bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of PWM control frequency on efficiency of drive with 1 kW permanent magnet synchronous motor
Authors: Rudnicki Tomasz , Sikora Andrzej , Czerwinski Robert , Glinka Tadeusz
Published: November 2017

Purpose

This paper aims to present the impact of Pulse Width Modulation (PWM) control frequency for specific Permanent Magnet Synchronous Motors (PMSMs) on the efficiency of the entire driving unit. Examinations were carried out for a PMSM unit with a power of 1 kW, rated speed of 1,000 rpm, and rated torque of 6 Nm.

Design/methodology/approach

The PWM frequency ranged from 4 to 20 kHz with increments of 1 kHz. Measurements were taken for each of the foregoing frequencies, for the different load torques, and for the different rotation speeds including overspeed. The results achieved allow the PWM control frequency to be properly adjusted for each PMSM to operate the entire driving unit in the most efficient way and, in consequence, save energy consumed by the drive.

Findings

Obtained results may be used as a kind of background for the design of drive system.

Research limitations/implications

For a specific PMSM-based drive system, one can find the optimal PWM control frequency. This frequency depends on the rotation speed and torque of the motor. However, the validity of the results presented in the paper is limited. They are valid for the specific motor drive under test and cannot be generalized easily.

Originality/value

This work shows that there is some maximal efficiency of the entire system depending on the rotation speed, load torque and switching frequency of the power transistors. For a specific motor working in a certain condition, we can find the minimum power loss.
Real-time implementation of discrete Fourier transform phase analysis and fault tolerant control for PMSM in electric vehicles
Authors: Abassi Moez , Khlaief Omar , Saadaoui Oussama , Chaari Abdelkader , Boussak Mohamed
Published: November 2017

Purpose

Electric vehicles (EVs) require uninterrupted and safe conditions during operations. Therefore, the diagnostic of power devices and electric motor faults are needed to improve the availability of the system. Hence, fault-tolerant control (FTC), which combines switch fault detection, hardware redundancy and post-fault control, is used. This paper aims to propose an accurate open-phase fault detection and FTC of a direct torque control permanent magnet synchronous motor electrical vehicles by using discrete Fourier-transform phase method.

Design/methodology/approach

The main idea is to propose detection and identification of open-phase fault (faulty leg) among three phases voltage source invertor (VSI)-fed permanent magnet synchronous motor drives. Once the faulty leg is detected and isolated, a redundant phase leg insertion, shared by a three-phase VSI, is done by using independent bidirectional TRIAC switches to conduct FTC system. This accurate fault detection significantly improves system availability and reliability. The proposed method of open-phase fault detection and identification is based only on stator phase current measurement.

Findings

A novel method is proposed with experimental validation for fault detection, isolation and FTC for a three-phase VSI-fed permanent magnet synchronous motor.

Originality/value

The novel discrete Fourier-transform phase method is proposed to detect an open phase based on the measurement in real time of the instantaneous phase of stator current components in the stationary frame. The experimental implementation is carried out on powerful dSpace DS1104 controller board based on the digital signal processor TMS320F240. The validity of the proposed method has been experimentally verified.
Small-signal parameter extraction of asymmetric DCDMG AlGaN/GaN HEMT
Authors: Yadav Rahis Kumar , Pathak Pankaj , Mehra R.M.
Published: November 2017

Purpose

This paper aims to report small-signal parameter extraction and simulation of enhanced dual-channel dual-material gate AlGaN/GaN high electron mobility transistor (HEMT) for the first time for the characterization of a device in microwave range of frequency.

Design/methodology/approach

For parameter extraction, a standard and well-known direct parameter extraction methodology is applied. Extrinsic elements of small-signal circuit model are extracted from measured S-parameters obtained using pinch-off cold field effect transistor (FET) biasing in the first step at a low frequency range and at a higher frequency range in the second step to ensure higher extraction accuracy. Intrinsic elements are extracted from intrinsic Y-parameters that are obtained after de-embedding all the extrinsic parasitic elements of the device. Figure of merits of radio frequency are also derived from the measured results and S-parameters of the proposed device.

Findings

Small signal parameters of the proposed device circuit model are extracted using the standard direct parameter extraction technique. Analysis of microwave figure of merits for device include maximum oscillation frequency, cut-off frequency, current gain, transducer power gain, available power gain, maximum stable gain, transconductance, drain conductance, stern stability factor and time delay.

Practical implications

The paper bridges the gaps between theory and experimental practices by validating extracted results with reported results of structurally matching devices.

