bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanistic origin of cell-size control and homeostasis in bacteria
Authors: Si Fangwei , Treut Guillaume Le , Sauls John T. , Vadia Stephen , Levin Petra Anne , Jun Suckjoon
Published: November 2018

Evolutionarily divergent bacteria share a common phenomenological strategy for cell-size homeostasis under steady-state conditions. In the presence of inherent physiological stochasticity, cells following this “adder” principle gradually return to their steady-state size by adding a constant volume between birth and division regardless of their size at birth. However, the mechanism of the adder has been unknown despite intense efforts. In this work, we show that the adder is a direct consequence of two general processes in biology: (1) threshold -- accumulation of initiators and precursors required for cell division to a respective fixed number, and (2) balanced biosynthesis -- maintenance of their production proportional to volume growth. This mechanism is naturally robust to static growth inhibition, but also allows us to “reprogram” cell-size homeostasis in a quantitatively predictive manner in both Gram-negativeEscherichia coliand Gram-positiveBacillus subtilis. By generating dynamic oscillations in the concentration of the division protein FtsZ, we were able to oscillate cell size at division and systematically break the adder. In contrast, periodic induction of replication initiator protein DnaA caused oscillations in cell size at initiation, but did not alter division size or the adder. Finally, we were able to restore the adder phenotype in slow-growingE. coli, the only known steady-state growth condition whereinE. colisignificantly deviates from the adder, by repressing active degradation of division proteins. Together these results show that cell division and replication initiation are independently controlled at the gene-expression level, and that division processes exclusively drive cell-size homeostasis in bacteria.

HIGHLIGHTS

The adder requires accumulation of division proteins to a threshold for division.

The adder requires constant production of division proteins during cell elongation.

InE. coliandB. subtilis, initiation and division are independently controlled.

InE. coliandB. subtilis, cell division exclusively drives size homeostasis.

GRAPHICAL ABSTRACT

eTOC Blurb

Si and Le Treutet al. show that cell-size homeostasis in bacteria is exclusively driven by accumulation of division proteins to a threshold and their balanced biosynthesis during cell elongation. This mechanistic insight allowed them to reprogram cell-size homeostasis in bothE. coliandB. subtilis. Evolutionary implications are discussed.
Deep-learning-based label-free segmentation of cell nuclei in time-lapse refractive index tomograms
Authors: Lee Jimin , Kim Hyejin , Cho Hyungjoo , Jo YoungJu , Song Yujin , Ahn Daewoong , Lee Kangwon , Park YongKeun , Ye Sung-Joon
Published: November 2018

In order to identify cell nuclei, fluorescent proteins or staining agents has been widely used. However, use of exogenous agents inevitably prevents from long-term imaging of live cells and rapid analysis, and even interferes with intrinsic physiological conditions. In this work, we proposed a method of label-free segmentation of cell nuclei in optical diffraction tomography images by exploiting a deep learning framework. The proposed method was applied for precise cell nucleus segmentation in two, three, and four-dimensional label-free imaging. A novel architecture with optimised training strategies was validated through cross-modality and cross-laboratory experiments. The proposed method would bring out broad and immediate biomedical applications with our framework publicly available.
Identification of large-scale genomic rearrangements during wheat evolution and the underlying mechanisms
Authors: Bariah Inbar , Keidar-Friedman Danielle , Kashkush Khalil
Published: November 2018

Following allopolyploidization, nascent polyploid wheat species react with massive genomic rearrangements, including deletion of transposable element-containing sequences. While such massive rearrangements are considered to be a prominent process in wheat genome evolution and speciation, their structure, extent, and underlying mechanisms remain poorly understood. In this study, we retrieved ~3500 insertions of a specific variant ofFatima, one of the most dynamic long-terminal repeat retrotransposons in wheat from the recently available high-quality genome drafts ofTriticum aestivum(bread wheat) andTriticum turgidum ssp. dicoccoidesor wild emmer, the allotetraploid mother of all modern wheats. The dynamic nature ofFatimafacilitated the identification of large (i.e., up to ~ 1 million bases)Fatima-containing insertions/deletions (InDels) upon comparison of bread wheat and wild emmer genomes. We characterized 11 such InDels using computer-assisted analysis followed by PCR validation, and found that they occurred via unequal intra-strand recombination or double-strand break events. In most cases, InDels breakpoints were located within transposable element sequences. Additionally, we observed one case of introgression of novel DNA fragments from an unknown source into the wheat genome. Our data thus indicate that massive large-scale DNA rearrangements might play a prominent role in wheat speciation.
The evolutionary advantage of condition-dependent recombination in a Red Queen model with diploid antagonists
Authors: Rybnikov Sviatoslav R. , Frenkel Zeev M. , Fahima Tzion , Korol Abraham B.
Published: November 2018

