bluuebunny/crossref_metadata_2025 huggingface dataset:
Copulas and their potential for ecology
Authors: Ghosh Shyamolina , Sheppard Lawrence W. , Holder Mark T. , Loecke Terrance D. , Reid Philip C. , Bever James D. , Reuman Daniel C.
Published: May 2019

All branches of ecology study relationships among and between environmental and biological variables. However, standard approaches to studying such relationships, based on correlation and regression, provide only a small slice of the complex information contained in the relationships. Other statistical approaches exist that provide a complete description of relationships between variables, based on the concept of the copula; they are applied in finance, neuroscience and other fields, but rarely in ecology. We here explore the concepts that underpin copulas and examine the potential for those concepts to improve our understanding of ecology. We find that informative copula structure in dependencies between variables is common across all the environmental, species-trait, phenological, population, community, and ecosystem functioning datasets we considered. Many datasets exhibited asymmetric tail associations, whereby two variables were more strongly related in their left compared to right tails, or vice versa. We describe mechanisms by which observed copula structure and asymmetric tail associations can arise in ecological data, including a Moran-like effect whereby dependence structures between environmental variables are inherited by ecological variables; and asymmetric or nonlinear influences of environments on ecological variables, such as under Liebig’s law of the minimum. We also describe consequences of copula structure for ecological phenomena, including impacts on extinction risk, Taylor’s law, and the stability through time of ecosystem services. By documenting the importance of a complete description of dependence between variables, advancing conceptual frameworks, and demonstrating a powerful approach, we aim to encourage widespread use of copulas in ecology, which we believe can benefit the discipline.
PhenoGeneRanker: A Tool for Gene Prioritization Using Complete Multiplex Heterogeneous Networks
Authors: Dursun Cagatay , Shimoyama Naoki , Shimoyama Mary , Schläppi Michael , Bozdag Serdar
Published: May 2019

Uncovering genotype-phenotype relationships is a fundamental challenge in genomics. Gene prioritization is an important step for this endeavor to make a short manageable list from a list of thousands of genes coming from high-throughput studies. Network propagation methods are promising and state of the art methods for gene prioritization based on the premise that functionally-related genes tend to be close to each other in the biological networks.

In this study, we present PhenoGeneRanker, an improved version of a recently developed network propagation method called Random Walk with Restart on Multiplex Heterogeneous Networks (RWR-MH). PhenoGeneRanker allows multi-layer gene and disease networks. It also calculates empirical p-values of gene ranking using random stratified sampling of genes based on their connectivity degree in the network.

We ran PhenoGeneRanker using multi-omics datasets of rice to effectively prioritize the cold tolerance-related genes. We observed that top genes selected by PhenoGeneRanker were enriched in cold tolerance-related Gene Ontology (GO) terms whereas bottom ranked genes were enriched in general GO terms only. We also observed that top-ranked genes exhibited significant p-values suggesting that their rankings were independent of their degree in the network.

CCS CONCEPTS

• Bioinformatics • Biological networks • System biology • Computational genomics

Availability and implementation

The source code is available on GitHub at https://github.com/bozdaglab/PhenoGeneRanker under Creative Commons Attribution 4.0 license

Contact

cdursun@mcw.edu or serdar.bozdag@marquette.edu
Diverse strategies link growth rate and competitive ability in phytoplankton responses to changes in CO2 levels
Authors: Collins Sinead , Schaum C. Elisa
Published: May 2019

Aquatic microbial primary producers exist in genetically variable populations, but are often studied as single lineages. However, the properties of lineages grown alone often fail to predict the composition of microbial assemblages. We demonstrate that different lineages of a marine picoplankter have unique growth strategies, and that they modulate their lineage growth rate in the presence of other lineages. This explains why growth rates of lineages in isolation do not reliably predict the lineage composition of assemblages. The diversity of growth strategies observed are consistent with lineage-specific energy-allocation that depends on social milieu. Since lineage growth is only one of many traits determining fitness in natural assemblages, we propose that in all but the poorest quality environments where allocating maximum energy to growth is the only viable strategy, we should expect intraspecific variation in growth strategies, with more strategies possible in ameliorated environments, such as high CO2 for many marine picoplankton. This emphasizes the importance of understanding and accounting for basic organismal biology in our models of aquatic primary producers.

