bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved multi-objective cuckoo search algorithm with novel search strategies for point-to-point part feeding scheduling problems of automotive assembly lines
Authors: Zhou Binghai , Li Xiujuan , Zhang Yuxian
Published: December 2020

Purpose

This paper aims to investigate the part feeding scheduling problem with electric vehicles (EVs) for automotive assembly lines. A point-to-point part feeding model has been formulated to minimize the number of EVs and the maximum handling time by specifying the EVs and sequence of all the delivery tasks.

Design/methodology/approach

First, a mathematical programming model of point-to-point part feeding scheduling problem (PTPPFSP) with EVs is presented. Because the PTPPFSP is NP-hard, an improved multi-objective cuckoo search (IMCS) algorithm is developed with novel search strategies, possessing the self-adaptive Levy flights, the Gaussian mutation and elite selection strategy to strengthen the algorithm’s optimization performance. In addition, two local search operators are designed for deep optimization. The effectiveness of the IMCS algorithm is verified by dealing with the PTPPFSP in different problem scales.

Findings

Numerical experiments are used to demonstrate how the IMCS algorithm serves as an efficient method to solve the PTPPFSP with EVs. The effectiveness and feasibility of the IMCS algorithm are validated by approximate Pareto fronts obtained from the instances of different problem scales. The computational results show that the IMCS algorithm can achieve better performance than the other high-performing algorithms in terms of solution quality, convergence and diversity.

Research limitations/implications

This study is applicable without regard to the breakdown of EVs. The current research contributes to the scheduling of in-plant logistics for automotive assembly lines, and it could be modified to cope with similar part feeding scheduling problems characterized by just-in-time (JIT) delivery.

Originality/value

Both limited electricity capacity and no earliness and tardiness constraints are considered, and the scheduling problem is solved satisfactorily and innovatively for an efficient JIT part feeding with EVs applied to in-plant logistics.
Opening up to startup collaborations: open business models and value co-creation in SMEs
Authors: Ghezzi Antonio , Cavallo Angelo , Sanasi Silvia , Rangone Andrea
Published: December 2020

Purpose

This study aims at exploring how small and medium enterprises (SMEs) can implement a more open and co-creational business model by actively collaborating with startups.

Design/methodology/approach

Because of the novelty of the SME–startup collaboration phenomenon and to the depth of the investigation required to grasp the mechanisms and logic of an open and co-creational business model, a single-case study has been performed related to investigating a collaboration between an SME and a startup.

Findings

The authors provide detailed empirical evidence on how SMEs may structure a “systematic” approach to design and execute an open business model enabled by startup collaboration. Moreover, this study suggests that the business model innovation process represents a necessary forerunner of an open business model. Finally, the authors contend that research on open business models should entail a broader perspective beyond the innovation process, to include business model validation through testing approaches like the lean startup.

Originality/value

This study takes as the locus of investigation the original perspective of the external partner of a focal firm willing to innovate. This study offers a unique contribution because, to date, few studies adopted such view within a relevant and under-remarked empirical setting linking SMEs and innovative startups.
Efficient VLSI architecture for FIR filter design using modified differential evolution ant colony optimization algorithm
Authors: John Tintu Mary , Chacko Shanty
Published: December 2020

Purpose

This paper aims to concentrate on an efficient finite impulse response (FIR) filter architecture in combination with the differential evolution ant colony algorithm (DE-ACO). For the design of FIR filter, the evolutionary algorithm (EA) is found to be very efficient because of its non-conventional, nonlinear, multi-modal and non-differentiable nature. While focusing with frequency domain specifications, most of the EA techniques described with the existing systems diverge from the power related matters.

Design/methodology/approach

The FIR filters are extensively used for many low power, low complexities, less area and high speed digital signal processing applications. In the existing systems, various FIR filters have been proposed to focus on the above criterion.

Findings

In the proposed method, a novel DE-ACO is used to design the FIR filter. It focuses on satisfying the economic power utilization and also the specifications in the frequency domain.

Originality/value

The proposed DE-ACO gives outstanding performance with a strong ability to find optimal solution, and it has got quick convergence speed. The proposed method also uses the Software integrated synthesis environment (ISE) project navigator (p.28xd) for the simulation of FIR filter based on DE-ACO techniques.
Effect of thickness on optoelectronic properties of ITO thin films
Authors: Mazur Michał , Pastuszek Roman , Wojcieszak Damian , Kaczmarek Danuta , Domaradzki Jarosław , Obstarczyk Agata , Lubanska Aneta
Published: December 2020

Purpose

Indium tin oxide (ITO) is a material belonging to the group of transparent conductive oxides, which are widely used in many fields of technology including optoelectronics and photovoltaics. However, the properties of ITO thin films depend on many factors. Therefore, the aim of the study was thorough investigation of the properties of sputtered ITO thin films of various thicknesses.

