bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuromyelitis optica and neuromyelitis optica spectrum disorders
Authors: Marignier Romain , Cobo Calvo Alvaro , Vukusic Sandra
Published: March 2017

Purpose of review

The discovery of highly specific auto-antibodies directed against the water channel aquaporin 4 was a quantum leap in the definition, classification and management of neuromyelitis optica (NMO). Herein, we propose an update on epidemiological, clinical and therapeutic advances in the field, underlining unmet needs.

Recent findings

Large-scale epidemiological studies have recently provided a more precise evaluation of NMO prevalence and a better stratification regarding ethnicity and sex. New criteria have been proposed for so-called NMO spectrum disorders (NMOSD) and their relevance is currently being assessed. The identification of a new clinical entity associated to antibodies against myelin oligodendrocyte glycoprotein questions the border of NMOSD.

The concept of NMOSD is opening a new era in clinical practice, allowing an easier and more homogeneous diagnosis and an increase in newly identified cases. This will facilitate clinical studies and support new therapeutic trial. Future researches should focus on the position of seronegative NMOSD and myelin oligodendrocyte glycoprotein-IgG disorders in the field and on promising strategies, including the immune tolerisation approaches, to eventually cure NMO.
Predictive Value of Electrocorticography in Patients With Mesial Temporal Lobe Epilepsy Undergoing Selective Amygdalohippocampectomy
Authors: Herlopian Aline , Shihabuddin Bashir
Published: March 2017

Purpose:

The utility of intraoperative electrocorticography has been reported in predicting seizure outcome in patients with mesial temporal lobe epilepsy due to mesial temporal sclerosis (MTS) undergoing standard temporal lobectomy. Three studies reported the predictive outcome in patients with MTS undergoing selective amygdalohippocampectomy (sAHE). We evaluate the predictive value of the intraoperative electrocorticography in postoperative outcome in patients with mesial temporal lobe epilepsy secondary to MTS undergoing sAHE.

Methods:

Retrospective analysis of 36 consecutive patients with mesial temporal lobe epilepsy undergoing sAHE between 2001 and 2012. A single neurosurgeon performed the sAHE. Preresection and postresection spikes were recorded in all patients and interpreted by two epileptologists. Long-term postoperative seizure freedom was correlated with intraoperative electrocorticography findings.

Results:

Ten patients had normal brain MRI (G1), whereas 26 had MTS (G2). All patients had MTS on histopathology. Mean duration of postoperative follow-up was 21.3 and 24.4 months for G1 and G2, respectively. In G1, 4/10 (40%) had resolution of spikes after sAHE, with 2/4 (50%) seizure free at last follow-up. Spikes were persistent in 6/10 (60%), with 5/6 (83%) seizure free at last follow-up (P value = 0.5). In G2, 7/26 (27%) had postresection resolution of spikes, with 5/7 (71%) seizure free at last follow-up. Spikes were persistent in 19/26 (73%), with 13/19 (68%) seizure free at last follow-up (P value = 0.62). The difference between the two arms of G1 and G2 was statistically insignificant.

Conclusions:

Postresection intraoperative electrocorticography has limited value in predicting postoperative seizure freedom in patients with mesial temporal lobe epilepsy secondary to MTS undergoing sAHE.
The evolution of transmission mode
Authors: Antonovics Janis , Wilson Anthony J. , Forbes Mark R. , Hauffe Heidi C. , Kallio Eva R. , Leggett Helen C. , Longdon Ben , Okamura Beth , Sait Steven M. , Webster Joanne P.
Published: March 2017

This article reviews research on the evolutionary mechanisms leading to different transmission modes. Such modes are often under genetic control of the host or the pathogen, and often in conflict with each other via trade-offs. Transmission modes may vary among pathogen strains and among host populations. Evolutionary changes in transmission mode have been inferred through experimental and phylogenetic studies, including changes in transmission associated with host shifts and with evolution of the unusually complex life cycles of many parasites. Understanding the forces that determine the evolution of particular transmission modes presents a fascinating medley of problems for which there is a lack of good data and often a lack of conceptual understanding or appropriate methodologies. Our best information comes from studies that have been focused on the vertical versus horizontal transmission dichotomy. With other kinds of transitions, theoretical approaches combining epidemiology and population genetics are providing guidelines for determining when and how rapidly new transmission modes may evolve, but these are still in need of empirical investigation and application to particular cases. Obtaining such knowledge is a matter of urgency in relation to extant disease threats.

