai Lin , You Qinglong , Jain Bhawik K. , Kovach Amanda , Graham Todd R. , Li Huilin
Published: August 2020

The P4 ATPases are a large family of membrane-embedded enzymes that use ATP hydrolysis to transport large lipid substrates across lipid bilayers. P4 ATPases differ in their cellular membrane location and their substrates. The structures of the endosome- and Golgi-localized class-1 phosphatidylserine flippases—such as the yeast Drs2 and human ATP8A1—have recently been reported, revealing a substrate binding site on the lumenal side and several transport states. However, a substrate binding site on the cytosolic side has not been found, and the transport mechanisms of P4 ATPases in other classes are still unknown. Here we report a systematic structural and functional study on two plasma-membrane localized, class-3 P4 ATPases that have broader substrate specificity, theS. cerevisiaeDnf1–Lem3 and Dnf2–Lem3 complexes. We have captured substrate lipids on both the exoplasmic and cytosolic sides, and we found that these two enzymes have very similar structures, consistent with their high sequence identity and redundant function. Unexpectedly, Lem3 contributes to substrate binding near the cytosolic surface. We found that the conformational transitions through the substrate transport cycle of these two class-3 enzymes match those of the class-1 enzymes, suggesting a conserved lipid-flipping mechanism among all classes of the P4 ATPases. Our study also revealed a helix-turn-helix insertion in the cytosolic P domain that is unique to the class-3 enzymes and plays a crucial role in their function. Therefore, the P4 ATPases may have retained an overall transport mechanism while evolving distinct features for cellular membrane localization, regulatory mechanisms, and transporting different lipid substrates.
Distributed Visual Category Processing Across Medial Superior Temporal and Lateral Intraparietal Cortices
Authors: Zhou Yang , Mohan Krithika , Freedman David J.
Published: August 2020

Categorization is an essential cognitive and perceptual process for recognition and decision making. The posterior parietal cortex (PPC), particularly the lateral intraparietal (LIP) area has been suggested to transform visual feature encoding into cognitive or abstract category representations. By contrast, areas closer to sensory input, such as the middle temporal (MT) area, encode stimulus features but not more abstract categorical information during categorization tasks. Here, we compare the contributions of PPC subregions in category computation by recording neuronal activity in the medial superior temporal (MST) and LIP areas during a categorization task. MST is a core motion processing area interconnected with MT, and often considered an intermediate processing stage between MT and LIP. Here we show that MST shows robust decision-correlated category encoding and working memory encoding similar to LIP, suggesting that MST plays a substantial role in cognitive computation, extending beyond its widely recognized role in visual motion processing.
Alcohol-induced Hsp90 acetylation is a novel driver of liver sinusoidal endothelial dysfunction and alcoholic liver disease
Authors: Yang Yilin , Sungwung Panjamaporn , Jung Yirang , Kondo Reiichiro , McConnell Matthew , Utsumi Teruo , Sessa William C. , Iwakiri Yasuko
Published: August 2020

Background

It is unknown whether liver sinusoidal endothelial cells (LSECs) metabolize alcohol. Chronic alcohol consumption decreases endothelial nitric oxide synthase (eNOS)-derived NO production typical of LSEC dysfunction. Heat shock protein 90 (Hsp90) interacts with eNOS to increase its activity. Cytochrome P450 2E1 (CYP2E1) is a key enzyme in alcohol metabolism and facilitates protein acetylation via acetyl-CoA, but its expression in LSECs is unknown. This study investigates alcohol metabolism by LSECs, the mechanism of alcohol-induced LSEC dysfunction and a potential therapeutic approach for alcohol-induced liver injury.

Methods

Primary human, rat and mouse LSECs were used. Histone deacetylase 6 (HDAC6) was overexpressed specifically in liver ECs using an adeno-associated virus (AAV)-mediated gene delivery system to decrease Hsp90 acetylation in ethanol fed mice.

Results

LSECs expressed CYP2E1 and alcohol dehydrogenase 1 (ADH1) and metabolized alcohol. Ethanol induced CYP2E1 in LSECs, but not ADH1. Alcohol metabolism by CYP2E1 increased Hsp90 acetylation and decreased its interaction with eNOS along with a decrease in NO production. A non-acetylation mutant of Hsp90 increased its interaction with eNOS and NO production, whereas a hyper-acetylation mutant decreased NO production, compared with wildtype Hsp90. These results indicate that Hsp90 acetylation is responsible for decreases in its interaction with eNOS and eNOS-derived NO production. Adeno-associated virus 8 (AAV8)-driven HDAC6 overexpression specifically in liver ECs deacetylated Hsp90, restored Hsp90’s interaction with eNOS and ameliorated alcohol-induced liver injury in mice.

