bluuebunny/crossref_metadata_2025 huggingface dataset:
Plumage manipulation alters the integration of social behavior, physiology, internal microbiome, and fitness
Authors: Taff Conor C. , Zimmer Cedric , Scheck David , Ryan Thomas A. , Houtz Jennifer L. , Smee Melanie R. , Hendry Tory A. , Vitousek Maren N.
Published: November 2019

Signals often covary with physiological and behavioral traits to form an axis of integrated phenotypic variation associated with reproductive performance. This pattern of phenotypic integration could result from intrinsic between-individual differences that are causally related to signal production, physiology, and behavior. Alternatively, signal expression itself might generate dynamic feedback between physiology, behavior, and the experienced social environment, resulting in an integrated phenotype. Here, we manipulated the plumage of female tree swallows (Tachycineta bicolor) to decouple the expression of a social signal from any pre-existing behavioral or physiological differences. We collected a time series of physiological samples, monitored social interactions with a sensor network, and tracked reproductive performance. Relative to sham controls, dulled females experienced an altered social environment; overall, these females were visited more by conspecific females and less by males. Dulled females subsequently changed their own behavior by initiating fewer interactions and increasing nestling provisioning. These differences resulted in an altered internal microbiome and glucose levels and, ultimately, dulled females produced more offspring. Moreover, dulled females produced larger clutches than control females in the year after the manipulation. Thus, signal variation alone—independent from any pre-existing differences—had a sustained causal affect on a suite of integrated traits. This finding suggests that dynamic feedback may play an important role in coordinating an integrated signaling phenotype. Our results have implications for understanding how variation in signal expression arises and is maintained and the extent to which the information encoded in signals is contingent upon their use in a social environment.
On the Boundary Conditions of Avoidance Memory Reconsolidation: An Attractor Network Perspective
Authors: Santiago Rodrigo MM , Tort Adriano BL
Published: November 2019

The reconsolidation and extinction of aversive memories and their boundary conditions have been extensively studied. Knowing their network mechanisms may lead to the development of better strategies for the treatment of fear and anxiety-related disorders. In 2011, Osan et al. developed a computational model for exploring such phenomena based on attractor dynamics, Hebbian plasticity and synaptic degradation induced by prediction error. This model was able to explain, in a single formalism, experimental findings regarding the freezing behavior of rodents submitted to contextual fear conditioning. In 2017, through the study of inhibitory avoidance in rats, Radiske et al. showed that the previous knowledge of a context as non-aversive is a boundary condition for the reconsolidation of the shock memory subsequently experienced in that context. In the present work, by adapting the model of Osan et al. (2011) to simulate the experimental protocols of Radiske et al. (2017), we show that such boundary condition is compatible with the dynamics of an attractor network that supports synaptic labilization common to reconsolidation and extinction. Additionally, by varying parameters such as the levels of protein synthesis and degradation, we predict behavioral outcomes, and thus boundary conditions that can be tested experimentally.
Collective MAPK Signaling Dynamics Coordinates Epithelial Homeostasis
Authors: Aikin Timothy J. , Peterson Amy F. , Pokrass Michael J. , Clark Helen R. , Regot Sergi
Published: November 2019

Epithelial tissues are constantly challenged by individual cell fate decisions while maintaining barrier function. During oncogenesis, mutant and normal cells also differ in their signaling states and cellular behaviors creating competitive interactions that are poorly understood. Here we show that the temporal patterns of MAPK activity are decoded by the ADAM17-EGFR paracrine signaling axis to coordinate migration of neighboring cells and promote extrusion of aberrantly-signaling cells. Concurrently, neighboring cells increase proliferation to maintain cell density while oncogene expressing cells undergo cell cycle arrest. Moreover, the stress MAPK p38 elicits the same paracrine signaling and extrusion response, suggesting that the ADAM17-EGFR pathway constitutes a quality control mechanism to eliminate and replace unfit cells from epithelial tissues. Overall, we show that the temporal patterns of MAPK activity coordinates both single and collective cell behaviors to maintain tissue homeostasis.
A Compendium of Kinetic Cell Death Modulatory Profiles Identifies Ferroptosis Regulators
Authors: Conlon Megan , Poltorack Carson , Forcina Giovanni C. , Wells Alex , Mallais Melodie , Kahanu Alexis , Magtanong Leslie , Pratt Derek A. , Dixon Scott J.
Published: November 2019

Cell death can be executed by regulated apoptotic and non-apoptotic pathways, including the iron-dependent process of ferroptosis. Small molecules are essential tools for studying the regulation of cell death. Using live-cell, time-lapse imaging, and a library of 1,833 small molecules including FDA-approved drugs and investigational agents, we assemble a large compendium of kinetic cell death ‘modulatory profiles’ for inducers of apoptosis and ferroptosis. From this dataset we identified dozens of small molecule inhibitors of ferroptosis, including numerous investigational and FDA-approved drugs with unexpected off-target antioxidant or iron chelating activities. ATP-competitive mechanistic target of rapamycin (mTOR) inhibitors, by contrast, were on-target ferroptosis inhibitors. Further investigation revealed both mTOR-dependent and mTOR-independent mechanisms linking amino acid levels to the regulation of ferroptosis sensitivity in cancer cells. These results highlight widespread bioactive compound pleiotropy and link amino acid sensing to the regulation of ferroptosis.
Iterative Subtractive Binning of Freshwater Chronoseries Metagenomes Identifies of over Four Hundred Novel Species and their Ecologic Preferences
Authors: Rodriguez-R LM , Tsementzi D , Luo C , Konstantinidis KT
Published: November 2019