This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’.
Host allometry influences the evolution of parasite host-generalism: theory and meta-analysis
Authors: Walker Josephine G. , Hurford Amy , Cable Jo , Ellison Amy R. , Price Stephen J. , Cressler Clayton E.
Published: March 2017

Parasites vary widely in the diversity of hosts they infect: some parasite species are specialists—infecting just a single host species, while others are generalists, capable of infecting many. Understanding the factors that drive parasite host-generalism is of basic biological interest, but also directly relevant to predicting disease emergence in new host species, identifying parasites that are likely to have unidentified additional hosts, and assessing transmission risk. Here, we use mathematical models to investigate how variation in host body size and environmental temperature affect the evolution of parasite host-generalism. We predict that parasites are more likely to evolve a generalist strategy when hosts are large-bodied, when variation in host body size is large, and in cooler environments. We then explore these predictions using a newly updated database of over 20 000 fish–macroparasite associations. Within the database we see some evidence supporting these predictions, but also highlight mismatches between theory and data. By combining these two approaches, we establish a theoretical basis for interpreting empirical data on parasites' host specificity and identify key areas for future work that will help untangle the drivers of parasite host-generalism.

This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’.
Contact structure, mobility, environmental impact and behaviour: the importance of social forces to infectious disease dynamics and disease ecology
Authors: Arthur Ronan F. , Gurley Emily S. , Salje Henrik , Bloomfield Laura S. P. , Jones James H.
Published: March 2017

Human factors, including contact structure, movement, impact on the environment and patterns of behaviour, can have significant influence on the emergence of novel infectious diseases and the transmission and amplification of established ones. As anthropogenic climate change alters natural systems and global economic forces drive land-use and land-cover change, it becomes increasingly important to understand both the ecological and social factors that impact infectious disease outcomes for human populations. While the field of disease ecology explicitly studies the ecological aspects of infectious disease transmission, the effects of the social context on zoonotic pathogen spillover and subsequent human-to-human transmission are comparatively neglected in the literature. The social sciences encompass a variety of disciplines and frameworks for understanding infectious diseases; however, here we focus on four primary areas of social systems that quantitatively and qualitatively contribute to infectious diseases as social–ecological systems. These areas are social mixing and structure, space and mobility, geography and environmental impact, and behaviour and behaviour change. Incorporation of these social factors requires empirical studies for parametrization, phenomena characterization and integrated theoretical modelling of social–ecological interactions. The social–ecological system that dictates infectious disease dynamics is a complex system rich in interacting variables with dynamically significant heterogeneous properties. Future discussions about infectious disease spillover and transmission in human populations need to address the social context that affects particular disease systems by identifying and measuring qualitatively important drivers.

This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’.
Contrasting determinants of mutation rates in germline and soma
Authors: Chen Chen , Qi Hongjian , Shen Yufeng , Pickrell Joseph , Przeworski Molly
Published: March 2017

Recent studies of somatic and germline mutations have led to the identification of a number of factors that influence point mutation rates, including CpG methylation, expression levels, replication timing and GC content. Intriguingly, some of the effects appear to differ between soma and germline: in particular, whereas mutation rates have been reported to decrease with expression levels in tumors, no clear effect has been detected in the germline. Distinct approaches were taken to analyze the data, however, so it is hard to know whether these apparent differences are real. To enable a cleaner comparison, we considered a statistical model in which the mutation rate of a coding region is predicted by GC content, expression levels, replication timing, and two histone repressive marks. We applied this model to both a set of germline mutations identified in exomes and to exonic somatic mutations in four types of tumors. Germline and soma share most determinants of mutations; notably, we detected an effect of expression levels on germline mutations as well as on somatic ones. However, whereas in somatic tissues, increased expression levels are associated with greater strand asymmetry anddecreasedmutation rates, in ovaries and testes, increased expression leads to greater strand asymmetry butincreasedmutation rates. This contrast points to differences in damage or repair rates during transcription in soma and germline.
Evaluation and Design of Genome-wide CRISPR/Cas9 Knockout Screens
Authors: Hart Traver , Tong Amy , Chan Katie , Leeuwen Jolanda Van , Seetharaman Ashwin , Aregger Michael , Chandrashekhar Megha , Hustedt Nicole , Seth Sahil , Noonan Avery , Habsid Andrea , Sizova Olga , Nedyalkova Lyudmila , Climie Ryan , Lawson Keith , Sartori Maria Augusta , Alibeh Sabriyeh , Tieu David , Masud Sanna , Mero Patricia , Weiss Alexander , Brown Kevin R. , Usaj Matej , Billmann Maximilian , Rahman Mahfuzur , Constanzo Michael , Myers Chad L. , Andrews Brenda J. , Boone Charles , Durocher Daniel , Moffat Jason
Published: March 2017

