bluuebunny/crossref_metadata_2025 huggingface dataset:
The adoption of 4D BIM in the UK construction industry: an innovation diffusion approach
Authors: Gledson Barry J. , Greenwood David
Published: October 2017

Purpose

British construction industry KPI data collected over recent years shows a trend in projects exceeding their time schedules. In 2013, the UK Government set a target for projects timeframes to reduce by 50 per cent. Proposed interventions included more rapid project delivery processes, and consistent improvements to construction delivery predictions, deployed within the framework of 4D Building Information Modelling (BIM). The purpose of this paper is to use Rogers’ Innovation Diffusion theory as a basis to investigate how this adoption has taken place.

Design/methodology/approach

In total, 97 construction planning practitioners were surveyed to measure 4D BIM innovation take-up over time. Classic innovation diffusion research methods were adopted.

Findings

Results indicated an increasing rate of 4D BIM adoption and reveal a time lag between awareness and first use that is characteristic of this type of innovation.

Research limitations/implications

Use of a non-probability sampling strategy prevents the results being generalisable to the wider construction population. Future research directions and methods are suggested, including qualitative investigations into decision-making processes around 4D BIM, and case studies exploring the consequences of 4D BIM adoption.

Practical implications

Recommendations of how to facilitate the adoption of 4D BIM innovation are proposed, which identify the critical aspects of system compatibility and safe trialling of the innovation.

Originality/value

This paper reinforces 4D BIM as an innovation and records its actual UK industry adoption rate using an accepted diffusion research method. By focusing on UK industry-wide diffusion the work also stands apart from more typical research efforts that limit innovation diffusion exploration to individual organisations.
Using jigsaw method to enhance the learning of research and consultancy techniques for postgraduate students
Authors: Yu Ann Tit Wan
Published: October 2017

Purpose

Students find courses in research methods delivered by lectures, both difficult and boring. The purpose of this paper is to provide empirical research on another teaching and learning method, jigsaw method, to three groups of postgraduate students over three academic years.

Design/methodology/approach

The fifth topic of the course, qualitative research methods, was selected for implementation of the jigsaw class. The students completed a feedback questionnaire after classes to express their opinions and comments on the new method. Descriptive statistics and content analysis were used to test these data.

Findings

The students believed that the jigsaw method is an innovative teaching and learning activity and were generally satisfied with the process and the execution. They stated that participation was a valuable experience which enabled them to share knowledge with other classmates and gain a better understanding of the subject. Further improvements were also proposed by the students.

Research limitations/implications

First, the analysis of the implementation of the jigsaw methods is based on student perceptions rather than objective measures of learning gains. Second, the classes for full-time postgraduate students are relatively small. Data were collected, therefore, over three academic years to provide enough valid responses for analysis.

Originality/value

The research may be regarded as pioneering in relation to jigsaw classes for teaching and learning research methods in postgraduate course. The findings provide confidence to architecture, engineering and construction (AEC) academics to incorporate jigsaw methods in their courses. The results of this study provide useful information for AEC lecturers assisting them to design their classes using jigsaw methods.
Critical factors impacting the performance of mega-projects
Authors: Caldas Carlos , Gupta Ashish
Published: October 2017

Purpose

Mega-projects (MP) are important not only to the stakeholders involved in their development and construction, but also to the societies, economies, and environments impacted by them. Given the importance of MP and the prevailing trend toward poor performance, the purpose of this paper is to identify changes in project development and execution to increase the likelihood of success on MP.

Design/methodology/approach

The researchers performed an extensive literature review in the initial phase. Then, interviews with experienced mega-project professionals were conducted to gather information on factors contributing to success and failure on MP. A detailed survey was then carried out to quantify and assess the frequency and impact levels of these factors. Finally, case studies were performed to analyze the manifestations of these impact factors on MP and identify mitigation strategies.

Findings

After gathering data from more than 100 projects, the researchers identified and prioritized 34 factors that have high frequency and negative performance impacts on MP, categorizing them into five categories. These factors were then used to create a mega-project preparedness assessment process and a lessons learned repository around these factors, which includes factor descriptions, examples from actual projects, and recommendations. The result is a structured method for enabling comprehensive mega-project risk management and mitigation planning.

Originality/value

The research has gone beyond any previous generic lessons learned, to enable project teams to make structured assessments of critical mega-project impact factors. Assessing these impact factors will enable more accurate and thorough mitigation planning for them and, thus, improve mega-project performance.
Framework for productivity and safety enhancement system using BIM in Singapore
Authors: Teo Ai Lin Evelyn , Ofori George , Tjandra Imelda , Kim Hanjoon
Published: October 2017

Purpose

Despite recognition of its importance to Singapore’s economy, the construction industry is plagued by poor safety and productivity performance. Improvement efforts by the government and industry have yielded little results. The purpose of this paper is to propose a framework for developing a productivity and safety monitoring system using Building Information Modelling (BIM).