Data archiving

Should this manuscript be accepted, data will be archived at Pangea, and the DOI be included at the end of the article
The Adaptor Protein Nck1, but not Nck2, Mediates Shear Stress-Induced Endothelial Permeability
Authors: Alfaidi Mabruka , Bhattarai Umesh , Cockerham Elizabeth D , Orr A.W.
Published: May 2019

Alteration in hemodynamic shear stress at atheroprone sites promotes endothelial paracellular pore formation and permeability. Previously, we have reported that a peptide inhibitor to Nck prevented shear stress-induced p21 activated kinase (PAK) activation and endothelial permeability. However, the specificity of this peptide is unclear, and the role of individual Nck isoforms remain unknown. Here, we show that genetic deletion of Nck1/2 adaptor proteins significantly ameliorates shear stress induced permeability, and selective isoform depletion suggests distinct signaling mechanisms. Only Nck1 deletion significantly reduces flow-induced paracellular pore formation and permeability, whereas Nck2 depletion has no significant effects. Additionally, Nck1 reexpression, but not Nck2, restores shear stress-induced permeability in Nck1/2 knockout cells, confirming the non-compensating roles. In vivo, using the partial carotid ligation model of disturbed flow, Nck1 knockout prevented the increase in vascular permeability, as assessed by both Evans blue extravasation and leakage of plasma fibrinogen into the vessel wall. Domain swap experiments mixing SH2 (phosphotyrosine binding) and SH3 (proline rich binding) domains between Nck1 and Nck2 showed a dispensable role for SH2 domains but a critical role for the Nck1 SH3 domains in rescuing shear stress-induced endothelial permeability. Consistent with this, both Nck1 and Nck2 bind to PECAM-1 (SH2 dependent) in response to shear stress, but only Nck1 ablation interferes with shear stress-induced PAK2 activation (SH3 dependent). This work provides the first evidence that Nck1 and Nck2 play distinct roles in flow-induced vascular permeability.

New and Noteworthy

The present study shows a specific role for Nck1 in endothelial permeability in response to shear stress. Using in vitro and in vivo models, we demonstrate improvement in endothelial barrier integrity in cells subjected to disturbed flow only following Nck1 but not Nck2 deletion. Selective Nck1 inhibition may limit endothelial permeability at sites of disturbed flow to reduce atherosclerosis without affecting angiogenesis, which requires both Nck1 and Nck2 inhibition.
Introgression of Austrian fire-bellied toads (Bombina bombina) into northern German populations confirmed by complete mitochondrial genomes and transcriptome-wide Single Nucleotide Polymorphisms (SNPs)
Authors: De Cahsan Binia , Westbury Michael V , Paraskevopoulou Sofia , Drews Hauke , Ott Moritz , Gollmann Günter , Tiedemann Ralph
Published: May 2019

The fire-bellied toad (Bombina bombina) is a small amphibian species inhabiting the lowlands of Central and Eastern Europe. Continual population fragmentation has caused a decrease in genetic diversity and gene flow in margin populations in Northern Germany. Previous research using mitochondrial control region data uncovered a translocation of allochthonous toads from Austria into a single northern German population, Högsdorf. Microsatellite and MHC data also confirmed this introgression, but were limited in revealing the true extent of this translocation for all investigated populations. Here, we utilize complete mitochondrial genomes and nuclear data, in the form of transcriptomes, to unravel the full extent of admixture from this translocation. The increased number of loci enabled us to uncover signs of introgression in four out of the five northern populations investigated. Moreover, as hybrids between B. bombina and its sister species, B. variegata, have been reported in Austria, we also investigated whether B. variegata alleles were translocated into the northern gene pool. We found evidence for hybridization between Austrian B. bombina and B. variegata, as well as traces of B. variegata alleles in one of the five German populations included in this study. These findings present the first reported case of introgressed relict B. variegata alleles from the Southern lineage being detected in Northern Germany.
Direct Pathway Neurons in Mouse Dorsolateral Striatum In Vivo Receive Stronger Synaptic Input than Indirect Pathway Neurons
Authors: Filipović Marko , Ketzef Maya , Reig Ramon , Aertsen Ad , Silberberg Gilad , Kumar Arvind
Published: May 2019

Striatal projection neurons, the medium spiny neurons (MSNs), play a crucial role in various motor and cognitive functions. MSNs express either D1 or D2 type dopamine receptors and initiate the direct-pathway (dMSNs) or indirect pathways (iMSNs) of the basal ganglia, respectively. dMSNs have been shown to receive more inhibition than iMSNs from intrastriatal sources. Based on these findings, computational modelling of the striatal network has predicted that under healthy conditions dMSNs should receive more excitatory input than iMSNs. To test this prediction, we analyzed in vivo whole-cell recordings from dMSNs and iMSNs in healthy and dopamine-depleted (6OHDA) anaesthetized mice. By comparing their membrane potential fluctuations, we found that dMSNs exhibited considerably larger membrane potential fluctuations over a wide frequency range. Furthermore, by comparing the spike-triggered average membrane potentials, we found that dMSNs depolarized towards the spike threshold significantly faster than iMSNs did. Together, these finding corroborate the theoretical prediction that direct-pathway MSNs receive stronger input than indirect-pathway neurons. Finally, we found that dopamine-depleted mice exhibited no difference between the membrane potential fluctuations of dMSNs and iMSNs. These data provide new insights into the question how a lack of dopamine may lead to behavior deficits associated with Parkinson’s disease.

