bluuebunny/crossref_metadata_2025 huggingface dataset:
Multimodel approach for modelling of nonlinear systems: validities’ optimal computation
Authors: Ben Messaoud Abdennacer , Talmoudi Samia , Ksouri-Lahmari Moufida
Published: November 2017

Purpose

The purpose of this paper is to propose a new method for computing validities in the multimodel approach.

Design/methodology/approach

The multimodel approach offers an interesting alternative and a powerful tool to bypass the difficulties to model, control and diagnose a nonlinear and complex system. Its idea is defined as the apprehension of a nonlinear behaviour of a system by a set of local models characterizing the system operation in different operating zones. In spite of the success of its application in different fields, many problems related to the synthesis of multimodel approach remain open. These include, in particular, the method of obtaining the contribution degrees, also called validities, of the base-models for the deduction of the multimodel output.

Findings

The presented method may lead to superior results in comparison with the residue approach commonly used in the calculation of validities. Numerical simulation results and an experimental validation on a semi-batch reactor clearly illustrated the effectiveness of the proposed method and proved its impact on the improvement of the performances of the multimodel approach. Moreover, the multimodel approach using the new validities’ computation method can lead to perfect modelling of the process.

Practical implications

The proposed method discussed in the paper has the potential to make the multimodel approach more efficient in the modelling of complex real systems.

Originality/value

A significant contribution of the paper is the formulation of a new constrained optimization problem that can be solved by using a powerful mathematical tool such as the active set method, allowing to estimate the validity indexes in the multimodel approach. The obtained optimal solution can lead to perfect modelling of nonlinear and complex real systems.
Analysis of strategies of circuit optimisation on basis of maximum principle
Authors: Zemliak Alexander
Published: November 2017

Purpose

This paper aims to propose a new approach on the problem of circuit optimisation by using the generalised optimisation methodology presented earlier. This approach is focused on the application of the maximum principle of Pontryagin for searching the best structure of a control vector providing the minimum central processing unit (CPU) time.

Design/methodology/approach

The process of circuit optimisation is defined mathematically as a controllable dynamical system with a control vector that changes the internal structure of the equations of the optimisation procedure. In this case, a well-known maximum principle of Pontryagin is the best theoretical approach for finding of the optimum structure of control vector. A practical approach for the realisation of the maximum principle is based on the analysis of the behaviour of a Hamiltonian for various strategies of optimisation and provides the possibility to find the optimum points of switching for the control vector.

Findings

It is shown that in spite of the fact that the maximum principle is not a sufficient condition for obtaining the global minimum for the non-linear problem, the decision can be obtained in the form of local minima. These local minima provide rather a low value of the CPU time. Numerical results were obtained for both a two-dimensional case and an N-dimensional case.

Originality/value

The possibility of the use of the maximum principle of Pontryagin to a problem of circuit optimisation is analysed systematically for the first time. The important result is the theoretical justification of formerly discovered effect of acceleration of the process of circuit optimisation.
Motives and constraints of participants in running events
Authors: Koronios Konstantinos , Psiloutsikou Marina , Kriemadis Athanasios
Published: November 2017

Purpose

The purpose of this paper is to acquire improved comprehension of the motivational factors and the various constraints associated with individuals’ participation in mass running events.

Design/methodology/approach

A quantitative method was used for the purpose of this research, and 1.357 questionnaires were completed. This study proposed two broad hypotheses: intrapersonal constraints influence motivation factors (amotivation, intrinsic and extrinsic motivation); and motivation factors influence the intention to continuous participation.

Findings

Both broad hypotheses were supported by the evidence while the lack of knowledge, interest, confidence and feelings of tiresomeness were found to contribute more to explaining motivation. All three motivational factors had a significant influence on intention.

Research limitations/implications

The empirical evidence for this study came from runners only. The special attributes of running may have influenced the explored relationships in a way that may not be directly applicable to other activities. Further research in various activities is necessary before such findings are generalized.

Originality/value

The aim of this paper is to provide empirical evidence of the relationships between the motivational factors and the various constraints associated with individuals’ participation in mass sporting and physical activity events. This research focused on developing a model to explain relationships among constraints, motivators and participation, and empirically test the proposed model within the marathon running participants context.
Drinking to the “edge”: gender differences in context-specific risks
Authors: Dresler Emma , Anderson Margaret
Published: November 2017

Purpose

The risk associated with heavy episodic drinking in young people has caused concern among public health professionals. The purpose of this paper is to investigate the gender differences in the perception of risk in alcohol consumption behaviour for better targeting of messages.

Design/methodology/approach

This qualitative descriptive study examines the narratives of 28 young people’s experience of a “night out” framed as the Alcohol Consumption Journey to examine the ways young men and women experience context-specific risks for alcohol use.