Originality/value

An enhanced device structure investigated for small signal parameters incorporates field plate over dual metal engineered gate to provide better electric field uniformity, effective suppression of short channel effect, reduction in current collapse, improvement in carrier transport efficiency and enhancement in drain current capabilities.
Dynamic and steady state modeling of permanent magnet induction machine
Authors: Izadfar Hamid Reza , Naseri Hamid
Published: November 2017

Purpose

Modeling electric machines is one of the powerful approaches for analyzing their performance. A dynamic model and a steady-state model are introduced for each electric machine. Permanent magnet induction machine (PMIM) is a dual-rotor electric machine, which has various advantages such as high-power factor and low magnetizing current. Studying PMIM and its modeling might be valuable. The purpose of this paper is to introduce a simple and accurate method for dynamic and steady-state modeling of PMIM.

Design/methodology/approach

In this paper, arbitrary dqo reference frame is used to model PMIM. First, three-phase dynamic equations of stator and rotors are introduced. Then, they are transferred to an arbitrary reference frame. The voltage and magnetic flux equations aligned at dqo axes are obtained. These equations give the dynamic model. To investigate the results, PMIM simulation is performed according to obtained dynamic equations. Simulation results verify the analytic calculations.

Findings

In this paper, dynamic equations of PMIM are obtained. These equations are used to determine dynamic equivalent circuits of PMIM. Steady-state equations and one phase equivalent circuit of the PMIM using phasor relations are also extracted.

Originality/value

PMIM equations along dqo axes and their dynamic and steady-state equivalent circuits are determined. These equations and the equivalent circuits can be transformed to different reference frames and analyzed easily.
Time-domain modelling of interconnects with highly oscillatory sources
Authors: Condon Marissa , Iserles Arieh
Published: November 2017

Purpose

This paper aims to explore a new approach for time-domain modelling of interconnects with highly oscillatory modulated sources.

Design/methodology/approach

The paper uses an asymptotic method in conjunction with the Green’s function of the telegrapher’s equations. The Green’s function is expressed as a series of rational functions in the Laplace domain and are converted to pole-residue form, thereby enabling time-domain implementation.

Findings

The results indicate that the method is accurate for modelling interconnects when wide-varying frequencies are present in the sources.

Originality/value

The technique is important in circuit design for assessing signal integrity and in electromagnetic compatibility testing.
Influence factors to affect eddy current loss of damper winding in 24 MW bulb tubular turbine generator
Authors: Qiu Hongbo , Fan Xiaobin , Feng Jianqin , Yang Cunxiang
Published: November 2017

Purpose

The purpose of this study is to find out the influence degree of harmonic current on the generator operating parameters. In practical operation of the salient-pole synchronous generator, the heat generated by eddy current loss may lead to the breaking of damper winding, and the damper winding is a key component for ensuring the reliable operation of generators. Therefore, it is important to study the distribution characteristics and the influence factors of eddy current loss. Taking a 24-MW bulb tubular turbine generator as a reference, the influence factors that affect the eddy current loss of damper winding are analyzed.

Design/methodology/approach

A two-dimensional (2-D) electromagnetic field model of the generator is established, and the correctness of the model is verified by comparing simulation results and experiment data. The eddy current losses of damper winding in various conditions are calculated by using the finite element method.

Findings

It is identified that the cogging effect, pole shoe magnetic saturation degree, pole arc coefficient and armature reaction are the main factors that affect the eddy current loss of the generator rotor. When the generator is installed with magnetic slot wedges, the distribution characteristic of eddy current loss is obtained through the study of the eddy current density distributions in the damper bars. The variations of eddy current losses with time are gained when the generator has different permeability slot wedges, pole arc coefficients and pole shoe magnetic saturation degrees.

Practical implications

The study of this paper provides a theoretical reference for the design and optimization of bulb tubular turbine generator structure.

Originality/value

The research can help enhance the understanding of eddy current distribution characteristics and influence factors of eddy current loss in bulb tubular turbine generator.
Too little, too late? Role of credit rating agencies in the Amtek AUTO default
Authors: Thukral Shagun , Korivi Sunder , Sharma Dipasha , Krishnakumar Dipali
Published: November 2017

Subject area

Fixed Income markets, Financial Markets and Institutions.

Study level/applicability

This case can be used in a postgraduate finance course such as an MBA and executive program for courses such as Fixed Income Markets and Financial Markets and Institutions.

Case overview

In late August 2015, the sudden downgrade and eventual default of Amtek AUTO Ltd (Amtek) on its debentures upset mutual fund investors and regulators. Questions were raised about the credit rating agencies and their lack of timely action as well as about the independent credit analysis followed by fund houses to protect the interests of investors. One such investor, Suresh Nair, decided to gather all possible available information on Amtek to determine whether it was sheer negligence on the part of all parties involved or if Amtek was in fact in a situation of sudden distress. The case seeks to highlight the credit analysis process, while looking out for red flags to identify potential default or financial stress in a company.

Expected learning outcomes

To understand the credit analysis process through a fundamental analysis process. To analyze and interpret the financial position of the company through various financial ratios. Identifying “red flags” while evaluating a potential credit that pose as “risks” to credit assessment. Understanding the role and relevance of credit rating agencies in the bond market.

Supplementary materials

Teaching Notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.

