bluuebunny/crossref_metadata_2025 huggingface dataset:
Brood parasitism in eusocial insects (Hymenoptera): role of host geographical range size and phylogeny
Authors: Suhonen Jukka , Ilvonen Jaakko J. , Nyman Tommi , Sorvari Jouni
Published: February 2019

Interspecific brood parasitism is common in many animal systems. Brood parasites enter the nests of other species and divert host resources for producing their own offspring, which can lead to strong antagonistic parasite–host coevolution. Here, we look at commonalities among social insect species that are victims of brood parasites, and use phylogenetic data and information on geographical range size to predict which species are most probably to fall victims to brood parasites in the future. In our analyses, we focus on three eusocial hymenopteran groups and their brood parasites: (i) bumblebees, (ii)
Myrmica
ants, and (iii) vespine and polistine wasps. In these groups, some, but not all, species are parasitized by obligate workerless inquilines that only produce reproductive-caste descendants. We find phylogenetic signals for geographical range size and the presence of parasites in bumblebees, but not in ants and wasps. Phylogenetic logistic regressions indicate that the probability of being attacked by one or more brood parasite species increases with the size of the geographical range in bumblebees, but the effect is statistically only marginally significant in ants. However, non-phylogenetic logistic regressions suggest that bumblebee species with the largest geographical range sizes may have a lower likelihood of harbouring social parasites than do hosts with medium-sized ranges. Our results provide new insights into the ecology and evolution of host–social parasite systems, and indicate that host phylogeny and geographical range size can be used to predict threats posed by social parasites, as well to design efficient conservation measures for both hosts and their parasites.

This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.
Host density predicts the probability of parasitism by avian brood parasites
Authors: Medina Iliana , Langmore Naomi E.
Published: February 2019

The spatial distribution of hosts can be a determining factor in the reproductive success of parasites. Highly aggregated hosts may offer more opportunities for reproduction but can have better defences than isolated hosts. Here we connect macro- and micro-evolutionary processes to understand the link between host density and parasitism, using avian brood parasites as a model system. We analyse data across more than 200 host species using phylogenetic comparative analyses and quantify parasitism rate and host reproductive success in relation to spatial distribution using field data collected on one host species over 6 years. Our comparative analysis reveals that hosts occurring at intermediate densities are more likely to be parasitized than colonial or widely dispersed hosts. Correspondingly, our intraspecific field data show that individuals living at moderate densities experience higher parasitism rates than individuals at either low or high densities. Moreover, we show for the first time that the effect of host density on host reproductive success varies according to the intensity of parasitism; hosts have greater reproductive success when living at high densities if parasitism rates are high, but fare better at low densities when parasitism rates are low. We provide the first evidence of the trade-off between host density and parasitism at both macro- and micro-evolutionary scales in brood parasites.

This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.
Defences against brood parasites from a social immunity perspective
Authors: Cotter S. C. , Pincheira-Donoso D. , Thorogood R.
Published: February 2019

Parasitic interactions are so ubiquitous that all multicellular organisms have evolved a system of defences to reduce their costs, whether the parasites they encounter are the
classic parasites
which feed on the individual, or
brood parasites
which usurp parental care. Many parallels have been drawn between defences deployed against both types of parasite, but typically, while defences against classic parasites have been selected to protect survival, those against brood parasites have been selected to protect the parent's inclusive fitness, suggesting that the selection pressures they impose are fundamentally different. However, there is another class of defences against classic parasites that have specifically been selected to protect an individual's inclusive fitness, known as
social immunity
. Social immune responses include the anti-parasite defences typically provided for others in kin-structured groups, such as the antifungal secretions produced by termite workers to protect the brood. Defences against brood parasites, therefore, are more closely aligned with social immune responses. Much like social immunity, host defences against brood parasitism are employed by a donor (a parent) for the benefit of one or more recipients (typically kin), and as with social defences against classic parasites, defences have therefore evolved to protect the donor's inclusive fitness, not the survival or ultimately the fitness of individual recipients This can lead to severe conflicts between the different parties, whose interests are not always aligned. Here, we consider defences against brood parasitism in the light of social immunity, at different stages of parasite encounter, addressing where conflicts occur and how they might be resolved. We finish with considering how this approach could help us to address longstanding questions in our understanding of brood parasitism.