Findings

The young people perceived participation in the Alcohol Consumption Journey involved risk to their personal safety. Both young men and young women described their alcohol consumption as controlled and perceived the risks as external inevitabilities linked to the public drinking establishments. However, they displayed noticeable gender-based differences in the perception and management of risk in diverse contexts of the Alcohol Consumption Journey. Young women drink in close friendship groups and have a collective view of risk and constructed group strategies to minimise it. Comparatively, the young men’s drinking group is more changeable and adopted a more individualistic approach to managing risk. Both groups exhibited prosocial tendencies to protect themselves and their friends when socialising together.

Originality/value

The concept of “edgework” is effective in providing an explanatory framework for understanding young people’s ritualised Alcohol Consumption Journey and to illustrate the context-specific risks associated with alcohol use.
The intention to quit smoking
Authors: Rahman Muhammad Sabbir , Mannan Mahafuz , Rahman Mohammad Mahboob
Published: November 2017

Purpose

From the perspective of developing countries, studies regarding the behavioral effects of quitting tobacco consumption on emerging psychological determinants are limited. The purpose of this paper is to examine the influence of emotional intelligence (EI), social norms, susceptibility and self-efficacy on the behavioral effects of quitting tobacco consumption among young smokers in developing countries.

Design/methodology/approach

By reviewing existing literature, this study developed a conceptual model to test the influences of significant psychological determinants in regards to a young smoker’s intention to quit smoking. Accordingly, a survey instrument was designed to collect data from young smokers in Bangladesh using the convenience sampling method. A total of 500 self-administered questionnaires were distributed, out of which only 400 questionnaires were used in final data analysis. This study applied partial least square structural equation modeling (PLS-SEM) to test the proposed model.

Findings

Perceived EI, perceived social norms and perceived susceptibility were found to have significant direct positive effects on intention to quit smoking. Perceived susceptibility and perceived self-efficacy were observed to have moderating effects on intention to quit smoking through perceived EI and perceived social norms respectively. However, perceived self-efficacy was not found to have any significant direct effect on intention to quit smoking.

Originality/value

This is the first study of its kind which combined EI, susceptibility, self-efficacy, and social norms in one theoretical framework to explain a young smoker’s intention to quit smoking. Also, in the context of Bangladesh and similar developing countries, there are no such studies which used the psychological components investigated in this study to predict a young smoker’s intention to quit smoking. Thus, the findings bring us closer to the goal of a tobacco-free society by allowing policy makers, NGOs, broader communities, and ultimately individual citizens to understand the psychological predictors of quitting tobacco consumption among young smokers in developing countries.
Involving teachers in reducing children’s media risks
Authors: Stiller Anja , Schwendemann Hanna , Bleckmann Paula , Bitzer Eva-Maria , Mößle Thomas
Published: November 2017

Purpose

The purpose of this paper is twofold: first, to introduce MEDIA PROTECT, a multi-modal intervention for parents and teachers with six components preventing problematic, and in the long run addictive, use of screen media by children; second, to present results of a formative evaluation of the teacher training, an important component of the intervention.

Design/methodology/approach

In presenting the intervention, the authors used a common framework to describe complex interventions systematically. For the evaluation, participants were recruited from German schools and kindergarten for a cluster-controlled trial. As part of a formative evaluation, the participants completed written questionnaires to determine the importance of different components of the intervention in addition to their overall satisfaction. Additional qualitative interviews with teachers were conducted.

Findings

The authors recruited n=50 kindergartens and n=9 schools; n=30 received the intervention. N=222 teachers participated in the training and n=192 completed the questionnaire (86 per cent). Seven qualitative interviews were conducted. Participants exhibited high levels of overall satisfaction with the training, considered it moderately to highly relevant to their work, and exhibited varying satisfaction levels with different components and multipliers. The qualitative data support these findings.

Originality/value

Few interventions to date have pursued a universal approach to the prevention of problematic screen media use. This evaluation of MEDIA PROTECT is the most recent study in Germany, which involves a complex programme through which teachers are taught ways to promote the age-adequate use of screen media in the family, parents are provided with guidance and healthy leisure time activities for children are fostered.
The Ripple Effect at an inter-suburban level in the Sydney Metropolitan area
Authors: Blake Jay Peter , Gharleghi Behrooz
Published: November 2017

Purpose

The purpose of this study is to investigate the Ripple Effect of house prices at an inter-suburban level of analysis in the Sydney metropolitan area. By doing this, more practical information of price transmission can be provided to improve residential real estate purchasing decisions of market participants. Equity from residential real estate is a major component of household wealth and is frequently used to improve and upgrade homes. With the ever-increasing prices of real estate in Sydney making more efficient purchasing decisions can grow this wealth quicker allowing a household to obtain financial related goals at a quicker pace.

Design/methodology/approach

Using a two-stage sampling technique strings of adjoining suburbs from different Sydney regions were analysed using a combination of price graphs, Engle–Granger and Johansen co-integration techniques and Granger causality tests.