Significance statement

The direct and indirect pathways of the basal ganglia originate from the D1 and D2 type dopamine receptor expressing medium spiny neurons (dMSNs and iMSNs), respectively. To understand the role of the striatum in brain function and dysfunction it is important to characterize the differences in synaptic inputs to the two MSN types. Theoretical results predicted that dMSNs should receive stronger excitatory input than iMSNs. Here, we studied membrane potential fluctuation statistics of MSNs recorded in vivo in anaesthetized mice and found that dMSNs, indeed, received stronger synaptic input than iMSNs. We corroborated this finding by spike-triggered membrane potential analysis, showing that dMSNs spiking required more synaptic input than iMSNs spiking did, as had been predicted by computational models.
Higher prevalence of homologous recombination-deficiency in lung squamous carcinoma from African Americans
Authors: Sinha Sanju , Mitchell Khadijah A. , Zingone Adriana , Bowman Elise , Sinha Neelam , Schäffer Alejandro A. , Lee Joo Sang , Ruppin Eytan , Ryan Bríd M.
Published: May 2019

To improve our understanding of the longstanding disparities in incidence and mortality across multiple cancer types among minority populations, we performed a systematic comparative analysis of molecular features in tumors from African American (AA) and European American (EA) ancestry. Our pan-cancer analysis on the cancer genome atlas (TCGA) and a more focused analysis of genome-wide somatic copy number profiles integrated with tumor-normal RNA sequencing in a racially balanced cohort of 222 non-small cell lung cancers (NSCLC) reveals more aggressive genomic characteristics of AA tumors. In general, we find AA tumors exhibit higher genomic instability (GI), homologous recombination-deficiency (HRD) levels, and more aggressive molecular features such as chromothripsis across many cancer types, including lung squamous carcinoma (LUSC). GI and HRD levels are strongly correlated across AA tumors, indicating that HRD plays an important role in GI in these patients. The prevalence of germline HRD is higher in AA tumors, suggesting that the somatic differences observed have genetic ancestry origins. Finally, we identify AA-specific copy number-based arm, focal and gene level recurrent features in lung cancer, including a higher frequency of PTEN deletion and KRAS amplification and a lower frequency of CDKN2A deletion. These results highlight the importance of including minority and under-represented populations in genomics research and may have therapeutic implications.
Dissecting the eQTL micro-architecture inCaenorhabditis elegans
Authors: Sterken Mark G. , Bevers Roel P. J. , Volkers Rita. J. M. , Riksen Joost A. G. , Kammenga Jan E. , Snoek L. Basten
Published: May 2019

The study of expression quantitative trait loci (eQTL) using natural variation in inbred populations has yielded detailed information about the transcriptional regulation of complex traits. Studies on eQTL using recombinant inbred lines (RILs) led to insights on local and distant regulatory loci of transcript abundance. However, determining the underlying causal polymorphic genes or variants is difficult, but ultimately essential for the understanding of regulatory networks of complex traits. This requires insight into whether associated loci are single eQTL or a combination of closely linked eQTL, and how this QTL micro-architecture depends on the environment. We addressed these questions by mapping eQTL in N2 x CB4856C. elegansRIL populations across three different environments (control, heat-stress, and recovery). To test for independent replication of the RIL eQTL, we used introgression lines (ILs). Both populations indicate that the overall heritability, number, and position of eQTL differed among environments. Across environments we were able to replicate 70% of the local- and 40% of the distant-eQTL using the ILs. Simulation models revealed that additive effects explain up to 60-93% of RIL/IL heritability across environments. Closely linked eQTL explained up to 40% of RIL/IL heritability in the control environment whereas only 7% in the heat-stress and recovery environments. In conclusion, we show that reproducibility of eQTL was higher for local vs. distant eQTL and that the environment affects the eQTL micro-architecture.
Fate mapping via Ms4a3 expression history traces monocyte-derived cells
Authors: Liu Zhaoyuan , Gu Yaqi , Chakarov Svetoslav , Bleriot Camille , Chen Xin , Shin Amanda , Huang Weijie , Dress Regine J. , Dutertre Charles-Antoine , Schlitzer Andreas , Chen Jinmiao , Wang Honglin , Liu Zhiduo , Su Bing , Ginhoux Florent
Published: May 2019

Most tissue-resident macrophage (RTM) populations are seeded by waves of embryonic hematopoiesis and are self-maintained independently of a bone-marrow contribution during adulthood. A proportion of RTMs, however, is constantly replaced by blood monocytes and their functions compared to embryonic RTM remains unclear. The kinetics and extent of the contribution of circulating monocytes to RTM replacement during homeostasis, inflammation and disease is highly debated. Here, we identified Ms4a3 as a specific marker expressed by granulocyte-monocyte progenitors (GMPs) and subsequently generated Ms4a3TdT reporter and Ms4a3Cre-RosaTdT fate mapper models to follow monocytes and their progenies. Our Ms4a3Cre-RosaTdT model traced efficiently blood monocytes (97%) and granulocytes (100%), but no lymphocytes or tissue dendritic cells. Using this model, we precisely quantified the contribution of monocytes to the RTM pool during homeostasis and inflammation. The unambiguous identification of monocyte-derived cells will permit future studies of their function under any condition.
Numerical Investigation of Drug Transport from Blood Vessels to Tumor Tissue Using a Tumor-Vasculature-on-a-Chip
Authors: Li Wei , Wang Hao-Fei , Li Zhi-Yong , Wang Tong , Zhao Chun-Xia
Published: May 2019