Subject code

CSS 1: Accounting and Finance
Teachers’ perspectives of a new food literacy curriculum in Australia
Authors: Nanayakkara Janandani , Margerison Claire , Worsley Anthony
Published: November 2017

Purpose

Implementation of a new food literacy curriculum provides multiple health and social benefits to school students. The success of any new curriculum execution is partly determined by teachers’ perceptions about the new curriculum contents, and barriers and challenges for its delivery. The purpose of this paper is to explore teachers’ views of a new food literacy curriculum named Victorian Certificate of Education Food Studies for senior secondary school students in Victoria, Australia.

Design/methodology/approach

A qualitative study design was used in this study. In total, 14 teachers who were planning to teach the new curriculum were individually interviewed in October-December 2016. The interviews were transcribed and analysed using the template analysis technique.

Findings

The majority of teachers appreciated the inclusion of food literacy and nutrition concepts in the new curriculum. However, half of the teachers had doubts about their readiness to teach it. Most teachers mentioned that they needed more training and resources to increase their confidence in teaching the curriculum.

Practical implications

These findings reveal that teachers need more awareness, resources, and guidance to increase their confidence in delivering the new curriculum. Provision of more resources and opportunities for training in food literacy concepts and instructional methods could facilitate its implementation.

Originality/value

These findings serve as an important first step to gain the perspectives of secondary school teachers’ opinions about the new curriculum. Moreover, these opinions and suggestions could inform the future design and implementation of similar food literacy curricula in Australia or elsewhere.
The effect of gamification on motivation and engagement
Authors: Alsawaier Raed S.
Published: November 2017

Purpose

Gamification is the application of game features, mainly video game elements, into non-game context for the purpose of promoting motivation and engagement in learning. The application of gamification in a pedagogical context provides some remedy for many students who find themselves alienated by traditional methods of instruction. The use of gamification could provide a partial solution to the decline in learners’ motivation and engagement the schooling system is facing today. Specifically, the college environment could benefit a lot from gamifying not only their graduate recruitment strategies, but also the college course content and curricula. This critical analysis of literature on gamification is intended to be part of a sequence on the effect of gamification on motivation and engagement. A proposed methodology in the study of gamification effect on motivation and engagement in addition to an empirical study on three college courses are being finalized to complete this trilogy. The paper aims to discuss these issues.

Design/methodology/approach

Themes covered in the literature review include: conceptualizing gamification, advantages of gamification over game-based learning, theoretical connections to gamification, motivation and engagement, connecting gamification to motivation and engagement, emotions and fun in gamification, player types and gamification features, gamification in action, and implementation guidelines.

Findings

The literature on the effect of gamification on motivation and gamification is still limited on multiple levels. There is a gap between theory and practice in the study of gamification. There is limited literature on the implementation guidelines of the gamified designs.

Practical implications

This critical analysis of literature is followed by connecting it to future research by the same author as part of a sequence on the effect of gamification on motivation and engagement. The second project, will be proposing a methodology for any successful design to provide a holistic understanding of the topic of gamification. Finally, an empirical study on the effect of gamification on students’ motivation and engagement in three college courses will be submitted to complete the trilogy.

Originality/value

This paper is a literature review, so there is a strong connection to literature on this topic. However, the synthesis of the themes and ideas are original. The literature review is extensive and covers the different aspects of the topic of gamification and its relationship to motivation and engagement.
Institutional distance, establishment mode choice and international experience: the case of Indian MNCs
Authors: Rienda Laura , Claver Enrique , Quer Diego
Published: November 2017

Purpose

Focusing on the growing importance of Indian multinational corporations in the past decades, this paper aims to understand how establishment mode decisions in a foreign market can differ depending on a series of factors. Specifically, the authors examine how institutional distance, including cultural distance and political risk, could affect these decisions, and how international acquisition experience could moderate this relationship.

Design/methodology/approach

The authors test their hypotheses using data from 114 outward foreign direct investments between 2000 and 2010.

Findings

The findings suggest that experience in international acquisitions increases the likelihood of subsequent acquisitions in high-risk and culturally distant countries.

Originality/value

By considering that the country of origin also matters, some differences among emerging-market multinational corporations (MNCs) may arise. Besides, since empirical research focusing on emerging-market MNCs is scarce, more empirical studies are needed to analyze the influence of cultural distance and political risk on some decisions. In the case of India, there are also additional motivations for analyzing those institutional factors. First, since this is a country with significant linkages to Western countries, it is interesting to know if the influence of cultural distance is similar or not. Second, there is a lack of empirical evidence on the relationship between political risk and establishment mode choice in the case of Indian MNCs. To fill this gap, the first aim of this paper is to analyze how cultural distance and political risk affect the establishment mode choice of Indian MNCs. Moreover, recognizing international experience to be an important factor in explaining international expansion, we focus on international experience interactions with sources of uncertainty inherent in the host market.
Mediating roles of capabilities between R&D-marketing integration and business performance
Authors: Ali Abdul , Matsuno Ken
Published: November 2017

Purpose

Following the resource-based view, this paper aims to investigate the business performance impact of R&D–marketing integration and marketing and technical capabilities at the organization level in a non-Western context. Specifically, this work explores the mediating role of the two capabilities, while accounting for potential moderating effects and under the contingency of technological turbulence.