Findings

Pairwise co-integration was lacking throughout the various suburb strings, whereas multivariate co-integration was found in the lower priced areas further from the central business district, as these areas also experience less price volatility. The geographical location of suburbs therefore plays an important role in the ability to predict an individual suburb’s price movements. For a prominent Ripple Effect to exist at this level the best conditions would consist of a singular demand centre with restricted geographical space to which this demand can spread. Causal pathways were subsequently mapped for each suburb string identifying price transmission pathways and confirming support that while the standard Ripple Effect does not exist at an inter-suburban level, it is still possible to predict price movements by considering the price behaviour of surrounding suburbs.

Originality/value

This paper adds to the literature by examining the Ripple Effect across different suburbs in Sydney. This is done via an extensive search through the literature and analysing recent real estate data.
Understanding challenges of using ICT in secondary schools in Sweden from teachers’ perspective
Authors: Ekberg Siri , Gao Shang
Published: November 2017

Purpose

The purpose of this paper is to investigate the challenges of using ICT in secondary schools in Sweden from teachers’ perspectives.

Design/methodology/approach

The research followed a qualitative research approach. First, a conceptual framework was developed based on previous research. Then, four teachers, teaching in six different subjects in secondary schools in Sweden, participated in semi-structured interviews that consisted of open-ended questions exploring their views on the challenges of using ICT in secondary schools.

Findings

According to the results, the authors found that the biggest challenges were associated with the perspective of teaching and teaching preparation. Most challenges from previous research have been re-confirmed by the interviewees in this study. In addition, some new challenges were identified in this study. For instance, the results indicated that it was time consuming to find plagiarism of students’ exercises, and there was a lack of ICT training of digital resources provided by the schools.

Originality/value

The investigation of using ICT in secondary schools is of scientific significance because it enriches the understanding of strengths and challenges of using ICT in educational activities. In particular, this research aims to shed light on challenges that teachers may face when using ICT in secondary schools. This research can also contribute to making future strategic plans for the use of ICT in secondary schools.
How teachers’ personality affect on their behavioral intention to use tablet PC
Authors: Camadan Fatih , Reisoglu Ilknur , Ursavas Ömer Faruk , Mcilroy David
Published: November 2017

Purpose

The purpose of this paper is to explore the effects of personality traits on teachers’ technology acceptance.

Design/methodology/approach

To this end, a demographic information survey, Five-Factor inventory, and technology acceptance measure were used for data collection. The data were analyzed via structural equation modeling.

Findings

According to the findings, conscientiousness has no significant effect on behavioral intention (BI) whereas openness and extraversion have positive indirect effects. On the other hand, agreeableness and neuroticism have negative indirect effects on BI. It was seen that the developed model explains 70 percent of BI, 77 percent of attitude toward use, 42 percent of perceived usefulness, 64 percent of perceived ease of use, and 15 percent of computer self-efficacy (CSE). It was revealed that CSE mediates the indirect effects of different personality traits on these variables.

Practical implications

In this regard, highlighting the conveniences to be brought by using Tablet PCs and equipping teachers with competencies to use relevant technologies during teacher training and in-service training may be effective in developing BI to use Tablet PCs among teachers.

Originality/value

The present study is different from previous studies in that it examines more than one technology through more than one measurement, takes personality as the predictor of technology use tendencies, and focuses on causal relationships between technology use and personality.
MOOCs: a differentiation by pedagogy, content and assessment
Authors: Mohamed Misrah Hamisah , Hammond Michael
Published: November 2017

Purpose

Massive open online courses (MOOCs) have often been divided between connectivist MOOCs and extended MOOCs (xMOOCs). Each form of MOOC proposes a distinctive view about knowledge acquisition. However, the breakdown between the two MOOCs is too broad in practice, and a more fine-grained approach is needed. Thus, the purpose of this paper is to describe the organisational features of exemplar MOOCs and their differences.

Design/methodology/approach

The study observed the ten newly available MOOCs aimed at teachers of English as a second language and included examples from existing providers: NovoEd, Coursera, FutureLearn and Canvas. These MOOCs were analysed and compared using a matrix with three main focuses: pedagogical assumptions, content materials and assessment.

Findings

The findings revealed that all courses corresponded to the idea of an xMOOC in that they were run on a model of instructional design. However, the course materials varied in respect to media used, use of networking, discussion forums and degree of openness. In terms of assessment, all MOOCs used formative approaches, all had automated responses but only some had summative and peer assessment.

Originality/value

The study succeeded in showing the variation in courses, thus enabling the range of possibilities open to course designers and providers.
Impact of investment efficiency on cost of equity: evidence from China
Authors: Majeed Muhammad Ansar , Zhang Xianzhi , Umar Muhammad
Published: November 2017

Purpose

The purpose of this study is to investigate the effect of investment efficiency on cost of equity capital.