Antagonistic interaction, like those between a host and its parasite, are known to cause oscillations in genetic structure of both species, usually referred to as Red Queen dynamics (RQD). The RQD is believed to be a plausible explanation for the evolution of sex/recombination, although numerous theoretical models showed that this may happen only under rather restricted parameter values (selection intensity, epistasis, etc.). Here, we consider two diploid antagonists, each with either two or three selected loci; the interaction is based on matching phenotypes model. We use the RQD, whenever it emerges in this system, as a substrate to examine the evolution of one recombination feature, condition dependence in diploids, which still remains an underexplored question. We consider several forms of condition-dependent recombination, with recombination rates in the host being sensitive either to the parasite’s mean fitness, or to the host’s infection status, or to the host’s genotype fitness. We show that all form of condition-dependent recombination can be favored over the corresponding optimal constant recombination rate, even including situations in which the optimal constant recombination rate is zero.
HNI9 and HY5 maintain ROS homeostasis under high nitrogen provision in Arabidopsis
Authors: Bellegarde Fanny , Maghiaoui Amel , Boucherez Jossia , Krouk Gabriel , Lejay Laurence , Bach Liên , Gojon Alain , Martin Antoine
Published: November 2018

One sentence summary

Excessive N nutrition leads to ROS accumulation, and requires the function of major transcriptional regulators to maintain plants under physiological conditions.

Author contributions

An.M. and A.G. conceived research plans and supervised the experiments; F.B, Am.M., J.B., L.L., L.B. and An.M performed most of the experiments; F.B, Am.M., J.B., G.K., L.L., L.B. and An.M analyzed the data; An.M. wrote the article with contributions of all the authors.

Competing interests

The authors declare no competing financial interests.

Reactive Oxygen Species (ROS) can accumulate in cells at excessive levels, leading to unbalanced redox status and to a potential oxidative stress, which can have damaging effects to the molecular components of plant cells. Several environmental conditions have been described as causing an elevation of ROS production in plants. Consequently, this requires the expression of detoxification responses in order to maintain ROS homeostasis at physiological levels. In case of mis-regulation of the detoxification systems, oxidative stress can lead ultimately to growth retardation and developmental defects. Here, we demonstrate that Arabidopsis plants growing under high nitrogen environment have to express a set of genes involved in detoxification of ROS in order to maintain ROS at physiological levels. We show that the chromatin factor HNI9 is an important actor of this response, required for the expression of these detoxification genes. Mutation in HNI9 leads to elevated ROS levels, and to ROS-dependent phenotypic defects under high but not low N provision. In addition, we identify HY5 as one of the major transcription factors also required for the expression of this detoxification program under high N condition. Our results demonstrate the requirement of a balance between N nutrition and ROS production, and identified the first major regulators required to control ROS homeostasis under excessive N nutrition.
Choice of assembly software has a critical impact on virome characterisation
Authors: Sutton Thomas D.S. , Clooney Adam G. , Ryan Feargal J. , Ross R. Paul , Hill Colin
Published: November 2018

Background

The viral component of microbial communities play a vital role in driving bacterial diversity, facilitating nutrient turnover and shaping community composition. Despite their importance, the vast majority of viral sequences are poorly annotated and share little or no homology to reference databases. As a result, investigation of the viral metagenome (virome) relies heavily on de novo assembly of short sequencing reads to recover compositional and functional information. Metagenomic assembly is particularly challenging for virome data, often resulting in fragmented assemblies and poor recovery of viral community members. Despite the essential role of assembly in virome analysis and difficulties posed by these data, current assembly comparisons have been limited to subsections of virome studies or bacterial datasets.

Design

This study presents the most comprehensive virome assembly comparison to date, featuring 16 metagenomic assembly approaches which have featured in human virome studies. Assemblers were assessed using four independent virome datasets, namely; simulated reads, two mock communities, viromes spiked with a known phage and human gut viromes.

Results

Assembly performance varied significantly across all test datasets, with SPAdes (meta) performing consistently well. Performance of MIRA and VICUNA varied, highlighting the importance of using a range of datasets when comparing assembly programs. It was also found that while some assemblers addressed the challenges of virome data better than others, all assemblers had limitations. Low read coverage and genomic repeats resulted in assemblies with poor genome recovery, high degrees of fragmentation and low accuracy contigs across all assemblers. These limitations must be considered when setting thresholds for downstream analysis and when drawing conclusions from virome data.
Nuclear arms races: experimental evolution for mating success in the mushroom-forming fungus Schizophyllum commune
Authors: Nieuwenhuis Bart P. S. , Aanen Duur K.
Published: November 2018