Recent advances in sequencing technology and accompanying bioinformatic pipelines have allowed unprecedented access to the genomes of yet-uncultivated microorganisms from a wide array of natural and engineered environments. However, the catalogue of available genomes from uncultivated freshwater microbial populations remains limited, and most genome recovery attempts in freshwater ecosystems have only targeted few specific taxa. Here, we present a novel genome recovery pipeline, which incorporates iterative subtractive binning and apply it to a time series of metagenomic datasets from seven connected locations along the Chattahoochee River (Southeastern USA). Our set of Metagenome-Assembled Genomes (MAGs) represents over four hundred genomospecies yet to be named, which substantially increase the number of high-quality MAGs from freshwater lakes and represent about half of the total microbial community sampled. We propose names for two novel species that were represented by high-quality MAGs: “CandidatusElulimicrobium humile” (“Ca. Elulimicrobiota” in the “Patescibacteria” group) and “CandidatusAquidulcis frankliniae” (“Chloroflexi”). To evaluate the prevalence of these species in the chronoseries, we introduce novel approaches to estimate relative abundance and a habitat-preference score that control for uneven quality of the genomes and sample representation. Using these metrics, we demonstrate a high degree of habitat-specialization and endemicity for most genomospecies observed in the Chattahoochee lacustrine ecosystem, as well as wider species ecological ranges associated with smaller genomes and higher coding densities, indicating an overall advantage of smaller, more compact genomes for cosmopolitan distributions.
Individualized multi-omic pathway deviation scores using multiple factor analysis
Authors: Rau Andrea , Manansala Regina , Flister Michael J. , Rui Hallgeir , Jaffrézic Florence , Laloë Denis , Auer Paul L.
Published: November 2019

Summary

Malignant progression of normal tissue is typically driven by complex networks of somatic changes, including genetic mutations, copy number aberrations, epigenetic changes, and transcriptional reprogramming. To delineate aberrant multi-omic tumor features that correlate with clinical outcomes, we present a novel pathway-centric tool based on the multiple factor analysis framework called padma. Using a multi-omic consensus representation, padma quantifies and characterizes individualized pathway-specific multi-omic deviations and their underlying drivers, with respect to the sampled population. We demonstrate the utility of padma to correlate patient outcomes with complex genetic, epigenetic, and transcriptomic perturbations in clinically actionable pathways in breast and lung cancer.
A probabilistic framework for decoding behavior from in vivo calcium imaging data
Authors: Etter Guillaume , Manseau Frederic , Williams Sylvain
Published: November 2019

Understanding the role of neuronal activity in cognition and behavior is a key question in neuroscience. Previously,in vivostudies have typically inferred behavior from electrophysiological data using probabilistic approaches including Bayesian decoding. While providing useful information on the role of neuronal subcircuits, electrophysiological approaches are often limited in the maximum number of recorded neurons as well as their ability to reliably identify neurons over time. This can be particularly problematic when trying to decode behaviors that rely on large neuronal assemblies or rely on temporal mechanisms, such as a learning task over the course of several days. Calcium imaging of genetically encoded calcium indicators has overcome these two issues. Unfortunately, because calcium transients only indirectly reflect spiking activity and calcium imaging is often performed at lower sampling frequencies, this approach suffers from uncertainty in exact spike timing and thus activity frequency, making rate-based decoding approaches used in electrophysiological recordings difficult to apply to calcium imaging data. Here we describe a probabilistic framework that can be used to robustly infer behavior from calcium imaging recordings and relies on a simplified implementation of a naive Baysian classifier. Our method discriminates between periods of activity and periods of inactivity to compute probability density functions (likelihood and posterior), significance and confidence interval, as well as mutual information. We next devise a simple method to decode behavior using these probability density functions and propose metrics to quantify decoding accuracy. Finally, we show that neuronal activity can be predicted from behavior, and that the accuracy of such reconstructions can guide the understanding of relationships that may exist between behavioral states and neuronal activity.
Cerebellar patients have intact feedback control that can be leveraged to improve reaching
Authors: Zimmet Amanda M. , Bastian Amy J. , Cowan Noah J.
Published: November 2019