The adaptation of CRISPR/Cas9 technology to mammalian cell lines is transforming the study of human functional genomics. Pooled libraries of CRISPR guide RNAs (gRNAs), targeting human protein-coding genes and encoded in viral vectors, have been used to systematically create gene knockouts in a variety of human cancer and immortalized cell lines, in an effort to identify whether these knockouts cause cellular fitness defects. Previous work has shown that CRISPR screens are more sensitive and specific than pooled library shRNA screens in similar assays, but currently there exists significant variability across CRISPR library designs and experimental protocols. In this study, we re-analyze 17 genome-scale knockout screens in human cell lines from three research groups using three different genome-scale gRNA libraries, using the Bayesian Analysis of Gene Essentiality (BAGEL) algorithm to identify essential genes, to refine and expand our previously defined set of human core essential genes, from 360 to 684 genes. We use this expanded set of reference Core Essential Genes (CEG2), plus empirical data from six CRISPR knockout screens, to guide the design of a sequence-optimized gRNA library, the Toronto KnockOut version 3.0 (TKOv3) library. We demonstrate the high effectiveness of the library relative to reference sets of essential and nonessential genes as well as other screens using similar approaches. The optimized TKOv3 library, combined with the CEG2 reference set, provide an efficient, highly optimized platform for performing and assessing gene knockout screens in human cell lines.
Colonization history of the Western Corn Rootworm (Diabrotica virgifera virgifera) in North America: insights from random forest ABC using microsatellite data
Authors: Lombaert Eric , Ciosi Marc , Miller Nicholas J. , Sappington Thomas W. , Blin Aurélie , Guillemaud Thomas
Published: March 2017

First described from western Kansas, USA, the western corn rootworm,Diabrotica virgifera virgifera, is one of the worst pests of maize. The species is generally thought to be of Mexican origin and to have incidentally followed the expansion of maize cultivation into North America thousands of years ago. However, this hypothesis has never been investigated formally. In this study, the genetic variability of samples collected throughout North America was analysed at 13 microsatellite marker loci to explore precisely the population genetic structure and colonization history ofD. v. virgifera. In particular, we used up-to-date Approximate Bayesian Computation methods based on random forest algorithms to test a Mexican versus a central-USA origin of the species, and to compare various possible timings of colonization. This analysis provided strong evidence that the origin ofD. v. virgiferawas southern (Mexico, or even further south). Surprisingly, we also found that the expansion of the species north of its origin was recent - probably not before 1100 years ago - thus indicating it was not directly associated with the early history of maize expansion out of Mexico, a far more ancient event.
Transformation from independent to integrative coding of multi-object arrangements in human visual cortex
Authors: Kaiser Daniel , Peelen Marius V.
Published: March 2017

To optimize processing, the human visual system utilizes regularities present in naturalistic visual input. One of these regularities is the relative position of objects in a scene (e.g., a sofa in front of a television), with behavioral research showing that regularly positioned objects are easier to perceive and to remember. Here we use fMRI to test how positional regularities are encoded in the visual system. Participants viewed pairs of objects that formed minimalistic two-object scenes (e.g., a “living room” consisting of a sofa and television) presented in their regularly experienced spatial arrangement or in an irregular arrangement (with interchanged positions). Additionally, single objects were presented centrally and in isolation. Multi-voxel activity patterns evoked by the object pairs were modeled as the average of the response patterns evoked by the two single objects forming the pair. In two experiments, this approximation in object-selective cortex was significantly less accurate for the regularly than the irregularly positioned pairs, indicating integration of individual object representations. More detailed analysis revealed a transition from independent to integrative coding along the posterior-anterior axis of the visual cortex, with the independent component (but not the integrative component) being almost perfectly predicted by object selectivity across the visual hierarchy. These results reveal a transitional stage between individual object and multi-object coding in visual cortex, providing a possible neural correlate of efficient processing of regularly positioned objects in natural scenes.
Aggressiveness as a latent personality trait of domestic dogs: testing local independence and measurement invariance
Authors: Goold Conor , Newberry Ruth C.
Published: March 2017

Studies of animal personality attempt to uncover underlying or ‘latent’ personality traits that explain broad patterns of behaviour, often by applying latent variable statistical models (e.g. factor analysis) to multivariate data sets. Two integral, but infrequently confirmed, assumptions of latent variable models in animal personality are: i) behavioural variables are independent (i.e. uncorrelated) conditional on the latent personality traits they reflect (local independence), and ii) personality traits are associated with behavioural variables in the same way across individuals or groups of individuals (measurement invariance). We tested these assumptions using observations of aggression in four age classes (4 - 10 months, 10 months - 3 years, 3 - 6 years, over 6 years) of male and female shelter dogs (N = 4,743) in 11 different contexts. A structural equation model supported the hypothesis of two positively correlated personality traits underlying aggression across contexts: aggressiveness towards people and aggressiveness towards dogs (comparative fit index: 0.96; Tucker-Lewis index: 0.95; root mean square error of approximation: 0.03). Aggression across contexts was moderately repeatable (towards people: intraclass correlation coefficient (ICC) = 0.479; towards dogs: ICC = 0.303).

