bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of Polymerase Chain Reaction: Pathogen-Specific Controls are better than Human Gene Amplification
Authors: Roux Guillaume , Ravel Christophe , Varlet-Marie Emmanuelle , Jendrowiak Rachel , Bastien Patrick , Sterkers Yvon
Published: June 2019

PCR inhibition is frequent in medical microbiology routine practice and may lead to false-negative results; however there is no consensus on how to detect it. Pathogen-specific and human gene amplifications are widely used to detect PCR inhibition. We aimed at comparing the value of PCR inhibitor detection using these two methods. We analysed Cp shifts (ΔCp) obtained from qPCRs targeting either the albumin gene or the pathogen-specific sequence used in two laboratory-developed microbiological qPCR assays. 3152 samples including various matrixes were included. Pathogen-specific amplification and albumin qPCR identified 62/3152 samples (2.0 %), and 409/3152 (13.0%) samples, respectively, as inhibited. Only 16 samples were detected using both methods. In addition, the use of the Youden’s index failed to determine adequate Cp thresholds for albumin qPCR, even when we distinguished among the different sample matrixes. qPCR targeting the albumin gene therefore appears not adequate to identify the presence of PCR inhibitors in microbiological PCR assays. Our data may be extrapolated to other heterologous targets and should discourage their use to assess the presence of PCR inhibition in microbiological PCR assays.
Protein Tyrosine Phosphatase 4A3 (PTP4A3) modulates Src signaling in T-cell Acute Lymphoblastic Leukemia to promote leukemia migration and progression
Authors: Wei M , Haney MG , Blackburn JS
Published: June 2019

T-cell Acute Lymphoblastic Leukemia (T-ALL) is an aggressive blood cancer, and currently, there are no immunotherapies or molecularly targeted therapeutics available for treatment of this malignancy. The identification and characterization of genes and pathways that drive T-ALL progression is critical for development of new therapies for T-ALL. Here, we determined that Protein Tyrosine Phosphatase 4A3 (PTP4A3) plays a critical role in disease initiation and progression by promoting cell migration in T-ALL. PTP4A3 expression was upregulated in patient T-ALL samples at both the mRNA and protein levels compared to normal lymphocytes. Inhibition of PTP4A3 function with a small molecule inhibitor and knock-down of PTP4A3 expression using short-hairpin RNA (shRNA) in human T-ALL cells significantly impeded T-ALL cell migration capacityin vitroand reduced their ability to engraft and proliferatein vivoin xenograft mouse models. Additionally, PTP4A3 overexpression in aMyc-induced zebrafish T-ALL model significantly accelerated disease onset and shortened the time needed for cells to enter blood circulation. Reverse phase protein array (RPPA) revealed that manipulation of PTP4A3 expression levels in T-ALL cells directly affected the SRC signaling pathway, which plays a well-characterized role in migratory behavior of several cell types. Taken together, our study revealed that PTP4A3 is a key regulator of T-ALL migration via SRC signaling, and suggests that PTP4A3 plays an important role as an oncogenic driver in T-ALL.

Highlights

A subset of T-cell Acute Lymphoblastic Leukemia (T-ALL) highly express the phosphatase PTP4A3

PTP4A3 expression promotes leukemia development in zebrafish T-ALL models

Loss of PTP4A3 prevents T-ALL engraftment in mouse xenograft models

Knock-down or small molecule inhibition of PTP4A3 prevents T-ALL migration in part via modulation of SRC signaling.
On-demand, cell-free biomanufacturing of conjugate vaccines at the point-of-care
Authors: Stark Jessica C. , Jaroentomeechai Thapakorn , Moeller Tyler D. , Dubner Rachel S. , Hsu Karen J. , Stevenson Taylor C. , DeLisa Matthew P. , Jewett Michael C.
Published: June 2019

Conjugate vaccines are among the most effective methods for preventing bacterial infections, representing a promising strategy to combat drug-resistant pathogens. However, existing manufacturing approaches limit access to conjugate vaccines due to centralized production and cold chain distribution requirements. To address these limitations, we developed a modular technology forin vitrobioconjugatevaccine expression (iVAX) in portable, freeze-dried lysates from detoxified, nonpathogenicEscherichia coli. Upon rehydration, iVAX reactions synthesize clinically relevant doses of bioconjugate vaccines against diverse bacterial pathogens in one hour. We show that iVAX synthesized vaccines against the highly virulent pathogenFranciscella tularensissubsp.tularensis(type A) strain Schu S4 elicited pathogen-specific antibodies in mice at significantly higher levels compared to vaccines produced using engineered bacteria. The iVAX platform promises to accelerate development of new bioconjugate vaccines with increased access through refrigeration-independent distribution and point-of-care production.
Illusory sound texture reveals multi-second statistical completion in auditory scene analysis
Authors: McWalter Richard , McDermott Josh H.
Published: June 2019