When many gametes compete to fertilize a limited number of compatible gametes, sexual selection will favour traits that increase competitive success during mating. In animals and plants, sperm and pollen competition have yielded many interesting adaptations for improved mating success. In fungi, similar processes have not been shown directly yet. We test the hypothesis that sexual selection can increase competitive fitness during mating, using experimental evolution in the mushroom-forming fungus Schizophyllum commune (Basidiomycota). Mating in mushroom fungi occurs by donation of nuclei to a mycelium. These fertilizing ‘male’ nuclei migrate through the receiving ‘female’ mycelium. In our setup, an evolving population of nuclei was serially mated with a non-evolving female mycelium for 20 sexual generations. From the twelve tested evolved lines, four had increased and one had decreased fitness relative to an unevolved competitor. Even though only two of those five remained significant after correcting for multiple comparisons, for all five lines we found a correlation between the efficiency with which the female mycelium is accessed and fitness, providing additional circumstantial evidence for fitness change in those five lines. In two lines, fitness change was also accompanied by increased spore production. The one line with net reduced competitive fitness had increased spore production, but reduced fertilisation efficiency. We did not find trade-offs between male reproductive success and other fitness components. We compare these findings with examples of sperm and pollen competition and show that many similarities between these systems and nuclear competition in mushrooms exist.
Beware the Jaccard: the choice of metric is important and non-trivial in genomic colocalisation analysis
Authors: Salvatore Stefania , Rand Knut Dagestad , Grytten Ivar , Ferkingstad Egil , Domanska Diana , Holden Lars , Gheorghe Marius , Mathelier Anthony , Glad Ingrid , Sandve Geir Kjetil
Published: November 2018

Background

The generation and systematic collection of genome-wide data is ever-increasing. This vast amount of data has enabled researchers to study relations between a variety of genomic and epigenomic features, including genetic variation, gene regulation, and phenotypic traits. Such relations are typically investigated by comparatively assessing genomic co-occurrence. Technically, this corresponds to assessing the similarity of pairs of genome-wide binary vectors. A variety of metrics have been proposed for this problem in other fields like ecology. However, while several of these metrics have been employed for assessing genomic co-occurrence, their appropriateness for the genomic setting has never been investigated.

Results

We show that the choice of metric may strongly influence results and propose two alternative modelling assumptions that can be used to guide this choice. On both simulated and real genomic data, the Jaccard index is strongly affected by dataset size and should be used with caution. The Forbes coefficient (fold change) and tetrachoric correlation are less affected by dataset size, but one should be aware of increased variance for small datasets.

Availability

All results on simulated and real data can be inspected and reproduced athttps://hyperbrowser.uio.no/sim-measure
The embryonic transcriptome ofArabidopsis thaliana
Authors: Hofmann Falko , Schon Michael A. , Nodine Michael D.
Published: November 2018

Cellular differentiation is associated with changes in transcript populations. Accurate quantification of transcriptomes during development can thus provide global insights into differentiation processes including the fundamental specification and differentiation events operating during plant embryogenesis. However, multiple technical challenges have limited the ability to obtain high quality early embryonic transcriptomes, namely the low amount of RNA obtainable and contamination from surrounding endosperm and seed-coat tissues. We compared the performance of three low-input mRNA sequencing (mRNA-seq) library preparation kits on 0.1 to 5 nanograms (ng) of total RNA isolated fromArabidopsis thaliana(Arabidopsis) embryos and identified a low-cost method with superior performance. This mRNA-seq method was then used to profile the transcriptomes of Arabidopsis embryos across eight developmental stages. By comprehensively comparing embryonic and post-embryonic transcriptomes, we found that embryonic transcriptomes do not resemble any other plant tissue we analyzed. Moreover, transcriptome clustering analyses revealed the presence of four distinct phases of embryogenesis which are enriched in specific biological processes. We also compared zygotic embryo transcriptomes with publicly available somatic embryo transcriptomes. Strikingly, we found little resemblance between zygotic embryos and somatic embryos derived from late-staged zygotic embryos suggesting that the molecular basis of somatic and zygotic embryogenesis are distinct from each other. In addition to the biological insights gained from our systematic characterization of the Arabidopsis embryonic transcriptome, we provide a data-rich resource for the community to explore.

Key Message

Arabidopsis embryos possess unique transcriptomes relative to other plant tissues including somatic embryos, and can be partitioned into four transcriptional phases with characteristic biological processes.
CNApp: quantification of genomic copy number alterations in cancer and integrative analysis to unravel clinical implications
Authors: Franch-Expósito Sebastià , Bassaganyas Laia , Vila-Casadesús Maria , Hernández-Illán Eva , Esteban-Fabró Roger , Díaz-Gay Marcos , Lozano Juan José , Castells Antoni , Llovet Josep M. , Castellví-Bel Sergi , Camps Jordi
Published: November 2018