The delivery of adequate concentration of anticancer drugs to tumor site is critical to achieve effective therapeutic treatment, but it is challenging to experimentally observe drug transport and investigate the spatial distribution of the drug in tumor microenvironment. In this study, we investigated the drug transport from a blood vessel to tumor tissue, and explored the effect of tumor size, tumor numbers and positioning on drug concentration distribution using a numerical method in combination with a microfluidic Tumor-Vasculature-on-a-Chip (TVOC) model. The TVOC model is composed of a vessel channel, a tumor channel sandwiched with a porous membrane. A species transport model based on computational fluid dynamics was adapted to investigate drug transport. The numerical simulation was firstly validated using experimental data, and then used to analyse the spatial-temporal structure of the flow, and to investigate the effect of tumor size and positioning on drug transport and drug concentration heterogeneity. We found the drug concentration surrounding the tumor is highly heterogeneous, with the most downstream point the most difficult for drugs to transport and the nearest point to the blood vessel the easiest. Moreover, tumor size and positioning contribute significantly to this drug concentration heterogeneity on tumor surface, which is dramatically augmented in large and downstream-positioned tumors. These studies established the relationship between solid tumor size/positioning and drug concentration heterogeneity in the tumor microenvironment, which could help to understand heterogenous drug distribution in tumor microenvironment.
Risk of complications among diabetics self-reporting oral health status in Canada: A population-based cohort study
Authors: Parbhakar Kamini Kaura , Rosella Laura C. , Singhal Sonica , Quiñonez Carlos R.
Published: May 2019

Background

Periodontitis has persistently been associated with diabetes and poor health outcomes. While clear associations have been identified for the diabetes–oral health link, less is known about the implications of poor oral health on incident complications of diabetes. This study sought to investigate the risk of diabetes complications associated with self-reported “poor to fair” and “good to excellent” oral health status among diabetics living in Ontario, Canada.

Methods

This cohort study was undertaken of diabetics from the Canadian Community Health Survey (2003 and 2007-8). Self-reported oral health was linked to electronic health records at the Institute for Clinical Evaluative Sciences. Participants under the age of 40, missing self-reported oral health and those who could not be identified in linked databases were excluded (N=5,183). A series of Cox Proportional hazard models were constructed to determine the risk of diabetes complications. Participants who did not experience any diabetes complication were censored at time of death or at the study termination date (March 31, 2016). Models were adjusted for age and sex, followed by social characteristics and behavioural factors.

Results

Diabetes complications differed by self-reported oral health. For those reporting “poor to fair” oral health, the hazard of a diabetes complication was 30% greater (HR 1.29 95%CI 1.03, 1.61) than those reporting “good to excellent” oral health.

Conclusions

Our findings indicate that oral health status is associated with increased risk for complications among diabetics, after adjusting for a wide range of confounders. Examining oral health and the risk for diabetes complications from a broader perspective including socio-behavioural and biological pathways is principal for informing policies and interventions that aim to mitigate the burdens of poor systemic health.
Degradations of tannin and saponin during co-composting of shell and seed cake of Camellia oleifera Abel
Authors: Zhang Jinping , Ying Yue , Yao Xiaohua
Published: May 2019

The degradation processes were studied in this paper of tannin and saponin during the co-composting of the shell and seed cake ofCamellia oleiferaAbel. Four treatments were designed with the dry weight of the seed cake accounting for 1/3(A1), 1/4(A2), 1/5(A3), and 1/10(A4) of the shell. The proportion of the seed cake is positively correlated with the duration of thermophilic phase, highest temperature and degradation rate of tannin and saponin whose maximum were in A1, but negatively correlated with C/N ratio and tannin content which were least in A1 of the final products. The content of saponin were all about 2% finally. The final content of saponin and tannin decreased 68.92-75.22% and 34.57-59.52%. The organic matters, total nutrient (N, P2O5and K2O) increased with the rising proportion of the seed cake. Overall, the addition of the seed cake promoted the stability, fertilizer efficiency and safety of the co-compost product.
Raman Open Database: first interconnected Raman–X-ray diffraction open-access resource for material identification
Authors: El Mendili Yassine , Vaitkus Antanas , Merkys Andrius , Gražulis Saulius , Chateigner Daniel , Mathevet Fabrice , Gascoin Stéphanie , Petit Sebastien , Bardeau Jean-François , Zanatta Marco , Secchi Maria , Mariotto Gino , Kumar Arun , Cassetta Michele , Lutterotti Luca , Borovin Evgeny , Orberger Beate , Simon Patrick , Hehlen Bernard , Le Guen Monique
Published: May 2019