Design/methodology/approach

Survey data were collected from the paired marketing and R&D executives of 207 Japanese manufacturing companies. Data were analyzed using structural equation modeling.

Findings

The results show that marketing capability – by itself and also coupled with technical capability – mediates the relationship between R&D–marketing integration and business performance, while technical capability alone does not.

Research limitations/implications

This study’s subjective performance measures and cross-sectional design have inherent limitations. The exploration of antecedents and other contingency variables would provide ample scope for future research.

Practical implications

The findings suggest that managers need to build these two capabilities, especially marketing capability, because R&D–marketing integration by itself will not be sufficient to improve business performance.

Originality/value

This study provides empirical evidence for a new theoretical link through which R&D–marketing integration impacts business performance at the program level. The findings may also partially explain the mixed and conflicting results often found in past studies.
Performance objectives of public private partnership implementation in Malaysia: perception of key players
Authors: Mohamad Rosnani , Ismail Suhaiza , Mohd Said Julia
Published: November 2017

Purpose

The objectives of this present study are twofold. First, it aims to investigate the performance objectives of PPP implementation in Malaysia. Second, it aims to examine the differences in the perceptions of two PPP key players – the public and private sectors – pertaining to the performance objectives.

Design/methodology/approach

A questionnaire survey was used to elicit the perceptions of the public and private sectors concerning the performance objectives of PPP projects in Malaysia; 237 usable responses were obtained and analysed using SPSS to rank the importance of the performance objectives and to examine the differences in the perceptions between the government and private sectors.

Findings

The results reveal that the five most important performance objectives for PPP implementation in Malaysia based on overall respondents’ perceptions are “High-quality public service”, “Provide convenient service for society”, “Within or under budget”, “On-time or earlier” and “Satisfy the need for more public facilities”. As for differences in the perceptions of the two key players, only one objective was perceived as statistically more important by the public sector respondents than by their private sector counterparts.

Originality/value

The contribution of this paper is that it not only provides empirical evidence for the performance objectives for PPP implementation in Malaysia, but also offers evidence concerning the differences in the perceptions of the public and private sectors pertaining to the performance objectives.
Forgetting corruption: unlearning the knowledge of corruption in the Indonesian public sector
Authors: Prabowo Hendi Yogi , Sriyana Jaka , Syamsudin Muhammad
Published: November 2017

Purpose

Based on the authors’ study, the main purpose of this paper is to ascertain a systematic long-term solution for the corruption problem in the Indonesian public sector from the knowledge management perspective. To achieve its objectives, this paper applies multiple perspectives and theories of corruption and knowledge management on the corruption problem in Indonesia.

Design/methodology/approach

This paper is based on the authors’ study to assess the corruption problem in the Indonesian public sector in the past decade through the examination of reports from various institutions and other relevant documents to highlight various behavioral issues in knowledge management in the Indonesian public sector and how they relate to corruption.

Findings

The authors establish that a major factor behind corruption’s ability to regenerate over time in the Indonesian public sector is the fact that it has become part of knowledge conversion in Indonesian public institutions for so long that removing it would be a very challenging task. To remove corruption from Indonesian public institutions is to remove it from the existing knowledge conversion spiral within these institutions by means of organizational unlearning and re-learning. The primary focus of the unlearning and re-learning process should be to eliminate the knowledge of corruption, in both tacit and explicit forms, and replace it with the knowledge of good governance, accountability and integrity. Through systematic organizational unlearning and re-learning along with other more repressive measures, the risk of corruption in public institutions in Indonesia will gradually diminish over time.

Research limitations/implications

This study is relying on documentary analysis to highlight the trend in behavioral problems in relation to knowledge conversion in the Indonesian public sector. Future studies should incorporate interviews with corruption offenders and local leaders to gain a more accurate view of how knowledge conversion plays its role in the growth and regeneration of corruption in the Indonesian public sector.

Practical implications

This paper contributes to the development of corruption eradication strategy by proposing a framework for systematically removing corruption knowledge from an organization. With this, framework resources can be allocated more effectively and efficiently to achieve the objectives of corruption prevention.

Originality/value

This paper highlights the importance of behavior-oriented approaches in mitigating corruption in the Indonesian public sector.
Reflections on Rwanda’s approaches to crime related asset recovery
Authors: Dusabe Francis
Published: November 2017

Purpose

In this paper, the author intends to showcase the effectiveness of the Rwandan legal regime governing criminal asset recovery. This paper aims to advocate for a need to enforce laws, which seems to be dormant, and to ensure fairness of action when confiscating or seizing assets that initially belongs to bonafide third parties.