Somatic copy number alterations (CNAs) are a hallmark of cancer. Although CNA profiles have been established for most human tumor types, their precise role in tumorigenesis as well as their clinical and therapeutic relevance remain largely unclear. Thus, computational and statistical approaches are required to thoroughly define the interplay between CNAs and tumor phenotypes. Here we developed CNApp, a user-friendly web tool that offers sample- and cohort-level computational analyses, allowing a comprehensive and integrative exploration of CNAs with clinical and molecular variables. By using purity-corrected segmented data from multiple genomic platforms, CNApp generates genome-wide profiles, computes CNA scores for broad, focal and global CNA burdens, and uses machine learning-based predictions to classify samples. We applied CNApp to a pan-cancer dataset of 10,635 genomes from TCGA showing that CNA patterns classify cancer types according to their tissue-of-origin, and that broad and focal CNA scores positively correlate in samples with low amounts of whole-chromosome and chromosomal arm-level imbalances. Moreover, using the hepatocellular carcinoma cohort from the TCGA repository, we demonstrate the reliability of the tool in identifying recurrent CNAs, confirming previous results. Finally, we establish machine learning-based models to predict colon cancer molecular subtypes and microsatellite instability based on broad CNA scores and specific genomic imbalances. In summary, CNApp facilitates data-driven research and provides a unique framework for the first time to comprehensively assess CNAs and perform integrative analyses that enable the identification of relevant clinical implications. CNApp is hosted at http://cnapp.bsc.es.
A Statistical Procedure for Genome-wide Detection of QTL Hotspots Using Public Databases with Application to Rice
Authors: Yang Man-Hsia , Wu Dong-Hong , Kao Chen-Hung
Published: November 2018

Genome-wide detection of quantitative trait loci (QTL) hotspots underlying variation in many molecular and phenotypic traits has been a key step in various biological studies since the QTL hotspots are highly informative and can be linked to the genes for the quantitative traits. Several statistical methods have been proposed to detect QTL hotspots. These hotspot detection methods rely heavily on permutation tests performed on summarized QTL data or individual-level data (with genotypes and phenotypes) from the genetical genomics experiments. In this article, we propose a statistical procedure for QTL hotspot detection by using the summarized QTL (interval) data collected in public web-accessible databases. First, a simple statistical method based on the uniform distribution is derived to convert the QTL interval data into the expected QTL frequency (EQF) matrix. And then, to account for the correlation structure among traits, the QTLs for correlated traits are grouped together into the same categories to form a reduced EQF matrix. Furthermore, a permutation algorithm on the EQF elements or on the QTL intervals is developed to compute a sliding scale of EQF thresholds, ranging from strict to liberal, for assessing the significance of QTL hotspots. With grouping, much stricter thresholds can be obtained to avoid the detection of spurious hotspots. Real example analysis and simulation study are carried out to illustrate our procedure, evaluate the performances and compare with other methods. It shows that our procedure can control the genome-wide error rates at the target levels, provide appropriate thresholds for correlated data and is comparable to the methods using individual-level data in hotspot detection. Depending on the thresholds used, more than 100 hotspots are detected in GRAMENE rice database. We also perform a genome-wide comparative analysis of the detected hotspots and the known genes collected in the Rice Q-TARO database. The comparative analysis reveals that the hotspots and genes are conformable in the sense that they co-localize closely and are functionally related to relevant traits. Our statistical procedure can provide a framework for exploring the networks among QTL hotspots, genes and quantitative traits in biological studies. The R codes that produce both numerical and graphical outputs of QTL hotspot detection in the genome are available on the worldwide webhttp://www.stat.sinica.edu.tw/~chkao/.
Low-dimensional bismuth(III) iodide hybrid material with high activity for the fast removal of rhodamine B
Authors: Chen Wei-Jun , Chu Kai-Bin , Song Jun-Ling
Published: November 2018

Organic–inorganic hybrid lead-based perovskite crystal materials have been widely studied due to their excellent optical–electronic properties. However, the toxicity of lead limits their widespread use. Here, a lead-free perovskite-type compound, tetrakis(1,2,3-trimethylimidazolium) di-μ3-iodido-tetra-μ2-iodido-decaiodidotetrabismuth(III), (C6H11N2)4[Bi4I16], has been successfully synthesized by a simple solvothermal method. It exhibits a zero-dimensional (0D) tetrameric structure, including edge-sharing [Bi4I16]4− distorted octahedra. The band gap of 2.0 eV is close to that of (NH4)3[Bi2I9]. Degradation ability measurements were performed to examine the potential application of this material as an alternative for waste-water treatment.
Investigations of thermal sprayed HAP and HAP-TiO2composite coatings for biomedical applications
Authors: Kaur Sarbjit , Bala Niraj , Khosla Charu
Published: November 2018

Purpose

The biomaterials are natural or synthetic materials used to improve quality of life either by replacing tissue/organ or assisting their function in medical field. The purpose of the study is to analyze the hydroxyapatite (HAP), HAP-TiO2(25 percent) composite coatings deposited on 316 LSS by High Velocity Flame Spray (HVFS) technique.