Design/methodology/approach

Prior research indicated that any governance mechanism which reduces the agency conflict reduces the cost of equity capital. This study provides empirical evidence that investment efficiency represents such governance mechanism which reduces agency conflict and hence cost of equity. The authors use price earning growth ratio (Easton, 2004) and Ohlson and Juettner-Nauroth (2005) model for the measurement of cost of equity while investment efficiency measure of Biddle et al. (2009) have been employed to examine the association. We also use Chen et al. (2013) measure of investment efficiency for robustness.

Findings

The results show that investment efficiency is negatively associated with cost of equity. It was also found that there is a strong relationship of investment efficiency with cost of equity for non-state-owned enterprises (NSOEs), while no significant relationship is found for state-owned enterprises. Furthermore, overinvestment is significantly associated with cost of equity capital. However, no significant relationship was found between underinvestment and cost of equity.

Originality/value

The results provide empirical support to the argument that investment efficiency acts as a mechanism which represents lower agency conflict. Moreover, the findings provide evidence that government act as “deep pocket” while NSOEs are punished by investors for inefficient resource allocation. This study also proposes that there is a positive relationship between overinvestment and cost of equity.
Anti-money laundering disclosures and banks’ performance
Authors: Nobanee Haitham , Ellili Nejla
Published: November 2017

Purpose

The purpose of this paper is to explore the extent of anti-Money laundering (AML) disclosures in the annual reports and websites by differentiating between UAE Islamic and conventional banks, and examine the effect of AML disclosure on UAE bank’s performance.

Design/methodology/approach

This study uses content analysis to explore the extent of AML disclosure in the annual reports and the dynamic panel data two-step robust system to study the impact of the AML disclosures on banking performance.

Findings

The findings show that AML disclosure is at a low level for all UAE banks, conventional and Islamic banks. The results also show that the degree of AML disclosure on the websites of the banks is higher than that in the annual reports.

Research limitations/implications

The sample for this study comes only from banks traded on UAE markets. Thus, the results may not be generalizable to banks traded on other financial markets.

Practical implications

Because of the cross-border character of the money laundry practices, our study suggests the UAE central bank to internationalize the AML regulations and develop an international AML regime as efforts to respond to the international development of the money laundry practices.

Originality/value

This is the first study that develops an index to measure the AML disclosure and contributes significantly in providing greater insight in respect to AML disclosure in banking industry within the emerging markets.
Liability for negligently issued anti-mafia certificates
Authors: Monaco Paola
Published: November 2017

Purpose

This paper aims to analyse the different forms of liability that might apply under Italian private law to anti-mafia advisors who negligently perform their duties, with particular regards to auditors concerning the drafting of mandatory anti-mafia certificates as bidding documents for public procurement contracts.

Design/methodology/approach

The analysis is based on the comparative law methodology of dissociation of “legal formants”, that is, on the study of separate contributions by each element of the legal system – from black-letter provisions to judicial dicta, from scholars’ arguments to administrative practices – to the making of legal rules in a given setting.

Findings

Neither case law nor academic writing is abundant on this topic. Yet, it can be fairly assumed that an advisor who negligently drafts anti-mafia certificates might incur both contractual and tortious liability.

Originality/value

The paper investigates an area, which has so far been largely unexplored, and, thus, contributes to paving the way for a better understanding of the legal framework applicable to the cases under examination.
Strategies for using ResearchGate to improve institutional research outcomes
Authors: Ali Muhammad Yousuf , Wolski Malcolm , Richardson Joanna
Published: November 2017

Purpose

The purpose of this paper is to investigate how to help improve a higher education institution’s research profile by using existing resources and existing research outputs.

Design/methodology/approach

This study was based on quantitative data extracted manually from QS University Rankings-Asia 2016, the 2015 Ranking of Pakistani higher education institutions (HEI) and ResearchGate (RG). Resultant data were loaded into Excel and analyzed in SPSS version 21.

Findings

The results of this study indicate that, while there is no direct correlation between an institution’s national/international ranking and its respective RG score, there is a tendency for lower-ranked institutions to have a lower RG score.

Research limitations/implications

This study was limited to data extracted from RG; however, it would be useful to apply the same methodology to other relevant academic scholarly network sites (ASNS).

Practical implications

This paper has suggested strategies which may be of relevance to those institutions in other countries which are aspiring to lift their national ranking through improved research profiles. Libraries are important contributors to the support of institutional research goals.

Originality/value

There have been no previous published research studies on either the potential for ASNS to contribute to enhancing research outcomes for Pakistani HEI or the role that libraries could play in supporting these outcomes.
Shared leadership in teams
Authors: Han Soo Jeoung , Lee Yunsoo , Beyerlein Michael , Kolb Judith
Published: November 2017

Purpose

This paper aims to examine the effect of shared leadership on student project team processes and outcomes. The authors focused on shared leadership and its association with team processes (coordination, goal commitment and knowledge sharing) and team performance.