It is thought that the brain does not simply react to sensory feedback, but rather uses an internal model of the body to predict the consequences of motor commands before sensory feedback arrives. Time-delayed sensory feedback can then be used to correct for the unexpected—perturbations, motor noise, or a moving target. The cerebellum has been implicated in this predictive control process. Here we show that the feedback gain in patients with cerebellar ataxia matches that of healthy subjects, but that patients exhibit substantially more phase lag. This difference is captured by a computational model incorporating a Smith predictor in healthy subjects that is missing in patients, supporting the predictive role of the cerebellum in feedback control. Lastly, we improve cerebellar patients’ movement control by altering (phase advancing) the visual feedback they receive from their own self movement in a simplified virtual reality setup.
Including Crystallographic Symmetry in Quantum-based Refinement: Q|R#2
Authors: Zheng Min , Biczysko Malgorzata , Xu Yanting , Moriarty Nigel W. , Kruse Holger , Urzhumtsev Alexandre , Waller Mark P. , Afonine Pavel V.
Published: November 2019

Three-dimensional structure models refined using low-resolution data from crystallographic or electron cryo-microscopy experiments can benefit from high quality restraints derived from quantum chemical methods. However, non-periodic atom-centered quantum chemistry codes do not inherently account for nearest neighbor interactions of crystallographic symmetry related copies in a satisfactory way. Herein, we have included these nearest neighbor effects in our model by expanding to a super-cell, and then truncating the super-cell to only include residues from neighboring cells that are interacting with the asymmetric unit. In this way our fragmentation approach can adequately and efficiently include the nearest neighbor effects. We have shown previously that a moderately sized X-ray structure can be treated with quantum methods if a fragmentation approach was applied. In this study, we partition a target protein (4gif) into a number of large fragments. The use of large fragments (typically hundreds of atoms) is tractable when a GPU based package such as TeraChem is employed or cheaper (semi-empirical) methods are used. We run the QM calculations at the HF-D3/6-31G level. We compare and contrast the models refined using a recently developed semi-empirical method (GFN2-xTB). To validate the refinement procedure for a non-P1 structure, we use a standard set of crystallographic metrics. We show the robustness of our implementation by refining 13 additional protein models across multiple space-groups and present the summary of the refinement metrics.

Synopsis

C-terminal coiled-coil domain of transient receptor potential channel TRPP3 in the P321 space group (PDB code: 4gif) is re-refined with restraints from quantum chemistry using Hartree-Fock theory.
The basal ganglia can control learned motor sequences independently of motor cortex
Authors: Dhawale Ashesh K. , Wolff Steffen B. E. , Ko Raymond , Ölveczky Bence P.
Published: November 2019

How the basal ganglia contribute to the execution of learned motor skills has been thoroughly investigated. The two dominant models that have emerged posit roles for the basal ganglia in action selection and in the modulation of movement vigor. Here we test these models in rats trained to execute highly stereotyped and idiosyncratic task-specific motor sequences. Recordings and manipulations of neural activity in the striatum were not well explained by either model, and suggested that the basal ganglia, in particular its sensorimotor arm, are crucial for controlling the detailed kinematic structure of the learned behaviors. Importantly, the neural representations in the striatum, and the control functions they subserve, did not depend on the motor cortex. Taken together, these results extend our understanding of basal ganglia function, by suggesting that they can control and modulate lower-level subcortical motor circuits on a moment-by-moment basis to generate stereotyped learned motor sequences.
Highlighting curcumin-induced crosstalk between autophagy and apoptosis: A biochemical approach coupling impedancemetry, imaging, and flow cytometry
Authors: Sala de Oyanguren Francisco José , Rainey Nathan E. , Moustapha Aoula , Saric Ana , Sureau Franck , O’Connor José-Enrique , Petit Patrice X.
Published: November 2019

Curcumin, a major active component of turmeric (Curcuma longa, L.), is known to have various effects on both healthy and cancerous tissues. In vitro studies suggest that curcumin inhibits cancer cell growth by activating apoptosis, but the mechanism underlying the anticancer effects of curcumin is still unclear. Since there is a consensus about endoplasmic reticulum (ER) stress being involved in the cytotoxicity of many natural compounds, we investigated by Amnis®Imaging flow cytometry the mechanistic aspects of curcumin’s destabilization of the ER, but also the status of the lysosomal compartment involved in curcumin-associated apoptosis. Curcumin induces ER stress thereby causing an unfolded protein response (UPR) and calcium release which destabilize the mitochondrial compartment and induce apoptosis. These events are also associated with secondary lysosomal membrane permeabilization and activation of caspase-8, mediated by activation of cathepsins and calpains. We previously showed that sequence lead to the generation of truncated tBid and disruption of mitochondrial homeostasis. These two pathways of different intensities and momentum converge towards an amplification of cell death that still needs to be studied in more detail. It has been suggested that it may be possible to exploit autophagy for cancer therapy. There is a complex interplay involving early autophagy as soon as mitochondria produce superoxide anions and hydrogen peroxide. Treatments with 10 µM to 20 µM curcumin induce autophagosome formation, while only early events of cell death are detectable.In the present study, curcumin-induced autophagy failed to rescue all cells since most cells underwent type II cell death following initial autophagic processes. However, a small number of cells blocked in the cell cycle escaped and were rescued to give rise to a novel proliferation phase.
MCMBP maintains genome integrity by protecting the MCM subunits from degradation
Authors: Santosa Venny , Kanemaki Masato T.
Published: November 2019