This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.
Parasitic cuckoo catfish exploit parental responses to stray offspring
Authors: Polačik M. , Reichard M. , Smith C. , Blažek R.
Published: February 2019

Interspecific brood parasitism occurs in several independent lineages of birds and social insects, putatively evolving from intraspecific brood parasitism. The cuckoo catfish,
Synodontis multipunctatus
, the only known obligatory non-avian brood parasite, exploits mouthbrooding cichlid fishes in Lake Tanganyika, despite the absence of parental care in its evolutionary lineage (family Mochokidae). Cuckoo catfish participate in host spawning events, with their eggs subsequently collected and brooded by parental cichlids, though they can later be selectively rejected by the host. One scenario for the origin of brood parasitism in cuckoo catfish is through predation of cichlid eggs during spawning, eventually resulting in a spatial and temporal match in oviposition by host and parasite. Here we demonstrate experimentally that, uniquely among all known brood parasites, cuckoo catfish have the capacity to re-infect their hosts at a late developmental stage following egg rejection. We show that cuckoo catfish offspring can survive outside the host buccal cavity and re-infect parental hosts at a later incubation phase by exploiting the strong parental instinct of hosts to collect stray offspring. This finding implies an alternative evolutionary origin for cuckoo catfish brood parasitism, with the parental response of host cichlids facilitating its evolution.

This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.
Reconstruction and Simulation of a Scaffold Model of the Cerebellar Network
Authors: Casali Stefano , Marenzi Elisa , Medini Chaitanya , Casellato Claudia , D’Angelo Egidio
Published: February 2019

Reconstructing neuronal microcircuits through computational models is fundamental to simulate local neuronal dynamics. Here a scaffold model of the cerebellum has been developed in order to flexibly place neurons in space, connect them synaptically and endow neurons and synapses with biologically-grounded mechanisms. The scaffold model can keep neuronal morphology separated from network connectivity, which can in turn be obtained from convergence/divergence ratios and axonal/dendritic field 3D geometries. We first tested the scaffold on the cerebellar microcircuit, which presents a challenging 3D organization, at the same time providing appropriate datasets to validate emerging network behaviors. The scaffold was designed to integrate the cerebellar cortex with deep cerebellar nuclei (DCN), including different neuronal types: Golgi cells, granule cells, Purkinje cells, stellate cells, basket cells and DCN principal cells. Mossy fiber (mf) inputs were conveyed through the glomeruli. An anisotropic volume (0.077 mm3) of mouse cerebellum was reconstructed, in which point-neuron models were tuned toward the specific discharge properties of neurons and were connected by exponentially decaying excitatory and inhibitory synapses. Simulations using pyNEST and pyNEURON showed the emergence of organized spatio-temporal patterns of neuronal activity similar to those revealed experimentally in response to background noise and burst stimulation of mossy fiber bundles. Different configurations of granular and molecular layer connectivity consistently modified neuronal activation patterns, revealing the importance of structural constraints for cerebellar network functioning. The scaffold provided thus an effective workflow accounting for the complex architecture of the cerebellar network. In principle, the scaffold can incorporate cellular mechanisms at multiple levels of detail and be tuned to test different structural and functional hypotheses. A future implementation using detailed 3D multi-compartment neuron models and dynamic synapses will be needed to investigate the impact of single neuron properties on network computation.
Cue-selective adaptation operates on a separable encoding of stereo and texture information
Authors: Cesanek Evan , Domini Fulvio
Published: February 2019

To perform accurate movements, the sensorimotor system must maintain a delicate calibration of the mapping between visual inputs and motor outputs. Previous work has focused on the mapping between visual inputs and individual locations in egocentric space, but little attention has been paid to the mappings that support interactions with 3D objects. In this study, we investigated sensorimotor adaptation of grasping movements targeting the depth dimension of 3D paraboloid objects. Object depth was specified by separately manipulating binocular disparity (stereo) and texture gradients. At the end of each movement, the fingers closed down on a physical object consistent with one of the two cues, depending on the condition (haptic-for-texture or haptic-for-stereo). Unlike traditional adaptation paradigms, where relevant spatial properties are determined by a single dimension of visual information, this method enabled us to investigate whether adaptation processes can selectively adjust the influence of different sources of visual information depending on their relationship to physical depth. In two experiments, we found short-term changes in grasp performance consistent with a process of cue-selective adaptation: the slope of the grip aperture with respect to a reliable cue (correlated with physical reality) increased, whereas the slope with respect to the unreliable cue (uncorrelated with physical reality) decreased. In contrast, slope changes did not occur during exposure to a set of stimuli where both cues remained correlated with physical reality, but one was rendered with a constant bias of 10 mm; the grip aperture simply became uniformly larger or smaller, as in standard adaptation paradigms. Overall, these experiments support a model of cue-selective adaptation driven by correlations between error signals and input values (i.e., supervised learning), rather than mismatched haptic and visual signals.
Layer 5 circuits in V1 differentially control visuomotor behavior
Authors: Tang Lan , Higley Michael J.
Published: February 2019