However, certain contexts related to aggressiveness towards people (but not dogs) shared significant residual relationships unaccounted for by latent levels of aggressiveness.

Furthermore, aggressiveness towards people and dogs in different contexts interacted with sex and age. Thus, sex and age differences in displays of aggression were not simple functions of underlying aggressiveness. Our results illustrate that the robustness of traits in latent variable models must be critically assessed before making conclusions about the effects of, or factors influencing, animal personality. Our findings are of concern because inaccurate ‘aggressive personality’ trait attributions can be costly to dogs, recipients of aggression and society in general.
Gene nucleotide composition accurately predicts expression and is linked to topological chromatin domains
Authors: Bessière Chloé , Taha May , Petitprez Florent , Vandel Jimmy , Marin Jean-Michel , Bréhélin Laurent , Lèbre Sophie , Lecellier Charles-Henri
Published: March 2017

Gene expression is orchestrated by distinct regulatory regions (e.g. promoters, enhancers, UTRs) to ensure a wide variety of cell types and functions. A challenge is to identify which regulatory regions are active, what are their associated features and how they work together in each cell type. Several approaches have tackled this problem by modeling gene expression based on epigenetic marks (e.g. ChIP-seq, methylation, DNase hypersensitivity), with the ultimate goal of identifying driving genomic regions and mutations that are clinically relevant in particular in precision medicine. However, these models rely on experimental data, which are limited to specific samples (even often to cell lines) and cannot be generated for all regulators and all patients. In addition, we show here that, although these approaches are accurate in predicting gene expression, their biological interpretation can be misleading. Finally these methods are not designed to capture potential regulation instructions present at the sequence level, before the binding of regulators or the opening of the chromatin. We develop here a method for predicting mRNA levels based solely on sequence features collected from distinct regulatory regions, which is as accurate as methods based on experimental data. Our approach confirms the importance of nucleotide composition in predicting gene expression and ranks regulatory regions according to their contribution. It also unveils strong influence of gene body sequence, in particular introns. We further provide evidence that the contribution of nucleotide content can be linked to co-regulations associated with genome 3D architecture and to associations of genes within topologically associated domains.
Intracellular production of hydrogels and synthetic RNA granules by multivalent enhancers
Authors: Nakamura Hideki , Lee Albert A. , Afshar Ali Sobhi , Watanabe Shigeki , Rho Elmer , Razavi Shiva , Suarez Allison , Lin Yu-Chun , Tanigawa Makoto , Huang Brian , DeRose Robert , Bobb Diana , Hong William , Gabelli Sandra B. , Goutsias John , Inoue Takanari
Published: March 2017

Non-membrane bound, hydrogel-like entities, such as RNA granules, nucleate essential cellular functions through their unique physico-chemical properties. However, these intracellular hydrogels have not been as extensively studied as their extracellular counterparts, primarily due to technical challenges in probing these materialsin situ.Here, by taking advantage of a chemically inducible dimerization paradigm, we developed iPOLYMER, a strategy for rapid induction of protein-based hydrogels inside living cells. A series of biochemical and biophysical characterizations, in conjunction with computational modeling, revealed that the polymer network formed in the cytosol resembles a physiological hydrogel-like entity that behaves as a size-dependent molecular sieve. We studied several properties of the gel and functionalized it with RNA binding motifs that sequester polyadenine-containing nucleotides to synthetically mimic RNA granules. Therefore, we here demonstrate that iPOLYMER presents a unique and powerful approach to synthetically reconstitute hydrogel-like structures including RNA granules in intact cells.
The metabolic programming of stem cells
Authors: Shyh-Chang Ng , Ng Huck-Hui
Published: March 2017

Advances in metabolomics have deepened our understanding of the roles that specific modes of metabolism play in programming stem cell fates. Here, we review recent metabolomic studies of stem cell metabolism that have revealed how metabolic pathways can convey changes in the extrinsic environment or their niche to program stem cell fates. The metabolic programming of stem cells represents a fine balance between the intrinsic needs of a cellular state and the constraints imposed by extrinsic conditions. A more complete understanding of these needs and constraints will afford us greater mastery over our control of stem cell fates.
Time-dependent genetic effects on gene expression implicate aging processes
Authors: Bryois Julien , Buil Alfonso , Ferreira Pedro G. , Panousis Nikolaos I. , Brown Andrew A. , Viñuela Ana , Planchon Alexandra , Bielser Deborah , Small Kerrin , Spector Tim , Dermitzakis Emmanouil T.
Published: March 2017