Design/methodology/approach

The author assesses the effectiveness of law No. 42/2014 of 27/01/2015 governing the recovery of offence-related assets in Rwanda and compares it with established international standards provided in major conventions to which Rwanda is a party. Primary and secondary sources of legal research have been used. Primary sources include international conventions, domestic laws and case laws. Secondary sources include books, chapters, journal articles and policy papers.

Findings

In this paper, the author submits that the law on crime-related asset recovery suffers from strategic deficiencies and gaps and posits that the process of asset recovery should be streamlined and balanced to meet the aims of crime prevention.

Originality/value

This research paper is a first of its kind. Through positive criticism, it showcases that Rwanda is doing well through the establishment of relevant laws to combat crime. However, it proposes solutions to identify gaps. This paper is original and has never been published anywhere else, and all sources used have duly been recognized.
Strengthening the effectiveness of whistleblowing system
Authors: Nurhidayat Ilham , Kusumasari Bevaola
Published: November 2017

Purpose

The purpose of this paper is to identify and map out various aspects and key elements, which are necessary to strengthen an effective and systematic whistleblowing system (WBS) and ensure adequate protection in accordance with the characteristics typical of Indonesia.

Design/methodology/approach

This research emphasizes the extensive use of literature review and previous research that analyze whistleblowing as an issue and ethical challenge in public institutions. This research also reviews documents pertaining to the formulation and implementation of existing WBS. Additionally, this research also analyzes some cases experienced by a number of whistleblower figures in Indonesia as a contribution and recommendation to parties interested in formulating a more effective and systematic WBS.

Findings

An effective and systematic WBS, assuring adequate protection, needs a number of key elements which will be identified and mapped out in this research and, subsequently, categorized into several aspects covering human and ethical culture; policy; legal protection; organizational structure; and procedures and process in accordance to Indonesia’s specific characteristics.

Practical implications

The paper can be a source to explore anti-corruption policy and the prevention approach of corruption based on Indonesian perspectives.

Originality/value

This paper is a significant undertaking aimed at raising public trust in public institutions and providing adequate protection to whistleblowers. It also contributes by encouraging the public organization to prevent corruption and other wrongdoing, which, nowadays, are common in Indonesia.
Single‐ and double‐loop organizational learning through a series of pipeline emergency exercises
Authors: Metallinou Maria Monika
Published: November 2017

Onshore pipelines represent a risk to society due to potential leaks. Training and exercising emergency response systems are therefore part of the legislation in affected countries. In the present work, a series of three biannual exercises, simulating leaks from Norwegian onshore hydrocarbon pipelines, is assessed. Single‐ and double‐loop learning theory is used to analyse the learning processes. Seven single‐loop and two double‐loop learning processes are documented. Among others, public notification and establishment of evacuation centres were greatly improved. A conceptual change in risk assessment, followed by development of artefacts and improved communication lines, also occurred. It is demonstrated that a series of full‐scale exercises, with successive learning steps, is a sound way to improve the performance of emergency response systems.
Effects of Hydrolyzed Rapeseed Cake Extract on the Quality Characteristics of Mayonnaise Dressing
Authors: Kim Ye‐Seul , Lee Jeung‐Hee
Published: November 2017

Combined fractions (H2O and 30% and 50% ethanol) of crude rapeseed cake extracts with 80% ethanol were hydrolyzed with NaOH solution. The hydrolyzed extract showed significantly higher contents of total phenolics (41.8 mg SAE/g) and sinapic acid (425.8 mg/g), as well as higher 1,1‐diphenyl‐2‐picryl‐hydrazyl radical‐scavenging capacity (91.98 RSC%) than the crude extract (P < 0.05). Antimicrobial activity of the hydrolyzed extract was remarkably higher than that of the crude extract against selected Gram‐positive and Gram‐negative bacteria as well as yeast, as determined by the minimum inhibitory concentration method. Hydrolyzed extract (100, 250, or 500 ppm) was added to mayonnaise dressing, and several quality characteristics of the dressing were investigated by assessments of microbial, physical, and oxidative stabilities during 8 wk of storage. Microbial stability was higher in the dressing with hydrolyzed extract added (4.3 to 4.6 Log CFU/g) than the control (4.9 Log CFU/g). Physical characteristics of the dressing with hydrolyzed extract added were better than those of the control, based on increased viscosity and reduced emulsion separation. Hydrolyzed extract increased oxidative stability in a concentration‐dependent manner, and the dressing with added 500 ppm of hydrolyzed extract resulted in a lower free fatty acid content (4.8% at week 8), peroxide value (13.5 meq/kg at week 6), and 2‐thiobarbituric acid‐reactive substances value (66.2 μg/100 g at week 8) than the control. Therefore, it is expected that hydrolyzed rapeseed cake extract containing high sinapic acid content can be used in emulsion system as a value‐added ingredient.