Conclusion

Restoring LSEC function is important for ameliorating alcohol-induced liver injury. To this end, blocking acetylation of Hsp90 specifically in LSECs via AAV-mediated gene delivery has the potential to be a new therapeutic strategy.
Single nucleus analysis of Arabidopsis seeds reveals new cell types and imprinting dynamics
Authors: Picard Colette L. , Povilus Rebecca A. , Williams Ben P. , Gehring Mary
Published: August 2020

Seeds are the basis of agriculture, yet their full transcriptional complexity has remained unknown. Here, we employ single-nucleus RNA-sequencing to characterize developingArabidopsis thalianaseeds, with a focus on endosperm. Endosperm, the site of gene imprinting in plants, mediates the relationship between the maternal parent and embryo. We identify new cell types in the chalazal endosperm region, which interfaces with maternal tissue for nutrient unloading. We further demonstrate that the extent of parental bias of maternally expressed imprinted genes varies with cell cycle phase, and that imprinting of paternally expressed imprinted genes is strongest in chalazal endosperm. These data indicate imprinting in endosperm is heterogeneous and suggest that parental conflict, which is proposed to drive the evolution of imprinting, is fiercest at the boundary between filial and maternal tissues.
The Bromodomains of the mammalian SWI/SNF (mSWI/SNF) ATPases Brahma (BRM) and Brahma Related Gene 1 (BRG1) promote chromatin interaction and are critical for skeletal muscle differentiation
Authors: Sharma Tapan , Witwicka Hanna , Imbalzano Anthony N.
Published: August 2020

Skeletal muscle differentiation induces changes in the epigenome of myoblasts as they proceed towards a myogenic phenotype. mSWI/SNF chromatin remodeling enzymes coordinate with lineage-determining transcription factors and are key regulators of differentiation. Three mSWI/SNF proteins, the mutually exclusive ATPases, BRG1 and BRM, and the BAF180 protein (Polybromo1, PBRM1) contain bromodomains belonging to the same structural subfamily. Bromodomains bind to acetylated lysines on histone N-terminal tails and on other proteins. Pharmacological inhibition of mSWI/SNF bromodomain function using the selective inhibitor PFI-3 reduced differentiation, decreased expression of myogenic genes, and increased the expression of cell cycle-related genes, and the number of cells that remained in the cell cycle. Knockdown of BAF180 had no effect on differentiation, suggesting that only the BRG1 and BRM bromodomains contributed to differentiation. Comparison with existing gene expression data from myoblasts subjected to knockdown of BRG1 or BRM showed that bromodomain function was required for a subset of BRG1- and BRM-dependent gene expression. ChIP analysis revealed decreased BRG1 and BRM binding to target gene promoters, indicating that the BRG1 and BRM bromodomains promote chromatin binding. Thus mSWI/SNF ATPase bromodomains contribute to cell cycle exit, to skeletal muscle-specific gene expression, and to stable promoter binding by the mSWI/SNF ATPases.
Auxin Regulates Sucrose Transport to Repress Petal Abscission in Rose (Rosa hybrida)
Authors: Liang Yue , Jiang Chuyan , Liu Yang , Gao Yuerong , Lu Jingyun , Aiwaili Palinuer , Fei Zhangjun , Jiang Cai-Zhong , Hong Bo , Ma Chao , Gao Junping
Published: August 2020