Sound sources in the world are experienced as stable even when intermittently obscured, implying perceptual completion mechanisms that “fill in” missing sensory information. We demonstrate a filling-in phenomenon in which the brain extrapolates the statistics of background sounds (textures) over periods of several seconds when they are interrupted by another sound, producing vivid percepts of illusory texture. The effect differs from previously described completion effects in that 1) the extrapolated sound must be defined statistically given the stochastic nature of texture, and 2) in lasting much longer, enabling introspection and facilitating assessment of the underlying representation. Illusory texture appeared to be integrated into texture statistic estimates indistinguishably from actual texture, suggesting that it is represented similarly to actual texture. The illusion appears to represent an inference about whether the background is likely to continue during concurrent sounds, providing a stable representation of the environment despite unstable sensory evidence.
Chromatin accessibility dynamics ofChlamydia-infected epithelial cells
Authors: Hayward Regan J. , Marsh James W. , Humphrys Michael S. , Huston Wilhelmina M. , Myers Garry S.A.
Published: June 2019

Chlamydiaare Gram-negative, obligate intracellular bacterial pathogens responsible for a broad spectrum of human and animal diseases. In humans,Chlamydia trachomatisis the most prevalent bacterial sexually transmitted infection worldwide and is the causative agent of trachoma (infectious blindness) in disadvantaged populations. Over the course of its developmental cycle,Chlamydiaextensively remodels its intracellular niche and parasitises the host cell for nutrients, with substantial resulting changes to the host cell transcriptome and proteome. However, little information is available on the impact of chlamydial infection on the host cell epigenome and global gene regulation. Regions of open eukaryotic chromatin correspond to nucleosome-depleted regions, which in turn are associated with regulatory functions and transcription factor binding. We applied Formaldehyde-Assisted Isolation of Regulatory Elements enrichment followed by sequencing (FAIRE-Seq) to generate temporal chromatin maps ofC. trachomatis-infected human epithelial cellsin vitroover the chlamydial developmental cycle. We detected both conserved and distinct temporal changes to genome-wide chromatin accessibility associated withC. trachomatisinfection. The observed differentially accessible chromatin regions, including several Clusters of Open Regulatory Elements (COREs) and temporally-enriched sets of transcription factors, may help shape the host cell response to infection. These regions and motifs were linked to genomic features and genes associated with immune responses, re-direction of host cell nutrients, intracellular signaling, cell-cell adhesion, extracellular matrix, metabolism and apoptosis. This work provides another perspective to the complex response to chlamydial infection, and will inform further studies of transcriptional regulation and the epigenome inChlamydia-infected human cells and tissues
Efficient and flexible tagging of endogenous genes by homology-independent intron targeting
Authors: Serebrenik Yevgeniy V. , Sansbury Stephanie E. , Kumar Saranya Santhosh , Henao-Mejia Jorge , Shalem Ophir
Published: June 2019

Genome editing tools have simplified the generation of knock-in gene fusions, yet the prevalent use of gene-specific homology-directed repair (HDR) templates still hinders scalability. Consequently, realization of large-scale gene tagging requires further development of approaches to generate knock-in protein fusions via generic donors that do not require locus-specific homology sequences. Here, we combine intron-based protein trapping with homology-independent repair-based integration of a generic donor and demonstrate precise, scalable, and efficient gene tagging. Because editing is performed in introns using a synthetic exon, this approach tolerates mutations in the unedited allele, indels at the integration site, and the addition of resistance genes that do not disrupt the target gene coding sequence, resulting in easy and flexible gene tagging.
Insertion Preference of Maize and Rice Miniature Inverted Repeat Transposable Elements as Revealed by the Analysis of Nested Elements [W]
Authors: Jiang Ning , Wessler Susan R.
Published: June 2019

A 128-bp insertion into the maize waxy-B2 allele led to the discovery of Tourist, a family of miniature inverted repeat transposable elements (MITEs). As a special category of nonautonomous elements, MITEs are distinguished by their high copy number, small size, and close association with plant genes. In maize, some Tourist elements (named Tourist-Zm) are present as adjacent or nested insertions. To determine whether the formation of multimers is a common feature of MITEs, we performed a more thorough survey, including an estimation of the proportion of multimers, with 30.2 Mb of publicly available rice genome sequence. Among the 6600 MITEs identified, >10% were present as multimers. The proportion of multimers differs for different MITE families. For some MITE families, a high frequency of self-insertions was found. The fact that all 340 multimers are unique indicates that the multimers are not capable of further amplification.
A new three-dimensional cobalt(II) coordination polymer based on V-shaped 3,4′-oxydibenzoate: synthesis, crystal structure and magnetic properties
Authors: Lan Wenlong , Zhou Zhen , Jia Fu-Chao , Hao Xiaoyun , Dou Yong , Yang Lu , Liu Hui , Liu Qingyun , Zhang Daopeng
Published: June 2019