Design/methodology/approach

The framework, Intelligent Productivity and Safety System (IPASS), takes advantage of mandatory requirements for building plans to be submitted for approval in Singapore in BIM format. IPASS is based on a study comprising interviews and a questionnaire-based survey. It uses BIM to integrate buildable design, prevention and control of hazards, and safety assessment.

Findings

The authors illustrate a development of IPASS capable of generating productivity and safety scores for construction projects by analysing BIM model information.

Research limitations/implications

The paper demonstrates that BIM can be used to monitor productivity and safety as a project progresses, and help to enhance performance under the two parameters.

Practical implications

IPASS enables collaboration among project stakeholders as they can base their work on analysis of productivity and safety performance before projects start, and as they progress. It is suggested that the BIM model submitted to the authorities should be used for the IPASS application.

Originality/value

IPASS has rule-checking, hazards identification and quality checking capabilities. It is able to identify hazards and risks with the rule-checking capabilities. IPASS enables practitioners to check mistakes and the rationality of a design. It helps to mitigate risks as there are built-in safety measures/controls rules to overcome the problems caused by design deficiency, wrong-material-choice, and more.
Empirical comparison of critical success factors for public-private partnerships in developing and developed countries
Authors: Osei-Kyei Robert , Chan Albert P.C.
Published: October 2017

Purpose

The purpose of this paper is to investigate the similarities and differences of critical success factors (CSFs) for public-private partnership (PPP) projects in developing and developed countries, using Ghana and Hong Kong as examples.

Design/methodology/approach

An empirical questionnaire survey was conducted with experienced PPP practitioners in Ghana and Hong Kong. Survey responses were analysed using Kendall’s concordance analysis, mean score ranking, quartile groupings analysis and Mann-Whitney U test.

Findings

The results indicate that a favourable legal and regulatory framework is very critical in both jurisdictions. Further, technology transfer, technological innovation, public/community participation and coordination and government providing financial support are of low importance in both jurisdictions. The non-parametric test shows that 16 CSFs are of different importance in Ghana and Hong Kong. Specifically, CSFs related to the socio-political and economic conditions of PPP projects are very critical in Ghana, whereas CSFs directly related to the organisation and relationship of PPP projects are very critical in Hong Kong.

Originality/value

The outputs of this study add to the international best practice framework for successful PPP implementation. Further, international private investors and governments who are yet to adopt the PPP concept would be considerably informed of the investment strategies to employ when engaging in PPP arrangements.
The role of customers and vendors in modern construction equipment technology diffusion
Authors: Sepasgozar Samad M.E. , Loosemore Martin
Published: October 2017

Purpose

The purpose of this paper is to address the gap in knowledge by exploring the role of customers and vendors in diffusion of modern equipment technologies into the construction industry.

Design/methodology/approach

To address the need to consider both vendors and customers in the innovation diffusion process and the need for in-depth cross-sectional studies, semi-structured interviews were undertaken with 147 participants including 85 vendors and 62 customers of modern construction technologies at company, project and operational levels in Australia and North America. Thematic analysis and an analytic hierarchy process illustrate the critical role of both customers and vendors in the diffusion process of modern equipment technologies.

Findings

A new conceptual model is presented which classifies modern equipment technology customers into four categories: visionaries (group I); innovators (group II); pragmatists (group III); and conservatives (group IV) based on the way in which they interact with vendors in the innovation diffusion process. The results also reveal that there is a significant emotional/affective aspect of innovation diffusion decisions which has not been recognised in previous research.

Originality/value

The major contribution of this study is that it analyses the role of both vendors and customers in the equipment technology diffusion process at three different levels (strategic, project and operational) in large corporations and small-to-medium-sized businesses. The findings not only advance construction innovation research beyond traditional linear models of innovation, but also provide new knowledge which enable customers and vendors to interact more effectively in the diffusion of new construction equipment technologies.
Civil engineers’ personal values/demographics linkage in project team building
Authors: Damci Atilla , Arditi David , Polat Gul
Published: October 2017

Purpose

The purpose of this paper is to explore the relationship between civil engineers’ demographics (e.g. age, marital status, education, work experience) and their personal values. The objective was to predict civil engineers’ personal values based on their demographics.