Detailed crystallographic information provided by X-ray diffraction (XRD) is complementary to molecular information provided by Raman spectroscopy. Accordingly, the combined use of these techniques allows the identification of an unknown compound without ambiguity. However, a full combination of Raman and XRD results requires an appropriate and reliable reference database with complete information. This is already available for XRD. The main objective of this paper is to introduce and describe the recently developed Raman Open Database (ROD, http://solsa.crystallography.net/rod). It comprises a collection of high-quality uncorrected Raman spectra. The novelty of this database is its interconnectedness with other open databases like the Crystallography Open Database (http://www.crystallography.net/cod and Theoretical Crystallography Open Database (http://www.crystallography.net/tcod/). The syntax adopted to format entries in the ROD is based on the worldwide recognized and used CIF format, which offers a simple way for data exchange, writing and description. ROD also uses JCAMP-DX files as an alternative format for submitted spectra. JCAMP-DX files are compatible to varying degrees with most commercial Raman software and can be read and edited using standard text editors.
Supramolecular networks and Hirshfeld surfaces of oxydiacetic acid and iminodiacetic acid salts
Authors: Gomathi V. , Theivarasu C.
Published: May 2019

Oxydiacetic acid (Oda) and iminodiacetic acid (Ida) have been combined with two diamines, namely ethylenediamine (en) and o-phenylenediamine (o-phen), to give three molecular crystals of compositions [(Oda2−)(en2+)]·H2O (Odaen), [(Ida−)(0.5en+)] (Idaen) and [(Oda−)(o-phen+)] (Odaophen). Single crystal X-ray structure determination of the three molecular salts revealed that the hydrogen bonding interactions form distinct supramolecular chains. In Odaen, water molecules and Oda2− anions generate one-dimensional supramolecular chains where two chains overlap each other in zigzag form. In Odaophen, Oda− anions generate a one-dimensional linear supramolecular chain. In Idaen, both intermolecular and intramolecular proton transfer occurs. Ida− anions generate a one-dimensional zigzag chain. These one-dimensional supramolecular chains extend to form different two-dimensional supramolecular chains by the interaction of diaminium and monoaminium cations. Intermolecular close contacts are also examined using Hirshfeld analysis to reveal similarities and differences in the crystal structures.
Magnetic properties of a new cobalt hydrogen vanadate with a dumortierite-like structure: Co13.5(OH)6(H0.5VO3.5)2(VO4)6
Authors: Hadouchi Mohammed , Assani Abderrazzak , Saadi Mohamed , Lahmar Abdelilah , El Marssi Mimoun , El Ammari Lahcen
Published: May 2019

The magnetic properties of a novel cobalt-based hydrogen vanadate, Co13.5(OH)6(H0.5VO3.5)2(VO4)6, are reported. This new magnetic material was synthesized in single-crystal form using a conventional hydrothermal method. Its crystal structure was determined from single-crystal X-ray diffraction data and was also characterized by scanning electron microscopy. Its crystal framework has a dumortierite-like structure consisting of large hexagonal and trigonal channels; the large hexagonal channels contain one-dimensional chains of face-sharing CoO6 octahedra linked to the framework by rings of VO4 tetrahedra, while the trigonal channels are occupied by chains of disordered V2O4 pyramidal groups. The magnetic properties of this material were investigated by DC magnetic measurements, which indicate the occurrence of antiferromagnetic interactions.
Analysis of crystalline and solution states of ligand-free spermidineN-acetyltransferase (SpeG) fromEscherichia coli
Authors: Filippova Ekaterina V. , Weigand Steven , Kiryukhina Olga , Wolfe Alan J. , Anderson Wayne F.
Published: May 2019

SpermidineN-acetyltransferase (SpeG) transfers an acetyl group from acetyl-coenzyme A to an N-terminal amino group of intracellular spermidine. This acetylation inactivates spermidine, reducing the polyamine toxicity that tends to occur under certain chemical and physical stresses. The structure of the SpeG protein fromVibrio choleraehas been characterized: while the monomer possesses a structural fold similar to those of other Gcn5-relatedN-acetyltransferase superfamily members, its dodecameric structure remains exceptional. In this paper, structural analyses of SpeG isolated fromEscherichia coliare described. LikeV. choleraeSpeG,E. coliSpeG forms dodecamers, as revealed by two crystal structures of the ligand-freeE. coliSpeG dodecamer determined at 1.75 and 2.9 Å resolution. Although bothV. choleraeSpeG andE. coliSpeG can adopt an asymmetric open dodecameric state, solution analysis showed that the oligomeric composition of ligand-freeE. coliSpeG differs from that of ligand-freeV. choleraeSpeG. Based on these data, it is proposed that the equilibrium balance of SpeG oligomers in the absence of ligands differs from one species to another and thus might be important for SpeG function.
CM01: a facility for cryo-electron microscopy at the European Synchrotron
Authors: Kandiah Eaazhisai , Giraud Thierry , de Maria Antolinos Alejandro , Dobias Fabien , Effantin Gregory , Flot David , Hons Michael , Schoehn Guy , Susini Jean , Svensson Olof , Leonard Gordon A. , Mueller-Dieckmann Christoph
Published: May 2019