Gene expression is dependent on genetic and environmental factors. In the last decade, a large body of research has significantly improved our understanding of the genetic architecture of gene expression. However, it remains unclear whether genetic effects on gene expression remain stable over time. Here, we show, using longitudinal whole-blood gene expression data from a twin cohort, that the genetic architecture of a subset of genes is unstable over time. In addition, we identified 2213 genes differentially expressed across time points that we linked with aging within and across studies. Interestingly, we discovered that most differentially expressed genes were affected by a subset of 77 putative causal genes. Finally, we observed that putative causal genes and down-regulated genes were affected by a loss of genetic control between time points. Taken together, our data suggest that instability in the genetic architecture of a subset of genes could lead to widespread effects on the transcriptome with an aging signature.
SAXS analysis of single- and multi-core iron oxide magnetic nanoparticles
Authors: Szczerba Wojciech , Costo Rocio , Veintemillas-Verdaguer Sabino , Morales Maria del Puerto , Thünemann Andreas F.
Published: March 2017

This article reports on the characterization of four superparamagnetic iron oxide nanoparticles stabilized with dimercaptosuccinic acid, which are suitable candidates for reference materials for magnetic properties. Particles p1 and p2 are single-core particles, while p3 and p4 are multi-core particles. Small-angle X-ray scattering analysis reveals a lognormal type of size distribution for the iron oxide cores of the particles. Their mean radii are 6.9 nm (p1), 10.6 nm (p2), 5.5 nm (p3) and 4.1 nm (p4), with narrow relative distribution widths of 0.08, 0.13, 0.08 and 0.12. The cores are arranged as a clustered network in the form of dense mass fractals with a fractal dimension of 2.9 in the multi-core particles p3 and p4, but the cores are well separated from each other by a protecting organic shell. The radii of gyration of the mass fractals are 48 and 44 nm, and each network contains 117 and 186 primary particles, respectively. The radius distributions of the primary particle were confirmed with transmission electron microscopy. All particles contain purely maghemite, as shown by X-ray absorption fine structure spectroscopy.
A comprehensive approach to understanding cooking behavior
Authors: Wolfson Julia A. , Bostic Stephanie , Lahne Jacob , Morgan Caitlin , Henley Shauna C. , Harvey Jean , Trubek Amy
Published: March 2017

Purpose

The purpose of this paper is to describe the development of – and need for – an expanded understanding of cooking (skills and knowledge) to inform research on the connection between cooking and health.

Design/methodology/approach

This paper describes a concept of “food agency” and contrasts it with how cooking is commonly conceived in food and nutrition literature. A food agency-based pedagogy and proposals for using it are also introduced.

Findings

Cooking is a complex process that may be crucial for making a difference in the contemporary problems of diet-related chronic diseases. There are two interlinked problems with present research on cooking. First, cooking has yet to be adequately conceptualized for the design and evaluation of effective public health and nutrition interventions. The context within which food-related decisions and actions occur has been neglected. Instead, the major focus has been on discrete mechanical tasks. In particular, recipes are relied upon despite no clear evidence that recipes move people from knowledge to action. Second, given the incomplete theorization and definition of this vital everyday practice, intervention designs tend to rely on assumptions over theory. This creates certain forms of tautological reasoning when claims are made about how behavior changes. A comprehensive theory of food agency provides a nuanced understanding of daily food practices and clarifies how to teach cooking skills that are generalizable throughout varied life contexts.

Originality/value

This commentary is of value to academics studying cooking-related behavior and public health practitioners implementing and evaluating cooking interventions.
The mediating effects of organization-based self-esteem for the relationship between workplace ostracism and workplace behaviors
Authors: Chung Yang Woon , Yang Ji Yeon
Published: March 2017

Purpose

The purpose of this paper is to investigate the mediating effects of organization-based self-esteem (OBSE) for the relationship between workplace ostracism with helping behavior, voicing behavior, in-role behavior, and deviant behavior. The workplace has now become a social context where ostracism occurs and the study emphasizes how ostracism can affect workplace behaviors.

Design/methodology/approach

The study was designed using a three-wave self-reported survey. Confirmatory factor analysis, structural equation modeling, and bootstrapping for indirect effects were conducted to test the study’s hypotheses.

Findings

The study found OBSE to fully mediate the relationship between workplace ostracism and helping behavior, voicing behavior, and in-role behavior, while OBSE partially mediated workplace ostracism and deviant behavior as workplace ostracism was found to have a direct effect on deviant behavior.

Originality/value

The study explores and empirically tests the mediating effects of OBSE with helping behavior, voicing behavior, in-role behavior, and deviant behavior. Therefore, the study extends research on workplace ostracism by investigating beyond the direct effects of workplace ostracism on workplace behaviors.
A neural network identifier for electromagnetic thermotherapy systems
Authors: Tai Cheng-Chi , Wang Wei-Cheng , Hsu Yuan-Jui
Published: March 2017

Purpose

This study aims to establish a dynamic process model of an electromagnetic thermotherapy system (ETS) to predict the temperature of a thermotherapy needle.