Design/methodology/approach

ITO coatings were deposited by magnetron sputtering in pure argon atmosphere using ceramic ITO target. Various deposition times resulted in obtaining thin films with different thickness, which had significant influence on the optoelectronic properties of deposited coatings. In this work the results of investigation of structural, surface, optical and electrical properties were presented.

Findings

Increase of the coating thickness caused change of the microstructure from amorphous to nanocrystalline and occurrence of grains with a size of 40 to 60 nm on their surface. Moreover, the fundamental absorption edge was red-shifted, whereas the average transmission in the visible wavelength range remained similar. Increase of the thickness caused considerable decrease of the sheet resistance and resistivity. It was found that even thin films with a thickness of 10 nm had antistatic properties.

Originality/value

The novelty and originality of presented work consists in, among other, determination of antistatic properties of ITO thin films with various sheet resistances that are in the range typical for dielectric and semiconducting material. To date, there are no reports on such investigations in the literature. Reported findings might be very helpful in the case of, for example, construction of transparent antireflective and antistatic multilayers.
A comparative study of satisfaction evaluation between students of mid-rise and high-rise student housing
Authors: Nazarpour Mohammad-Taghi , Norouzian-Maleki Saeid
Published: December 2020

Purpose

The purpose of the current research is to examine the student’s residential satisfaction (SRS) of dormitories in Tehran and Shiraz. Providing homes for non-native students is considered as one of the key issues in university development.

Design/methodology/approach

A combination of qualitative and quantitative measurements (mixed methods) was used to compare some of the design features between middle-rise and high-rise student housing. Questionnaire forms were distributed between male students of “Shahid Beheshti University” and “Shiraz University” dormitories. Cluster sampling is done among residential blocks in each university. Students assessed perceived attributes of dormitories by indicating their satisfaction from different categories. The obtained data were analysed by SPSS software and the Mann-Whitney test.

Findings

Findings show that although in comparing two samples with only some of the criteria, Shahid Beheshti University dormitory was ranked higher, generally Shiraz University dormitory was more successful in meeting resident’s satisfaction. Among the physical features, the pleasant views and landscape are important components which are related to aesthetic preferences.

Research limitations/implications

More research examining student/environment interactions is needed to pay close attention to cultural aspects. The consideration of culturally diverse individuals in the assessment may also provide valuable insight into the students’ residential satisfaction.

Practical implications

In sum, the design implications resulting from the data analysis act as a step toward an evidence-based design approach. Housing designers can integrate the research findings with design solutions. They take active part in the design process by developing new methodologies to highlight their role in creating high-quality student housing.

Originality/value

The relationship between students and their residential environment has been a mainstream topic in environmental psychology. Some previous studies have focused on socio-demographic characteristics, whereas others have dealt with the physical characteristics of the student housing that affect SRS.
Identifying and prioritizing delay factors in Iran’s oil construction projects
Authors: Kazemi Aliyeh , Kim Eun-Seok , Kazemi Mohammad-Hossein
Published: December 2020

Purpose

Successful implementation of construction projects is one of the crucial factors for the economic development of every country. The main part of the countries’ capital is allocated to civil and infrastructure projects annually, most of which are accomplished with delay. Construction projects are often criticized for overrunning time and budgets. Analyzing the factors causing delay is essential for omitting them and timely implementation of these projects. Due to the importance of oil projects, this study aims to investigate and analyze the factors causing a delay in Iran’s oil construction projects.

Design/methodology/approach

In this research, after a broad literature review, using the fuzzy Delphi method, a total of 75 delay factors were identified under 11 major categories of owner, contractor, consultant, equipment, labor, materials, design, contract and contractual relations, laws and regulations, environmental factors, and managerial factors. Then, by using the best-worst method, the factors were prioritized.

Findings

The results showed that sanction, governmental management systems, weak project management by the contractor, technical and managerial weaknesses of the consultant, financial problems and delay in payment by the owner, low efficiency of the equipment, low productivity of the workforce, changes in laws and regulations, inappropriate organizational structure linking to the project, changes in the design, and changes in the price of materials are the most crucial factors causing a delay in Iran’s oil construction projects.

Research limitations/implications

These findings are expected to have significant contributions to Iran’s oil construction industry in controlling the time overruns in construction contracts.

Originality/value

The main contribution of this study is to develop a comprehensive framework in which, causes of delay in Iran’s oil construction projects are addressed and prioritized.
Evaluation of energy sources based on sustainability factors using integrated fuzzy MCDM approach
Authors: Saraswat Santosh K. , Digalwar Abhijeet K.
Published: December 2020

Purpose

The purpose of this paper is to develop an integrated fuzzy multi-criteria decision-making (MCDM) model for evaluation of the energy alternates in India based on their sustainability.

Design/methodology/approach

A fuzzy analytical hierarchy process approach is used for the weight calculation of the criteria and the fuzzy technique for order preference by similarity to the ideal solution is used for ranking of the energy alternates. Seven energy sources – thermal, gas power, nuclear, solar, wind, biomass and hydro energy are considered for the assessment purpose on the basis of sustainability criteria, namely, economic, technical, social, environmental, political and flexible.