Design/methodology/approach

A questionnaire survey was administered to civil engineers to collect data on their demographics and their personal values. Statistical analysis was performed to verify whether a significant statistical relationship exists between civil engineers’ demographics and their personal values.

Findings

The most important and the least important personal values were identified for civil engineers. Statistical analysis indicated that civil engineers’ values do vary based on their demographics.

Research limitations/implications

The results of this study cannot be generalized, because individuals’ personal values and demographics are, by definition, local. Location and culture may affect the personal values of civil engineers.

Practical implications

Team leaders normally have access to information about the demographics of the engineers they employ; based on the results of this study, they should be able to predict their personal values, and to make more informed decisions when appointing them to particular positions on project teams.

Originality/value

The research presented in this paper, establishes for the first time, that a linkage exists between civil engineers’ personal values and their demographics, and makes it easier for team leaders to make assignment decisions.
Construction safety and health problems of ethnic minority workers in Hong Kong
Authors: Chan Albert P.C. , Wong Francis K.W. , Hon Carol K.H. , Ali Javed Arshad , Lyu Sainan
Published: October 2017

Purpose

With increasing employment of ethnic minority (EM) workers from different nationalities to mitigate the growing demand for a construction workforce, the safety and health problems of these workers have become a significant concern. The purpose of this paper is to identify and rank according to severity the safety and health-related problems confronted by EM construction workers.

Design/methodology/approach

Grounded theory approach was employed to construct the main categories and subcategories of the construction safety and health problems of EM workers. A two-round Delphi survey of 18 experts, who are highly experienced in managing EM workers, was conducted to rank the relative severity of the identified safety and health problems.

Findings

A total of 14 subcategories and 4 categories of construction safety and health problems of EM workers were identified. Among the 14 subcategories, the most urgent and serious ones were insufficient safety materials and training in their native language, insufficient safety staff from EM origin, and safety communication barriers. In addition, safety and health problems at the corporate and governmental levels are also worth paying attention.

Originality/value

This study contributes to the update on the existing body of knowledge on safety and health problems encountered by EM construction workers and revelation of their peculiar situation in Hong Kong. Findings of the study will be of value to various stakeholders in formulating safety and health measures for EM construction workers.
Modular concrete construction
Authors: Hamzeh Farook , Abdul Ghani Omar , Saleh Bacha Mohammad Bassel , Abbas Yara
Published: October 2017

Purpose

This study evaluates the enablers and barriers for modular concrete construction in Lebanon. The purpose of this paper is to investigate various factors (time, cost, technical know-how, organizational, sustainability, etc.) and their influence on the choice of the construction method. The paper examines the different assessments of designers, manufacturers, and contractors regarding precast construction in comparison to traditional in-situ methods, and highlights the major differences in their views.

Design/methodology/approach

Structured face-to-face surveys were conducted with top management personnel of precast manufacturers, architectural and engineering firms, and contracting companies in Lebanon. In addition, a case study from the largest precast project in Lebanon was used to provide a deeper understanding of factors encouraging the use of precast concrete, and to highlight major onsite issues associated with its implementation.

Findings

On the one hand, the findings highlight technical, logistical, organizational, and cultural factors that inhibit the use of precast concrete as a construction method. On the other hand, results reveal that cost, time, sustainability, and flexibility factors are the main enablers for increasing the uptake of modular concrete construction.

Originality/value

The main contribution to knowledge is that this study presents different stakeholders’ perspectives on precast concrete construction. Moreover, this is the first research addressing precast concrete construction in the Middle East and Lebanon. The results of the study provide valuable global insights and recommendations that may help increase the uptake of precast concrete construction. They can also guide project stakeholders to properly match project characteristics and precast concrete as a construction method.
Power distance and landlord-tenant practices across countries
Authors: Gholipour Fereidouni Hassan , Tajaddini Reza
Published: October 2017

Purpose

This paper aims to investigate whether cultural dimension of power distance, which is the extent that inequality is expected and accepted in societies, can explain underlying differences in landlord-tenant practices (LTP) across countries.

Design/methodology/approach

The authors use a sample covering countries from different regions. They apply the ordered probit regressions to estimate the relationships between the explanatory variables and LTP.

Findings

The results show that hierarchical societies demonstrate more pro-landlord practices. This finding is robust to alternative measures of power distance and different sample sizes. In addition, the authors find that countries with larger rental sectors and larger numbers of landlords with mortgages demonstrate more pro-tenant practices. The results also show that differences in LTP across countries are not significantly influenced by legal origin.