Design/methodology/approach

The model is used for real-time predicting the static and dynamic responses of temperature and can therefore provide a valuable analysis for system monitoring.

Findings

The electromagnetic thermotherapy process is a nonlinear problem in which the system identification is implemented by a neural network identifier. It can simulate the input/output relationship of a real system with an excellent approximation ability to uncertain nonlinear system. A system identifier for an ETS is analyzed and selected with recurrent neural networks models to deal with various treatment processes.

Originality/value

The Elman neural network (ENN) prediction model on ETS proposed in this study is an easy and feasible method. Comparing two situations of inputs with more and fewer data, both are trained to present low mean squared error, and the temperature response error appears within 15 per cent. The ENN, with the advantages of simple design and stable efficacy, is useful for establishing the temperature prediction model to ensure the security in the thermotherapy.
Lattice Boltzmann modelling for multiphase bubble flow in electroconducting liquids
Authors: Tatulcenkovs Andrejs , Jakovics Andris , Baake Egbert , Nacke Bernard
Published: March 2017

Purpose

The purpose of this paper is to the study the multiphase bubbles flow motion in a vertical channel with an electroconducting liquid without and under the influence of a magnetic field.

Design/methodology/approach

For numerical calculations, the lattice Boltzmann method (LBM) is used, which is based on the kinetic theory for solving fluid mechanics and other physical problems. The phase-field lattice Boltzmann model is developed to simulate the behaviour of multiphase bubble–bubble interaction while rising in the fluid with high density ratios.

Findings

The behaviour of the rising bubble flow in a rectangular column of two phases is investigated with the two-dimensional LBM.

Originality/value

The multiphase flow in electroconducting liquids with high ratio of density is studied using the LBM.
Transactive knowledge from communities of practice to firms
Authors: Longo Maria Cristina , Narduzzo Alessandro
Published: March 2017

Purpose

The purpose of this paper is to analyze to what extent and under which conditions R&D projects benefit from team members’ participation in spontaneous and work-related communities of practice (CoPs).

Design/methodology/approach

This is a quantitative empirical study. R&D projects are the unit of analysis. Data are collected through interviews to 121 informants who are members of 60 R&D projects and participants in 195 CoPs.

Findings

The participation of project team members in work-related CoPs positively affects the R&D project performance. This positive effect applies also to radically innovative projects. The diversity in the institutional affiliation of CoPs members is also highly significant and positively correlated with the project performance.

Research limitations/implications

The paper considers only work-related CoPs, thus neglecting the knowledge transacted through other types of CoPs.

Practical implications

Practitioners should support the autonomous participation of project team members to spontaneous and work-related CoPs that cut across the organizational boundaries. Team leaders may enhance team innovative capabilities and performance by ensuring diversity of knowledge and skills from CoPs whose members work for institutions that differ from each other.

Originality/value

First, this study provides quantitative evidence of the CoPs ability to support innovation. Second, this research is focused on spontaneous and work-related CoPs within business environments. Third, this study does not analyze CoPs performance, but it postulates a connection between innovative organizational units (i.e. R&D projects) and spontaneous CoPs that cut across the firms’ boundaries.
Organizational service orientation and job satisfaction
Authors: Bellou Victoria , Andronikidis Andreas
Published: March 2017

Purpose

Given the polyphony around service orientation related constructs coming from both Marketing and Organizational Behavior researchers, the first purpose of this paper is to delineate the construct of service orientation, and second, recognizing the focal role of employees for offering services of high quality, it investigates the complex relationship between service orientation and job satisfaction.

Design/methodology/approach

This paper draws upon theories and arguments from marketing and organizational behavior to identify “organizational service orientation” (OSO) as a common basis for both scholarships. Grounded on the review of the impact of OSO and job satisfaction constructs to each other, the authors develop research propositions, and discuss implications of the proposed relationships for both.

Findings

The paper explicates the positive impact of OSO on job satisfaction but also puts forward a positive influence of job satisfaction on OSO, suggesting hence a reciprocal relationship between the two.

Originality/value

First, this paper offers construct clarification for OSO, bridging disciplinary and audience divides. Second, it argues over the reciprocal relationship between OSO and job satisfaction, indicating the necessity to invest on maximizing both constructs in order to ultimately optimize the service experience of customers.
Success factors in university sport partnerships: a case study
Authors: Franco Mário , Haase Heiko
Published: March 2017

Purpose

From a resource-based perspective, the purpose of this paper is to analyse the key success factors underlying inter-organisational partnerships in the university sport sector.

Design/methodology/approach

To attain this objective, the paper uses a qualitative approach, performing an exploratory case study in a Portuguese higher education institution. Four interviews with key informants and documentary analysis served for data collection.

Findings

Based on the case evidence, five generic success factors emerged: relationships, partner selection, complementarity, sporting performance and organisation, which are likely to determine the success of partnerships in the field of university sport.