Findings

The result of the analysis shows that economics is the highest weight criterion, followed by environmental and technical criteria. Solar energy was chosen as the most sustainable energy alternate in India, followed by wind and hydro energy.

Research limitations/implications

Few other MCDM techniques such as VIseKriterijumska Optimizacija I Kompromisno Resenje (multi-criteria optimization and compromise solution), weighted sum method and preference ranking organization method for enrichment evaluations – II can also be explored for the sustainability ranking of the energy alternates. However, the present model has also provided a good result.

Practical implications

The present research work will help the decision-makers and organizations in the evaluation and prioritizing the various energy sources on the scale of sustainability.

Social implications

Research finding provides guidance to government and decision-makers regarding the development of social conditions through energy security, job creation and economic benefits.

Originality/value

Research work can be act as a supplement for the investors and decision-makers specifically in prioritizing the investment perspective and to support other multi-perspective decision-making problems.
“That’s not a man’s drink”. The construction of gendered identities through stories of wine consumption in Kenya
Authors: Clifton Tim , Clifton Jonathan , Velikova Natalia
Published: December 2020

Purpose

The purpose of this paper is to explore how gendered wine-drinker identities are constructed through stories of wine consumption in Kenya.

Design/methodology/approach

The data comes from a corpus of 19 in-depth semi-structured interviews collected in Nairobi, Kenya. Taking a narrative approach, this paper uses positioning theory as a fine-grained linguistic methodological tool to analyze stories of gendered wine consumption.

Findings

A key finding of the study is that wine consumption can enact, and be enacted by, wider normative societal gendered discourses of what men and women should and, should not, be drinking. In short, in some societies (Kenya being an example here) men drinking wine is subject to the normative gaze of their peers; and if men drink wine, they are not considered “real men.” This is so even when chatting up women, in which case male wine-drinkers are ascribed to the subordinate male identities of either the “new man” or the romantic man. However, male wine-drinkers can retain a real man identity if they are wealthy (and powerful) enough not to care what other men think.

Practical implications

The study provides new insights for targeting consumers in emerging export markets. Wine companies need to be aware that the purchase drivers in established markets may not be central to consumers in developing markets. In developing markets, wine consumption may be influenced by the normative gaze of peers which enacts, and is enacted by, societal gendered discourses. Crucially, a thorough understanding of consumer behavior leads to a more critical consideration for focused marketing strategies aimed at establishing relationships with customers in developing markets.

Originality/value

The study offers an original contribution to the barely existent body of knowledge on wine consumption in sub-Saharan Africa and gendered wine-drinking identity construction. Additionally, from a methodological perspective, no previous study on wine consumption has used a narrative identity approach to the fine-grained linguistic analysis of transcripts of stories elicited during research interviews.
Strong alien or weak acquaintance? The effect of perceived institutional distance and cross-national uncertainty on ownership level in foreign acquisitions
Authors: Askarzadeh Fatemeh , Yousefi Hamed , Forghani Bajestani Mahdi
Published: December 2020

Purpose

Focusing on the direction of foreign acquisition, this study aims to differentiate the effect of institutional distance on the level of ownership. The authors identify several theoretical and methodological issues that might account for the inconsistencies in the literature and provide remedies accordingly. Specifically, the authors propose perceived institutional distance as a conceptualization of distance that controls for asymmetric uncertainty.

Design/methodology/approach

The authors test the framework with ordinary least squares regression for a sample of 14,192 firm-entries in 115 target countries over 2007–2017.

Findings

The authors find that institutional distance shows a negative effect on equity ownership in all-inclusive global samples, while there are two imbalanced opposite effects if direction is considered. This casts doubt on the validity of studies that ignore direction. The authors suggest that multinational enterprises entering countries with lower-quality institutions tend to perceive more pronounced distance effects than those expanding the other way around. Hence, the authors argue that “perceived institutional distance” better explains the functional role of distance than simple distance.

Practical implications

This study better delineates the link between distance and uncertainty and enhances managerial insights for entry mode selection. For policy-making purposes, the authors also show that improvement in institutional quality has a different effect on foreign resource commitment in developed and developing countries.

Originality/value

To the best of authors’ knowledge, this is the first study that considers both directionality and imbalance in institutional distance and proposes a measure to control for non-linear asymmetric relationship between distance and ownership. The authors extend the institutional theory and show the superiority of perceived institutional distance in predicting ownership implications.
How teams perform under emergent and dynamic situations: the roles of mental models and backup behaviors
Authors: Zhou Zikai , Pazos Pilar
Published: December 2020

Purpose

The purpose of this study is to evaluate the roles of team mental models (TMMs) and backup behaviors for teams operating under emergent and dynamic situations. Specifically, the authors used a biased-corrected bootstrapping approach to assess the mediation effects of backup behaviors between the similarity of TMMs and team performance.