Originality/value

To the best of the authors’ knowledge, very limited studies have investigated the determinants of LTP across countries. In addition, while cultural values such as power distance have been used to explain the economic, social and financial variables, less, if any, number of studies have used them to explain the variation of real estate market variables such as LTP.
Market heterogeneity, investment risk and portfolio allocation
Authors: Amédée-Manesme Charles-Olivier , Baroni Michel , Barthélémy Fabrice , Des Rosiers François
Published: October 2017

Purpose

The purpose of this paper is to address the heterogeneity of real estate assets with regard to investment risk measurement, with Paris’ apartment market as a case study.

Design/methodology/approach

Quantile regression is used to handle the fact that willingness to pay for housing attributes may vary greatly over both space and asset value categories. The method is alternately applied on central and peripheral districts of Paris, or “arrondissements”, with hedonic indices built for nine deciles over a 17-year period (1990-2006). Portfolio allocation is subsequently analysed with deciles being the assets.

Findings

The findings suggest that during the slump, peripheral districts show better resilience and define the efficient frontier while also exhibiting a lower volatility. In addition, higher returns are observed for lower-priced apartments, both central and peripheral. During the recovery and boom stages of the cycle, the highest returns are experienced for the cheapest apartments in central locations, whereas upper-priced, centrally located units yield the lowest returns.

Originality/value

The originality of this research resides in the application of quantile regression in a real estate investment and risk management context. The methodology may raise individual investors’ and practitioners’ attention, especially index providers’.
Robot-enabled execution system for perishables auction logistics
Authors: Kong Xiang T.R. , Zhong Ray Y. , Xu Gangyan , Huang George Q.
Published: October 2017

Purpose

The purpose of this paper is to propose a concept of cloud auction robot (CAR) and its execution platform for transforming perishable food supply chain management. A new paradigm of goods-to-person auction execution model is proposed based on CARs. This paradigm can shift the management of traditional manual working to automated execution with great space and time saving. A scalable CAR-enabled execution system (CARES) is presented to manage logistics workflows, tasks and behavior of CAR-Agents in handling the real-time events and associated data.

Design/methodology/approach

An Internet of Things enabled auction environment is designed. The robot is used to pick up and deliver the auction products and commends are given to the robot in real-time. CARES architecture is proposed while integrating three core services from auction workflow management, auction task management, to auction execution control. A system prototype was developed to show its execution through physical emulations and experiments.

Findings

The CARES could well schedule the tasks for each robot to minimize their waiting time. The total execution time is reduced by 33 percent on average. Space utilization for each auction studio is improved by about 50 percent per day.

Originality/value

The CAR-enabled execution model and system is simulated and verified in a ubiquitous auction environment so as to upgrade the perishable food supply chain management into a new level which is automated and real-time. The proposed system is flexible to cope with different auction scenarios, such as different auction mechanisms and processes, with high reconfigurability and scalability.
Three-level supply chain coordination of fresh agricultural products in the Internet of Things
Authors: Yan Bo , Wu Xiao-hua , Ye Bing , Zhang Yong-wang
Published: October 2017

Purpose

The Internet of Things (IoT) is used in the fresh agricultural product (FAP) supply chain, which can be coordinated through a revenue-sharing contract. The purpose of this paper is to make the three-level supply chain coordinate in IoT by considering the influence of FAP on market demand and costs of controlling freshness on the road.

Design/methodology/approach

A three-level FAP supply chain that comprises a manufacturer, distributor, and retailer in IoT is regarded as the research object. This study improves the revenue-sharing contract, determines the optimal solution when the supply chain achieves maximum profit in three types of decision-making situations, and develops the profit distribution model based on the improved revenue-sharing contract to coordinate the supply chain.

Findings

The improved revenue-sharing contract can coordinate the FAP supply chain that comprises a manufacturer, distributor, and retailer in IoT, as well as benefit all enterprises in the supply chain.

Practical implications

Resource utilization rate can be improved after coordinating the entire supply chain. Moreover, loss in the circulation process is reduced, and the circulation efficiency of FAPs is improved because of the application of IoT. The validity of the model is verified through a case analysis.

Originality/value

This study is different from other research in terms of the combination of supply chain coordination, FAPs, and radio frequency identification application in IoT.
Representation of indigenous cultures: considering the Hawaiian hula
Authors: Hajibayova Lala , Buente Wayne
Published: October 2017

Purpose

The purpose of this paper is to explore the representation of Kanaka Maoli (Hawaiian) Hula Dance in traditional systems of representation and organization.

Design/methodology/approach

This exploratory study analyzes the controlled and natural language vocabularies employed for the representation and organization of Hawaiian culture, in particular Hawaiian hula. The most widely accepted and used systems were examined: classification systems (Library of Congress Classification and Dewey Decimal Classification), subject heading systems (Library of Congress Subject Headings and authority files (Library of Congress and OCLC Authority Files), and citation indexing systems (Web of Science Social Sciences and Art and Humanities databases).