Practical Application

Crude extract of rapeseed cake was fractionated and alkaline‐hydrolyzed to convert sinapine into sinapic acid, and the produced hydrolyzed extract showed higher antimicrobial and antioxidative activities than the crude extract. When the hydrolyzed extract was added to mayonnaise dressing, microbial stability increased along with physical characteristics and oxidative stability, thereby supporting the potential of hydrolyzed rapeseed extract as a food additive for quality management of mayonnaise dressing during storage.
Non‐declining amphibians can be important reservoir hosts for amphibian chytrid fungus
Authors: Brannelly L. A. , Webb R. J. , Hunter D. A. , Clemann N. , Howard K. , Skerratt L. F. , Berger L. , Scheele B. C.
Published: November 2017

Amphibian chytridiomycosis, caused by infection with Batrachochytrium dendrobatidis (Bd), is the most devastating vertebrate disease on record. Reservoir hosts are likely to be important in the Bd‐amphibian system because many amphibian species can carry infections without experiencing mortality. However, while a variety of reservoirs have been proposed, few have been empirically demonstrated to act as competent reservoir hosts. In this study, we investigate whether the common eastern froglet, Crinia signifera, a non‐declining species that is widespread in eastern Australia, is a reservoir host for Bd infection. We conducted a long‐term, large‐scale field survey to investigate disease dynamics in C. signifera at sites where four sympatric, threatened anuran species have severely declined. We also monitored Bd‐infected C. signifera in the laboratory to determine susceptibility and survivorship. Finally, we assessed population age structure to investigate disease impact in the wild. We found that C. signifera is a competent reservoir host, maintaining high prevalence and infection intensities in the wild and in the laboratory, with no signs of sub‐lethal effects or clinical disease. In the wild, the modal age is 4 years with individuals living up to 6 years, indicating that adults can survive across multiple years despite high infection prevalence and intensity. The occurrence of C. signifera at sites with remnant populations of threatened species likely contributes to ongoing disease impact in declining species decades after the arrival of Bd. The presence of C. signifera at sites where threatened species have become extinct inhibits effective reintroductions, and we recommend avoiding sites with high reservoir host abundance when planning reintroductions.
The modulatory role of cytokines IL‐4 and IL‐17 in the functional activity of phagocytes in diabetic pregnant women
Authors: Fagundes Danny L. G. , França Eduardo L. , Gonzatti Michelangelo B. , Rugde Marilza V. C. , Calderon Iracema M. P. , Honorio‐França Adenilda C.
Published: November 2017

The study investigated the role of cytokines IL‐4 and IL‐17 in the modulation of the functional activity of mononuclear phagocytes in diabetic pregnant women with hyperglycemia. Sixty pregnant women were assigned to the following groups: nondiabetic (ND), mild gestational hyperglycemia (MGH), gestational diabetes mellitus (GDM), or type 2 diabetes mellitus (DM2). The functional activity of phagocytes from maternal blood, cord blood, and colostrum was assessed by determining their superoxide release, phagocytosis, microbicidal activity, and intracellular Ca2+ release. Irrespective of glycemic status, colostrum and blood cells treated with IL‐4 and IL‐17 increased superoxide release in the presence of enteropathogenic Escherichia coli (EPEC). The highest phagocytosis rate was observed in cells from the DM2 group treated with IL‐4. In all the groups, phagocytes from colostrum, maternal blood, and cord blood exhibited higher microbicidal activity against EPEC when treated with cytokines. IL‐17 increased intracellular Ca2+ release by colostrum phagocytes in diabetic groups. The results indicate that the IL‐4 and IL‐17 modulate the functional activity of phagocytes in the maternal blood, cord blood, and colostrum of diabetic mother. The natural immunity resulting from the interaction between the cells and cytokines tested may be an alternative procedure to improve the prognosis of maternal and newborn infections.
Association of Helicobacter pylori infection with Toll‐like receptor‐4 Thr399Ile polymorphism increased the risk of peptic ulcer development in North of Iran
Authors: Tourani Mehdi , Habibzadeh Maryam , Shokri‐Shirvani Javad , Teymournejad Omid , Mostafazadeh Amrollah , Khafri Soraya , Nouri Hamid Reza
Published: November 2017