Design/methodology/approach

TMMs are a representation of the common understanding and beliefs in terms of task requirements or teamwork skills among different team members. It has wide implementations in various teams that are required to adapt quickly to an emergent and dynamic environment. The construct of TMMs has been studied extensively in previous literature, indicating a strong relationship between TMMs and team performance. However, how TMMs affect team performance under emergent and dynamic situations is only partially understood.

Findings

The findings of this study suggest that the similarity of task-focused mental models positively affects team performance through the mediation effects of backup behaviors. In contrast, the similarity of team-focused mental models does not positively affect backup behaviors and team performance.

Originality/value

This study contributes to the TMMs literature by investigating how teams perform in an emergent and dynamic environment. It not only provides theoretical support to the similarity of TMMs–backup behaviors–team performance relationships but has important implications in terms of team training and decision-making for teams operating under such conditions.
Redesigning the cycloidal drive for innovative applications in machines for smart construction yards
Authors: Allotta Benedetto , Fiorineschi Lorenzo , Papini Susanna , Pugi Luca , Rotini Federico , Rindi Andrea
Published: December 2020

Purpose

This study aims to carry out an investigation of design approaches that should be used for the design of unconventional, innovative transmission system for construction yards to privilege a smooth behaviour efficiency, and the use of innovative production techniques. Results are quite surprising, as with a proper method it is possible to demonstrate that a cycloidal drive with Wolfrom topology should be an interesting solution for the proposed application.

Design/methodology/approach

With a functional approach, also considering materials and specifications related to the investigated application, it is possible to demonstrate that possible optimal solutions should be quite different respect to the ones that can be suggested with a conventional approach. In particular for proposed applications constraints related to encumbrances, the choice of new material has led to the innovative unconventional choice of a Wolfrom cycloidal speed reducer.

Findings

Provided solution is innovative respect current state of the art for machine currently used in construction yards: in terms of adopted transmission layout; in terms of chosen materials, resulting in an innovative solution.

Research limitations/implications

Current research has strong implications on the adoption of polimeric materials for the construction of reliable transmission for harsh industrial environment as the proposed case study (concrete mixer for construction yard).

Originality/value

Proposed transmission system is absolutely original and innovative respect current state of art also considering proposed materials and consequently production methods. This is an example of transmission designed to be built with polymeric materials by optimizing chosen topology respect to chosen material.
Buckling capacity of cold-formed steel structure column member with perforation section in affordable house framing system
Authors: De'nan Fatimah , Hashim Nor Salwani , Mustafa Zafira Nur Ezzati
Published: December 2020

Purpose

The purpose of this study is to know the buckling capacity for cold-formed C-column with perforation. Cold-formed C-column have been used in interior wall construction. The concept of web perforation in the column has been introduced to the construction sector to overcome the issue of material cost.

Design/methodology/approach

Initially, the determination of the suitable spacing for the space column for the affordable house is investigated. Analysis house frame has been done in STAAD Pro. (Staad Pro, 2003) software using cold-formed C-column without perforation. Perforation with circular shape has been used in this study with the size of 0.4, 0.6 and 0.8 D (D = 180 mm). Perforation spacing is 150, 250 and 350 mm are adopted.

Findings

For the specimen with 0.4 D perforation and the edge distance is 539 mm have the highest buckling capacity (26.59 kN). Reduction of buckling capacity is 5.31% from cold-formed C-column without perforation and reduction of the volume is −2.16%. For the same case with 0.8 D perforation, the buckling capacity reduces with 22.52% and volume is −6.85%.

Originality/value

The conclusion of this analysis, C-column without perforation have higher buckling capacity compare to C-column with perforations.
Darcy–Forchheimer flow of a magneto-radiated couple stress fluid over an inclined exponentially stretching surface with Ohmic dissipation
Authors: Das S. , Ali Akram , Jana R.N.
Published: December 2020

Purpose

In this communication, a theoretical simulation is aimed to characterize the Darcy–Forchheimer flow of a magneto-couple stress fluid over an inclined exponentially stretching sheet. Stokes’ couple stress model is deployed to simulate non-Newtonian microstructural characteristics. Two different kinds of thermal boundary conditions, namely, the prescribed exponential order surface temperature (PEST) and prescribed exponential order heat flux, are considered in the heat transfer analysis. Joule heating (Ohmic dissipation), viscous dissipation and heat source/sink impacts are also included in the energy equation because these phenomena arise frequently in magnetic materials processing.

Design/methodology/approach

The governing partial differential equations are transformed into nonlinear ordinary differential equations (ODEs) by adopting suitable similar transformations. The resulting system of nonlinear ODEs is tackled numerically by using the Runge–Kutta fourth (RK4)-order numerical integration scheme based on the shooting technique. The impacts of sundry parameters on stream function, velocity and temperature profiles are viewed with the help of graphical illustrations. For engineering interests, the physical implication of the said parameters on skin friction coefficient, Nussult number and surface temperature are discussed numerically through tables.