A new coordination polymer (CP), namely poly[(μ-4,4′-bipyridine)(μ3-3,4′-oxydibenzoato)cobalt(II)], [Co(C14H8O5)(C10H8N2)]
n
or [Co(3,4′-obb)(4,4′-bipy)]
n
(1), was prepared by the self-assembly of Co(NO3)2·6H2O with the rarely used 3,4′-oxydibenzoic acid (3,4′-obbH2) ligand and 4,4′-bipyridine (4,4′-bipy) under solvothermal conditions, and has been structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography and powder X-ray diffraction (PXRD). Single-crystal X-ray diffraction reveals that each CoII ion is six-coordinated by four O atoms from three 3,4′-obb2− ligands, of which two function as monodentate ligands and the other as a bidentate ligand, and by two N atoms from bridging 4,4′-bipy ligands, thereby forming a distorted octahedral CoN2O4 coordination geometry. Adjacent crystallographically equivalent CoII ions are bridged by the O atoms of 3,4′-obb2− ligands, affording an eight-membered Co2O4C2 ring which is further extended into a two-dimensional [Co(3,4′-obb)]
n
sheet along the ab plane via 3,4′-obb2− functioning as a bidentate bridging ligand. The planes are interlinked into a three-dimensional [Co(3,4′-obb)(4,4′-bipy)]
n
network by 4,4′-bipy ligands acting as pillars along the c axis. Magnetic investigations on CP 1 disclose an antiferromagnetic coupling within the dimeric Co2 unit and a metamagnetic behaviour at low temperature resulting from intermolecular π–π interactions between the parallel 4,4′-bipy ligands.
The heteroscorpionate ligand 2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethanol and an easy preparation of its tungsten complex
Authors: Böhme Uwe , Schwarzer Anke , Günther Betty
Published: June 2019

The heteroscorpionate ligand 2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethanol, C24H26N4O, features in the solid state an intramolecular O—H...N hydrogen bond. A heteroscorpionate tungsten complex, cis-[2,2-bis(3,5-dimethylpyrazolyl)-1,1-diphenylethanolato]chloridodioxidotungsten(VI) tetrahydrofuran monosolvate, [W(C24H25N4O)ClO2]·C4H8O, was prepared by the simple mixing of solutions of the ligand and WOCl4 in tetrahydrofuran. The tungsten complex was isolated after standing for several weeks. The complex exhibits a κ3
N,N′,O-coordination of the ligand. This simple synthetic procedure allows access to the cis isomer in high yield without additional purification steps. The Hirshfeld surface analysis shows a change of the intermolecular contacts due to the coordination of the WO2Cl unit with the ligand molecule.
Skill development research in India: a systematic literature review and future research agenda
Authors: Cabral Clement , Dhar Rajib Lochan
Published: June 2019

Purpose

The purpose of this paper is to conduct an in-depth analysis of the literature and provide new insights on skill development research in India. Objectives in the study are twofold. First is to conduct descriptive analysis in terms of structural dimensions such as geographical context, focus on skill development, research methods, economic sector, type of training and origin of the study. The second objective is to conduct thematic analysis on importance of skill development, institutional and regulatory mechanisms, skill development as an antecedent for technology adoption, role of skill development in women empowerment, integrating skill development with secondary education and labour market reforms for skill development.

Design/methodology/approach

Systematic literature review method is employed to review 45 articles on skill development research in India conducted between 2004 and 2017.

Findings

The review discusses about the importance of skill development, the role of institutions such as NSDA and PMKVJ, skill development as a necessity in the advent of technological changes, an effective measure to empower women in the country and the need of integrating skill development with secondary education. Labour market reforms are required to overcome challenges such as mismatch between theory and practice, low quality of skills assimilated, the mismatch between demand and supply of skilled labour force, low level of in-house training, low cooperation from students and employees due to lack of incentives and lack of qualified teachers.

Originality/value

This study is the first to offer a systematic literature review on skill development. The study provides insights into the concept of skill development, specifically for academicians to carry out research in a niche area and for government authorities in policy formulation.
Modelling internet of things driven sustainable food security system
Authors: Kaur Harpreet
Published: June 2019

Purpose

The purpose of this paper is to model the sustainable food security system using various technologies driving internet of things (IoT). The right to food is a fundamental right of humans. With increasing population and urbanization, less land is being used for agricultural purposes. In addition, the climate change due to global warming often leads to frequent disasters such as droughts and floods, adversely affecting the food production. This leads to increased levels of poverty and hunger. Ensuring food security has become the prime agenda for all the policymakers and government bodies across the world. With changing global dynamics, traditional ways of ensuring food security will not be sufficient alone.