Design/methodology/approach

To examine the shared leadership, team processes and performance model, the authors conducted two separate surveys of 158 graduate and undergraduate students working in project teams at a large southwestern university.

Findings

Results showed that shared leadership positively affected coordination activities, goal commitment and knowledge sharing, which in turn positively affect team performance. Each team process factor had a mediation effect, although shared leadership had no direct effect on team performance.

Research limitations/implications

This research adds to the knowledge of important team process factors through which shared leadership indirectly affects team performance.

Practical implications

Based on the findings, the authors provided implications for students and instructors that shared leadership can facilitate team performance by enabling team members to coordinate activities, commit to goals and share knowledge effectively.

Originality/value

This study presents an initial understanding of the shared leadership-team performance relationship by introducing influential variables, such as coordination activities, goal commitment and knowledge sharing in a team.
MTS coordination in practice: micro-level insights to increase MTS performance
Authors: Wijnmaalen Julia , Voordijk Hans , Rietjens Bas
Published: November 2017

Purpose

This paper aims to generate insight into the processes that lie at the heart of multiteam system (MTS) coordination and how MTS coordination develops. The four propositions developed can set a future MTS research agenda and enable MTS leaders to increase MTS performance.

Design/methodology/approach

A military and civilian construction MTS has been studied over several months. The longitudinal character, micro-level focus and abductive research approach respond to the call for more in-depth, empirical studies of MTS processes.

Findings

Based on the research findings, four propositions are advanced: the interrelatedness of trust, communication and shared mental models is at the heart of MTS coordination; MTSs are sensitive to a downward spiral triggered by the negative relationship between MTS coordination and the occurrence of negative events; a salient component team identity accelerates this downward spiral; and effective MTS leadership is a perquisite for successful MTS coordination. The findings also indicate that because the MTS research field is still maturing, there is value in testing the degree to which existing knowledge on teams is generalizable to an MTS context.

Practical implications

The research generates three practical suggestions for MTS leaders to increase MTS performance: usual ways of structuring or leading a team might elicit intergroup behavior in MTSs, a conventional “fun” teambuilding program is not effective in an MTS situation and balance formal and informal coordination.

Originality/value

The abductive and empirical character of this study is unique in the field of MTS research. Moreover, the four propositions on MTS coordination advance current knowledge on MTS processes. Additionally, the study generates new insights that could enable MTS leaders to increase MTS performance.
Nutrient deficiencies and the restriction of compensatory mechanisms in copepods
Authors: Burian Alfred , Grosse Julia , Winder Monika , Boschker Henricus T. S.
Published: November 2017

The flexible regulation of feeding behaviour and nutrient metabolism is a prerequisite for consumers to grow and survive under variable food conditions. Thus, it is essential to understand the ecological trade‐offs that restrict regulatory mechanisms in consumers to evaluate the consequences of nutrient limitations for trophic interactions.

Here, we assessed behavioural and physiological adjustments to nutrient deficiencies in copepods and examined whether energy limitation, food digestibility or co‐limitation with a second nutrient restricted compensatory mechanisms.

A combination of 13C‐labelling and compound‐specific stable isotope measurements revealed that copepods compensated nitrogen deficiencies by raising retention efficiencies of amino acids (AA). The costs of higher retention efficiencies were reflected in the doubling of structural fatty acids (FA), probably required for morphological adaptations of the gut. A depletion of highly unsaturated FA in storage lipids and their selective retention suggested that these FA became co‐limiting and restricted a further increase in AA retention efficiencies.

Copepods feeding on phosphorus‐limited algae showed a marked increase in ingestion rates but were not fully able to compensate dietary deficiencies. The increase in ingestion rates was thereby not restricted by higher foraging costs because energy storage in copepods increased. Instead, thicker cell walls of nutrient‐limited algae indicated that algal digestion resistance restricted the extent of surplus feeding.

The strongly nutrient‐specific response of copepods had large implications for recycling rates, growth efficiencies and the potential top‐down control at the plant–animal interface. Compensatory mechanisms to mitigate nutrient deficiencies are therefore an essential aspect of trophic interactions and have the potential to alter the structure of food web.

A plain language summary is available for this article.
The added value of including key microbial traits to determine nitrogen‐related ecosystem services in managed grasslands
Authors: Pommier Thomas , Cantarel Amélie A. M. , Grigulis Karl , Lavorel Sandra , Legay Nicolas , Baxendale Catherine , Bardgett Richard D. , Bahn Michael , Poly Franck , Clément Jean‐Christophe
Published: November 2017

Despite playing central roles in nutrient cycles and plant growth, soil microbes are generally neglected in the study of ecosystem services (ES), due to difficulties to assess their diversity and functioning. However, to overcome these hurdles, new conceptual approaches and modern tools now provide a means to assess the role of micro‐organisms in the evaluation of ES.