Findings

As a key outcome, it is noted that the augmented Chandrasekhar number, porosity parameter and Forchhemeir parameter diminish the stream function as well as the velocity profile. The behavior of the Darcian drag force is similar to the magnetic field on fluid flow. Temperature profiles are generally upsurged with the greater magnetic field, couple stress parameter and porosity parameter, and are consistently higher for the PEST case.

Practical implications

The findings obtained from this analysis can be applied in magnetic material processing, metallurgy, casting, filtration of liquid metals, gas-cleaning filtration, cooling of metallic sheets, petroleum industries, geothermal operations, boundary layer resistors in aerodynamics, etc.

Originality/value

From the literature review, it has been found that the Darcy–Forchheimer flow of a magneto-couple stress fluid over an inclined exponentially stretching surface with heat flux conditions is still scarce. The numerical data of the present results are validated with the already existing studies under limited cases and inferred to have good concord.
Prediction of wear resistance model for magnesium metal composite by response surface methodology using central composite design
Authors: Sagar Prem , Handa Amit
Published: December 2020

Purpose

In recent days, friction stir processing (FSP) has emerged as a pioneering approach for the manufacture of composites with enhanced mechanical and tribological properties. The present study aims to examine the impact of process parameters such as tool rotation speed and number of FSP pass on the AZ61A/TiC magnesium metal composite for responses such as hardness and wear resistance.

Design/methodology/approach

To minimize number of experimental runs, design of experiment was configured according to the response surface methodology using central composite design. Analysis of variance has been conducted to develop mathematical and empirical model for studying relationship between tool rotation and number of pass for responses such as microhardness and wear resistance. Microhardness was checked on vickers microhardness testing machine, and tribological behavior were examined on pin-on-disc using tribotester. Wear morphology was analyzed via scanning electron microscopy.

Findings

The responses were predicted using validated mathematical model, and contour plots were generated to study the interaction and influence of process parameters. Wear observations suggest that for the base magnesium alloy adhesive wear mechanism was dominating and for the developed nanocomposites, abrasive wear mechanism is a prominent factor. It was also observed that both the selected parameters significantly influenced the responses.

Originality/value

To the best of the authors’ knowledge, no prior work has been conducted with this material and preparation of composites with TiC nanoparticles. Furthermore, no mathematical models have been developed to predict the response values.
Low planting densities for early maturation of Mauritia flexuosa for the sustainable management of plantations in Alto Huallaga, Peru
Authors: Vargas Ytavclerh , Puerta Ronald H. , Palomino Vera Frits , Esenarro Vargas Doris , Rodriguez Rodriguez Ciro , Pandey Bishwajeet
Published: December 2020

Purpose

This paper aims to characterize the sexual maturation of M. flexuosa plantations in Tulumayo.

Design/methodology/approach

The methodology in this paper was selection of three plots in open field and usage of different densities of planting, after the maturation of the first plants, we began the quarterly evaluation. There was total 28 evaluations in seven years of age.

Findings

As a result, it was determined that at 12 years, the plots with lower density presented a greater number of mature individuals, with a predominance of female palms that produced an average of four bunches of fruit per year, and males five inflorescences. In addition, 15% of adult female plants went dormant, whereas males accounted for 3.4%. Reproductive cycles began in September and culminated in October of the following year, which were synchronized with rainfall.

Originality/value

Planting density was a determining factor in the early maturity of M. flexuosa and sustainable plantation management.
A meta‐analysis of effects of physiological integration in clonal plants under homogeneous vs. heterogeneous environments
Authors: Wang Jianyong , Xu Tongtong , Wang Yue , Li Guangyin , Abdullah Iram , Zhong Zhiwei , Liu Jushan , Zhu Wanyue , Wang Ling , Wang Deli , Yu Fei‐Hai
Published: December 2020

Clonal plants play key roles in maintaining community productivity and stability in many ecosystems. Connected individuals (ramets) of clonal plants can translocate and share, for example, photosynthates, water and nutrients, and such physiological integration may affect performance of clonal plants both in heterogeneous and homogeneous environments. However, we still lack a general understanding of whether or how physiological integration in clonal plants differs across homogeneous versus heterogeneous environments.

We compiled data from 198 peer‐reviewed scientific studies conducted in 19 countries with 108 clonal plant species from 35 families, and carried out a meta‐analysis of effects of physiological integration on 16 traits related to plant growth, morphology, physiology or allocation. Our analyses evaluated these relationships in (A) heterogeneous environments where at least one resource essential for plant growth (e.g. light, soil water and mineral nutrients) or non‐resource factor (e.g. grazing, trampling and burial) is spatially non‐uniformly distributed and (B) homogeneous environments where all these factors are spatially uniformly distributed.