Design/methodology/approach

There is a need to develop a sustainable food security system that not only focusses on food production but also equally emphasizes on the efficacy of food distribution and reducing food wastage. In this digital age, the emerging disruptive technologies like Block chain, robotics, big data analytics, and cloud computations, etc., are increasingly changing the functioning of various sectors, giving rise to IoT-based working environment. The policymakers are also exploring these technologies to maximize their outreach so as to benefit the larger set of population and to gain visualization and control over policy implementation using IoT. This paper attempts to model the sustainable food security system using various technologies driving IoT. It also studies the interrelationship among various technologies and their application in various levels of policy implementation. The methodology used in the paper is fuzzy-TISM, which not only provides the causal relationship among two technologies but also provides the magnitude of the cause–effect relationship and the hierarchical framework for the complex problem.

Findings

The paper is addressed to the design of sustainable food security system in the Indian context wherein government ensures food security for all, using public distribution system (PDS).

Social implications

The paper is addressed to the design of sustainable food security system in Indian context wherein government ensures food security for all, using PDS.

Originality/value

This study is a novel attempt to integrate the IoT into the design of the PDS to ensure food security. The enabling factors for IOT are modelled using Fuzzy-TISM.
Practical model of the axial magnetic field in the end region of large turbo-generators
Authors: Demian Cristian , Romary Raphael , Vogt Gilles , Costan Valentin
Published: June 2019

Purpose

The axial magnetic field occurs in the end-region of large turbo-generators is known to induce hot points or voltages between laminations, that may cause insulation breakdown and thus stator faults.

Design/methodology/approach

It is important to dispose of simple methods for estimating the axial flux rapidly with regard to the operating point of the machine.

Findings

The authors provide a practical model of the axial magnetic field based on a simplified vector diagram. The parameters required to build the vector composition of the flux densities are assessed with a limited number of finite element method simulations of the whole end-region of the machine. These simulations were validated by an experimental test on a real turbo-generator. Then the axial flux density was simply estimated for various operating points.

Originality/value

The originality of the paper concerns the practical model of the axial magnetic field based on a simplified vector diagram.
Construction delay risk taxonomy, associations and regional contexts
Authors: Derakhshanfar Hossein , Ochoa J. Jorge , Kirytopoulos Konstantinos , Mayer Wolfgang , Tam Vivian W.Y.
Published: June 2019

Purpose

The purpose of this paper is to systematically develop a delay risk terminology and taxonomy. This research also explores two external and internal dimensions of the taxonomy to determine how much the taxonomy as a whole or combinations of its elements are generalisable.

Design/methodology/approach

Using mixed methods research, this systematic literature review incorporated data from 46 articles to establish delay risk terminology and taxonomy. Qualitative data of the top 10 delay risks identified in each article were coded based on the grounded theory and constant comparative analysis using a three-stage coding approach. Word frequency analysis and cross-tabulation were used to develop the terminology and taxonomy. Association rules within the taxonomy were also explored to define risk paths and to unmask associations among the risks.

Findings

In total, 26 delay risks were identified and grouped into ten categories to form the risk breakdown structure. The universal delay risks and other delay risks that are more or less depending on the project location were determined. Also, it is realized that delays connected to equipment, sub-contractors and design drawings are highly connected to project planning, finance and owner slow decision making, respectively.

Originality/value

The established terminology and taxonomy may be used in manual or automated risk management systems as a baseline for delay risk identification, management and communication. In addition, the association rules assist the risk management process by enabling mitigation of a combination of risks together.
How brand visual aesthetics foster a transnational imagined community
Authors: Buschgens Mark , Figueiredo Bernardo , Rahman Kaleel
Published: June 2019

Purpose

The purpose of this paper is to investigate how visual aesthetic referents used in branding can help foster a transnational imagined community (TIC). The authors use brands embedded with Middle Eastern visual aesthetics as a research context. As such, the study aims to examine how Middle Eastern non-figurative art is used by non-Middle Eastern brands to foster an imagined Middle Easternness.

Design/methodology/approach

Through a critical visual analysis, the authors apply a visual social semiotic approach to Middle Eastern art canons to better understand the dimensions of transnational imagined communities.

Findings

The study finds and discusses six sub-dimensions of Middle Easternness, which compose two overarching dimensions of TIC, namely, temporal and spatial. These sub-dimensions provide brand managers and designers with six different ways to foster transnational imagined communities through the use of visual aesthetic referents in branding.

Research limitations/implications

This research identifies the specific visual sub-dimensions of brands that enable transnational communities to be imagined.

Practical implications

Understanding the visual aesthetic sub-dimensions in this study provides brand managers with practical tools that can help develop referents that foster transnational imagined communities in brand building to achieve competitive advantage and reach a transnational segment.