In managed grasslands, soil microbes are central in providing nitrogen (N)‐related ES such as maintenance of soil fertility and retention of mineral forms of N. Here, we applied state‐of‐the‐art techniques in microbial ecology and plant functional ecology to uncover the intrinsic link between N‐related bacterial functional groups, important plant functional traits, environmental factors and three proxies of maintenance of soil fertility and potential for N‐leaching across managed grasslands in three regions of Europe.

By constructing well‐defined structural equation modelling, we showed that including key microbial traits improve on average more than >50% of the total variances of ES proxies, that is, ammonium () or nitrate () leaching, and soil organic matter content. Geographic differences arose when considering the direct relationships of these ES proxies with specific microbial traits: nitrate leaching was positively correlated to the maximum rate of nitrification, except in the Austrian site and potentially leached –N was negatively correlated to the fungi/bacteria ratio, with the exception of the French site.

Synthesis and applications. The integration of soil microbial functional traits in the assessment of nitrogen‐related grassland ecosystem services has direct contributions for understanding sustainable management of grassland ecosystems. The fundamental aspects of this study suggest that integrating a soil microbial component in grassland management may enhance sustainability of such grass‐based agroecosystems.
Domesticated honeybees facilitate interspecific hybridization between two Taraxacum congeners
Authors: Peng Youhong , Dong Yuran , Xu Haigen , Xi Xinqiang , Niklas Karl J. , Sun Shucun
Published: November 2017

Interspecific hybridization is common in plants under natural conditions, but the ecological mechanisms underlying when and how it happens have not fully been understood.

Taraxacum calanthodium and Taraxacum lugubre are two herbaceous annals co‐occurring in alpine meadows of the eastern Tibetan Plateau that share the same pollinators including domestic honeybees during their overlapping flowering times. Because honeybees tend to visit flowers less discriminatively when bee densities are high, we hypothesized that intense apiculture would facilitate hybridization between these two congeneric species.

We tested this hypothesis by examining the frequencies of the two parent species occurrence and the hybrid (based on morphological and genetic differences) along three transects radiating from well‐established apiaries.

Experiments show that both T. calanthodium and T. lugubre produce seeds sexually and asexually, and that they can hybridize via pollen transfer. Bee visitation rates and the frequency of the hybrid were significantly higher in the sites nearest to apiaries compared to distant site along each of the three transects. The hybrids were consistently genetically intermediate between the two species, as indicated by simple sequence repeat‐based analyses.

Synthesis. These data indicate that domestic honeybees foster interspecific hybridization between the two Taraxacum species and that anthropogenic effects on pollen vectors can significantly influence species hybridization in nature. We suggest that more effort should be made to quantify the effects of environmental change on pollinators and their effects on species evolution.
Land use in mountain grasslands alters drought response and recovery of carbon allocation and plant‐microbial interactions
Authors: Karlowsky Stefan , Augusti Angela , Ingrisch Johannes , Hasibeder Roland , Lange Markus , Lavorel Sandra , Bahn Michael , Gleixner Gerd
Published: November 2017

Mountain grasslands have recently been exposed to substantial changes in land use and climate and in the near future will likely face an increased frequency of extreme droughts. To date, how the drought responses of carbon (C) allocation, a key process in the C cycle, are affected by land‐use changes in mountain grassland is not known.

We performed an experimental summer drought on an abandoned grassland and a traditionally managed hay meadow and traced the fate of recent assimilates through the plant–soil continuum. We applied two 13CO2 pulses, at peak drought and in the recovery phase shortly after rewetting.

Drought decreased total C uptake in both grassland types and led to a loss of above‐ground carbohydrate storage pools. The below‐ground C allocation to root sucrose was enhanced by drought, especially in the meadow, which also held larger root carbohydrate storage pools.

The microbial community of the abandoned grassland comprised more saprotrophic fungal and Gram(+) bacterial markers compared to the meadow. Drought increased the newly introduced AM and saprotrophic (A+S) fungi:bacteria ratio in both grassland types. At peak drought, the 13C transfer into AM and saprotrophic fungi, and Gram(−) bacteria was more strongly reduced in the meadow than in the abandoned grassland, which contrasted the patterns of the root carbohydrate pools.

In both grassland types, the C allocation largely recovered after rewetting. Slowest recovery was found for AM fungi and their 13C uptake. In contrast, all bacterial markers quickly recovered C uptake. In the meadow, where plant nitrate uptake was enhanced after drought, C uptake was even higher than in control plots.