Physiological integration increased growth of whole clones in both homogeneous and heterogeneous environments due to its highly significant contribution to growth of recipient ramets. Integration did not affect growth of donor ramets in heterogeneous environments, but decreased it in homogeneous environments.

Integration affected physiological traits of donor ramets in neither homogeneous nor heterogeneous environments. It did not affect any physiological traits of recipient ramets in homogeneous environments, but increased most of them in heterogeneous environments. For donor ramets, integration increased height by 53% and internode length by 37% in heterogeneous environments, but had no effect in homogeneous environments. For recipient ramets, integration increased height by 73% in homogeneous environments and by 115% in heterogeneous environments, and increased internode length by 35% only under heterogeneous environments. In heterogeneous environments, integration increased biomass allocation to roots of donor ramets under high water/nutrient conditions and decreased it under high light.

Physiological integration plays a strong role in clonal plant physiology, morphology and growth, especially for recipient ramets in heterogeneous environments. Therefore, physiological integration may have contributed to the widespread of clonal plants in nature and their dominance in many ecosystems. It may also play important roles in invasion success of alien clonal plants and in maintaining functions and stability of ecosystems where clonal plants are abundant.

A free Plain Language Summary can be found within the Supporting Information of this article.
Social learning by mate‐choice copying increases dispersal and reduces local adaptation
Authors: Sapage Manuel , Varela Susana A. M. , Kokko Hanna
Published: December 2020

In heterogeneous environments, dispersal may be hampered not only by direct costs, but also because immigrants may be locally maladapted. While maladaptation affects both sexes, this cost may be modulated in females if they express mate preferences that are either adaptive or maladaptive in the new local population.

Dispersal costs under local adaptation may be mitigated if it is possible to switch to expressing traits of locally adapted residents. In a sexual selection context, immigrant females may learn to mate with locally favoured males. Mate‐choice copying is a type of social learning, where individuals, usually females, update their mating preferences after observing others mate. If it allows immigrant females to switch from maladapted to locally adapted preferences, their dispersal costs are mitigated as mate choice helps them create locally adapted offspring.

To study if copying can promote the evolution of dispersal, we created an individual‐based model to simulate the coevolution of four traits: copying, dispersal, a trait relevant for local adaptation, and female preference. We contrast two scenarios with copying—either unconditional or conditional such that only dispersers copy—with a control scenario that lacks any copying.

We show copying to lead to higher dispersal, especially if copying is conditionally expressed. This leads to an increase in gene flow between patches and, consequently, a decrease in local adaptation and trait‐preference correlations.

While our study is phrased with female preference as the learned trait, one may generally expect social learning to mitigate dispersal costs, with consequent feedback effects on the spatial dynamics of adaptation.

A free Plain Language Summary can be found within the Supporting Information of this article.
Phytoplankton trigger the production of cryptic metabolites in the marine actinobacterium Salinispora tropica
Authors: Chhun Audam , Sousoni Despoina , Aguiló‐Ferretjans Maria del Mar , Song Lijiang , Corre Christophe , Christie‐Oleza Joseph A.
Published: December 2020

Filamentous members of the phylum Actinobacteria are a remarkable source of natural products with pharmaceutical potential. The discovery of novel molecules from these organisms is, however, hindered because most of the biosynthetic gene clusters (BGCs) encoding these secondary metabolites are cryptic or silent and are referred to as orphan BGCs. While co‐culture has proven to be a promising approach to unlock the biosynthetic potential of many microorganisms by activating the expression of these orphan BGCs, it still remains an underexplored technique. The marine actinobacterium Salinispora tropica, for instance, produces valuable compounds such as the anti‐cancer molecule salinosporamide but half of its putative BGCs are still orphan. Although previous studies have used marine heterotrophs to induce orphan BGCs in Salinispora, its co‐culture with marine phototrophs has yet to be investigated. Following the observation of an antimicrobial activity against a range of phytoplankton by S. tropica, we here report that the photosynthate released by photosynthetic primary producers influences its biosynthetic capacities with production of cryptic molecules and the activation of orphan BGCs. Our work, using an approach combining metabolomics and proteomics, pioneers the use of phototrophs as a promising strategy to accelerate the discovery of novel natural products from marine actinobacteria.
The ‘right’ level for the superannuation guarantee: identifying the key considerations
Authors: Khemka Gaurav , Tang Yifu , Warren Geoffrey J.
Published: December 2020

We deploy a stochastic life‐cycle model to examine how the superannuation guarantee (SG) impacts on welfare for Australian superannuation fund members under a reference‐dependent utility function that evaluates consumption relative to target, allowing for existing superannuation, taxation and Age Pension eligibility rules. The analysis highlights how the optimal SG can vary substantially with pre‐retirement income, the post‐retirement consumption target and various other assumptions. We conclude that no single SG rate is appropriate for all members and suggest that the main reason for increasing the SG above 9.5 percent would be an aim of replacing the Age Pension where possible.
The effect of board of directors’ expertise and tax avoidance on corporate debt
Authors: Lanis Roman , Richardson Grant , Govendir Brett , Pazmandy Gregory
Published: December 2020