Sensory areas of the mammalian neocortex are thought to act as distribution hubs, transmitting information about the external environment to various cortical and subcortical structures in order to generate adaptive behavior. However, the exact role of cortical circuits in sensory perception remains unclear. Within primary visual cortex (V1), various populations of pyramidal neurons (PNs) send axonal projections to distinct targets, suggesting multiple cellular networks that may be independently engaged during the generation of behavior. Here, we investigated whether PN subpopulations differentially support sensory-guided performance by training mice in a visual detection task based on eyeblink conditioning. Applying 2-photon calcium imaging and optogenetic manipulation of anatomically-defined PNs in behaving animals, we show that layer 5 corticopontine neurons strongly encode task information and are selectively necessary for performance. These results contrast with recent observations of operant behavior showing a limited role for the neocortex in sensory detection. Instead, our findings support a model in which target-specific cortical subnetworks form the basis for adaptive behavior by directing relevant information to downstream brain areas. Overall, this work highlights the potential for neurons to form physically interspersed but functionally segregated networks capable of parallel, independent control of perception and behavior.
A charge-dependent phase transition determines interphase chromatin organization
Authors: Strickfaden Hilmar , Sharma Ajit K. , Hendzel Michael J.
Published: February 2019

An emerging principle of cellular compartmentalization is that liquid unmixing results in formation of compartments by phase separation. We used electron spectroscopic Imaging (ESI), a transmission electron microscopy technology, to distinguish chromatin and nucleoplasmic phases of mammalian cell lines and their responses towards different environmental changes. We tested the hypothesis that charge-dependent phase separation mediated by the histone N-termini could explain the organization of chromatin. 3D images of nuclear chromatin with electron spectroscopic imaging (ESI) demonstrates that the amount of chromatin proximal to the interchromatin compartment (IC) differs between cell types, reflecting major differences in chromatin organization. These differences were lost when cells were treated overnight with a histone deacetylase inhibitor. We show that drastic, reversible changes in chromatin mixing or unmixing with the nucleoplasm/interchromatin space can be induced by modulating osmolarity of the medium or acetylation status of the chromatin. In vitro phase separation experiments demonstrated that chromatin separated from solution through a phase transition towards a more solid chromatin state.
Caribbean multi-centre study of Klebsiella pneumoniae: whole genome sequencing, antimicrobial resistance and virulence factors
Authors: Heinz Eva , Brindle Richard , Morgan-McCalla Andrina , Peters Keisha , Thomson Nicholas R.
Published: February 2019

The surveillance of antimicrobial resistant isolates has proven to be one of the most valuable tools to understand the global rise of multidrug-resistant bacterial pathogens. We report the first insights into the current situation in the Caribbean, where a pilot project to monitor antimicrobial resistance through phenotypic resistance measurements combined with whole-genome sequencing was set up in collaboration with the Caribbean Public Health Agency (CARPHA). Our first study focused on Klebsiella pneumoniae, a highly relevant organism amongst the Gram-negative opportunistic pathogens world-wide today causing hospital, as well as community-acquired, infections. Our results show that not only carbapenem resistance, but also hypervirulent strains, are circulating in patients in the Caribbean. Our current data does not allow us to infer their prevalence in the population. We argue for the urgent need to further support antimicrobial resistance surveillance and stewardship in this almost uncharted territory, which can make a significant impact on the reduction of antimicrobial usage.

DATA SUMMARY

-Raw sequencing data is deposited at the sequence read archive (SRA), and assemblies are deposited at GenBank, accession numbers for all are given in Dataset S1.

-The data of measured resistance phenotypes (Vitek) is also provided in Dataset S1.

-The tree file and associated metadata can be investigated and downloaded through the free online platform microreact (https://microreact.org/project/S1-a7KAkV).

✓ I/We confirm all supporting data, code and protocols have been provided within the article or through supplementary data files. ⊠

Significance as a BioResource to the community

This BioResource contains whole-genome sequence data of 270 Klebsiella pneumoniae isolates, information about encoded resistance genes and the phylogeny of the isolates, their distribution in the global K. pneumoniae population, and their resistance phenotype data as determined by the VITEK 2 compact system. The isolates are recent (2017 through 2018) and represent clinically relevant patient isolates from 15 different sites in 12 Caribbean states. These data will be of interest for researchers working on K. pneumoniae and other opportunistic pathogens as well as those interested in mobile genetic elements carrying antimicrobial resistance cassettes. Our data is the only recent survey of antimicrobial resistant opportunistic pathogens from multiple sites within the Caribbean, and is of high significance for the global surveillance of K. pneumoniae and antimicrobial resistance elements. This BioResource is made available through data tables provided with this article, as well deposition of the raw data in the relevant archives, and an interactive platform (microreact) to enquire and download analyses (phylogenetic tree, metadata).
Improving drug discovery using image-based multiparametric analysis of epigenetic landscape
Authors: Farhy Chen , Orozco Luis , Zeng Fu-Yue , Pass Ian , Ylanko Jarkko , Hariharan Santosh , Huang Chun-Teng , Andrews David , Terskikh Alexey V.
Published: February 2019