Practical implications

University sport managers and other actors in the field should bear the major success factors in mind when taking strategic decisions. Specifically, relational capital and the complementarity of resources seem to be important in initiating and managing sport partnerships.

Originality/value

This exploratory study contributes to advancing knowledge of inter-organisational partnerships in a particular area: sport in higher education. More precisely, this research outlines which success factors are relevant in sport partnerships and deserve further investigation with other research designs.
A supply chain framework for characterizing indirect vulnerability
Authors: Gotangco Charlotte Kendra , Favis Abigail Marie , Guzman Ma. Aileen Leah , Tan Marion Lara , Quintana Carissa , Josol Jairus Carmela
Published: March 2017

Purpose

Climate vulnerability assessments are often operationalized by the analysis of indicators defined by the spatial boundaries of the community under study. These, however, sometimes fail to capture interdependency among communities for basic resources. This paper aims to propose a framework for characterizing vulnerability caused by interdependency by adapting a supply chain lens.

Design/methodology/approach

The paper proposes a definition for “indirect vulnerability” that recognizes the transboundary and teleconnected nature of vulnerability arising from resource networks among cities and communities. A conceptual framework using a supply chain approach is presented for climate hazards in particular. This approach is then demonstrated through a rapid appraisal of the rice, energy and water supply chains and the waste management chains of Metro Manila.

Findings

The application of the supply chain lens to assessing the indirect vulnerability of Metro Manila brings to fore issues extending beyond the decision-making boundaries of local government units. Addressing these will require vertical government coordination and horizontal inter-sectoral collaboration. Thus, this supply chain-based indirect vulnerability assessment can be complementary to traditional vulnerability assessments in providing a larger systems perspective.

Originality/value

Innovative tools are needed to make community vulnerability assessments both holistic and tractable. Existing methods in the private sector can be adapted rather than reinventing the wheel. This supply chain framework can be a useful decision support and planning tool across governance levels to comprehensively address vulnerability.
Corporate governance structure and capital adequacy: implications to bank risk taking
Authors: Abou-El-Sood Heba
Published: March 2017

Purpose

The purpose of this paper is to show the importance of policy discussions on the role of governance in limiting excessive risk-taking at times of turmoil.

Design/methodology/approach

Corporate governance measures are regressed on measures of risk taking using a sample of US bank holding companies (BHCs) during 2002-2014.

Findings

Results show that BHCs with more concentrated shareholders, more managerial ownership, smaller boards, and less outside directors undertake less risky investments with respect to total assets, loans, and off-balance-sheet items. Capital adequacy effect is overpowering pushing for more risky positions. Finally, banks with good governance push for less risky positions, even with larger capital ratios, during the financial crisis period relative to the precrisis boom.

Practical implications

This paper extends research on the association between bank ownership structure and risk taking. It adds to prior research by examining a key feature of banks, namely, their bank-specific capital adequacy. The relevance of this study stems from recent initiatives undertaken by the Basel Committee, the Group of Thirty (G30), and bank regulators to address deficient corporate governance structures that led to bank breakdowns.

Originality/value

One of the innovations of this paper is the use of risk-weighted measures to proxy for risk taking in banks, using risk weights used by bank regulators to adjust for operational risk, credit risk, and market risk.
Family ownership and free cash flow
Authors: Sitthipongpanich Thitima
Published: March 2017

Purpose

The purpose of this paper is to investigate the effect of family ownership on investment-cash flow sensitivity and on firm performance.

Design/methodology/approach

The author uses panel data to examine the relationship between investment and cash flow and between family ownership and the firm performance of Thai listed firms from 2001 to 2008. To account for the endogeneity of the lagged dependent variable, the investment equation is estimated by the generalized method of moments, following Arellano and Bond (1991).

Findings

The presence of family owners reduces the sensitivity of investment and cash flow. At low and high levels of family ownership, an increase in family shareholding leads to lower investment-cash flow sensitivity. In contrast, firms with medium family ownership levels have higher investment-cash flow sensitivity. Only at high levels of family ownership is firm performance positively related to family shareholding.

Originality/value

The ownership levels of family shareholders affect the investment-cash flow sensitivity in an S-shaped relation, supporting the interest alignment and entrenchment effects. When family shareholders have high ownership incentives, their interest alignment reduces the agency costs of free cash flow problems and leads to higher firm performance.
Corporate financial policy and the value of cash under uncertainty
Authors: Chakraborty Atreya , Baum Christopher F. , Liu Boyan
Published: March 2017

Purpose

The purpose of this paper is to provide evidence on how firm-specific and macroeconomic uncertainty affects shareholders’ valuation of a firm’s cash holdings. This extends previous work on this issue by highlighting the importance of the source of uncertainty. The findings indicate that increases in firm-specific risk generally increase the value of cash while increases in macroeconomic risk generally decrease the value of cash. These findings are robust to alternative definitions of the unexpected change in cash. The authors extend the analysis to financially constrained and unconstrained firms.