The hetero-hexameric MCM2–7 helicase plays a central role in eukaryotic DNA replication. The expression of MCM2–7 is maintained at a high level for creating dormant origins, which are important for maintaining genome integrity. However, other than transcriptional activation for the de novo synthesis, little is known about how cells maintain a high level of MCM2–7. We show that human MCMBP is a short-lived nuclear protein associating mainly with MCM5, 6, and 7. Loss of MCMBP down-regulates MCM2–7, leading to replication stress and DNA-damage accumulation. Our work demonstrates MCMBP protects the MCM subunits from degradation and suggests its chaperone-like role to achieve a high level of functional MCM2–7 using the nascent and recycled subunits.
DNB-Based On-Chip Motif Finding (DocMF): a High-Throughput Method to Profile Different Types of Protein-DNA Interactions
Authors: Li Zhuokun , Wang Xiaojue , Xu Dongyang , Zhang Dengwei , Wang Dan , Dai Xuechen , Wang Qi , Li Zhou , Gu Ying , Ouyang Wenjie , Zhao Shuchang , Huang Baoqian , Gong Jian , Zhao Jing , Chen Ao , Shen Yue , Dong Yuliang , Zhang Wenwei , Xu Xun , Xu Chongjun , Jiang Yuan
Published: November 2019

Here we report a highly sensitive DNB-based on-chip Motif Finding (DocMF) system that utilizes high throughput next-generation-sequencing (NGS) chips to profile protein binding or cleaving activity. Using DocMF, we successfully identified a variety of endonuclease recognition sites and the protospacer-adjacent-motif (PAM) sequences of different CRISPR systems. Our DocMF platform can simultaneously screen both 5’ and 3’ PAM regions with high coverage using the same NGS library/chip. For the well-studied SpCas9, our DocMF platform identified a small proportion of noncanonical 5’-NAG-3’ (∼5%) and 5’-NGA-3’ (∼1.6%), in addition to its common PAMs, 5’-NGG-3’ (∼89.9%). We also used the DocMF to assay two uncharacterized Cas endonucleases, VeCas9 and BvCpf1. VeCas9 PAMs were not detected by the conventional PAM depletion method. However, DocMF discovered that both VeCas9 and BvCpf1 required broader and more complicated PAM sequences for target recognition. VeCas9 preferred the R-rich motifs, whereas BvCpf1 used the T-rich PAMs. Moreover, after slightly changing the experimental protocol, we observed that dCas9, a DNA-binding protein lacking endonuclease activity, preferably binded to the previously reported PAMs 5’-NGG-3’. In summary, our studies demonstrate that DocMF is the first tool with the capacity to exhaustively assay both the binding and the cutting properties of different DNA-binding proteins.
Heritable genetic variants in key cancer genes link cancer risk with anthropometric traits
Authors: Di Giovannantonio Matteo , Harris Benjamin H.L , Zhang Ping , Kitchen-Smith Isaac , Xiong Lingyun , Sahgal Natasha , Stracquadanio Giovanni , Wallace Marsha , Blagden Sarah , Lord Simon , Harris David A. , Harris Adrian L. , Buffa Francesca M. , Bond Gareth
Published: November 2019

Inherited genetic variants in tumour suppressors and oncogenes can increase the cancer risk, but little is known about their influence on anthropometric traits. Through the integration of inherited and somatic cancer genetic data, we define functional single nucleotide polymorphisms (SNPs) associated with cancer risk and explore potential pleiotropic associations with anthropometic traits in a cohort of 500,000 individuals. We identify three regulatory SNPs for three important cancer genes that associate with both anthropometric traits and cancer risk. We describe a novel association of a SNP in TP53 (rs78378222) with height, lean body mass measures and basal metabolic rate, as well as validating its known associations with brain and non-melanomatous skin cancer susceptibility. Our results clearly demonstrate that heritable variants in key cancer genes can associate with both differential cancer risk and anthropometric traits in the general population, thereby lending support for a role of genetics in linking these human phenotypes.
Phasic and tonic serotonin modulate alarm reactions and post-exposure behavior in zebrafish
Authors: Lima-Maximino Monica , Pyterson Maryana Pereira , do Carmo Silva Rhayra Xavier , Vidal Gomes Gabriela Cristini , Rocha Sueslene Prado , Herculano Anderson Manoel , Rosemberg Denis Broock , Maximino Caio
Published: November 2019