Design/methodology/approach

The coatings exhibit almost uniform and dense microstructure with porosity (HAP = 0.153 and HAP-TiO2composite = 0.138). Electrochemical corrosion testing was done on the uncoated and coated specimens in Ringer solution (SBF). As-sprayed coatings were characterized by XRD, SEM/EDS and cross-sectional X-ray mapping techniques before and after dipping in Ringer solution. Microhardness of composite coating (568.8 MPa) was found to be higher than HAP coating (353 MPa).

Findings

During investigations, it was observed that the corrosion resistance of steel was found to have increased after the deposition of HAP and HAP-TiO2composite coatings. Thus, coatings serve as an effective diffusion barrier to prohibit the diffusion of ions from the SBF into the substrate. Composite coatings have been found to be more corrosion resistant as compared to HAP coating in the simulated body fluid.

Research limitations/implications

It has been concluded that corrosion resistance of HAP as well as composite coating is because of the desirable microstructural changes such as low porosity high microhardness and flat splat structures in coatings as compared to bare specimen.

Practical implications

This study is useful in the selection of biomedical implants.

Social implications

This study is useful in the field of biomaterials.

Originality/value

No reported literature on corrosion behavior of HAP+ 25%- TiO2has been noted till now using flame spray technique. The main focus of the study is to investigate the HAP as well as composite coatings for biomedical applications.
When is silence golden? The use of strategic silence in crisis communication
Authors: Le Phuong D. , Teo Hui Xun , Pang Augustine , Li Yuling , Goh Cai-Qin
Published: November 2018

Purpose

Scholars have discouraged using silence in crises as it magnifies the information vacuum (see Pang, 2013). The purpose of this paper is to argue for its viability and explore the type of silence that can be used.

Design/methodology/approach

Eight international cases were analyzed to examine how silence was adopted, sustained and broken.

Findings

The findings uncovered three intention-based typologies of strategic silence: delaying, avoiding and hiding silences. Among such, avoiding/hiding silence intensified crises and adversely affected post-silence organizational image when forcefully broken, while delaying silence helped preserve/restore image with primary stakeholders if successfully sustained and broken as planned.

Research limitations/implications

First, these findings may lack generalizability due to the limited number of cases studied. Second, local sentiments may not be fully represented in the English-language news examined as they may be written for a different audience. Finally, a number of cases studied were still ongoing at the time of writing, so the overall effectiveness of the strategy employed might be compromised as future events unfold.

Practical implications

A stage-based practical guide to adopting delaying silence is proposed as a supporting strategy before the execution of crisis response strategies.

Originality/value

This is one of the few studies to examine the role of silence in crisis communication as silence is not recognized as a type of response in dominant crisis theories – be it the situational crisis communication theory or the image repair theory (An and Cheng, 2010; Benoit, 2015; Benoit and Pang, 2008; Xu and Li, 2013).
Artificial intelligence-based training learning from application
Authors: Upadhyay Ashwani Kumar , Khandelwal Komal
Published: November 2018

Purpose

This paper aims to discuss the rationale, theoretical foundation, application, and future of artificial intelligence (AI)-based training.

Design/methodology/approach

A review of relevant research papers, articles and case studies is done to highlight developments in research and practice.

Findings

AI-based training systems are smart, intelligent and expert in handling queries. These systems can curate content, grade, evaluate, and provide feedback to trainee, thus making learning adaptive and contextual.

Practical implications

Application of AI is vital in the field of training, as it helps personalization and customization of training programs to increase the effectiveness of training.

Originality/value

Executives and researchers can save time by reading relevant information on the linkage, and its contribution to AI is discussed and summarized in an easy to read format.
Women leaders and organizational diversity: their critical role in promoting diversity in organizations
Authors: Gupta Anuja
Published: November 2018

Purpose

The purpose of this paper is to analyze the role of women leaders in enhancing and managing diversity in organizations.

Design/methodology/approach

The approach of this paper is to combine the findings of two fields of research, namely, effectiveness of women leaders, and organizational diversity, and propose that women leaders have a critical role to play in enhancing organizational diversity and its effectiveness.

Findings

The main findings of the paper are that women leaders outperform their male counterparts in many of the necessary skills and competencies required to create democratic and inclusive organizations. Their leadership style is also best suited to effectively manage and take advantage of diversity in organizations.

Practical implications

Women leaders can create a very significant impact on creating inclusive environments in which diversity is valued and on organizational performance overall. Thus, it is imperative for firms to overcome gender bias and create meritocracies in which women leaders can be hired, retained, and promoted.

Social implications

Societies need to create grassroots change where perceptions of women in the workplace change.