Developmental transitions in plants require adequate carbon resources, and organ abscission often occurs due to competition for carbohydrates/assimilates. Physiological studies have indicated that organ abscission may be activated by Suc deprivation; however, an underlying regulatory mechanism that links Suc transport to organ shedding has yet to be identified. Here, we report that transport of Suc and the phytohormone auxin to petals through the phloem of the abscission zone (AZ) decreases during petal abscission in rose (Rosa hybrida), and that auxin regulates Suc transport into the petals. Expression of the Suc transporter RhSUC2 decreased in the AZ during rose petal abscission. Similarly, silencing of RhSUC2 reduced the Suc content in the petals and promotes petal abscission. We established that the auxin signaling protein RhARF7 binds to the promoter of RhSUC2, and that silencing of RhARF7 reduces petal Suc contents and promotes petal abscission. Overexpression of RhSUC2 in the petal AZ restored accelerated petal abscission caused by RhARF7 silencing. Moreover, treatment of rose petals with auxin and Suc delayed ethylene-induced abscission, whereas silencing of RhARF7 and RhSUC2 accelerated ethylene-induced petal abscission. Our results demonstrate that auxin modulates Suc transport during petal abscission, and that this process is regulated by a RhARF7-RhSUC2 module in the AZ.
Establishment of Proximity-Dependent Biotinylation Approaches in Different Plant Model Systems
Authors: Arora Deepanksha , Abel Nikolaj B. , Liu Chen , Van Damme Petra , Yperman Klaas , Eeckhout Dominique , Vu Lam Dai , Wang Jie , Tornkvist Anna , Impens Francis , Korbei Barbara , Van Leene Jelle , Goossens Alain , De Jaeger Geert , Ott Thomas , Moschou Panagiotis Nikolaou , Van Damme Daniël
Published: August 2020

Proximity labeling is a powerful approach for detecting protein-protein interactions. Most proximity labeling techniques use a promiscuous biotin ligase or a peroxidase fused to a protein of interest, enabling the covalent biotin labeling of proteins and subsequent capture and identification of interacting and neighboring proteins without the need for the protein complex to remain intact. To date, only a few studies have reported on the use of proximity labeling in plants. Here, we present the results of a systematic study applying a variety of biotin-based proximity labeling approaches in several plant systems using various conditions and bait proteins. We show that TurboID is the most promiscuous variant in several plant model systems and establish protocols that combine mass spectrometry-based analysis with harsh extraction and washing conditions. We demonstrate the applicability of TurboID in capturing membrane-associated protein interactomes using Lotus japonicus symbiotically active receptor kinases as a test case. We further benchmark the efficiency of various promiscuous biotin ligases in comparison with one-step affinity purification approaches. We identified both known and novel interactors of the endocytic TPLATE complex. We furthermore present a straightforward strategy to identify both nonbiotinylated and biotinylated peptides in a single experimental setup. Finally, we provide initial evidence that our approach has the potential to suggest structural information of protein complexes.
Study on micro-arc oxidation coating of magnetic metal powder composite magnesium alloy
Authors: Su Zhaowei , Mu Rui , Cui Yonghui , Zhu Hongda , Li Xuetian , Shao Zhongcai
Published: August 2020

Purpose

The purpose of this paper is to prepare composite micro-arc oxide coatings with better wear resistance and corrosion resistance.

Design/methodology/approach

A nickel powder composite micro-arc oxide film was prepared on the surface of the magnesium alloy by the method of organically combining ultra-fine Ni powder with micro arc oxidation film layer. In this experiment, the changes in the corrosion resistance and microstructure of the composite film layer after adding Ni powder were studied, and the effect of the addition of glycerin on the corrosion resistance of the film layer was analyzed.

Findings

The results show that the ultra-fine nickel powder was successfully prepared by the liquid phase reduction method, and the micro-arc oxidation process was modified under the optimal addition amount. The surface of the micro-arc oxide film made of ultra-fine nickel powder was found by SEM to have smooth surfaces and few holes. According to X-ray diffraction analysis, the phase composition of the micro-arc oxide film layer was Mg, Ni, NiSiO4, MgNi (SiO4) and Mg2SiO4. According to the results of electrochemical tests, the corrosion resistance of the micro-arc oxidation composite film layer was improved after the addition of ultra-fine Ni powder, the corrosion current was greatly reduced and the impedance has been improved. And after adding glycerin, the surface of the film layer becomes denser, and the corrosion resistance of the micro-arc oxide film is significantly improved.

Originality/value

Through this experimental research, a micro-arc oxide coating of powder composite magnesium alloy was successfully prepared. The corrosion resistance of the micro-arc oxidation film layer has been improved, and certain functions had been given to the micro-arc oxidation composite film, which has increased the application field of magnesium alloys.
Effect of managerial ownership on bank value: insights of an emerging economy
Authors: Moudud-Ul-Huq Syed , Biswas Tanmay , Proshad Dola Shukla
Published: August 2020

Purpose

This study aims to empirically investigate the effect of managerial ownership on bank value concerning conventional and Islamic bank. The analysis uses a balanced panel data set based on a sample consisting of 480 bank-year observations between 2003 and 2017.