Originality/value

Prior studies have primarily focussed on how visual aesthetics help in understanding issues related to national identity. In contrast, this paper examines the use of visual aesthetics in branding from a transnational perspective.
A comparison of topology optimization and genetic algorithms for the optimization of thermal energy storage composites
Authors: Badenhorst Heinrich
Published: June 2019

Purpose

The purpose of this paper is to apply two optimization methods to the issue of sensible energy store design.

Design/methodology/approach

This paper is a comparison of topology optimization and genetic algorithms.

Findings

Genetic algorithms are prone to converge to local maxima while requiring significantly longer convergence times compared to topology optimization. Topology optimization resulted in structures representing parallel sheets, which are as thin as the grid allows. These configurations can maintain the maximum surface area between the low and high conductivity materials at high refinement, resulting in the best performance.

Practical implications

Time required for 99 per cent store discharge is decreased by 70 per cent using a 50 × 50 optimization grid at a loading of 10 Vol.%.

Originality/value

These approaches have not been compared nor applied to this specific problem before. Value is in the key finding that maximization of surface area is only possible with fins/sheets and not tree structures. This dictates the optimal solution for dynamic behaviour.
Improvement of drug delivery micro-circulatory system with a novel pattern of CuO-Cu/blood hybrid nanofluid flow towards a porous stretching sheet
Authors: Dinarvand Saeed , Nademi Rostami Mohammadreza , Dinarvand Rassoul , Pop Ioan
Published: June 2019

Purpose

This paper aims to simulate the steady laminar mixed convection incompressible viscous and electrically conducting hybrid nanofluid (CuO-Cu/blood) flow near the plane stagnation-point over a horizontal porous stretching sheet along with an external magnetic field and induced magnetic field effects that can be applicable in the biomedical fields like the flow dynamics of the micro-circulatory system and especially in drug delivery.

Design/methodology/approach

The basic partial differential equations (PDEs) are altered to a set of dimensionless ordinary differential equations (ODEs) with the help of suitable similarity variables which are then solved numerically using bvp4c scheme from MATLAB. Inasmuch as validation results have shown a good agreement with previous reports, the present novel mass-based algorithm can be used in this problem with great confidence. Governing parameters are both nanoparticle masses, base fluid mass, empirical shape factor of both nanoparticles, suction/injection parameter, magnetic parameter, reciprocal magnetic Prandtl number, Prandtl number, heat source parameter, mixed convection parameter, permeability parameter and frequency ratio. The effect of these parameters on the flow and heat transfer characteristics of the problem is discussed in detail.

Findings

It is shown that the use of CuO and Cu hybrid nanoparticles can reduce the hemodynamics effect of the capillary relative to pure blood case. Moreover, as the imposed magnetic field enhances, the velocity of the blood decreases. Besides, when the blade shapes for both nanoparticles are taken into account, the local heat transfer rate is maximum that is also compatible with experimental observations.

Originality/value

An innovative mass-based model of CuO-Cu/blood hybrid nanofluid has been applied. The novel attitude to one-phase hybrid nanofluid model corresponds to considering nanoparticles mass as well as base fluid mass to computing the solid equivalent volume fraction, the solid equivalent density and also solid equivalent specific heat.
Flow and heat transfer of couple stress nanofluid sandwiched between viscous fluids
Authors: Umavathi C. Jawali , Sheremet Mikhail
Published: June 2019

Purpose

The purpose of this study is a numerical analysis of steady-state heat transfer behavior of couple-stress nanofluid sandwiched between viscous fluids. It should be noted that this research deals with the development of a cooling system for the electronic devices.

Design/methodology/approach

Stokes model is used to define the couple-stress fluid and the single-phase nanofluid model is used to define the nanofluid transport processes. The fluids in all regions are assumed to be incompressible, immiscible and the transport properties in all the three layers are assumed to be constant. The governing coupled linear ordinary differential equations are made dimensionless by using appropriate fundamental quantities. The exact solutions obtained for the velocity and temperature fields are evaluated numerically for various model parameters.

Findings

The results are demonstrated using different types of nanoparticles such as copper, silver, silicon oxide (SiO2), titanium oxide (TiO2) and diamond. The investigations are carried out using copper–water nanofluid for different values of couple-stress parameter a with a range of 0 = a = 12, solid volume fraction ϕ with a range of 0.0 ≤ ϕ ≤ 0.05, Eckert number Ec with a range of 0.001 ≤ Ec ≤ 6 and Prandtl number Pr with a range of 0.001 ≤ Pr ≤ 6. It was found that the Nusselt number increases by increasing the couple stress parameter, Eckert number and Prandtl number and it decreases with a growth of the solid volume fraction parameter. It was also observed that using SiO2–water nanofluid, the optimal Nusselt number is obtained. Further, using copper, silver, diamond and TiO2, nanoparticles and water as a base fluid does not show any significant changes in the rate of heat transfer. The couple-stress parameter enhances the velocity and temperature fields whereas the solid volume fraction suppresses the flow field for both Newtonian and couple-stress fluid.