Originality/value

The study creates a connection between two bodies of literature: one that explores the effectiveness of women leaders on leadership competencies and the second that looks at diversity in organizations, and how organizations can take advantage of this diversity. It shows that women leaders are well suited to promote and manage diversity in organizations by virtue of their skills and leadership style.
Expansion decision: HC Securities and Investment
Authors: Choucri Ali H. , Dietterich Anne , Gillern Victoria , Ivy Julia
Published: November 2018

Learning outcomes

Expected learning outcomes: To respond to the case question, students would analyze macro- and microeconomic differences to determine HC Securities’ preferred global strategy and appropriate market entry mode. The case demonstrates how instability in a local market, in this case Egypt, can force a company to go global. It also demonstrates how two superficially similar markets, Singapore and Hong Kong, provide different opportunities for HC Securities and require different global strategies: Singapore provides a jumping-off point to its predominantly Muslim neighbors Malaysia and Indonesia, whereas Hong Kong gives access to China and could provide a new customer base of Asian investors willing to invest in Africa and the Middle East.

Case overview/synopsis

Brief overview of the case: The case introduces the Egyptian investment company HC Securities, which is facing challenges related to Egypt’s political instability and economic slowdown. HC Securities’ CEO, Mr. Choucri, feels expansion to one of the Asia-Pacific countries could help with the company’s growth and stability. He identifies Hong Kong and Singapore as the most compelling locations because of their sophisticated economies and growth potential in the investments industry. This case provides information about each market, allowing students to respond to the question “What should Choucri do to assure a market-based solution for his company?”

Complexity academic level

Student level and proposed courses: The case is appropriate for use in undergraduate courses in international business or strategic management.

Supplementary materials

Teaching Notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.

Subject code

International Business.
Lump, breather and solitary wave solutions to new reduced form of the generalized BKP equation
Authors: Kaur Lakhveer , Wazwaz Abdul-Majid
Published: November 2018

Purpose

The purpose of this paper is to explore new reduced form of the (3 + 1)-dimensional generalized B-type Kadomtsev-Petviashvili (BKP) equation by considering its bilinear equations, derived from connection between the Hirota’s transformation and Bell polynomials.

Design/methodology/approach

Based on the bilinear form of new reduced form of the (3 + 1)-dimensional generalized BKP equation, lump solutions with sufficient and necessary conditions to guarantee analyticity and rational localization of the solutions are discovered. Also, extended homoclinic approach is applied to considered equation for finding solitary wave solutions.

Findings

A class of the bright-dark lump waves are fabricated for studying different attributes of (3 + 1)-dimensional generalized BKP equation and some new exact solutions including kinky periodic solitary wave solutions and line breathers periodic are also obtained by Following the extended homoclinic approach.

Research limitations/implications

The paper presents that the implemented methods have emerged as a promising and robust mathematical tool to manage (3 + 1)-dimensional generalized BKP equation by using the Hirota’s bilinear equation.

Practical implications

By considering important characteristics of lump and solitary wave solutions, one can understand the shapes, amplitudes and velocities of solitons after the collision with another soliton.

Social implications

The analysis of these higher-dimensional nonlinear wave equations is not only of fundamental interest but also has important practical implications in many areas of mathematical physics and ocean engineering.

Originality/value

To the best of the authors’ knowledge, the acquired solutions given in various cases have not been reported for new reduced form of the (3 + 1)-dimensional generalized BKP equation in the literature. These obtained solutions are advantageous for researchers to know objective laws and grab the indispensable features of the development of the mathematical physics.
Teamwork of temporary employees: multiple perspectives
Authors: Chakraborty Saikat , Chakravarti Sushmita
Published: November 2018

Purpose

The purpose of this study is to understand the teamwork of temporary employees by taking into consideration the impact and role of the management’s perspective, temporary employee’s perspective and contextual perspective.

Design/methodology/approach

Based on reviews of workplace literature pertaining to temporary employments, conversations with managers and temporary and permanent employees of organizations engaging temporary employees on a perennial basis have been thematically analyzed.

Findings

Multiple perspectives of teamwork of temporary employees exist in organizations. However, one rarely finds the interaction and collective treatment of these perspectives, which are critical to understanding teamwork of temporary employees. The paper reports on these perspectives.

Practical implications

With rise in temporary employments in organizations and teamwork being crucial to participative work cultures, organizations need to consider multiple perspectives of the phenomenon before making an informed decision.

Originality/value

There is limited research that delves into teamwork of temporary employees despite the phenomenon becoming increasingly significant in organizations. This paper offers an approach to look at teamwork of temporary employees through multiple perspectives.
The drivers and challenges of improving the energy efficiency performance of listed pre-1919 housing
Authors: Rispoli Maria , Organ Samantha
Published: November 2018

Purpose

Concerns about climate change and the availability of energy has resulted in countries setting targets to improve energy efficiency and reduce carbon emissions. A large proportion of energy is consumed by existing housing. Europe has a large proportion of historic housing, some of which also represent significant value in relation to historical, cultural and/or architectural importance. Upgrading their energy efficiency whilst retaining their significance is crucial for the sustainability of heritage buildings. The purpose of this paper is to focus on the challenges and barriers to improving the energy efficiency of listed pre-1919 housing.