Recent improvements in direct electron detectors, microscope technology and software provided the stimulus for a `quantum leap' in the application of cryo-electron microscopy in structural biology, and many national and international centres have since been created in order to exploit this. Here, a new facility for cryo-electron microscopy focused on single-particle reconstruction of biological macromolecules that has been commissioned at the European Synchrotron Radiation Facility (ESRF) is presented. The facility is operated by a consortium of institutes co-located on the European Photon and Neutron Campus and is managed in a similar fashion to a synchrotron X-ray beamline. It has been open to the ESRF structural biology user community since November 2017 and will remain open during the 2019 ESRF–EBS shutdown.
High redundancy electromechanical actuator for thrust vector control of a launch vehicle
Authors: B. Biju Prasad , N. Biju , M.R. Radhakrishna Panicker
Published: May 2019

Purpose

The purpose of this paper is to design an electromechanical actuator which can inherently tolerate a stuck or loose failure without any need for fault detection isolation and reconfiguration.

Design/methodology/approach

Generalized design methodology for a thrust vector control application is adopted to reduce the design iterations during the initial stages of the design. An optimum ball screw pitch is selected to minimize the motor sizing and maximize the load acceleration.

Findings

A high redundancy electromechanical actuator for thrust vector control has lower self-inertia and higher reliability than a direct drive simplex configuration. This configuration is a feasible solution for thrust vector control application because it offers a more acceptable and graceful degradation than a complete failure.

Research limitations/implications

Future work will include testing on actual hardware to study the transient disturbances caused by a fault and their effect on launch vehicle dynamics.

Practical implications

High redundancy electromechanical actuator concept can be extended to similar applications such as solid motor nozzle in satellite launch vehicles and primary flight control system in aircraft.

Social implications

High redundancy actuators can be useful in safety critical applications involving human beings. It can also reduce the machine downtime in industrial process automation.

Originality/value

The jam tolerant electromechanical actuator proposed for the launch vehicle application has a unique configuration which does not require a complex fault detection isolation and reconfiguration logic in the controller. This enhances the system reliability and allows a simplex controller having a lower cost.
Designing a Cultural Heritage Articulated Warning System (CHAWS) strategy to improve disaster risk preparedness in Brazil
Authors: Marchezini Victor , Iwama Allan Yu , Pereira Danilo Celso , da Conceição Rodrigo Silva , Trajber Rachel , Olivato Débora
Published: May 2019

Purpose

The purpose of this paper is to study an articulated warning system that provides information about the heritage at risk and encourages a dialogue between the heritage sector, civil defense agencies and local communities.

Design/methodology/approach

The databases from the National Heritage Institute, National Civil Defense, National Geological Service and National Early Warning System were investigated and the local community provided input which helped form a participatory risk mapping strategy for a warning system in the heritage sector.

Findings

There is little knowledge of the Brazilian heritage that is at risk and a lack of coordination between the cultural heritage and DRR sectors. This means that there is a need to organize the geo-referenced databases so that information can be shared and the public provided with broader access. As a result, there can be a greater production, dissemination and application of knowledge to help protect the cultural heritage.

Practical implications

The findings can be included in the debate about the importance of framing disaster risk management (DRM) policies in the Brazilian heritage sector.

Social implications

The findings and maps of the case study in the town of São Luiz do Paraitinga involve the heritage sector, civil defense agencies and local people and can be used for disaster risk preparedness.

Originality/value

A DRM program is being formulated in Brazil. However, the kind of strategy needed to incorporate the heritage sector in this program stills needs to be planned, and the knowledge of the cultural heritage at risk is a key factor when faced with this new social and scientific challenge.
Key elements of an information security culture in organisations
Authors: Nel Frans , Drevin Lynette
Published: May 2019

Purpose

The purpose of this paper is to report on a study that investigated the information security culture in organisations in South Africa, with the aim of identifying key aspects of the culture. The unique aspects for building an information security culture were examined and presented in the form of an initial framework. These efforts are necessary to address the critical human aspect of information security in organisations where risky cyber behaviour is still experienced.

Design/methodology/approach

Literature was investigated with the focus on the main keywords security culture and information security. The information security culture aspects of different studies were compared and analysed to identify key elements of information security culture after which an initial framework was constructed. An online survey was then conducted in which respondents were asked to assess the importance of the elements and to record possible missing elements/aspects regarding their organisation’s information security culture to construct an enhanced framework.