With the advent of automatic cell imaging and machine learning, high-content phenotypic screening has become the approach of choice for drug discovery due to its ability to extract drug specific multilayered data and compare it to known profiles. In the field of epigenetics such screening approaches has suffered from the lack of tools sensitive to selective epigenetic perturbations. Here we describe a novel approach Microscopic Imaging of Epigenetic Landscapes (MIEL) that captures patterns of nuclear staining of epigenetic marks (e.g. acetylated and methylated histones) and employs machine learning to accurately distinguish between such patterns (1). We demonstrated that MIEL has superior resolution compared to conventional intensity thresholding techniques and enables efficient detection of epigenetically active compounds, function-based classification, flagging possible off-target effects and even predict novel drug function. We validated MIEL platform across multiple cells lines and using dose-response curves to insure the robustness of this approach for the high content high throughput drug discovery.
Electrically induced bacterial membrane potential dynamics correspond to cellular proliferation capacity
Authors: Stratford James P , Edwards Conor LA , Ghanshyam Manjari J , Malyshev Dmitry , Delise Marco A , Hayashi Yoshikatsu , Asally Munehiro
Published: February 2019

Membrane-potential dynamics mediate bacterial electrical signaling at both intra- and inter- cellular levels. Membrane potential is also central to cellular proliferation. It is unclear whether the cellular response to external electrical stimuli is influenced by the cell proliferative capacity. A new strategy enabling electrical stimulation of bacteria with simultaneous monitoring of single-cell membrane potential dynamics would allow bridging this knowledge gap and further extend electrophysiological studies into the field of microbiology. Here we report that an identical electrical stimulus can cause opposite polarization dynamics depending on cellular proliferation capacity. This was demonstrated using two model organisms, namely B. subtilis and E. coli, and by developing an apparatus enabling exogenous electrical stimulation and single-cell time-lapse microscopy. Using this bespoke apparatus, we show that a 2.5 sec electrical stimulation causes hyperpolarization in unperturbed cells. Measurements of intracellular K+ and the deletion of the K+ channel suggested that the hyperpolarization response is caused by the K+ efflux through the channel. When cells are pre-exposed to UV-violet light, the same electrical stimulation depolarizes cells instead of causing hyperpolarization. A mathematical model extended from the FitzHugh-Nagumo neuron model suggested that the opposite response dynamics are due to the shift in resting membrane potential. As predicted by the model, electrical stimulation only induced depolarization when cells are treated with antibiotics, protonophore or alcohol. Therefore, electrically induced membrane potential dynamics offer a novel and reliable approach for rapid detection of proliferative bacteria and determination of their sensitivity to antimicrobial agents at the single-cell level.
Phages associated with horses provide new insights into the dominance of lateral gene transfer in virulent bacteriophages evolution in natural systems
Authors: Babenko V.V. , Golomidova A.K. , Ivanov P.A. , Letarova M.A. , Kulikov E.E. , Manolov A.I. , Prokhorov N.S. , Kostrukova E.S. , Matyushkina D.M. , Prilipov A.G. , Maslov S. , Belalov I.S. , Clokie M.R.J.C. , Letarov A.V.
Published: February 2019

Tailed bacteriophages (Caudovirales order) are omnipresent on our planet. Their impressive ecological and evolutionary success largely relies on the bacteriophage potential to adapt to great variety of the environmental conditions found in the Biosphere. It is believed that the adaptation of bacteriophages, including short time scale adaptation, is achieved almost exclusivelyviathe (micro)evolution processes. In order to analyze the major mechanisms driving adaptation of phage genomes in a natural habitat we used comparative genomics of G7C-like coliphage isolates obtained during 7 years period from the feces of the horses belonging to a local population. The data suggest that even at this relatively short time scale the impact of various recombination events overwhelms the impact of the accumulation of point mutations. The access to the large pool of the genes of a complex microbial and viral community of the animal gut had major effect on the evolutionary trajectories of these phages. Thus the “real world” bacteriophage evolution mechanisms may differ significantly from those observed in the simplified laboratory model systems.
OrganellarGenomeDRAW (OGDRAW) version 1.3.1: expanded toolkit for the graphical visualization of organellar genomes
Authors: Greiner Stephan , Lehwark Pascal , Bock Ralph
Published: February 2019