Design/methodology/approach

Ordinary least squares, fixed effect and random effect have been used primarily to examine the relationship between managerial ownership and banks' value. Later, the authors validate the core results by using the generalized linear model.

Findings

This study provides general support for the claim of interest alignment that encourages bank standards with a high level of managerial ownership and partly opposes the view of the entrenchment effects.In addition, the study finds a U-shaped and insignificant relation between managerial ownership and bank value. This indicates that initially, managerial ownership is a blessing, and later, it becomes a curse in considering bank value. Moreover, bank value affects managerial ownership positively both for conventional and Islamic banks.

Originality/value

A good number of studies are available in the current literature, which examine the impact of managerial ownership on either bank performance or risk-taking. However, very few studies are found that examine the bidirectional relationship between managerial ownership and banks' value. Moreover, to the best of authors’ knowledge, there is a dearth of literature on this topic that is built on the comparative analysis between conventional and Islamic banks.
Sustainable architectural design: towards climate change mitigation
Authors: Sijakovic Milan , Peric Ana
Published: August 2020

Purpose

Excessive amounts of carbon dioxide (CO2) undoubtedly lead to climate change, which directly affects both the natural and the built environment. Observing the impact of climate change on the construction industry, this paper examines sustainable architectural design as a tool to mitigate climate change.

Design/methodology/approach

To achieve the previous goal, the authors conduct a comprehensive documentary analysis of three types of sources: (1) scholarly articles in the fields of climate research, sustainable construction, green buildings and sustainable architecture; (2) contemporary global reports on climate change and its impact on the built environment and (3) practitioners' guides explaining practical architectural solutions to the climate crisis.

Findings

The systematic analysis provides three types of results: objectives, strategies and principles of sustainable architectural design aimed at mitigating the effects of climate change. On the one hand, the research results provide a solid basis for further conceptual research into architectural design responsive to the effects of changing climate. On the other hand, the detailed strategies and principles are relevant for urban designers and architects.

Originality/value

Among a range of literature in the field of climate change and its effects on the built environment, a particular value of the paper is in addressing a very local level, i.e. the level of individual building and its immediate surroundings. More specifically, this paper provides concrete design components that help reduce CO2 emissions, finally decreasing the vulnerability index of urban systems.
Development of a conceptual life cycle performance measurement system for build–operate–transfer (BOT) projects
Authors: Okudan Ozan , Budayan Cenk , Dikmen Irem
Published: August 2020

Purpose

The purpose of this paper is to develop a new conceptual life cycle performance measurement system (PMS) based on stage level key performance indicators (KPIs) to measure the performance of build–operate–transfer (BOT) projects.

Design/methodology/approach

This study uses a literature review to reveal the deficiencies of existing PMSs for public–private partnership (PPP) projects. Based on these deficiencies, four recommendations were proposed for developing a PMS. The validation of these recommendations was performed via focus group discussion sessions conducted with 12 experts. Then, a conceptual framework was developed based on the validated recommendations and the additional recommendations emerged during focus group discussions. Finally, the recommendations proposed by the focus group were tested by a questionnaire survey, the findings of the Friedman test and descriptive analysis validated these recommendations.

Findings

Findings of the focus group discussion, Friedman test and descriptive analysis indicated that the PMS should have four crucial features to develop an efficient, effective and comprehensible PMS for the BOT project. Firstly, non-financial and financial KPIs should be integrated. Secondly, the PMS should be developed as a process-based system with stage level KPIs. The performance of the BOT projects should be monitored and reviewed continuously, however the most important KPIs should be used for continuous performance measurement to increase the applicability of the system and allocate the resources more efficiently.

Research limitations/implications

This survey was conducted on experts who have experience with BOT projects located in Turkey, therefore, judgments of experts might be affected by external factors specific to Turkey such as geopolitical situations, investment environment. However, due to the nature of BOT projects, the experience of experts can also be utilized at the international level.