Originality/value

The originality of this work is to analyze the heat transfer behavior of couple-stress nanofluid sandwiched between viscous fluids. The results would benefit scientists and engineers to become familiar with the analysis of convective heat transfer and flow structures in nanofluids and the way to predict the heat transfer rate in advanced technical systems, in industrial sectors including transportation, power generation, chemical sectors, electronics, etc.
Mixed convective non-linear radiative flow with TiO2-Cu-water hybrid nanomaterials and induced magnetic field
Authors: Ahmad Khan Sohail , Khan Muhammad Ijaz , Hayat Tasawar , Faisal Javed Muhammad , Alsaedi Ahmed
Published: June 2019

Purpose

The purpose of this paper is to address the impact of induced magnetic field in mixed convective stagnation flow of TiO2-Cu-water hybrid nanofluid towards a stretchable sheet. Non-linear thermal radiation and heat source/sink are accounted. Flow of hybrid nanofluid is discussed. Non-linear partial differential expressions are converted to ordinary ones through appropriate transformations.

Design/methodology/approach

The obtained systems are solved for convergence solutions via homotopy analysis method. Graphical results are discussed for different physical variables on the velocity, induced magnetic field and temperature fields for both Cu water nanofluid and TiO2-Cu-water hybrid nanofluid. Finally, the effect of different physical variables on skin friction coefficient (Cfx) and Nusselt number Nux in the presence of water nanofluid and TiO2-Cu-water hybrid nanofluid are discussed.

Findings

Velocities and induced magnetic field are increasing functions of mixed convection parameter and nanoparticle volume fraction. Temperature rises for higher radiation parameter. Skin friction is greater in case of Cu-water nanoliquid, while Nusselt number is less for Cu-water nanofluid when they are compared with hybrid nanoliquid TiO2-Cu-water.

Originality/value

No such work is not yet present in the literature.
Optimization of entropy generation in motion of magnetite-Fe3O4 nanoparticles due to curved stretching sheet of variable thickness
Authors: Qayyum Sumaira , Hayat Tasawar , Alsaedi Ahmed
Published: June 2019

Purpose

Investigation for convective flow of water-based nanofluid (composed of ferric oxide asnanoparticles) by curved stretching sheet of variable thickness is made. Bejan number andentropy generation analysis is presented in presence of viscous dissipation, mixed convectionand porous medium.

Design/methodology/approach

In this paper, by using NDSolve of MATHEMATICA, the nonlinear system of equations is solved. Velocity, temperature, Bejan number and entropy generation for involved dimensionless variables are discussed.

Findings

Increase in velocity is depicted for larger curvature parameter, and opposite trend is witnessed for higher nanoparticle volume concentration. Enhancement in temperature is seen for higher Eckert number while reverse behavior is noticed for larger curvature parameter. Entropy rate increases for variation of curvature parameter, Brinkman number and nanoparticle volume fraction. Bejan number decays for mixed convection and curvature parameters.

Originality/value

To the authors’ knowledge, there exists no study yet which describes flow by curved sheet of variable thickness. Such consideration with nanoparticles seems important task. Thus, the main objective here is to determine entropy generation in ferromagnetic nanofluid flow due to variable thickened curved stretching surface. Additionally, effects of Joule heating, porous medium, mixed convection and viscous dissipation are taken into account.
Magneto-hydrostatic lubrication of thrust bearings considering different configurations of recess
Authors: Kumar Vivek , Sharma Satish C.
Published: June 2019

Purpose

This paper aims to numerically investigate the influence of magnetic field and recess configurations on performance of hydrostatic thrust bearing. Electrically conducting fluid is supplied to bearing, operating in external magnetic field. Influences of recess geometric shapes (circular, rectangular, elliptical and triangular) and restrictor (capillary and orifice) are numerically examined on stead-state and dynamic performance characteristics of bearing.

Design/methodology/approach

Numerical simulation of hydrostatic thrust bearing has been performed using finite element (FE) method based on Galerkin’s technique. An iterative source code based on FE approach, Gauss–Siedel and Newton–Raphson method is used to compute steady-state and dynamic performance indices of bearings.

Findings

The presence of magnetic field is observed to be enhancing load-carrying capacity and damping coefficient of bearings. The effect is observed to be more pronounced at low value of Hartmann number, because of the saturation effect observed at higher values of Hartmann number. The enhancement in abovementioned performance indices is observed to be highly dependent on geometry of recess and restrictor.

Research limitations/implications

This study presents a FE-based approach to numerically simulate a hydrostatic thrust bearing. It will help bearing designers and academician in selecting an appropriate recess shape, restrictor and strength of magnetic field, for obtaining optimum performance from hydrostatic thrust bearing.