Key points

OGDRAW has become the standard tool for displaying maps of organellar genomes

it converts GenBank entries into graphical maps

a new version with improved functionality has been released

Organellar (plastid and mitochondrial) genomes play an important role in resolving phylogenetic relationships, and next-generation sequencing technologies have led to a burst in their availability. The ongoing massive sequencing efforts require software tools for routine assembly and annotation of organellar genomes as well as their display as physical maps. OrganellarGenomeDRAW (OGDRAW) has become the standard tool to draw graphical maps of plastid and mitochondrial genomes. Here were present a new version of OGDRAW equipped with a new front end. Besides several new features, OGDRAW has now access to a local copy of the organelle genome database of the NCBI RefSeq project. Together with batch processing of (multi-)GenBank files, this enables the user to easily visualize large sets of organellar genomes spanning entire taxonomic clades. The new OGDRAW server can be accessed at https://chlorobox.mpimp-golm.mpg.de/OGDraw.html.
Biomarker-based outcome prediction in prostate adenocarcinoma depends on theTMPRSS2-ERGstatus
Authors: Gerke Julia S. , Orth Martin F. , Tolkach Yuri , Romero-Pérez Laura , Wehweck Fabienne , Stein Stefanie , Musa Julian , Knott Maximilian M. L. , Hölting Tilman L. B. , Li Jing , Sannino Giuseppina , Marchetto Aruna , Ohmura Shunya , Cidre-Aranaz Florencia , Müller-Nurasyid Martina , Strauch Konstantin , Stief Christian , Kristiansen Glen , Kirchner Thomas , Buchner Alexander , Grünewald Thomas G. P.
Published: February 2019

Background

Prostate adenocarcinoma (PCa) with/without theTMPRSS2-ERG(T2E)-fusion represent distinct molecular subtypes.

Objective

To investigate gene-signatures associated with metastasis in T2E-positive and -negative PCa, and to identify and validate subtype-specific prognostic biomarkers.

Design, setting and participants

Gene expression and clinicopathological data of two discovery PCa cohorts (totaln=783) were separately analyzed regarding the T2E-status. Selected subtype-specific biomarkers were validated in two additional cohorts (totaln=405).

Outcome measurements and statistical analysis

From both discovery cohorts, we generated two gene lists ranked by their differential intratumoral expression in patients with/without metastases stratified by T2E-status, which were subjected to gene set enrichment and leading-edge analyses. The resulting top 20 gene-signatures of both gene lists associated with metastasis were analyzed for overlaps between T2E-positive and -negative cases. Genes shared by several functional gene-signatures were tested for their association with event-free survival using the Kaplan-Meier method in a validation cohort. Immunohistochemistry was performed in another validation cohort.

Results and limitations

Metastatic T2E-positive and -negative PCa are characterized by different gene-signatures. Five genes (ASPN, BGN, COL1A1, RRM2andTYMS) were identified whose high expression was significantly associated with worse outcome exclusively in T2E-negative PCa. This was validated in an independent cohort for all genes and additionally for RRM2 by immunohistochemistry in a separate validation cohort. No prognostic biomarkers were identified exclusively for T2E-positive tumors.

Conclusions

Our study demonstrates that the prognostic value of biomarkers critically depends on the molecular subtype, i.e. the T2E-status, which should be considered when screening for and applying novel prognostic biomarkers for outcome prediction in PCa.

Patient summary

Outcome prediction for PCa is complex. The results of this study highlight that the validity of prognostic biomarkers depends on the molecular subtype, specifically the presence/absence of T2E. The reported new subtype-specific biomarkers exemplify that biomarker-based outcome prediction in PCa should consider the T2E-status.
The Out of East Asia model versus the African Eve model of modern human origins in light of ancient mtDNA findings
Authors: Zhang Ye , Huang Shi
Published: February 2019

The first molecular model of modern human origins published in 1983 had the mtDNA phylogenetic tree rooted in Asia. This model was subsequently overlooked and superseded by the African Eve model in 1987 that was premised on the unrealistic infinite site assumption and the now failed molecular clock hypothesis. We have recently developed a new framework of molecular evolution, the maximum genetic diversity (MGD) hypothesis, which has in turn led us to discover a new model of modern human origins with the roots of uniparental DNAs placed in East Asia. While the African mtDNA Eve model has haplotype N as ancestral to R, our Asia model places R as the ancestor of all. We here examined ancient mtDNAs from the literature focusing on the relationship between N and R. The data showed that all three oldest mtDNAs were R with the 45000 year old Ust-Ishim a basal type and the two ~40000 year old samples sub-branch of R. Among the numerous mtDNAs of 39500-30000 year old, most were R subtype U and only two were N samples, the 39500 year old Oase1 and the 34425 year old Salkhit. These N types are basal and hence likely close to the root of N. These ancient DNA findings suggest that basal R is ~5000 years older than basal N, thereby confirming the East Asia model and invalidating the African Eve model.
The effect of sword bean extract on the relationship between rheumatoid arthritis and periodontitis in mice
Authors: Matsumoto Kosei , Nakatsuka Yuko , Shirai Kaname , Shimizu Shintaro , Yanase Shunshuke , Abiko Yoshihiro , Furuichi Yasushi
Published: February 2019

Objectives

Several studies in humans and experimental animals have reported an interaction between rheumatoid arthritis (RA) and periodontitis (PD). We previously showed that extracts of Canavalia gladiata (sword bean extract, SBE) can treat PD in rats. Here, we investigated the relationship between RA and PD and the effects of SBE in an experimental mouse model.