Current theories on the role of serotonin (5-HT) in vertebrate defensive behavior suggest that this monoamine increases anxiety but decreases fear, by acting at different levels of the neuroaxis. This paradoxical, dual role of 5-HT suggests that a serotonergic tone inhibits fear responses, while an acute increase in 5-HT would produce anxiety-like behavior. However, so far no evidence for a serotonergic tone has been found. Using zebrafish alarm responses, we investigate the participation of phasic and tonic 5-HT levels in fear-like behavior, as well as in behavior after stimulation. Conspecific alarm substance (CAS) increased bottom-dwelling and erratic swimming, and animals transferred to a novel environment after CAS exposure (post-exposure behavior) showed increased bottom-dwelling and freezing. Clonazepam blocked CAS effects during and after exposure. Acute fluoxetine dose-dependently decreased fear-like behavior, but increased post-exposure freezing. Metergoline had no effect on fear-like behavior, but blocked the effects of CAS on post-exposure behavior; similar effects were observed with pCPA. Finally, CAS was shown to decrease the activity of monoamine oxidase in the zebrafish brain after exposure. These results suggest that phasic and tonic serotonin encode an aversive expectation value, switching behavior towards cautious exploration/risk assessment/anxiety when the aversive stimulus is no longer present.
Phosphatidylinositol 4-kinase III beta regulates cell shape, migration and Focal Adhesion number
Authors: Bilodeau Patricia , Jacobsen Daniel , Law-Vinh Denise , Lee Jonathan M
Published: November 2019

Cell shape is regulated by cell adhesion and cytoskeletal and membrane dynamics. Cell shape, adhesion and motility have a complex relationship and understanding them is important in understanding developmental patterning and embryogenesis. Here we show that the lipid kinase phosphatidylinositol 4-kinase III beta (PI4KIIIβ) regulates cell shape, migration and Focal Adhesion (FA) number. PI4KIIIβ generates phosphatidylinositol 4-phosphate from phosphatidylinositol and is highly expressed in a subset of human breast cancers. PI4KIIIβ and the PI4P it generates regulate a variety of cellular functions, ranging from control of Golgi structure, fly fertility and Akt signaling. Here, we show that loss of PI4KIIIβ expression decreases cell migration and alters cell shape in NIH3T3 fibroblasts. The changes are accompanied by an increase in the number of FA in cells lacking PI4KIIIβ. Furthermore, we find that PI4P-containing vesicles move to the migratory leading-edge during migration and that some of these vesicles tether to and fuse with FA. Fusion is associated with FA disassembly. This suggests a novel regulatory role for PI4KIIIβ and PI4P in cell adhesion and cell shape maintenance.
Sexual imprinting overrides order effects
Authors: Moreira Luis , Zinck Léa , Nomoto Kensaku , Lima Susana Q.
Published: November 2019

Mate choice is a complex decision that requires the integration of cues from potential mates with individual preferences. Choosers’ preferences are shaped by recent events, early life experience and by the evolutionary history of its own species. To better understand the interaction between these factors, we studied mate choice in the female house mouse, Mus musculus. Females of one of the musculus subspecies, Mus musculus musculus, show preference for males of their own subspecies compared to males of the sibling subspecies, Mus musculus domesticus. Such an assortative preference is ecologically relevant at contact zones, where it contributes to the reproductive isolation of sympatric populations and can be reproduced in controlled laboratory conditions, but its origins are still under debate. Here, we show that female mouse mate choice depends on both early postnatal life experience and the order of prospective mates encountered as an adult and that these effects interact asymmetrically. Whereas females raised in their normal M. m. musculus environment display a robust assortative preference, females fostered in a M. m. domesticus family prefer the first male encountered, regardless of subspecies. Thus, early life experience of M. m. musculus females, when concordant with genetic self-identity, overrides sampling order effects, ensuring robust assortative choice. In the absence of this match between phylogeny and early life experience, first impression effects dominate mate choice.
Estimation of Cell Number by Hemocytometry Counting
Authors: Green Michael R. , Sambrook Joseph
Published: November 2019

The number of mammalian cells in a defined volume of medium can be measured using a hemocytometer. Automated methods using cell-counting devices such as those produced by Coulter are desirable when large numbers of individual samples are to be counted. A hemocytometer contains two chambers, each of which when filled and coverslipped contains a total volume of 9 µL. Each chamber is ruled into nine major squares, and each square is 1 × 1 mm with a depth of 0.1 mm. Thus, when coverslipped, the volume of each square is 0.1 mm3 or 0.1 µL. Additional subdivisions of the major nine squares are not necessary for counting and can be ignored.
Single-Cell Cloning of Hybridoma Cells by Limiting Dilution
Authors: Greenfield Edward A.
Published: November 2019

Isolating a stable clone of hybridoma cells that all secrete the correct antibody is the most time-consuming step in the production of hybridomas. Single-cell cloning ensures that cells that produce the antibody of interest are truly monoclonal and that the secretion of this antibody can be stably maintained. The original positive well will often contain more than one clone of hybridoma cells, and many hybrid cells have an unstable assortment of chromosomes. Both of these problems may lead to the desired cells being outgrown by cells that are not producing the antibody of interest. Cloning hybridoma cells by limiting dilution is the easiest of the single-cell-cloning techniques. Two approaches are presented here, one rapid technique for generating cultures that are close to being single-cell-cloned and one for single-cell cloning directly. Even though every attempt is made to ensure that the cells are in a single-cell suspension before plating, there is no way to guarantee that the colonies do not arise from two cells that were stuck together. Therefore, limiting dilution cloning should be performed at least twice to generate a clonal population.
Effect of hydrogen addition on exergetic performance of gas turbine engine
Authors: Gunasekar P. , Manigandan S. , S. Venkatesh , Gokulnath R. , Vimal Rakesh , Boomadevi P.
Published: November 2019

Purpose

The depletion of fossil fuel and emissions of harmful gases forced the pioneers in search of alternate energy source. The purpose of this study is to present an effective use of hydrogen fuel for turbojet engines based on its exergetic performance.