This study examines the effect of board of directors’ expertise and tax avoidance on corporate debt. We find that there is no association between financially expert outside directors on the board and corporate debt, which is contrary to some prior research findings. However, we do find a positive association between the proportion of financially expert inside directors on the board and debt. We also find that the debt substitution effect is significantly intensified by the presence of outside directors on the board with financial expertise, which suggests that the advice offered by these directors better informs managers to make decisions about the trade‐off between the benefits and costs of debt and non‐debt tax shields. We find no such effect for inside directors. Overall, this study extends the literature on corporate governance, tax avoidance and corporate debt.
European unification as lived memory: Shared and diverse representations in textbooks of six countries
Authors: Sakki Inari , Hakoköngäs Eemeli , Brescó de Luna Ignacio , Csertó Istvan , Kello Katrin , Miguel Isabel , O’Mahoney Jennifer , Pólya Tibor , Pires Valentim Joaquim
Published: December 2020

Concerned about a lack of legitimacy, European Union (EU) institutions have increasingly engaged in memory politics to enhance European identity. Yet, memory of the EU is still closely connected to the collective identity formation of nation‐states, especially in the field of education, the focus of this study. Inspired by this dilemma, the present paper examines the representations of European unification in textbooks of six countries: Ireland, Spain, Portugal, Finland, Hungary, and Estonia. By focusing on countries on the margins of Europe, the present study explores shared and diverse narratives of the European unification process and asks whether or not a shared historical charter of European unification exists. All together 86 history textbooks used in upper secondary school were analysed by adopting a three‐step multi‐method approach. The results suggest that the representation of European unification is more diverse than it is homogenous. It can be narrated as a political value community or as a community based on utilitarian interests, or it can be represented from a unified European or from a more national perspective. Exploring representations of European unification is crucial to understanding how they can be used as legitimizing charters to navigate through the European challenges of the 21st century.
Different collective memories of Japanese colonization in Korea: Consequences for distinct preferences for strategies to deal with the past
Authors: Jeong Hu Y. , Ray Vollhardt Johanna
Published: December 2020

Although many Koreans’ attitudes towards Japan are marked by hostility and distrust due to the memories of Japanese colonization, others have different views on the past and different preferences for dealing with Japan. The current study examines the links between different construals of historical victimization (i.e., collective victim beliefs) and distinct intergroup strategies: collective action demanding apology and reparation from Japan, reconciliation, and retribution. A survey among 249 South Koreans identified four collective victim beliefs: preserving memories and supporting survivors, ingroup fragmentation about how to address the past, grievances concerning historical suffering and perpetrators’ denial, and perceived prevalence of ingroup resistance. Grievances concerning historical suffering and present‐day denial predicted increased willingness to participate in collective action, desire for retribution, and decreased willingness for reconciliation. Perceived importance of preserving memories and supporting survivors predicted greater willingness to participate in collective action and more desire for retribution. Unexpectedly, perceived ingroup fragmentation and resistance also predicted willingness for reconciliation. Most of the effects of collective victim beliefs on intergroup strategies were mediated by resentment towards the Japanese. Overall, this study expands the literature on collective victimhood in the understudied context of Koreans’ collective memories of colonization.
Interactions of dye compounds that are structurally related to methylene blue with acetylcholinesterase and butyrylcholinesterase
Authors: Cloete Stephanus J. , Petzer Anél , Petzer Jacobus P.
Published: December 2020

The phenothiazine dye, methylene blue, is reported to be an inhibitor of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Inhibitors of these enzymes are established medications for the treatment of Alzheimer's disease, whilst methylene blue has been investigated for its potential to slow cognitive decline in Alzheimer's disease. Based on these observations, 31 dye compounds that are structurally related to methylene blue were evaluated as inhibitors of human AChE and equine BuChE. This study attempted to derive structure–activity relationships for the inhibition of AChE and BuChE by dye compounds, whilst discovering good potency inhibitors amongst the dyes. The results showed that several dyes exhibit good potency AChE (11 compounds) and BuChE (15 compounds) inhibition with IC50 < 10 µM. Methylene green (IC50 = 0.467 µM) and new methylene blue N (IC50 = 0.799 µM) were found to be particularly potent AChE inhibitors, whilst acridine orange (IC50 = 0.220 µM), 1,9‐dimethyl‐methylene blue (IC50 = 0.277 µM), acridine yellow G (IC50 = 0.509 µM), Nile blue (IC50 = 0.678 µM) and pyronin B (IC50 = 0.946 µM) proved to be highly potent BuChE inhibitors. These dye compounds thus exhibit improved inhibition compared to methylene blue [IC50(AChE) = 2.74 μM; IC50(BuChE) = 2.27 μM].
Trajectories of early‐onset rhinitis in the Singapore GUSTO mother‐offspring cohort
Authors: Loo Evelyn Xiu Ling , Liew Tau Ming , Yap Gaik Chin , Wong Lydia Su Yin , Shek Lynette Pei‐Chi , Goh Anne , Van Bever Hugo P.S. , Teoh Oon Hoe , Yap Fabian , Tan Kok Hian , Thomas Biju , Ramamurthy Mahesh Babu , Goh Daniel Yam Thiam , Eriksson Johan G , Chong Yap‐Seng , Godfrey Keith M. , Lee Bee Wah , Tham Elizabeth Huiwen
Published: December 2020

Background

The natural history of childhood rhinitis is not well described.