Findings

Analysis of various tools of representation and organization revealed biases and diasporization in depictions of Hawaiian culture. The study emphasizes the need to acknowledge the aesthetic perspective of indigenous people in their organization and presentation of their own cultural knowledge and advocates a decolonizing methodology to promote alternative information structures in indigenous communities.

Originality/value

This study contributes to the relatively limited scholarship on representation and organization for indigenous knowledge organization systems, in particular Hawaiian culture. Research suggests that access to Native Hawaiian cultural heritage will raise awareness among information professionals in Hawai’i to the beauty of Native Hawaiian epistemology.
Heuristics elements of information-seeking strategies and tactics: a conceptual analysis
Authors: Savolainen Reijo
Published: October 2017

Purpose

The purpose of this paper is to elaborate the picture of strategies and tactics for information seeking and searching by focusing on the heuristic elements of such strategies and tactics.

Design/methodology/approach

A conceptual analysis of a sample of 31 pertinent investigations was conducted to find out how researchers have approached heuristics in the above context since the 1970s. To achieve this, the study draws on the ideas produced within the research programmes on Heuristics and Biases, and Fast and Frugal Heuristics.

Findings

Researchers have approached the heuristic elements in three major ways. First, these elements are defined as general level constituents of browsing strategies in particular. Second, heuristics are approached as search tips. Third, there are examples of conceptualizations of individual heuristics. Familiarity heuristic suggests that people tend to prefer sources that have worked well in similar situations in the past. Recognition heuristic draws on an all-or-none distinction of the information objects, based on cues such as information scent. Finally, representativeness heuristic is based on recalling similar instances of events or objects and judging their typicality in terms of genres, for example.

Research limitations/implications

As the study focuses on three heuristics only, the findings cannot be generalized to describe the use of all heuristic elements of strategies and tactics for information seeking and searching.

Originality/value

The study pioneers by providing an in-depth analysis of the ways in which the heuristic elements are conceptualized in the context of information seeking and searching. The findings contribute to the elaboration of the conceptual issues of information behavior research.
Service innovations breaking institutionalized rules of health care
Authors: Wallin Arto Juhani , Fuglsang Lars
Published: October 2017

Purpose

Although the digital era has given rise to major transformations in many industries, health care has been remarkably resistant to radical innovations coming outside the field. The purpose of this paper is to explore and explain how new ventures aim to break institutional arrangements (i.e. regulations, normative rules, and cultural-cognitive beliefs) protecting the field by introducing digitally enabled service innovations into health care markets.

Design/methodology/approach

The study is qualitative and interpretative in nature and utilizes case study as a research strategy. The paper is based on data that were collected through narrative interviews and document analysis from seven new ventures participating in a start-up accelerator program.

Findings

Results indicate that service innovations that require a change in the institutional structures of the health care system are enacted through three highly iterative key processes: institutional sensemaking that creates an understanding of prevailing institutional arrangements and that constructs meaning for institutional change efforts, theorization of change through linguistic device, and modifications of institutions by building legitimacy and mobilizing external constituencies.

Practical implications

The findings provide practical insights into how new ventures struggle, navigate, and negotiate on specific alternatives related to institutional change while pursuing the introduction of innovations to market.

Originality/value

This research extends the institutional perspective on service innovation by zooming into micro-level processes of institutional change driven by new ventures. The study develops the theory of institutional entrepreneurship by highlighting cognitive processes of change, and suggests incorporating “institutional thinking” more tightly into the study and management of service innovation.
Undergraduate student information self-efficacy and library intervention
Authors: Tang Yingqi , Tseng Hungwei
Published: October 2017

Purpose

The purpose of this study is to investigate undergraduate student information self-efficacy to find out how much the students learned from library instruction classes and to determine whether information seeking skills can be developed with a library instruction class.

Design/methodology/approach

A quantitative research method was conducted to collect survey data and to perform statistical analysis. A Web-based survey was distributed to undergraduate students who were enrolled in the Fall term of 2014. In all, 98 students completed the survey.

Findings

The study reported that undergraduate students’ capability of information finding, retrieving, analyzing, evaluating and presenting were on and above medium level (M = 3.40). They reported higher skills in information evaluation and information objects and types but lower skills in using catalog/database and organizing/synthesizing information. Students in the multiple library instruction group showed a significantly higher information self-efficacy. One-single instruction has a limited effect on improving information seeking skills.