Design/methodology/approach

This study was performed to measure the assessment of exergetic data of turbojet engines. Initially, the test was carried out on the Jet A-1 fuel. Then, a series of similar tests were carried out on turbojet engines with hydrogen fuel to measure their performance results. Finally, the exergetic values of both were compared with each other.

Findings

The introduction of hydrogen fuel reduced the exergy efficiency, and a 10 per cent reduction was observed in exergy efficiency. Simultaneously, the waste exergy rate increased by 9 per cent. However, because of the high specific fuel exergy, hydrogen fuel was better than Jet A-1 fuel. Note that parameters such as environmental effect factor and ecological effect witnessed an increase in their index owing to the addition of hydrogen.

Practical implications

Introduction of alternative blends is necessary for achieving lower emission of gases such as CO, NOx and CO2 from gas turbine engines without compromising on performance. The Jet A fuels were replaced by blends to obtain better emission characteristics.

Originality/value

The use of hydrogen in turbojet engines showed an adverse effect on exergetic performance. However, it was very impressive to see a 200 per cent reduction in emissions. From the comparison of exergy efficiency results of inlet, combustion and nozzle, it is evident that the combustion chamber has the largest values of exergy ratio, waste exergy ratio, cost flow, ecological factor, environmental factor and fuel ratio owing to irreversibility in the combustion process.
The mediating role of career resilience on the relationship between career competency and career success
Authors: Ahmad Bilal , Latif Shahid , Bilal Ahmad Raza , Hai Mahnoor
Published: November 2019

Purpose

The purpose of this paper is to empirically investigate the relationships between career competency, career resilience and career success. The study further examines the mediating role of career resilience on the relationship between career competency and career success.

Design/methodology/approach

Data were collected from 284 Islamic bank employees across Pakistan through a cross-sectional, self-reporting, online questionnaire. Partial least squares structural equation modeling was used to test the proposed hypotheses using Smart PLS version 3.0.

Findings

The study’s results indicate that career competency is a significant predictor of career resilience, and that career resilience is subsequently a significant predictor of career success. Further, the results of the structural equation model analyses supported the proposition that career resilience mediates the relationship between career competency and career success.

Practical implications

Human resource practitioners and managers can increase the likelihood of their employees’ career resilience by focusing on developing career-related competencies – an antecedent of career success.

Originality/value

The study clarifies prevailing misconceptions that assume a direct linear relationship between career competency and career success by establishing, through empirical evidence, that success is not an ultimate outcome of competence. In addition, it proposes an oversimplified model of the competence–resilience–success relationship.
Firm-level agreements, employment strategies and temporary workers
Authors: Minardi Saverio
Published: November 2019

Purpose

The purpose of this paper is to investigate the impact of two-tier firm-level collective agreements on firms’ propensity to use temporary employment, accounting for the process of self-selection of firms into different bargaining levels in the Italian context. It further examines which firm-level characteristics drive this process of selection.

Design/methodology/approach

The empirical analysis uses a panel data set of Italian firms for the years 2005, 2007, 2010 and 2015. Estimations are produced and compared through ordinary least square regression, random-effects and fixed-effects models.

Findings

Results show that enterprises adopting two-tier firm-level agreements (TTFA) are associated with lower levels of temporary workers. However, a longitudinal analysis suggests that introducing a TTFA does not impact firms’ propensity to employ temporary workers. This novel finding highlights the presence of a selection process based on firm-level time-constant characteristics. The paper argues that these characteristics refer to management orientation toward high-road rather than low-road employment strategies. Further evidence is brought in support of this claim, showing that firms’ propensity toward the provision of training for their labor force partially explain the process of selection.

Originality/value

The study is the first to analyze the impact of secondary-level collective agreements on firms’ reliance on temporary employment, offering new evidence on the causes of the expansion of temporary employment. It further highlights the relevance of employers’ strategies in shaping the impact of the bargaining structure.
The nexus of corporate social responsibility (CSR), affective commitment and organisational citizenship behaviour in academia
Authors: Ahmad Rashid , Ahmad Saima , Islam Talat , Kaleem Ahmad
Published: November 2019

Purpose

The purpose of this paper is to advance knowledge on the implications of perceived corporate social responsibility (CSR) on employee levels of commitment and citizenship behaviour (OCB) by investigating a trust-based mediational process in the context of academia.

Design/methodology/approach

The research data are collected from a sample of 736 academics through a questionnaire based survey administered in different Pakistani universities. The nature of trust-based mechanism underlying the relationships between CSR, affective commitment and OCB is determined through structural equation modelling of the research data.