Methods

Female SKG mice were assigned to eight groups (n=6/group): (1) Untreated controls, (2) RA (induced at 6 weeks of age), (3) PD (induced at 10 weeks of age), (4) RA + PD, (5) SBE (2 mg/ml in drinking water starting at 5 weeks of age), (6) PD + SBE, (7) RA + SBE, and (8) RA + PD + SBE. Mice were sacrificed at 13 weeks of age, and alveolar bone resorption, periodontal tissue inflammation, and paw joint inflammation were assessed by histology and immunohistochemistry.

Results

Mice in the RA + PD group exhibited significantly higher inflammation scores in the joint tissues as well as more abundant IL-17-positive cells and cathepsin K-positive osteoclasts in the radial bone compared with the RA mice. Alveolar bone resorption was also significantly more severe in the RA + PD mice than in the PD mice. SBE treatment significantly improved all bone resorption and tissue inflammation scores in mice with RA + PD.

Conclusion

Concomitant RA and PD exacerbates the tissue destruction symptomatic of each condition. SBE suppresses all parameters evaluated, suggesting that it is has anti-inflammatory activities in both RA and PD.
Effects of reduced sulfur on passive film properties of steam generator (SG) tubing: an overview
Authors: Xia Da-Hai , Luo Jing-Li
Published: February 2019

Purpose

Corrosion is considered as one of the issues that threaten the safe operation of steam generator (SG) tubing. Some sulfur-related specie can cause corrosion degradation of SG tubing. Sulfur-induced corrosion of SG alloys in high temperature and high-pressure water is one of the most complicated processes. The purpose of this study is to study the effect of reduced sulphur on passive film properties of steam generator (SG) tubing.

Design/methodology/approach

In this paper, the effects of reduced sulfur on passive film properties of SG tubing were reviewed from the aspects of thermodynamic calculations and experimental.

Findings

Thermodynamic calculations are mainly presented by E-pH diagrams, volt equivalent diagrams and species distribution curves. The stability of sulphur species highly depends on temperature, solution pH, and electrochemical potential. Experimental data indicated that reduced sulfur species can interact with the passive film, which led to changes in film thickness, film structure, semiconductivity and pitting growth rate.

Originality/value

The state-of-the-art discussed in this paper gives basis for resolving engineering problems regarding with sulfur-induced corrosion.
The impact of perceived CSR on corporate reputation and purchase intention
Authors: Bianchi Enrique , Bruno Juan Manuel , Sarabia-Sanchez Francisco J.
Published: February 2019

Purpose

The purpose of this paper is to examine the influence of consumers’ perceived corporate social responsibility (CSR). The aim is to provide insight into the effect of perceived CSR on purchase intention (short-term effect) and corporate reputation (long-term effect), whilst considering the role of brand image, satisfaction (affective and cognitive) and brand loyalty.

Design/methodology/approach

The sample comprised 429 consumers selected using non-probabilistic sampling with age and gender quotas. Confirmatory factor analysis was used to validate the measurement model. Structural equation modelling was used to validate the research hypotheses.

Findings

All direct and mediated influences in the model were significant, except for the effects of perceived CSR on affective satisfaction. Thus, the proposed causal chain is valuable to understand how perceptions of CSR influence purchase intention and perceived reputation.

Research limitations/implications

Perception is considered a dual phenomenon (cognitive and affective). It would be advisable to consider both dimensions in the future. The same is true of affective satisfaction.

Originality/value

Direct and mediated relationships that have previously been studied separately are considered together in a single model. This approach provides a better understanding of how perceived CSR influences purchase intention and reputation.
Forensic analysis of Google Allo messenger on Android platform
Authors: Agrawal Vinayak , Tapaswi Shashikala
Published: February 2019

Purpose

The purpose of this paper is to conduct a forensic analysis of Google Allo messenger on an Android-based mobile phone. The focus was on the analysis of the data stored by this application in the internal memory of the mobile device, with minimal use of third-party applications. The findings were compared with the already existing works on this topic. Android is the most popular operating system for mobile devices, and these devices often contain a massive amount of personal information about the user such as photos and contact details. Analysis of these applications is required in case of a forensic investigation and makes the process easier for forensic analysts.

Design/methodology/approach

Logical acquisition of the data stored by these applications was performed. A locked Android device was used for this purpose. Some scripts are presented to help in data acquisition using Android Debug Bridge (ADB). Manual forensic analysis of the device image was performed to see whether the activities carried out on these applications are stored in the internal memory of the device. A comparative analysis of an existing mobile forensic tool was also performed to show the effectiveness of the methodology adopted.