Research limitations/implications

The number of students who participated in library instruction classes was relatively low. More data need to be collected to give credence to the findings in the future, and data collected from individual class would yield more accurate result.

Originality/value

This study extends the literature on information literacy and library instruction. The findings suggest that information literacy instruction should go beyond the one-session mode and should offer hands-on practices that will foster students’ critical thinking behavior more effectively.
Export promotion programmes and export performance
Authors: Quaye Daniel M. , Sekyere Kwame Ntim , Acheampong George
Published: October 2017

Purpose

Many nations now engage in economic promotion of their countries in foreign countries. One major aspect of this activity is export promotions. This paper aims to understand the relationship between export promotional activity participation and export performance by Ghanaian manufacturing firms.

Design/methodology/approach

The list of manufacturing exporters was obtained from the Ghana Export Promotion Authority, and the convenience and snowballing approach was used to reach and administer research instrument. The relationship between export promotion and performance was estimated using a multiple regression.

Findings

The results of this study indicate that exporters should implement specific export promotion programmes if they want to enhance export performance and become successful. The findings of this study show that the programmes that have a strong positive relationship with export performance are trade fairs, foreign offices and tax and financial incentives.

Originality/value

The results of this study contribute to the international entrepreneurship literature in several ways. First, findings from this study contribute to the limited literature on exports in developing countries such as Ghana. Again, the study framework provides assistance to assess and monitor emerging trends in export promotion strategies. Also, export promotion, as a whole, provides a framework in which firms formulate strategies, allocates resources and seeks opportunities in a coordinated way. Finally, in the international marketplace, firms need to maintain their competitive edge, and it is important to operate efficiently and effectively using an appropriate export promotional strategy.
Stable isotope tracers reveal a trade‐off between reproduction and immunity in a reptile with competing needs
Authors: Durso Andrew M. , French Susannah S.
Published: October 2017

Trade‐offs between the reproductive and immune systems are predicted when resources are limited, but are difficult to measure.

We used 15N‐labelled amino acids to directly compare protein allocation by lizards to eggs and healing wounds.

We showed that these two demands compete for the same resource, and that the ratio of protein allocation between them was related to body size, reproductive stage and plasma corticosterone levels.

On average, rates of leucine deposition into eggs (0.022 μg/day) were an order of magnitude greater than those into scabs (0.002 μg/day), similar to leucine excretion rates (0.027 μg/day), and about half as large as leucine egestion rates (0.054 μg/day).

We found that earlier reproductive stages and greater amounts of stored energy, but not manipulated food availability or the amount of food consumed, increased the absolute and relative allocation of protein to self‐maintenance.

We provide direct evidence for amino acid trade‐offs between reproduction and wound healing.

A plain language summary is available for this article.
Are exotic plants more abundant in the introduced versus native range?
Authors: Pearson Dean E. , Eren Özkan , Ortega Yvette K. , Villarreal Diego , Şentürk Muhyettin , Miguel M. Florencia , Weinzettel C. Miguel , Prina Aníbal , Hierro José L.
Published: October 2017

Many invasion hypotheses postulate that introducing species to novel environments allows some organisms to escape population controls within the native range to attain higher abundance in the introduced range. However, introductions may also allow inherently successful species access to new regions where they may flourish without increasing in abundance.

To examine these hypotheses, we randomly surveyed semi‐arid grasslands in the native and two introduced ranges (12,000–21,000 km2 per range) to quantify local abundance (mean cover per occupied plot) and occurrence (percentage of 1‐m2 plots occupied) for 20 plant introductions that included pest and non‐pest species. For each of these metrics, we evaluated relationships between abundance in the introduced vs. native range (1) across all species and (2) according to designated pest status in the introduced range. We predicted that if escape from population controls primarily explained invader success, then these species would be more abundant in the introduced range; while if invader success was driven primarily by intrinsic species attributes, then their abundance would be correlated between ranges.

Across all 20 invaders, we found that neither cover nor occurrence metrics were correlated between ranges. While cover was significantly higher in the introduced range, this result was driven by pest species. When the four pest species were excluded, cover but not occurrence was correlated between ranges. Interestingly, whereas cover of pest and non‐pest species was comparably low in the native range, pest species cover increased sevenfold in the introduced range.