Toll‐like receptor‐4 (TLR4) polymorphisms may influence host immune response against Helicobacter pylori (H. pylori). This study aimed to investigate whether TLR4 polymorphisms are associated with H. pylori susceptibility and risk of peptic ulcer development or not. The TLR4 + 3725 G/C polymorphism was studied using polymerase chain reaction with confronting two‐pair primers (PCR–CTPP). In addition, TLR4 Asp299Gly and Thr399Ile polymorphisms were evaluated by PCR‐restriction fragment length polymorphism (RFLP). There was no significant difference in TLR4 + 3725 G/C and Asp299Gly genotype frequencies between non‐peptic ulcer (NPUD) and peptic ulcer (PUD) individuals in the context of peptic ulcer development and susceptibility to infection with H. pylori. Nevertheless, a significant association with increased risk for PUD development was observed for polymorphism TLR4 Thr399Ile [odds ratio (OR) = 4.2; 95% confidence interval (CI) = 1.35–13.26; p = 0.01]. Correspondingly, TLR4 Thr399Ile polymorphism was associated with H. pylori susceptibility (OR = 0.27; 95% CI = 0.08–0.88; p = 0.04). In addition, TLR4 Thr399Ile polymorphism increased 4.2‐fold, the risk of peptic ulcer development in individuals infected by H. pylori carrying CT + TT genotype. Our results showed that TLR4 Thr399Ile polymorphism along with H. pylori infection may play critical roles in peptic ulcer development in North of Iran.
Unique contribution of Ecuadorian kindergartners’ spontaneous focusing on numerosity to their early numerical abilities
Authors: Torbeyns Joke , Bojorque Gina , Van Hoof Jo , Van Nijlen Daniël , Verschaffel Lieven
Published: November 2017

Recent evidence indicates that young children's spontaneous focusing on numerosity (SFON) uniquely contributes to their early numerical abilities. This study complements previous findings by validating the relation between young children's SFON and their early numerical abilities in a developing country, namely Ecuador. We analysed 355 Ecuadorian 5‐ to 6‐year‐olds’ SFON in relation to their early numerical abilities at the start of kindergarten, controlling for children's socio‐demographic (socio‐economic status, age) and general cognitive (working memory, intelligence) characteristics. Our results evidence the unique contribution of Ecuadorian kindergartners’ SFON to their early numerical abilities, controlling for children's working memory, intelligence, socio‐economic status, and age. Our findings support the validity of previous findings on the unique contribution of SFON to young children's early numerical abilities in developed countries for developing countries. Additionally, they raise timely questions for further theoretical and methodological studies on young children's numerical development worldwide, in developing and developed countries.

Statement of contribution

What is already known?

SFON uniquely contributes to early numerical abilities.

However, this is only documented in Finnish samples.

Previously only limited control for domain‐general cognitive and socio‐demographic characteristics.

What does the study add?

SFON uniquely contributes to early numerical abilities in Ecuadorian 5‐ to 6‐year‐olds.

This unique contribution remains after controlling for WM, IQ, SES, and age.

Evidence for the universal nature of the association between SFON and early numerical ability.
Homozygous XYLT2 variants as a cause of spondyloocular syndrome
Authors: Umair M. , Eckstein G. , Rudolph G. , Strom T. , Graf E. , Hendig D. , Hoover J. , Alanay J. , Meitinger T. , Schmidt H. , Ahmad W.
Published: November 2017

Spondyloocular syndrome (SOS) is a rare autosomal recessive, skeletal disorder. Two recent studies have shown that it is the result of biallelic sequence variants in the XYLT2 gene with pleiotropic effects in multiple organs, including retina, heart muscle, inner ear, cartilage, and bone. The XYLT2 gene encodes xylosyltransferase 2, which catalyzes the transfer of xylose (monosaccharide) to the core protein of proteoglycans (PGs) leading to initiating the process of PG assembly. SOS was originally characterized in 2 families A and B of Iraqi and Turkish origin, respectively. Using DNA from affected members of the same 2 families, we performed whole exome sequencing, which revealed 2 novel homozygous missense variants (c.1159C > T, p.Arg387Trp) and (c.2548G > C, p.Asp850His). Our findings extend the body of evidence that SOS is caused by homozygous variants in the XYLT2 gene. In addition, this report has extended the phenotypic description of SOS by adding follow‐up data from 5 affected individuals in one of the two families, presented here.
The use of detailed statistical data in customs reforms: The case of Madagascar
Authors: Chalendard Cyril , Raballand Gaël , Rakotoarisoa Antsa
Published: November 2017

To carry out their various missions—collecting revenue, facilitating trade and ensuring security— many customs administrations have established a risk management unit. In developing countries, however, because of the lack of dedicated human and material resources, intelligence and risk analysis remain insufficiently developed. In view of the lack of resources, this article proposes a simple methodology aiming at detecting risky import operations. The mirror analysis first helps to identify and target products or sectors with the greatest risk. Based on the examination of customs declarations patterns (data mining), it is then possible to identify and target higher risk economic operators (importers and customs brokers). When implemented in Madagascar, this method has helped to reveal probable fraud cases in the context of current customs reforms.
Phillips Lecture – Why Some Times Are Different: Macroeconomic Policy and the Aftermath of Financial Crises
Authors: Romer Christina D. , Romer David H.
Published: November 2017