Findings

Forensic artifacts were recovered from Allo application. Multimedia content such as images were also retrieved from the internal memory.

Research limitations/implications

As this study was conducted for forensic analysis, it assumed that the mobile device used already has USB debugging enabled on it, although this might not be the applicable in some of the cases. This work provides an optimal approach to acquiring artifacts with minimal use of third-party applications.

Practical implications

Most of the mobile devices contain messaging application such as Allo installed. A large amount of personal information can be obtained from the forensic analysis of these applications, which can be useful in any criminal investigation.

Originality/value

This is the first study which focuses on the Google Allo application. The proposed methodology was able to extract almost as much as the data obtained using earlier approaches, but with minimal third-party application usage.
Socio-technical systems cybersecurity framework
Authors: Malatji Masike , Von Solms Sune , Marnewick Annlizé
Published: February 2019

Purpose

This paper aims to identify and appropriately respond to any socio-technical gaps within organisational information and cybersecurity practices. This culminates in the equal emphasis of both the social, technical and environmental factors affecting security practices.

Design/methodology/approach

The socio-technical systems theory was used to develop a conceptual process model for analysing organisational practices in terms of their social, technical and environmental influence. The conceptual process model was then applied to specifically analyse some selected information and cybersecurity frameworks. The outcome of this exercise culminated in the design of a socio-technical systems cybersecurity framework that can be applied to any new or existing information and cybersecurity solutions in the organisation. A framework parameter to help continuously monitor the mutual alignment of the social, technical and environmental dimensions of the socio-technical systems cybersecurity framework was also introduced.

Findings

The results indicate a positive application of the socio-technical systems theory to the information and cybersecurity domain. In particular, the application of the conceptual process model is able to successfully categorise the selected information and cybersecurity practices into either social, technical or environmental practices. However, the validation of the socio-technical systems cybersecurity framework requires time and continuous monitoring in a real-life environment.

Practical implications

This research is beneficial to chief security officers, risk managers, information technology managers, security professionals and academics. They will gain more knowledge and understanding about the need to highlight the equal importance of both the social, technical and environmental dimensions of information and cybersecurity. Further, the less emphasised dimension is posited to open an equal but mutual security vulnerability gap as the more emphasised dimension. Both dimensions must, therefore, equally and jointly be emphasised for optimal security performance in the organisation.

Originality/value

The application of socio-technical systems theory to the information and cybersecurity domain has not received much attention. In this regard, the research adds value to the information and cybersecurity studies where too much emphasis is placed on security software and hardware capabilities.
Mitigating cyber attacks through the measurement of non-IT professionals’ cybersecurity skills
Authors: Carlton Melissa , Levy Yair , Ramim Michelle
Published: February 2019

Purpose

Users’ mistakes due to poor cybersecurity skills result in up to 95 per cent of cyber threats to organizations. Threats to organizational information systems continue to result in substantial financial and intellectual property losses. This paper aims to design, develop and empirically test a set of scenarios-based hands-on tasks to measure the cybersecurity skills of non-information technology (IT) professionals.

Design/methodology/approach

This study was classified as developmental in nature and used a sequential qualitative and quantitative method to validate the reliability of the Cybersecurity Skills Index (CSI) as a prototype-benchmarking tool. Next, the prototype was used to empirically test the demonstrated observable hands-on skills level of 173 non-IT professionals.

Findings

The importance of skills and hands-on assessment appears applicable to cybersecurity skills of non-IT professionals. Therefore, by using an expert-validated set of cybersecurity skills and scenario-driven tasks, this study established and validated a set of hands-on tasks that measure observable cybersecurity skills of non-IT professionals without bias or the high-stakes risk to IT.

Research limitations/implications

Data collection was limited to the southeastern USA and while the sample size of 173 non-IT professionals is valid, further studies are required to increase validation of the results and generalizability.

Originality/value

The validated and reliable CSI operationalized as a tool that measures the cybersecurity skills of non-IT professionals. This benchmarking tool could assist organizations with mitigating threats due to vulnerabilities and breaches caused by employees due to poor cybersecurity skills.
Segregated and not equal? Occupation, earnings gap between urban residents and rural migrants in Vietnam
Authors: Liu Amy Y.C.
Published: February 2019

Purpose

The purpose of this paper is to examine the earnings differentials between the locals and the rural–urban migrants in urban labor market in Vietnam.

Design/methodology/approach

Using the new Vietnam Rural-Urban Migration Survey 2013 (VRUMS2013) that is specifically designed for rural–urban migration, the author applies Appletonet al.’s (1999) procedure correcting for potential selectivity to decompose the offered earnings gap between the locals and the rural–urban migrants into within- and between-occupation pay differential. Bootstrapping is used to derive the standard errors for the decomposition results. The author further applies the propensity score matching (PSM) method to check whether the results are robust by restricting the sample to the “common support.”