Findings

A list of 21 unique security culture elements was identified from the literature. These elements/aspects were divided into three groups based on the frequency each was mentioned or discussed in studies. The number of times an element was found was interpreted as an indication of how important that element/aspect is. A further four aspects were added to the enhanced framework based on the results that emerged from the survey.

Originality/value

The value of this research is that an initial framework of information security culture aspects was constructed that can be used to ensure that an organisation incorporates all key aspects in its own information security culture. This framework was further enhanced from the results of the survey. The framework can also assist further studies related to the information security culture in organisations for improved security awareness and safer cyber behaviour of employees.
Performance analysis of Polyvinylpyrrolidone
Authors: Rathinamoorthy R.
Published: May 2019

Purpose

The purpose of this paper is to focus on the performance analysis of Polyvinylpyrrolidone (PVP) – Chitosan composite dye transfer inhibitor (DTI) for household laundry. The developed composite DTI is tested against different commercial dyes and detergent powders normally used in the household laundry for its performance.

Design/methodology/approach

The DTI article is tested for its performance against five commercial dyes and five commercial detergent compositions. The dye re-deposition behaviour of the control fabric was measured in terms of the colour difference (ΔE) values. The influence of PVP on the washing efficiency of detergent was evaluated against tea, coffee and juice stains.

Findings

The results showed that there is an excellent performance of the developed product noted in terms of DTI performance against reactive, basic and sulfur dyes. The DTI product showed a significantly (p<0.05) less performance against acid and direct dyes. There is no significant differences noted in the stain removal efficiency of the detergent in the presence of PVP in the wash liquor (p>0.05).

Originality/value

The usage of DTI polymer in the household laundry has no significant influence on the detergents performance in terms of stain removing efficiency. The DTI polymer’s function in the wash liquor depends up on the type of polymer used, as they are sensitive to the type of detergent compositions used and the type of dyes bleeds in the wash liquor.
Reliability engineering application to pipeline design
Authors: Omoya Olanrewaju Ayobami , Papadopoulou Kassandra A. , Lou Eric
Published: May 2019

Purpose

The purpose of this paper is to investigate the application of reliability engineering to oil and gas (O&G) pipeline systems with the aim of identifying means through which reliability engineering can be used to improve pipeline integrity, specifically with regard to man-made incidents (e.g. material/weld/equipment failure, corrosion, incorrect operation and excavation damages).

Design/methodology/approach

A literature review was carried out on the application of reliability tools to O&G pipeline systems and four case studies are presented as examples of how reliability engineering can help to improve pipeline integrity. The scope of the paper is narrowed to four stages of the pipeline life cycle; the decommissioning stage is not part of this research. A survey was also carried out using a questionnaire to check the level of application of reliability tools in the O&G industry.

Findings

Data from survey and literature show that a reliability-centred approach can be applied and will improve pipeline reliability where applied; however, there are several hindrances to the effective application of reliability tools, the current methods are time based and focus mainly on design against failure rather than design for reliability.

Research limitations/implications

The tools identified do not cover the decommissioning of the pipeline system. Research validation sample size can be broadened to include more pipeline stakeholders/professionals. Pipeline integrity management systems are proprietary information and permission is required from stakeholders to do a detailed practical study.

Originality/value

This paper proposes the minimum applied reliability tools for application during the design, operation and maintenance phases targeted at the O&G industry. Critically, this paper provides a case for an integrated approach to applying reliability and maintenance tools that are required to reduce pipeline failure incidents in the O&G industry.
Internal auditors’ perceptions of the function’s ability to investigate fraud
Authors: Hazami-Ammar Sourour
Published: May 2019

Purpose

The purpose of this paper is to examine the relation between internal audit function (IAF) characteristics and organizational variables and IAF’s self-investigation about fraud and irregularities (SIFI) in the French context.

Design/methodology/approach

This paper uses the responses of 96 chief audit executives (CAEs) to a global survey of the internal auditing profession carried out by the Institute of Internal Auditors Research Foundation (IIARF) in 2010. A logistic regression model is used to determine factors influencing IAF’s SIFI.

Findings

The authors’ findings reveal that IAF’s SIFI is positively correlated to independence and objectivity, the number of activities performed by the function, adoption of a systematic approach to evaluate the effectiveness of risk management and the size of the company.

Research limitations/implications

This study examines the factors associated only to IAF’s investigation rather than assessment of the risk of fraud. It remains for future research to analyze determinants those related to internal auditors’ approaches when they evaluate the risk of fraud.

Practical implications

The findings have implications for CAEs who wish to improve the IAF’s ability to investigate fraud.

Originality/value

Even if the IIA has stipulated since 2009 that internal auditors must have knowledge to evaluate the risk of fraud, no disclosure requirement exists, in France, for IAF or its charter. The areas of research related to internal audit behavior in relation to fraud concern fraud risk investigation of financial fraud and management/employee misconduct.
Controlling shareholders and the effect of diversification on firm value: evidence from Indonesian listed firms
Authors: Brahmana Rayenda Khresna , Setiawan Doddy , Hooy Chee Wooi
Published: May 2019

Purpose

The purpose of this paper is to investigate whether the presence of controlling shareholder affects the value of diversification based on Indonesian listed firms. It further examines whether the degree of controlling ownership and the types of controlling ownership matter.