Originality/value

This is the first time a PMS has been developed to measure the performance of a BOT project. In addition, this system has unique features when compared with the PMS proposed in the literature. Especially, the stage level KPIs and continuous performance measurement with the most important KPIs throughout each stage has never been used. This research provides both public sector and private entities with an insight into effectively measure, control and manage their BOT infrastructure projects' performances throughout their life cycles.
As above, not so below: developing social procurement practices on strategic and operative levels
Authors: Troje Daniella , Andersson Thomas
Published: August 2020

Purpose

Procurement is increasingly used as a strategic tool to mitigate societal issues such as social exclusion and unemployment of marginalized groups. By conducting social procurement and imposing so-called employment requirements, organizations can create job opportunities for marginalized people. Such practices are becoming increasingly popular in the construction sector, but remain scattered, which hinders the effective creation, use and dissemination of cohesive and commonly shared social procurement practices. Accordingly, this paper analyzes the creation, use and dissemination of social procurement practices in the Swedish construction sector.

Design/methodology/approach

The theory of proto-institutions, which refers to institutions under development, is applied to analyze 46 interviews with construction practitioners.

Findings

There is currently little convergence of social procurement practices, due to practices not being fully internalized across organizations and projects; interns hired through employment requirements not having strong enough incentives to engage with their internships; actors working strategically and operatively having different possibilities to create social procurement practices; and the development of maintenance mechanisms for the formalization of sustainable practices being weak.

Originality/value

This paper contextualizes efforts to increase equality, diversity and inclusion of marginalized groups in the construction sector. The adoption of an institutional perspective of practice development elucidates the institutional constellation of existing institutional logics that impact on this practice development. This paper also indicates how the work with social procurement can become more effective and efficient and maximize the social value output for marginalized people living in social exclusion. For institutional theory, it illustrates how proto-institutions can be driven by both top-down and bottom-up perspectives.
Working capital management and managerial talent
Authors: Ujah Nacasius U. , Tarkom Augustine , Okafor Collins E.
Published: August 2020

Purpose

Talented managers arguably remain quintessential to firm value and performance. While the literature offers evidence for the long-term orientation of talented managers, there is a paucity of evidence on the short-term performance of managers. Here, we examine the relationship between managerial talent and working capital management (WCM).

Design/methodology/approach

This study primarily employs a panel fixed-effect method controlling for firm-year and firm-industry for non-financial and non-utility firms for the years 1980 through 2016. Also, the authors control of potential bias that may impact the result. These controls include social capital, financial constraints and tests for endogeneity and spurious correlation.

Findings

The authors find the association between managerial talent and WCM to be positive and significant. The results indicate that talented managers have a higher cash conversion cycle. The empirical evidence still holds after controlling for social capital, religiosity and financial constraints. Also, the evidence still holds by employing an interaction term between Tobin's Q as a proxy for investment opportunities and talented managers.

Practical implications

The finding may lend credence to executive contracts. Human nature, by default, is only vested on a net benefit for self-aggrandization. Self-aggrandization can be evident through structures in managerial contracts. These contracts usually tie consequences to long-term growths. If a benefit is offered based on short-term operational goals, talented managers may do more to the management of working capital.

Originality/value

In the managerial talent literature, talents reflect a holistic picture of one that can succeed in both the short-term and long-term goals of a company. Here, the authors show that talented managers are inefficient in meeting short-term goal – working capital management. Thus, the authors add to the research by providing evidence that talented managers are myopic.
Inequality and human development: How inclusive the growth is in Uttar Pradesh?
Authors: Maurya Nagendra Kumar , Kanaujiya Karuna Shanker
Published: August 2020

Purpose

The present research has been conceptualized to make an inter-district analysis in terms of IHDI of Uttar Pradesh. It aims to provide district-wise estimates of HDI and IHDI with the latest available data, which may prove to be a critical policy input to the policy makers that how different districts are performing in terms of education, health and standard of living parameters and help in implementing tailor made policy actions.

Design/methodology/approach

The paper utilizes the Census of India data and unit-level data of National Sample Survey (NSS) for constructing HDI and IHDI. The broad framework for computing IHDI in this study is similar to the approach of UNDP's HDR 2010. To adjust the inequality aspect, the Atkinson inequality aversion parameter has been estimated at indicator level on the basis of NSS unit record data.

Findings

The study reveals that inequality discounted income index is on an average 30 percent lower than unadjusted income index. However, quite high variation exists in case of education and health. The difference ranges from 30 percent to 40 percent in the case of education and from 3 to 36 percent in the health dimension. The surprising fact which study finds that health infrastructure and education infrastructure are poorly correlated with their respective outcomes.

Research limitations/implications

The study offers a policy suggestion that increasing investment on educational and health infrastructure will not have any significant impact on their respective outcomes unless distributional inequalities are reduced. The study also suggests that rising income inequalities are threat to inclusive growth and sustainable development goals agenda. Thus, it recommends policy makers to take pro-active timely policy measures to reduce income inequalities. The educational achievement should be fixed in terms of average years of schooling and expected years of schooling rather than in terms of literacy rate.