Findings

The findings suggest that the perceived CSR is an important predictor of academics’ attitudes and behaviour in universities. Whilst the findings implicate the mediating role of trust in the process by which perceived CSR influences academics’ commitment, trust does not appear to mediate the perceived CSR’s relationship with OCB.

Research limitations/implications

This study utilises single-sourced and cross-sectional data, which may have resulted in common method bias.

Practical implications

By furnishing evidence of the beneficial effects of perceived CSR on academics’ levels of trust, commitment and citizenship behaviour, this study provides a business case for universities’ involvement in CSR. The findings are particularly useful to academic administrators and managers who are interested in nurturing positive attitudes and behaviours amongst academic staff.

Originality/value

There is a paucity of research on CSR in the academic work settings of developing countries. This is the first study to examine the trust-based microfoundation of CSR in the context of academia in Pakistan.
The relationship between entrepreneurial intent, gender and personality
Authors: Zisser Mackenzie R. , Johnson Sheri L. , Freeman Michael A. , Staudenmaier Paige J.
Published: November 2019

Purpose

The purpose of this study is to examine gender differences in personality traits of people with and without entrepreneurial intent to assess whether women who intend to become entrepreneurs exhibit particular tendencies that can be fostered.

Design/methodology/approach

Participants completed an online battery of well-established questionnaires to cover a range of personality traits relevant to entrepreneurship and gender. Participants also answered items concerning intent to become an entrepreneur. A factor analysis of personality traits produced four factors (esteem and power, ambition, risk propensity and communal tendency, the latter reflecting openness and cooperation, without hubris). The authors constructed four parallel regression models to examine how gender, entrepreneurial intent and the interaction of gender with intent related to these four personality factor scores.

Findings

Participants who endorsed a desire to become an entrepreneur reported higher ambition. Women with entrepreneurial intentions endorsed higher levels of communal tendency than men with entrepreneurial intent. Those without entrepreneurial intent did not show gender differences in communal tendency.

Research limitations/implications

Current findings suggest that men and women who intend to become entrepreneurs share many traits, but women with entrepreneurial intent show unique elevations in communal tendencies. Thus, a worthwhile locus for intervention into the gender disparity in self-employment would be providing space and acknowledgement of prosocial motivation and goals as one highly successful route to entrepreneurship.

Originality/value

Given the underused economic potential of women entrepreneurs, there is a fundamental need for a rich array of research on factors that limit and promote women’s entry into entrepreneurship. Current findings indicate that personality may be one piece of this puzzle.
Applying innovation attributes to predict purchase intention for the eco-labeled products
Authors: Hosseinikhah Choshaly Sahar
Published: November 2019

Purpose

This paper aims to make use of the innovation diffusion theory to predict the purchase intention for eco-labeled products.

Design/methodology/approach

Data are collected from 180 individuals in the Mid Valley shopping mall area in Malaysia. It is then analyzed using SPSS and Smart PLS. The measurement model is analyzed using composite reliability, convergent and discriminate validity, while the structural model is used to predict the relationships between variables.

Findings

Results indicate that the relative advantage, trialability and observability are positively related to eco-labeled products purchase intention, while the complexity is negatively related to eco-labeled products purchase intention. However, compatibility is not positively related to eco-labeled products purchase intention.

Practical implications

Marketers should enhance the observability of eco-labeled as it is the most influential attribute affecting eco-labeled products purchase intention. Relative advantages of eco-labeled products are also important to stimulate purchase intention. Marketers could best relate the innovation to context-specific use situations enabling consumers to evaluate the use consequences of the innovation, and therefore, may assess its particular benefits.

Originality/value

It explores the potential of a theoretical framework based on innovation diffusion theory to explain eco-labeled products purchase intention.
How open is OpenGLAM? Identifying barriers to commercial and non-commercial reuse of digitised art images
Authors: Valeonti Foteini , Terras Melissa , Hudson-Smith Andrew
Published: November 2019

Purpose

In recent years, OpenGLAM and the broader open license movement have been gaining momentum in the cultural heritage sector. The purpose of this paper is to examine OpenGLAM from the perspective of end users, identifying barriers for commercial and non-commercial reuse of openly licensed art images.

Design/methodology/approach

Following a review of the literature, the authors scope out how end users can discover institutions participating in OpenGLAM, and use case studies to examine the process they must follow to find, obtain and reuse openly licensed images from three art museums.

Findings

Academic literature has so far focussed on examining the risks and benefits of participation from an institutional perspective, with little done to assess OpenGLAM from the end users’ standpoint. The authors reveal that end users have to overcome a series of barriers to find, obtain and reuse open images. The three main barriers relate to image quality, image tracking and the difficulty of distinguishing open images from those that are bound by copyright.

Research limitations/implications

This study focusses solely on the examination of art museums and galleries. Libraries, archives and also other types of OpenGLAM museums (e.g. archaeological) stretch beyond the scope of this paper.

Practical implications

The authors identify practical barriers of commercial and non-commercial reuse of open images, outlining areas of improvement for participant institutions.