Originality/value

The present investigation provides a coupled solution of modified Reynolds equation and restrictor equation, which is essential for accurately predicting the performance of hydrostatic thrust bearings.
Guarantees used in refundable financing of innovation in micro, small and medium-sized enterprises
Authors: Cunha Schmidt Richard , Hoffmann Micheline Gaia
Published: June 2019

Purpose

Despite the increasing availability of financing programs for innovation, micro, small and medium-sized enterprises (MSMEs) often find it difficult to access credit for their projects. Among the reasons, the lack of the types of guarantees required by financial institutions stands out. Focused on this problem, in 2013, the Regional Bank for the Development of the Extreme South (BRDE) created a policy to stimulate innovation, making the required guarantees for financing operations of innovative companies more flexible: the BRDE Inova Program. This paper aims to analyze the guarantees used in the bank operations since the beginning of the program.

Design/methodology/approach

In the first stage of the research, the authors identified the guarantees used in each of the signed contracts, through a documentary survey. Next, semi-structured interviews showed the perceptions of the players involved in the innovation ecosystem of the state of Santa Catarina, regarding aspects related to the guarantees. Specifically, the authors investigated the following elements: strengths and limitations of the programs regarding access to credit for innovation; adequacy of existing guarantee mechanisms. To strengthen the conclusions, they used triangulated data collection in different stages.

Findings

The results showed that, on the one hand, the initiative helped BRDE to consolidate itself as the main financing agent of innovation in MSMEs; on the other hand, the need for traditional guarantees still plays a significant role for innovative MSMEs to access credit.

Originality/value

In addition to practical implications for the bank and other financing agents’ policies, this paper contributes to fill a gap in the literature on guarantee systems applied to the specificities of knowledge-intensive MSMEs.
How does incidental curiosity affect consumers’ unhealthy eating?
Authors: Wang Chen
Published: June 2019

Purpose

This paper aims to examine how, why and when incidental curiosity might have an influence on consumers’ unhealthy eating behaviors in a subsequent, irrelevant context.

Design/methodology/approach

Three experiments were conducted. Study 1 tested the basic main effect; Study 2 further tested the proposed process; Study 3 identified an important moderator and offered additional support for the mechanism.

Findings

Study 1 demonstrated the basic main effect that incidental curiosity increases consumers’ preference for unhealthy food. Study 2 replicated the effect in a simulated grocery-shopping task and further provided direct process evidence that a reward-approaching orientation underlies the effect of curiosity on unhealthy food choice. Finally, Study 3 identified information nature as an important moderator of the effect. That is, when people are curious about threatening information, they are likely to adopt an avoidance motivation, which prevents them from seeking any unhealthy food.

Practical implications

On the one hand, consumers could benefit from being educated that incidental exposure to curiosity cues might lead to unhealthy eating behaviors. On the other hand, public policymakers and responsible marketers should be mindful that, though widely used in marketing, the tactics that elicit consumers’ curiosity might sometimes backfire and undermine their healthy food choices.

Originality/value

This research contributes to the curiosity literature by demonstrating that incidental curiosity could have motivational impacts in the non-information domain, such as food choice. It also adds to the food decision literature by documenting incidental curiosity as an important situational factor of consumers’ food decisions.
A detailed investigation on thermal behaviour of slim floor beams with web openings at elevated temperatures
Authors: Alam Naveed , Nadjai Ali , Vassart Olivier , Hanus Francois
Published: June 2019

Purpose

In recent times, the use of steel sections with web openings has become common as slim floor beams because they offer a reduction in weight of the steelwork, accommodate services within the floor depth and provide the composite action. The composite action in these beams is achieved either through the concrete dowels or through concrete plugs. Though these web openings offer several benefits in slim floor beams, they induce the material discontinuity in the steel web, which may affect their shear capacity and/or thermal behaviour. The purpose of this study is to investigate the thermal behaviour of slim floor beams with web openings in fire.

Design/methodology/approach

This research presents findings from experimental and analytical investigations conducted to study the thermal behaviour of slim floor beams with web openings in fire. For this purpose, an experimental investigation was conducted, which shows that the presence of web openings has a major influence on temperature development across the steel section as well as along the span of these beams. The behaviour of the tested slim floor beam is validated using finite element modelling. The validated finite element model is then used to conduct a sensitivity study to analyse the influence of different opening spacings, sizes and shapes on the thermal performance of slim floor beams in fire.

Findings

Test results show that the presence of web openings has a major influence on temperature development across the steel section as well as along the span of these beams. Temperatures on the web below the openings are found to be higher as compared to those recorded on the adjacent solid steel web. It is also observed that temperatures on the steel web above the openings are lesser than those on the adjacent solid steel web. Parametric studies conducted using the verified analytical modelling methods show that different opening spacings, sizes and shapes have a variable impact on the thermal behaviour of slim floor beams in fire. Closely spaced and larger opening sizes were found to have a more severe influence on their thermal behaviour in fire as compared to widely spaced and smaller openings. It was also found that the behaviour of these beams is influenced by the shape of the openings with rectangular openings resulting in more severe thermal distributions as compared to circular openings.