Design/methodology/approach

Panel data were used over the period 2006-2010 with dynamic generalised method-of-moments estimations and it defined diversification as industrial diversification, international diversification or diversification in both. A few different thresholds for the control rights of the largest shareholder are also set.

Findings

The results show that industrial diversification improves firm value but international diversification does not, while diversified in both strategies discounted firm value. The presence of a controlling shareholder is found to have a significant diversification discount, and the effect is nonlinear, where the entrenchment effect occurs around 20 to60 per cent threshold of controlling across all types of diversified firms. Last, foreign firms are found to enjoy more value from industrial diversification, but it takes an adverse turn when these involve both diversification strategies. Government firms do not seem to be different from family firms.

Research limitations/implications

The study shows the need to differentiate diversification strategies and account for non-linearity and ownership identity in modelling diversification value. Also, the degree of shareholders’ control can be a significant channel to address the agency issue on diversification value.

Practical implications

Under the backdrop of unique Indonesian corporate ownership, the presence of controlling owners is shown, and their ownership affects the value of diversification. The entrenchment effect however appears only at a certain range of ownership. This is a crucial guide for the shareholders to ensure an appropriate monitoring system is installed to maximize the shareholder’s value, especially in family firms.

Originality/value

The value of this paper is twofold. At first, the first empirical evidence on the diversification debate with Indonesian firms for its unique institutional setting is presented. Second, the standard modelling framework to investigate the types of ownership on diversification value is extended, which has rarely been covered in previous investigations.
A mind model for intelligent machine innovation using future thinking principles
Authors: Botha Anthon P.
Published: May 2019

Purpose

The purpose of this paper is to address the possible future evolution of innovation from a human-only initiative, to human–machine co-innovation, to autonomous machine innovation and to arrive at a conceptual mind model that outlines the role of innovation regimes and innovation agents.

Design/methodology/approach

This is a concept paper where a theoretical “thought experiment” is done, using future thinking principles and data that originate from the literature.

Findings

A conceptual mind model is developed to facilitate a better understanding of complexity at the edge of innovation where intelligent machines will emerge as innovators of the cyber world. It was found that innovation will gradually evolve from a human-only activity, to human–machine co-innovation, to incidences of autonomous machine innovation, based on the growth of machine intelligence and the adoption of human–machine partnership management models in future.

Research limitations/implications

Very little information is available in the literature on intelligent machines doing innovation. The work is based on a theoretical approach that presents new concepts to be debated, but have not been tested in engineering and technology management practice, except for a conference presentation and academic discussion.

Practical implications

The current world view is that future “smartness” is only possible through the creative abilities that humans have, but as machines are entering the workplace and our daily lives, not only as static robots on a manufacturing line, but as intelligent systems with the potential to replace lawyers and accountants, doctors and teachers, companions and partners, their role in innovation in complex environments needs to be explored.

Social implications

Human–machine interaction is often an emotional social issue of concern in terms of the replacement of human intelligence with machine intelligence. It should be asked whether humans will or should remain in control of innovation? Artificial intelligence (AI) may complement and even substitute human intelligence, but huge value is embedded in the new goods, services and innovations AI will enable, especially in manufacturing, where value embedded in the project becomes complex and dynamic.

Originality/value

The thinking presented in this paper is original and should lead to debate to question the way innovation systems will work in future and inspires thinking about AI and innovation.
Financialisation and development: a case study of Ethiopia
Authors: Löscher Anne
Published: May 2019

Purpose

This paper aims to shed light on financial development in Ethiopia and its implications for overall economic development. It does so with particular focus on development understood as industrial development and with special attention drawn on inequality and debt levels as well as the real estate market in Ethiopia. Two research questions are focussed on in particular, where the first serves as prerequisite for the assessment of the second: What kind of financial development took place in Ethiopia in the past quarter of a century? Furthermore, are processes of financialisation visible in Ethiopia, and if so, to what effect?

Design/methodology/approach

The paper is based on publicly available macro-data and qualitative and quantitative data collected by the author herself during a three months’ research stay in Ethiopia.

Findings

It is found that despite higher levels of financial inclusion and deepening, industrialisation is on a relative decline. What is more, inequality and debt levels increase, and the recent growth spurts seem to be rooted in the construction sector with prices in the real estate market surging. In can be concluded that despite a flourishing financial sector, the Ethiopian economy is faced with the peril of crises associated with an inflated real estate market, inequality, debt burdens and impeded industrialisation.

Originality/value

African economies and, in particular, the development and effects of financial markets are still a blind spot in economic research. By combining quantitative and qualitative data on and gathered in Ethiopia, this paper therefore conducts greenfield research.