Originality/value

The authors contribute to the understudied field of research examining OpenGLAM from the end users’ perspective, outlining recommendations for end users, as well as for museums and galleries.
Exploring pornography use in secure hospitals: a qualitative analysis
Authors: Mellor Emily , Duff Simon
Published: November 2019

Purpose

This research paper reports findings from a qualitative analysis which explored pornography use in secure hospitals. The purpose of this paper is to investigate what attitudes staff working in secure hospital have towards patients having access to pornography, how they make decisions regarding access to pornography and what factors they take into account during this process. This research is an extension of a prior quantitative research study (Mellor and Duff, 2019).

Design/methodology/approach

The study utilised a qualitative approach using semi-structured interviews to explore professionals’ attitudes towards pornography use in a secure hospital. The sample comprised of six volunteers who had taken part in a previous research study (Mellor and Duff, 2019) requesting to discuss the topic area further. As such this research study was developed. Thematic analysis (Braun and Clarke, 2006) was used to analyse the qualitative data and the Attitudes towards Pornography Scale (Evans-DeCicco and Cowan, 2001) was used to collect demographic information.

Findings

Six themes were identified from the transcripts. The first theme explores staff members’ attitudes towards pornography. The second relates to the use of boundaries and monitoring of pornography. The third theme looks at the potential impact that pornography could have on the patient, either positive or negative. The fourth theme explores the extent to which patients are still considered as human beings, whereas the fifth theme explores the vulnerabilities that may make patients more at risk of being negatively influenced by pornography. The final theme looks at decision making regarding access to pornography.

Practical implications

The research offers an insight into how pornography within secure hospitals is managed. The research also provides an exploration into multi-disciplinary team decision making with regard to pornographic material and notes the general openness of staff towards patients having access to pornography.

Originality/value

The findings have important messages for services with regard to policy making. The findings are also relevant for understanding how pornography is managed with in secure hospitals.
Impact of intellectual capital on productivity of insurance companies in Ghana
Authors: Oppong Godfred Kesse , Pattanayak Jamini Kanta , Irfan Mohd.
Published: November 2019

Purpose

The purpose of this paper is to empirically investigate the effect of intellectual capital (IC) efficiency on changes in the productivity of insurance companies in Ghana.

Design/methodology/approach

Using a panel of 33 insurance companies from 2008 to 2016, the study applied Value Added Intellectual Coefficients model as a measure of IC efficiency, whilst Malmquist Productivity Index is employed to capture changes in the productivity of insurance companies. In estimating the effects of IC on productivity, System Generalised Method of Moment (GMM) is applied because of its power over endogeneity and heteroscedasticity.

Findings

Robust empirical findings on productivity analysis showed that improvements in insurer’s productivity were experienced in three year intervals out of the overall studied year. In addition, panel regression results revealed that IC along with human capital and capital employed significantly affect the productivity of insurance companies.

Research limitations/implications

The generalisability of the study findings could be questioned because it is limited to insurance firms operating in Ghana; some firms were omitted due to mergers and acquisition that reduced the final sample. Yet, the findings facilitate the validation of IC concept and, hence, informs manager/policy makers on IC utilisation as a source of competitive edge.

Practical implications

Having robust empirical findings, the study expands on the existing literature by unveiling the dynamic nature of IC relationship and productivity. The findings also serve as a benchmark for managers/policymakers in insurance companies to increase the operational efficiency by investing in IC, which will help guarantee improve returns on generated premiums.

Originality/value

Although a few studies have investigated the effect of IC in Ghana, this study is the first to examine the dynamic relationship between IC and changes in productivity in a Ghanaian context.
Real estate portfolios – the case for globally diversified core property funds
Authors: Jadevicius Arvydas
Published: November 2019

Purpose

The purpose of this paper is to build a case for globally diversified core real estate funds portfolio.

Design/methodology/approach

It uses Monte Carlo simulation technique to construct synthetic real estate funds portfolios.

Findings

Benefit of maintaining globally diversified real estate funds portfolio merits admission. An optimal portfolio has an almost even split between Europe, USA and Asia Pacific, ceteris paribus. Likewise, currency effect for Europe domiciled investors is undeniable.

Practical implications

The overall estimates suggest that a blend of APAC, European and US allocations enhance portfolio risk return profile.

Originality/value

The study adds additional evidence on the contested issue of real estate diversification.
How to provide public digital cultural services in China?
Authors: Wanyan Dengdeng , Hu Jiahao
Published: November 2019

Purpose

The purpose of this paper is to understand the consumption and demand of Chinese citizens for public digital culture, and make suggestions for government-supported public digital culture providers.

Design/methodology/approach

Through a questionnaire survey, this study investigates the provision of public digital cultural services (PDCS) from the perspective of consumption and demands.

Findings

The results indicate: the Chinese populace as a whole had low expenses on digital cultural services, and had not effectively utilized them to support their own development; significant disparities exist between demographics, particularly between urban and rural residents; the populace were strongly interested in participation in public digital culture, but the services had low actual utilization rates; and the services had been unable to meet the users’ quality-related demands.

Originality/value

The first study to approach the provision of PDCS from the side of consumption and user demand.