Originality/value

The findings from this research study are highly valuable as they contribute to the existing knowledge database. There is a lack of experimental and analytical investigation on performance of slim floor beams with web openings at elevated temperatures. The results and conclusions from this study will help in developing innovative designs for slim floor beams and will help in reducing the fire related risk associated with structures comprising of slim floor beams with web openings.
Optimal risk-taking in corporate defined benefit plans under risk-shifting
Authors: Kitamura Tomoki , Omori Kozo
Published: June 2019

Purpose

The purpose of this paper is to theoretically examine the risk-taking decision of corporate defined benefits (DB) plans. The equity holders’ investment problem that is represented by the position of a vulnerable option is solved.

Design/methodology/approach

The simple traditional contingent claim approach is applied, which considers only the distributions of corporate cash flow, without the model expansions, such as market imperfections, needed to explain the firms’ behavior for DB plans in previous studies.

Findings

The authors find that the optimal solution to the equity holders’ DB investment problem is not an extreme corner solution such as 100 percent investment in equity funds as in the literature. Rather, the solution lies in the middle range, as is commonly observed in real-world economies.

Originality/value

The major value of this study is that it develops a clear mechanism for obtaining an internal solution for the equity holders’ DB investment problem and it provides the understanding that the base for corporate investment behavior for DB plans should incorporate the fact that in some cases the optimal solution is in the middle range. Therefore, the corporate risk-taking behavior of DB plans is harder to identify than the results of the empirical literature have predicted.
Identification of ß-carotene producing bacteria from terrestrial habitats of Jaipur, Rajasthan
Authors: Chokriwal Ankit , Stephen Bjorn John , Singh Abhijeet
Published: June 2019

Purpose

Carotenoids are pigments that have significant value as colorants and antioxidants in pharmaceutical, food, textile and cosmetic industries. Owing to its high demand, this study aims to identify ß-carotene producing bacteria from different terrestrial habitats of Jaipur region.

Design/methodology/approach

In this paper, standard isolation and purification process was used, followed by colony morphology and biochemical characterization of ß-carotene producing bacteria. ß-carotene concentration was determined quantitatively using spectrophotometric method.

Findings

Out of 43 isolates, 21 isolates showed peak range between 400 and 500 nm confirming the presence of carotenoids. Only one bacteria SAN-A has capacity to produce ß-carotene confirmed by the thin layer chromatography and high performance liquid chromatography (HPLC) with a yield of 1.68 mg/l. The 2, 2-Diphenyl-2-picrylhydrazil (DPPH) assay showed an IC50 value of 4.0 mg/ml.

Originality/value

The present study revealed the presence of ß-carotene producing bacteria in the soil of different terrestrial habitat of Jaipur region which can be exploited as an economical source for ß-carotene production.
Urban bumblebees are smaller and more phenotypically diverse than their rural counterparts
Authors: Eggenberger Helen , Frey David , Pellissier Loïc , Ghazoul Jaboury , Fontana Simone , Moretti Marco
Published: June 2019

With urbanization identified as being one of the key drivers of change in global land use, and the rapid expansion of urban areas world‐wide, it is relevant to evaluate how novel ecological conditions in cities shape species functional traits, which are essential for how species interact with their environments and with each other.

Despite the many comparative studies on organisms living in urban and non‐urban areas, our knowledge on species responses to urban environments remains limited. For one, much of the ecological research has assumed that the environment changes in a linear fashion from the city core to the city edges, whereas in reality the environments within the cities are highly heterogeneous. Furthermore, studies on species responses to these highly variable ecosystems are often based on interspecific mean trait values, which ignore the potential for high levels of intraspecific variation among individuals in key functional traits.

The current study investigated intraspecific functional trait differences for four functional traits associated with body size, mobility and resource selection among rural and urban populations of two common bumblebee species, Bombus pascuorum and Bombus lapidarius, in urban centres and adjacent rural areas in Switzerland.

We document shifts in functional traits towards smaller individuals and higher multidimensional trait variation in urban populations compared to rural conspecifics of both species. This shows that urban individuals for both species are on average smaller sized but populations are distinctively different from rural population by increasing their trait richness and diversifying their trait combinations. In addition, we found bimodality in tongue length within urban B. pascuorum populations.

Our results suggest that urban and rural populations possibly experience differential selection pressures resulting in trait differences across and among populations. We argue that variations in the respective foraging landscapes in cities leads to smaller sized but phenotypically more diverse populations, and drive functional trait divergence.