Design/methodology/approach

The research utilised semi-structured interviews to explore the debates surrounding sustainability and conservation, identifying the key drivers and barriers to achieving a balance between these concepts.

Findings

Concern about climate change and the desire to preserve a heritage asset were the main drivers to balancing sustainability with conservation through energy efficiency improvements. The main challenges included the risk of detrimentally affecting the significance of the building, the lack of communication and collaboration between stakeholders, the availability of adequately skilled professionals and the lack of appropriate energy efficiency solutions for heritage buildings. The cost of improvements was found to be both a barrier and driver.

Originality/value

Heritage buildings perform differently to their modern counterparts and therefore the measures the authors apply to these historic properties must be done with sufficient understanding of this difference. Such measures must be compatible with these buildings in line with conservation principles. Further, the discussion of developing an alternative version of energy calculation for these buildings should be entered into.
Economic performance and efficiency determinants of crop-producing farms in Norway
Authors: Alem Habtamu , Lien Gudbrand , Hardaker J. Brian
Published: November 2018

Purpose

The purpose of this paper is to explore the economic performance of Norwegian crop farms using a stochastic frontier analysis.

Design/methodology/approach

The analysis was based on a translog cost function and unbalanced farm-level panel data for 1991–2013 from 455 Norwegian farms specialized in crop production in eastern and central regions of Norway.

Findings

The results of the analysis show that the mean efficiency was about 78–81 percent. Farm management practices and socioeconomic factors were shown to significantly affect the economic performance of Norwegian crop farms.

Research limitations/implications

Farmers are getting different types of support from the government and the study does not account for the different effects of different kinds of subsidy on cost efficiency. Different subsidies might have different effects on farm performance. To get more informative and useful results, it would be necessary to repeat the analysis with less aggregated data on subsidy payments.

Practical implications

One implication for farmers (and their advisers) is that many of them are less efficient than the estimated benchmark (best performing farms). Thus, those lagging behind the best performing farms need to look at the way they are operating and to seek out ways to save costs or increase crop production. Perhaps there are things for lagging farmers to learn from their more productive farming neighbors. For instance, those farmers not practicing crop rotation might be well advised to try that practice.

Social implications

For both taxpayers and consumers, one implication is that the contributions they pay that go to subsidize farmers appear to bring some benefits in terms of more efficient production that, in turn, increase the supply of some foods so possibly making food prices more affordable.

Originality/value

Unlike previous performance studies in the literature, the authors estimated farm-level economic performance accounting for the contribution of both an important farm management practice and selected socioeconomic factors. Good farm management practices, captured through crop rotation, land tenure, government support and off-farm activities were found to have made a positive and statistically significant contribution to reducing the cost of production on crop-producing farms in the Central and Eastern regions of Norway.
Influence of wear on the performance of capillary compensated hole entry hybrid conical journal bearing
Authors: Pawar Sanjay Rangrao , Phalle Vikas M.
Published: November 2018

Purpose

Hybrid conical journal bearings have received great attraction by design engineers and researchers due to their incomparable performance. However, performance of these bearings is affected due to wear. This paper aims to present an analytical study concerning the performance of hole entry worn hybrid conical journal bearings.

Design/methodology/approach

The Reynolds equation governing the flow of lubricant in the clearance space along with the restrictor flow equations has been solved using finite element method.

Findings

The numerically simulated results of worn bearing performance parameters indicate significant change in the performance due to wear. Therefore, for semi cone angle γ = 25°, the value of C¯22 reduces by 24.6 per cent at the wear value of about 50 per cent of radial clearance for the given configuration of bearing.

Originality/value

The present results are original of its kind and surely useful to bearing designers and researchers in predicting actual performance of worn hole entry hybrid conical journal bearing.
Influence of WS2/SnS2on the tribological performance of copper-free brake pads
Authors: I. Justin Antonyraj , R. Vijay , D. Lenin Singaravelu
Published: November 2018

Purpose

The purpose of this study is to investigate the influence of solid lubricants (tungsten disulfide [WS2]/ Tin disulfide [SnS2]) on the tribological performance of brake pads.

Design/methodology/approach

In this study, the brake pads were developed by varying the solid lubricants (WS2/SnS2) without varying the other ingredients. The brake pads were developed as per the industrial procedure. Thermal stability was found for varying ingredients and developed pads. The physical, mechanical and thermal properties of the developed brake pads were analyzed as per the industrial standards. The tribological properties were analyzed using the Chase test. The worn surface analysis was done using scanning electron microscopy, elemental mapping and three-dimensional profile analysis.

Findings

The experimental results indicate that the WS2-based brake pads possess good physical, chemical and mechanical properties with stable friction and less wear rate due to its good lubrication film formation and thermal stability natures of WS2.