Synthesis. Our results confirm previous findings that local abundance in the native range predicts local abundance in the introduced range for many introduced plants, suggesting that intrinsic species’ attributes may determine most invasion outcomes. However, we also found that some species increased in local abundance in the introduced range, suggesting that changes in biogeographic context may also play an important role. While these latter species were pests, the small sample size precluded strong inferences. Determining what underlies the success of invasive pests remains elusive due to their low representation among introduced species.
Biotic homogenization of regional wetland plant communities within short time‐scales in the presence of an aggressive invader
Authors: Price Edward P. F. , Spyreas Greg , Matthews Jeffrey W.
Published: October 2017

Biotic homogenization (BH), a process by which β‐diversity erodes, represents a severe threat to biodiversity. Wetland plant communities may be especially susceptible to BH; however, this process has rarely been quantified and represents just one of many possible outcomes of compositional change. Likewise, few studies have used more than two timepoints to investigate BH as a dynamic temporal process.

To address these issues, we quantified changes in β‐diversity amongst 48 herbaceous emergent wetlands across a landscape over four timepoints from 1997 to 2015. Pairwise occurrence‐ and abundance‐based dissimilarity metrics were used to quantify β‐diversity. Nonmetric multidimensional scaling was used to map these changes in compositional similarity through time, and repeated measures ANOVA via randomization was used to test for a significant effect of time on β‐diversity.

Results indicated that herbaceous emergent wetlands homogenized in Illinois over 15 years due to the increased presence and abundance of Phalaris arundinacea and the decline of several other species. Temporal dynamics of β‐diversity differed between occurrence‐ and abundance‐based analyses.

Synthesis. Using both presence–absence and abundance data to investigate BH helped avoid underestimating the impact of BH on β‐diversity, and drew attention to different temporal dynamics in β‐diversity at these two resolutions of community structure. This study highlights challenges associated with investigating BH, such as problems documenting the process where homogenization is not occurring in every site in a region, or where sites are converging towards more than one homogenized state. Incorporating concepts like alternative stable states may be helpful in resolving these issues, and present a more realistic picture of ecological change.
Evaluation of total phenol content and antioxidant properties of encapsulated grape seed extract in yoghurt
Authors: Yadav Kanta , Bajaj Rajesh Kumar , Mandal Surajit , Saha Priti , Mann Bimlesh
Published: October 2017

The effect of encapsulated (En) and nonencapsulated (NE) grape seed extract (GSE) at 1% level added to milk before its fermentation was evaluated on the physicochemical properties, total phenolic content and antioxidant activity of the resulting yoghurt. Encapsulated GSE resulted in a product comparable to the control, based on sensory properties, acidity, water‐holding capacity, viscosity and colour, along with a threefold increase in total phenolic content and fourfold increase in antioxidant activity. The GSE addition resulted in no effect on the viability of Streptococcus thermophilus and Lactobacillus bulgaricus subsp. delbrueckii counts. The product with NE‐GSE had poor sensory properties and lesser polyphenol stability during storage as compared to En‐GSE yoghurt.
An efficient technique for dairy wastewater treatment
Authors: Davarnejad Reza , Nikseresht Mehrazin , Ajideh Iman
Published: October 2017

The aim of this study was to consider the efficiency of the electro‐Fenton process for organic compound reduction in an industrial dairy effluent. Experiments were conducted to evaluate the effect of several parameters, such as reaction time, pH, H2O2/Fe2+ molar ratio and volume fraction of H2O2 to dairy wastewater (mL/L), on the process performance. The Taguchi technique was applied to investigate the optimum operating conditions. The optimum chemical oxygen demand removal (93.24%) was experimentally obtained at a pH value of 7.58, reaction time of 87.13, current density of 58.5, H2O2/Fe2+ molar ratio of 3.62 and volume fraction of H2O2 to dairy wastewater of 1.39 mL/L.
Antioxidant Capacity In Vitro and In Vivo of Various Ecotypes of Mexican Plum (Spondias purpurea L.)
Authors: Villa‐Hernández Juan Manuel , Mendoza‐Cardoso Gabriela , Mendoza‐Espinoza José Alberto , Vela‐Hinojosa Cristián , Díaz de León‐Sánchez Fernando , Rivera‐Cabrera Fernando , Alia‐Tejacal Irán , Pérez‐Flores Laura J.
Published: October 2017