Design/methodology/approach

The authors test the hypothesis that the marginal effect of cash holdings on excess stock returns is sensitive to uncertainty. To compute this marginal effect, the authors adopt and extend the approach of Faulkender and Wang (2006) to the authors’ more elaborate model.

Findings

The findings indicate that different sources of uncertainty affect the value of cash holdings differently. Findings indicate that increases in firm-specific risk generally increase the value of cash while increases in macroeconomic risk generally decrease the value of cash. These findings are robust to alternative definitions of the unexpected change in cash. The authors also extend the findings to financially constrained and unconstrained firms.

Originality/value

The findings indicate that the source of uncertainty firm-specific vs macroeconomic risk matters. The two sources of risk may have quite different effects on shareholders’ valuation of a firm’s cash holdings. Results from alternative sources of findings are new. These new findings are robust to alternative definitions of the unexpected change in cash.
Cross-enterprise value stream assessment
Authors: Oberhausen Christof , Plapper Peter
Published: March 2017

Purpose

In most cases, the conventional assessment of value streams is based on key performance indicators (KPIs) like the share of added value, the degree of flow or a comprehensive lead time analysis. To evaluate cross-enterprise value streams of manufacturing, business or service processes in detail, a holistic methodology is needed. The paper aims to discuss this issue.

Design/methodology/approach

In this research paper, the assessment of value streams within complex cross-company networks is described. After a presentation of relevant KPIs in the fields of value stream management (VSM) and supply chain management (SCM), an approach for a cross-enterprise evaluation of value streams on different levels of detail is shown. In addition, the use of an absolute VSM evaluation, in contrast to a relative VSM assessment, is examined.

Findings

Based on a uniform and well-balanced set of KPIs and other VSM and SCM parameters, a performance assessment on different levels of value stream detail is enabled. Further investigations reveal the advantages of a relative compared with an absolute VSM assessment.

Research limitations/implications

In addition to a comprehensive overview of existing KPIs for a value stream assessment beyond company borders, a holistic and multi-level VSM approach is presented in this paper. In contrast to existing VSM approaches, the described method allows an evaluation and subsequent improvement of value streams within supply chain networks. Up to now, the presented approach for the assessment of cross-enterprise value streams has only been tested in specific industrial environments. In future, the proposed methodology shall also be validated for other process types like business, service or further manufacturing processes.

Practical implications

The described cross-company performance measurement approach shows a high practical relevance for organizations operating in supply chain networks. Due to the integrated use of different VSM parameters, the evaluation of highly interconnected value streams across corporate boundaries is facilitated. By means of a case study, the proposed methodology is validated under real industry conditions and proves its practical applicability.

Originality/value

One of the novel features of this research is the extension of the traditional VSM method with respect to a relative evaluation of value streams based on a set of significant KPIs. In addition, the allocation of these KPIs to different value stream layers and categories leads to an innovative approach for a multi-level assessment according to the needs of the specific VSM application, e.g. a more standardized use of VSM in complex supply chain networks.
Variable selection framework for allocating products to recommended replenishment models in VMI applications
Authors: Anzanello Michel , Mazzillo Cézar , Tortorella Guilherme , Marodin Giuliano
Published: March 2017

Purpose

The purpose of this paper is to propose a multivariate-based method to classify products in replenishment categories based on principal component analysis (PCA) along with two classification algorithms, k-nearest neighbor (KNN) and linear discriminant analysis (LDA).

Design/methodology/approach

In the propositions, PCA is applied to data describing products’ features and demand behavior, and a variable importance index (VII) is derived based on PCA parameters. Next, products are allocated to inventory replenishment models applying the KNNs to all original variables; the classification accuracy is then assessed. The variable with the smallest VII is removed and a new classification is carried out; this iterative procedure is performed until a single variable is left. The subset yielding the maximum classification accuracy is recommended for future classification. The aforementioned procedure is repeated replacing the KNN by the LDA.

Findings

When applied to real data from a consulting company, the KNN classification technique led to higher performance levels than LDA, yielding 89.4 percent average accuracy and retaining about 80 percent of the original variables. On the other hand, LDA reached 87.1 percent average accuracy and retained 95 percent of the variables. Based on such results, the authors’ findings suggest that 14 out of the 24 variables are crucial in determining an inventory replenishment model for a product in a specific location replacement. Several of the retained variables were typically used in reorder point estimation or associated to market profile in specific locals.

Originality/value

The idea of this paper is to remove irrelevant and noisy market metrics that jeopardize the correct allocation of products to the most appropriate replenishment model.