Originality/value

This paper explains the effect of solid lubricants in brake pads for enhancing the tribological performance by the shearing of crystal structure, thermal stability and tribo film properties of the lubricants.
Knowledge acquisition via internet-enabled platforms
Authors: Glavas Charmaine , Mathews Shane , Russell-Bennett Rebekah
Published: November 2018

Purpose

Technology has profoundly transformed the international business environment, particularly regarding the flow of information and the way in which knowledge is acquired and shared. Yet, the extent of this transformation is still underappreciated. The purpose of this paper is to examine how small and medium-sized enterprise (SME) owner/founders acquire and utilize knowledge for internationalization via internet-enabled platforms.

Design/methodology/approach

The empirical analysis draws on multiple case study methodology to examine 13 Australian SME owner/founders and the knowledge they acquire from utilization of internet-enabled platforms.

Findings

The analysis reveals four differing types of internet-enabled experiences: “technical internet-enabled experiences,” “operational internet-enabled experiences,” “functional internet-enabled experiences,” and “immersive internet-enabled experiences.” The findings indicate that internet-enabled experiences can generate both explicit and tacit forms of knowledge for the pre, early and later phases of internationalization.

Practical implications

The findings provide a structured approach by allowing SMEs to “plot” themselves against the classification of internet-enabled experiences to denote their level of technological involvement, and for discerning the types of knowledge that can be acquired. The findings are particularly helpful for owner/founders, highlighting that internet-enabled platforms are affecting the ways in which knowledge can be acquired and applied to international businesses processes.

Originality/value

The findings extend the conventional notion of knowledge acquisition for international business by highlighting how information and knowledge can be acquired via internet-enabled platforms. The findings lay the necessary groundwork for building an evidence base and theoretically extending the concept of knowledge acquisition via internet-enabled platforms.
Capitalising on knowledge from big-science centres for internationalisation
Authors: Eerme Tõnis , Nummela Niina
Published: November 2018

Purpose

The purpose of this paper is to investigate how resource-constrained, knowledge-intensive firms capitalise on the knowledge from collaboration with big-science centres. It pays particular attention to what kind of knowledge a firm obtains and how it can be efficiently used in exploring and exploiting opportunities in international markets.

Design/methodology/approach

The empirical basis for the study is a longitudinal case study of knowledge-intensive Estonian companies that collaborate with the European Space Agency (ESA). A rich data set was collected over three years.

Findings

By studying the inward and outward activities of the two case companies collaborating with the ESA, the authors found that the internationalisation process of these firms had unique characteristics. Their international expansion was not driven by increasing market knowledge and reducing risk or uncertainty, but by resource seeking for research and development efforts. It was a cyclical, non-linear process, which was advanced by co-creation, learning and exploitation of the emergent knowledge, leading to an improved network position and identification of further opportunities.

Research limitations/implications

The focus was on knowledge-intensive, resource-constrained firms and their collaboration with big-science centres. The transfer of the proposed framework to another context may not be straightforward. The authors relied on informants from the firms, thus ignoring the view of their partner, the big-science centre. It may be that because of this perspective, the authors did not capture some aspects of the collaboration. A broader range of cases would have provided more powerful support to the findings. Although the cases were sufficient for theory refinement and building a tentative framework, they also call for further cases that would clarify whether these conclusions would be valid for other companies.

Practical implications

Collaboration with big-science centres provides companies with access to diverse types of knowledge. However, its impact on the future success in internationalisation also depends on other factors, such as the firm’s absorptive capacity and technological competence.

Social implications

Governments invest substantially on the development of big-science centres with the expectation that they would have significant knowledge spillovers on the technology development. A more qualitative approach to impact assessment opens new ideas how to develop their activities and in particular their collaboration with SMEs.

Originality/value

The study reassesses the theory on the internationalisation process of the firm and gives voice to companies which have been marginalised in earlier research.
End users’ purchasing task involvement, power and influence strategies in organizational buying
Authors: Pedeliento Giuseppe , Andreini Daniela , Bergamaschi Mara , Salo Jari
Published: November 2018

Purpose

End users are often involved in organizational buying, but very little is known about the role that they play and how they influence purchasing decisions. This study aims to explore the factors behind end users’ attempts to influence purchasing and the strategies they use.

Design/methodology/approach

The research draws on the concept of purchasing task involvement, which describes the feelings of personal relevance that a buying center member has for a specific organizational purchasing decision. This concept is used to gain a deeper understanding of users’ influence in organizational purchasing and link it to sources of power and the corresponding influence strategies. The study is based on 90 in-depth interviews with buyers, drivers and sellers of heavy trucks.

Findings

End users’ purchasing task involvement is only marginally determined by the product’s performance or technical features. Purchasing task involvement leads to influence when there are specific power relationships between the buyer and the user and under specific circumstances.

Originality/value

This is the first study that links end users’ purchasing task involvement, power and influence strategies in organizational buying.