Originality/value

The present research is an original work. This is the first study in the case of Uttar Pradesh which attempted to estimate district-wise IHDI following the internationally accepted UNDP (2010) methodology.
Archival knowledge in the field of personal archiving: an exploratory study based on grounded theory
Authors: Huang Tiyang , Nie Rui , Zhao Yue
Published: August 2020

Purpose

The purpose of this paper is to propose a theoretical framework to illustrate the archival knowledge applied by archivists in their personal archiving (PA) and the mechanism of the application of archival knowledge in their PA.

Design/methodology/approach

The grounded theory methodology was adopted. For data collection, in-depth interviews were conducted with 21 archivists in China. Data analysis was performed using the open coding, axial coding and selective coding to organise the archival knowledge composition of PA and develops the awareness-knowledge-action (AKA) integration model of archival knowledge application in the field of PA, according to the principles of the grounded theory.

Findings

The archival knowledge involved in the field of PA comprises four principal categories: documentation, arrangement, preservation and appraisal. Three interactive factors involved in archivists' archival knowledge application in the field of PA behaviour: awareness, knowledge and action, which form a pattern of awareness leading, knowledge guidance and action innovation, and archivists' PA practice is flexible and innovative. The paper underscored that it is need to improve archival literacy among general public.

Originality/value

The study constructs a theoretical framework to identify the specialised archival knowledge and skills of PA which is able to provide solutions for non-specialist PA and develops an AKA model to explain the interaction relationships between awareness, knowledge and action in the field of PA.
UK REIT conversion and institutional ownership dynamic
Authors: Wong Woei Chyuan
Published: August 2020

Purpose

The purpose of this paper is to examine the impact of conversion to REIT status by former listed property companies in the United Kingdom on the level of institutional ownership during the period of 2007–2016.

Design/methodology/approach

This paper uses an event study framework to track the change in institutional ownership three years before and after a REIT conversion event. This event study approach circumvents the sample selection bias issue associated with the conversion event wherein the decision to convert to REIT is likely to be endogenous.

Findings

Panel regression analysis reveals that changing to REIT status led to a 12.8 and 15.2% increase in institutional ownership and number of institutional investors, respectively. The first order of priority in institutional investors' investment in REIT shares is their preference for liquidity. Further analysis shows that institutional investors changed their preferences towards characteristics associated with systematic risk, firm age and liquidity after the conversion event by becoming less averse to firm-specific risk, placing more emphasis on firm age and less emphasis on systematic risk and liquidity.

Practical implications

Overall, conversion to REIT status helps increase former property companies' investor base, which is in line with the regulator's aim to open up the property market to a wide range of investors through the introduction of a REIT regime. Findings from this paper also have policy implications for countries that are considering a REIT regime for their capital market and existing REIT regimes without a formal conversion mechanism.

Originality/value

This paper offers, for the first time, evidence on 1) how conversion to REITs influences firms' institutional ownership and 2) the determinants of converted REITs' institutional ownership.
Organizational support and Chinese police officers’ attitudes toward intervention into domestic violence
Authors: Wu Yuning , Lin Kai , Li Luye , Wang Xiying
Published: August 2020

Purpose

The purpose of this paper is to examine Chinese police officers’ general support for police intervention into domestic violence, emphasizing adequate protection of the victims, and specific support for utilizing arrests to deal with the offenders.

Design/methodology/approach

This study relies on survey data collected from 1,064 police officers who worked in multiple areas in two provinces of China between June and July of 2019. OLS models were used to test whether organizational variables are significant predictors of officer attitudes toward domestic violence intervention.

Findings

Both agency endorsement and supervisory support are positively related to officers’ favorable attitudes toward police intervention into domestic violence and using arrests to handle offenders. The amount of training received from the agency on the recently promulgated Anti-Domestic Violence Law, however, has a negative influence on officer support for general intervention into domestic violence and no influence on officer attitudes toward arrests.

Originality/value

This study represents one of the first attempts to investigate the connections between organizational and managerial factors and Chinese officers’ support for both general and specific interventions into domestic violence. It contributes to the current literature that only included police cadets in the analysis of Chinese police attitudes toward domestic violence despite the fundamental differences between cadets and active-duty officers.