Findings

Within-job difference, particularly, the favorable treatment toward urban workers contributes significantly to the overall and total unexplained earnings gap. Further, between-job pay differential attributed to the over-representation of urban workers in high-paying job also helps to widen the gap. These results are robust restricting to the “common support” sample using PSM.

Research limitations/implications

Due to the sample size, occupations are only classified into three broad categories. Finer classification will allow a better comparison between the contributions of between and within-occupation to earning inequality. The data are only limited to a few cities and do not include other urban centers that also receive rural–urban migrants.

Practical implications

Policies to promote equal pay and alleviate within-job “discrimination,” especially the preferential treatment favoring the locals (rather than to provide equal access to different jobs) are crucial for migrants’ labor outcome. Moreover, this study can, to some extent, be seen as a timely contribution for the debate on household registration reform in general and in Vietnam specifically. Given China’s announcement to grant permanent household registration (hukou) to unregistrated migrants in late 2015, investigating whether there is a two-tier labor market in the cities in Vietnam is particularly important for the ongoing debate regarding future of household registration system (ho khau).

Originality/value

This is the first study in Vietnam on rural–urban migration and occupation segregation – an area that has been relatively less well studied in developing/transitional countries. Vietnam is also one of the few developing countries who have household registration system in place. This has made it an interesting case. The author uses a new survey data to apply the Appletonet al.(1999) decomposition on the offered wage gap rather than observed wage gap. Standard errors of the decomposition results are bootstrapped and a robust check using propensity score method is conducted.
Supply chain adaptations for the base-of-the-pyramid business: towards a theoretical model
Authors: Zomorrodi Maryam , Fayezi Sajad , Lau Kwok Hung , McMurray Adela
Published: February 2019

Purpose

Research has not yet captured nor synthesized the supply chain (SC) adaptations exercised by various base of the pyramid (BoP) initiators for successful BoP business. This is a crucial shortcoming that the study has taken a step to address, with the aim of advancing theory in BoP supply chain management (SCM). The paper aims to discuss this issue.

Design/methodology/approach

The authors draw on Carteret al.’s (2015) theory of the SC and use a multi-method approach combining systematic literature review and embedded case studies based on the secondary data.

Findings

The authors compare BoP SC adaptations of MNCs, local companies, NGOs, social enterprises and governments and develop propositions. The authors find that SC adaptations exercised by BoP initiators are influenced by their sense making of institutional and agency drivers at the BoP, and contingent on whether the poor are engaged as recipients or value co-creators.

Practical implications

The authors develop a multi-initiator understanding of SC adaptations for BoP business. This is useful for BoP initiators who struggle to leverage their BoP business as well as for those who are considering entering the BoP. The authors offer these entities insights for aligning strategy and developing capabilities for BoP markets.

Originality/value

The authors develop an original model of BoP initiator-based configurations of SC adaptations for BoP business. As such, the authors contribute toward advancing BoP SCM theory and practice by mapping substantive concepts and their relationships associated with BoP SC adaptations.
An exploratory study of the results of the implementation of EFQM in private Spanish firms
Authors: Gómez-López Raquel , Serrano-Bedia Ana Maria , López-Fernández María Concepción
Published: February 2019

Purpose

The implementation of business excellence models is becoming a key competitive priority for companies, but the type of results they obtain by implementing such models and the importance of such results remain open issues. The purpose of this paper is to clarify the results obtained by companies that implement the European Foundation for Quality Management (EFQM) excellence model, with a focus on their importance and nature.

Design/methodology/approach

An empirical study was conducted in 68 Spanish firms that were immersed in the process of implementing EFQM. The methodology consists of a descriptive analysis and factor analysis in order to determine which groups of results are the most important. Finally, clusters of firms are analyzed to establish their profile in relation to these groups, using cluster analysis.

Findings

This study shows that the main results of the implementation of EFQM are an improvement in the external image of the company and an increased efficiency of internal processes. In addition, the results can be grouped into internal results, human resources results and economic results, with the first group being the most important. Finally, the results show that there are three groups of firms, categorized according to their results orientation: highly results-oriented, moderately results-oriented and minimally results-oriented.

Practical implications

Companies are in a better position to anticipate and solve the problems that may arise during the implementation process if they understand the results of the implementation of EFQM, along with the motivations for and barriers to the implementation. Also, this research shows that the bodies promoting and motivating quality should make a special effort to emphasize the importance of non-financial results in companies that implement EFQM.

Originality/value

This paper extends the knowledge in the field of business excellence models by developing an instrument to measure implementation results from the perspective of quality managers who were specifically appointed to lead the implementation of the EFQM excellence model in companies.