Synthesis. Our results suggest that resistance and resilience (i.e. recovery) of plant C dynamics and plant‐microbial interactions are negatively related, that is, high resistance is followed by slow recovery and vice versa. The abandoned grassland was more resistant to drought than the meadow and possibly had a stronger link to AM fungi that could have provided better access to water through the hyphal network. In contrast, meadow communities strongly reduced C allocation to storage and C transfer to the microbial community in the drought phase, but in the recovery phase invested C resources in the bacterial communities to gain more nutrients for regrowth. We conclude that the management of mountain grasslands increases their resilience to drought.
The effect of social media on the dynamics of (self) resilience during disasters: A literature review
Authors: Jurgens Manon , Helsloot Ira
Published: November 2017

As is well known for decades, citizens are highly resilient during and after a disaster, they save the day by helping themselves and others. A relatively new phenomenon is the abundant use of social media. In this literature review, the authors bring together recent findings on how social media affects citizens' self‐resilience by looking into its effect on four elements of self‐resilience: information gathering, information dissemination, collaborative problem‐solving, and coping. Social media supports citizens in their search for reliable information to reduce their uncertainty about the situation far beyond the regular but late information provided by authorities. This ability to gather information of their own accord is further aided by the enhanced ability of citizens (and authorities) to disseminate the information they possess quickly and widely. The ability of social media to connect people through time and space enhances collaborative problem‐solving and citizens' ability to make sense of the situation and cope with it. And yet, authorities by and large find it troublesome to get used to this new reality.
The potential for inoculation messages and postinoculation talk to minimize the social impact of politically motivated acts of violence
Authors: Ivanov Bobi , Sellnow Tim , Getchell Morgan , Burns William
Published: November 2017

The objective was to test whether precrisis inoculation‐stimulated conversations can positively impact key beliefs vital to the prosperity of a nation following an act of terrorism. The experiment introduced a precrisis inoculation message about the Department of Homeland Security prior to a simulated crisis portraying the downing of an aircraft. Results affirmed: that, compared to individuals in the control condition, inoculated individuals were less likely to believe that past failures of acts of terrorism resulted from terrorist incompetence; inoculated individuals indicated greater belief that the politically motivated acts of violence will not limit their future opportunities; and that interpersonal talk about such acts and the government's ability to effectively handle them were inversely associated with the likelihood of postponing air travel.
Heterogeneous Relationships between Labor Income and Health by Race/Ethnicity
Authors: Meraya Abdulkarim M. , Dwibedi Nilanjana , Innes Kim , Mitra Sophie , Tan Xi , Sambamoorthi Usha
Published: November 2017

Objective

To examine the race‐stratified relationships between labor income and health among working‐age adults in the United States.

Data Sources

Data from eight waves of the Panel Study of Income Dynamics from 1999 through 2013 were used for this study.

Study Design

The study utilized a retrospective observational longitudinal design with repeated measures of labor income and health measures. System‐generalized method of moment and heteroscedasticity‐based instrument regressions were used to examine the relationships between labor income and physical and mental health measures, respectively. Dynamic panel models were used to examine the effect of loss in income on health measures.

Data Collection/Extraction Methods

We performed secondary data analysis.

Principal Findings

Adults in higher labor income quartiles had better self‐rated health than those in the lowest quartile regardless of racial group. The relationship between labor income and psychological distress varied by race groups. Reductions in labor income were associated with increases in psychological distress among whites only.

Conclusion

These findings suggest heterogeneous relationships between labor income and overall health across racial groups. Our results highlight the need to provide safety nets for adults who experience a decline in income to prevent deterioration in health.
Molecular phylogeny ofEntomobrya(Collembola: Entomobryidae) from China: Color pattern groups and multiple origins
Authors: Ding Yin‐Huan , Yu Dao‐Yuan , Guo Wei‐Bo , Li Jian‐Nan , Zhang Feng
Published: November 2017

Highly diversified colorations among springtails (Collembola) have been widely used for species diagnosis, but their phylogenetic significance is poorly known. We addressed this issue in the largest Entomobryinae genusEntomobrya, which possesses variable color patterns among species. The relationships within the genus and to other genera have also rarely been studied. Based on material mainly from China, we have conducted a multilocus phylogeny and topology tests with likelihood and Bayesian algorithms, and accordingly demonstrated the non‐monophyly of ChineseEntomobrya. The division of five clades, includingEntomobryaand several related genera, coincided well with five types of colorations, respectively. Further analyses of divergence time and historical biogeography revealed that ChineseEntomobryaoriginated mainly from Palearctic (northern and western) China in the Paleocene and Eocene. This study highlights the great phylogenetic values as well as taxonomic uses of coloration in ChineseEntomobrya. Multiple phylogenetic and biogeographic origins ofEntomobryaimply its complicated relationships with both scaled and unscaled genera of Entomobryinae.
Community level impacts of invasive mosquitofish may exacerbate the impact to a threatened amphibian
Authors: Klop‐Toker Kaya , Valdez Jose , Stockwell Michelle , Clulow Simon , Clulow John , Mahony Michael
Published: November 2017