Spondias purpurea L. is a fruit native to Mexico, however, it is found as far away as Brazil. It possesses a high commercial potential owing to its sensorial and nutritional qualities and its low cost of production. There exists a variety of ecotypes that have not been characterized and their adequate selection process, according to their strongest functional characteristics, will allow the establishment of improvement programs for this genetic resource. The object of this study was the chemical characterization and the determination of the in vitro and in vivo antioxidant capacity of 7 Spondias purpurea L. ecotypes. Differences were observed in the antioxidant capacity and the content of functional compounds among all the ecotypes analyzed. A high total phenolic content and a low flavonoid and carotenoid content were found, both in the epicarp and in the pulp. In each ecotype, the hydrophilic phase presented up to 40 times greater antioxidant capacity compared to the lipophilic phase. The hydrophilic phase of the epicarp of “Costeña Tierra Colorada” had the greatest antioxidant capacity and highest total phenolic content, whereas “Jocote” presented the lowest antioxidant capacity and total phenolic content. A positive correlation was observed between phenol levels and the antioxidant capacity in the epicarp. Regarding antioxidant activity in vivo, it was observed that in all analyzed concentrations of hydrophilic extracts of the epicarp of “Costeña Tierra Colorada” and in the highest “Jocote” concentrations, they provided thermo‐protection against heat stress as well as a general well‐being to the worm as evidenced by their high mobility.
First use of Micro Vascular Plugs in Australia: Endovascular treatment of pulmonary arteriovenous malformation
Authors: Barrett Liat , Brown Nicholas I , Joseph Varghese Pynadath
Published: October 2017

This report describes the first Australian experience with the Micro Vascular Plug System (MVP), as a permanent embolic device for the treatment of pulmonary arteriovenous malformations (PAVMs). MVPs deployed in small vessels between 2 mm and 5 mm are demonstrated to be feasible, safe and effective treatment for PAVMs.
Therapeutic bronchoscopy vs. standard of care in acute respiratory failure: a systematic review
Authors: Ellekjaer K. L. , Meyhoff T. S. , Møller M. H.
Published: October 2017

Background

We aimed to assess patient‐important benefits and harms of therapeutic bronchoscopy vs. standard of care (no bronchoscopy) in critically ill patients with acute respiratory failure (ARF).

Methods

We conducted a systematic review with meta‐analysis and trial sequential analysis (TSA) according to the Cochrane Handbook and GRADE methodology, including a predefined protocol (PROSPERO no. CRD42016046235). We included randomized clinical trials (RCTs) comparing therapeutic bronchoscopy to standard of care in critically ill patients with ARF. Two reviewers independently assessed trials for inclusion, extracted data and assessed risk of bias. Risk ratios (RR) with 95% confidence intervals (CI) were estimated by conventional meta‐analysis. The risk of random errors was assessed by TSA. Exclusively patient‐important outcomes were evaluated.

Results

We included five trials (n = 212); all were judged as having high risk of bias. There was no difference in all‐cause mortality between therapeutic bronchoscopy and standard of care (TSA adjusted RR 0.39; 95% CI 0.14 to 1.07; I2 0%), and only 3% of the required information size had been accrued. There was no difference in ICU length of stay. A shorter duration of mechanical ventilation was suggested by conventional meta‐analysis, however TSA highlighted that only 42% of the required information size had been accrued, indicating high risk of random errors. No trials reported data on adverse events, hospital length of stay, quality of life or performance status.

Conclusions

The quantity and quality of evidence supporting therapeutic bronchoscopy in critically ill patients with ARF is very low with no firm evidence for benefit or harm.
Intensive care admissions due to poisoning
Authors: Lindqvist E. , Edman G. , Hollenberg J. , Nordberg P. , Ösby U. , Forsberg S.
Published: October 2017

Background

Poisoning represents a significant part of admissions to intensive care units. The aim of this nationwide study was to describe recent national quality register data of demographics and mortality for these patients.

Method

A retrospective national observational study including all patients over 19 years admitted to an ICU in Sweden, between 1 January 2010 and 31 December 2011, with an ICD‐10 code for poisoning. The data were collected from three national registers (The Swedish Intensive Care Register, The National Patient Register, and The Cause of Death Register).

Results

The incidence of ICU‐treated poisonings was 43/100,000. Twenty‐one per cent (n = 8155) of all poisoned patients seeking medical care were admitted to the ICU. Their median age was 38 years (q1–q3: 26–51), as many men as women and 46.5% (n = 3790) had a previous registered poisoning. A mix of different substances was the most common type of suspected poisoning (29.7%, n = 2424). The in‐hospital mortality was 1.9% and was correlated to invasive mechanical ventilation (OR 6.91 CI 95% 4.59–10.42), age > 40 (OR 4.54 CI 95% 2.86–7.21) and no previous hospitalisation for poisoning (OR 3.23 CI 95% 2.06–5.07). For 78.3% (n = 119) of the deceased patients, the fatal poisoning was their first diagnosed poisoning. The 30‐day mortality was 2.7%, a majority died from poisoning (P < 0.01).

Conclusion

In Sweden, patients treated in the ICU due to poisoning represent a fifth of all poisoned patients seeking medical care. Older men with no previous poisoning were considered a high‐risk group.