Objective

This study aimed to identify different rhinitis trajectories in early childhood and their predictors and allergic associations.

Methods

Rhinitis symptoms were ascertained prospectively from birth until 6 years using standardized questionnaires in 772 participants. Rhinitis was defined as one or more episodes of sneezing, runny and/or blocked nose >2 weeks duration. Latent trajectories were identified using group‐based modelling, and their predictive risk factors and allergic associations were examined.

Results

Three rhinitis trajectory groups were identified: 7.6% (n = 59) were termed early transient rhinitis, 8.6% (n = 66) late transient rhinitis, and 6.6% (n = 51) persistent rhinitis. The remaining 77.2% (n = 596) were classified as non‐rhinitis/reference group. Early transient rhinitis subjects were more likely of Indian ethnicity, had siblings, reported childcare attendance, early wheezing and eczema in the first 3 years of life. Late transient rhinitis was associated with antenatal exposure to smoking, higher maternal education levels, and wheezing at age 36‐72 months. Persistent rhinitis was associated with male gender, paternal and maternal history of atopy, eczema, and house dust mite sensitization.

Conclusions & Clinical Relevance

Risk factors for early transient rhinitis involve a combination of genetic and early environmental exposures, whereas late transient rhinitis may relate to maternal factors and early respiratory infections independent of atopy. In contrast, persistent rhinitis is strongly associated with atopic risk and likely represents the typical trajectory associated with allergic disorders. Allergic rhinitis symptoms may commence as early as the first year of life and may inform development of early interventive strategies.
Using outcome measures in child protection work
Authors: Hood Rick , Lansley Sue , Mitchell Toni , Gaskell‐Mew Elaine
Published: December 2020

While many evidence‐based tools and measures exist to support child protection practice, in the United Kingdom, there is little evidence of their routine use in casework. This paper reports on a qualitative study exploring the use of such tools with children and families receiving statutory social care services. Fifteen social workers working in child safeguarding teams in two local authorities in Southeast England agreed to incorporate the use of outcome measures into their casework over a 6‐month period. Qualitative data were collected through monthly action learning workshops held separately in each local authority. The results showed how the impact of using the measures was shaped by a combination of institutional factors, practice context and the dynamics of casework. Outcome measures were found to have benefits as well as limitations with respect to partnership working, assessment and decision‐making and overall social work practice. Implications are discussed for the prospects of enhancing the use of evidence‐based tools in statutory social work with children and families.
Long‐term efficacy of fibrin glue injection for perianal fistulas in patients with Crohn's disease
Authors: Vidon Mathias , Munoz‐Bongrand Nicolas , Lambert Jérôme , Maggiori Léon , Zeitoun Jean‐David , Corte Hélène , Panis Yves , Seksik Philippe , Treton Xavier , Abramowitz Laurent , Allez Matthieu , Gornet Jean‐Marc
Published: December 2020

Aim

The treatment of perianal fistulas in Crohn's disease remains challenging. Fibrin glue injection has previously shown short‐term efficacy in a randomized controlled trial. No long‐term data are available to assess the benefit of this treatment.

Methods

This retrospective multicentre study included all patients with drained fistulas treated by at least one fibrin glue injection between January 2004 and June 2015 in three tertiary French centres. The primary end‐point was the rate of complete clinical remission at 1 year after injection defined by the closure of all fistula tracts with no need for iterative anal surgery or for optimization of immunosuppressants and/or biologics.

Results

In all, 119 patients (median age 33 years, complex fistulas 65%, median previous anal surgery two, median Harvey Bradshaw score 3, immunosuppressants exposure 50%, anti‐tumor necrosis factor exposure 60% with median time of administration of 1.1 year) were analysed with a median follow‐up of 18.3 months. The complete clinical remission rate at 1 year was 45.4%. The primary end‐point was achieved in 63% of the cases in the combination therapy group and 37% in other patients. The only predictor of complete clinical remission at 1 year was combination therapy at the time of injection (P = 0.01). The rate of early reintervention after glue injection was 2.5%. The cumulative incidence of iterative anal surgery and ostomy in the whole population was 54% and 5.6% respectively at 5 years.

Conclusion

An adjunct of fibrin glue to conventional medical therapy may be an effective and safe treatment for perianal fistulas in patients with Crohn's disease.