Invasive fish threaten many native freshwater fauna. However, it can be difficult to determine how invasive fish impact animals with complex life cycles as interaction may be driven by either predation of aquatic larvae or avoidance of fish‐occupied waterbodies by the terrestrial adult stage. Mosquitofish (Gambusia spp.) are highly successful and aggressive invaders that negatively impact numerous aquatic fauna. One species potentially threatened by Gambusia holbrooki is the green and golden bell frog (Litoria aurea). However, G. holbrooki's role in this frog's decline was unclear due to declines driven by the chytrid fungal disease and the continued co‐existence of these fish and frogs in multiple locations. To clarify the extent to which Gambusia is impacting L. aurea, we conducted 3 years of field surveys across a deltaic wetland system in south‐east Australia. We measured the presence and abundance of aquatic taxa including G. holbrooki, and L. aurea frogs and tadpoles, along with habitat parameters at the landscape and microhabitat scale. Generalized linear models were used to explore patterns in the abundance and distributions of L. aurea and G. holbrooki. We found strong negative associations between G. holbrooki and tadpoles of most species, including L. aurea, but no apparent avoidance of G. holbrooki by adult frogs. Native invertebrate predators (Odonata and Coleoptera) were also absent from G. holbrooki‐occupied ponds. Due to the apparent naivety of adult frogs toward G. holbrooki, the separation of G. holbrooki and tadpoles, plus the abundance of alternative predators in G. holbrooki‐free ponds, we conclude that the impact of G. holbrooki on L. aurea recruitment is likely substantial and warrants management action.
Chronic endometritis in patients with unexplained infertility: Prevalence and effects of antibiotic treatment on spontaneous conception
Authors: Cicinelli Ettore , Matteo Maria , Trojano Giueseppe , Mitola Paola C. , Tinelli Raffaele , Vitagliano Amerigo , Crupano Francesco M. , Lepera Achiropita , Miragliotta Giuseppe , Resta Leonardo
Published: November 2017

Problem

The correlations between chronic endometritis and unexplained infertility are unexplored.

Method of Study

We performed a retrospective study on consecutive patients referred to our hysteroscopy service due to unexplained infertility. All women underwent endometrial sampling with histological and cultural examinations. If chronic endometritis was diagnosed, patients received antibiotic therapy, and chronic endometritis resolution was subsequently ascertained by histological examination. We aimed to estimate chronic endometritis prevalence and the effects of antibiotic therapy on spontaneous conception during the year following hysteroscopy.

Results

A total number of 95 women were included. Pooled prevalence of chronic endometritis was 56.8%. Antibiotic therapy resulted in chronic endometritis resolution in 82.3% of patients, while in 17.6% disease was persistent. Women with cured chronic endometritis showed higher pregnancy rate and live birth rate in comparison with both women with persistent disease and women without chronic endometritis diagnosis (pregnancy rate = 76.3% vs 20% vs 9.5%, P < .0001; live birth rate = 65.8% vs 6.6% vs 4.8%, P < .0001).

Conclusion

Chronic endometritis is highly prevalent in patients with unexplained infertility. Diagnosis and treatment of chronic endometritis improve spontaneous pregnancy rate and live birth rate in such patients.
Low molecular weight heparin and aspirin exacerbate human endometrial endothelial cell responses to antiphospholipid antibodies
Authors: Quao Zola Chihombori , Tong Mancy , Bryce Elena , Guller Seth , Chamley Lawrence W. , Abrahams Vikki M.
Published: November 2017

Problem

Women with antiphospholipid antibodies (aPL) are at risk for pregnancy complications despite treatment with low molecular weight heparin (LMWH) or aspirin (ASA). aPL recognizing beta2 glycoprotein I can target the uterine endothelium, however, little is known about its response to aPL. This study characterized the effect of aPL on human endometrial endothelial cells (HEECs), and the influence of LMWH and ASA.

Method of study

HEECs were exposed to aPL or control IgG, with or without low‐dose LMWH and ASA, alone or in combination. Chemokine and angiogenic factor secretion were measured by ELISA. A tube formation assay was used to measure angiogenesis.

Results

aPL increased HEEC secretion of pro‐angiogenic VEGF and PlGF; increased anti‐angiogenic sFlt‐1; inhibited basal secretion of the chemokines MCP‐1, G‐CSF, and GRO‐α; and impaired angiogenesis. LMWH and ASA, alone and in combination, exacerbated the aPL‐induced changes in the HEEC angiogenic factor and chemokine profile. There was no reversal of the aPL inhibition of HEEC angiogenesis by either single or combination therapy.

Conclusion

By aPL inhibiting HEEC chemokine secretion and promoting sFlt‐1 release, the uterine endothelium may contribute to impaired placentation and vascular transformation. LMWH and ASA may further contribute to endothelium dysfunction in women with obstetric APS.