Analysis based on a new measure of financial distress for 24 advanced economies in the postwar period shows substantial variation in the aftermath of financial crises. This paper examines the role that macroeconomic policy plays in explaining this variation. We find that the degree of monetary and fiscal policy space prior to financial distress—that is, whether the policy interest rate is above the zero lower bound and whether the debt‐to‐GDP ratio is relatively low—greatly affects the aftermath of crises. The decline in output following a crisis is less than 1% when a country possesses both types of policy space, but almost 10% when it has neither. The difference is highly statistically significant and robust to the measures of policy space and the sample. We also consider the mechanisms by which policy space matters. We find that monetary and fiscal policy are used more aggressively when policy space is ample. Financial distress itself is also less persistent when there is policy space. The findings may have implications for policy during both normal times and periods of acute financial distress.
Genomewide association study identifies GALC as susceptibility gene for mucous membrane pemphigoid
Authors: Sadik Christian D. , Bischof Julia , van Beek Nina , Dieterich Anabelle , Benoit Sandrine , Sárdy Miklós , Worm Margitta , Meller Stephan , Gläser Regine , Zillikens Detlef , Homey Bernhard , Setterfield Jane , Minassian Darwin , Schmidt Enno , Dart John ,   the MMP study group 2009 – 2014,   the Autoimmune Bullous Diseases Study Group, Ibrahim Saleh M.
Published: November 2017

Mucous membrane pemphigoid (MMP) is a rare, chronic and often aggressive subepidermal autoimmune blistering disease potentially affecting several mucous membranes with blisters and secondary erosions and scars. The pathogenesis of MMP is poorly understood, and the contribution of genetic predispositions, other than HLA class II allele variants to MMP, is unknown. The objective of this study is to identify susceptibility genes for MMP in a British cohort of MMP patients. A GWAS was conducted in a British cohort of 106 MMP patients. Publicly available genotypes of 2900 blood donors of the UK Blood Service and of 6740 individuals of the 1958 British Birth Cohort served as control. Subsequently, putative susceptibility genes were independently replicated in a German cohort of 42 MMP patients. The GWAS found 38 SNPs in 28 haploblocks with an odds ratio >2 reaching genomewide significance (P < 5.7 × 10−7). Replication confirmed an association of MMP with SNPs in rs17203398 (OR: 3.9), located intronically in the β‐galactocerebrosidase gene (GALC) on chromosome 14 and with recessive polymorphisms in rs9936045 (OR: 3.1) in the intergenic region between CASC16 and CHD9 on chromosome 16. The risk of developing MMP is partially genetically determined. SNPs in GALC enhance the risk for MMP, indicating that β‐galactocerebrosidase may be involved in the pathogenesis of MMP. Likewise, impacts of polymorphisms in the intergenic region between CASC16 and CHD9 on the activity of neighbouring genes may facilitate the emergence of MMP. The putative role of both polymorphisms requires functional studies in the future.
A decrease in the abundance and strategic sophistication of cleaner fish after environmental perturbations
Authors: Triki Zegni , Wismer Sharon , Levorato Elena , Bshary Redouan
Published: November 2017

Coral reef ecosystems are declining worldwide and under foreseeable threat due to climate change, resulting in significant changes in reef communities. It is unknown, however, how such community changes impact interspecific interactions. Recent extreme weather events affecting the Great Barrier Reef, that is, consecutive cyclones and the 2016 El Niño event, allowed us to explore potential consequences in the mutualistic interactions involving cleaner fishLabroides dimidiatus(hereafter “cleaner”). After the perturbations, cleaner densities were reduced by 80%, disproportionally compared to the variety of reef fish clients from which cleaners remove ectoparasites. Consequently, shifts in supply and demand yielded an increase in the clients’ demand for cleaning. Therefore, clients became less selective toward cleaners, whereas cleaners were able to choose from a multitude of partners. In parallel, we found a significant decline in the ability of cleaners to manage their reputation and to learn to prioritize ephemeral food sources to maximize food intake in laboratory experiments. In other words, cleaners failed to display the previously documented strategic sophistication that made this species a prime example for fish intelligence. In conclusion, low population densities may cause various effects on individual behavior, and as a consequence, interspecific interactions. At the same time, our data suggest that a recovery of population densities would cause a recovery of previously described interaction patterns and cleaner strategic sophistication within the lifetime of individuals.
Selection for life‐history traits to maximize population growth in an invasive marine species
Authors: Jaspers Cornelia , Marty Lise , Kiørboe Thomas
Published: November 2017

Species establishing outside their natural range, negatively impacting local ecosystems, are of increasing global concern. They often display life‐history features characteristic for r‐selected populations with fast growth and high reproduction rates to achieve positive population growth rates (r) in invaded habitats. Here, we demonstrate substantially earlier maturation at a 2 orders of magnitude lower body mass at first reproduction in invasive compared to native populations of the comb jelly Mnemiopsis leidyi. Empirical results are corroborated by a theoretical model for competing life‐history traits that predicts maturation at the smallest possible size to optimize r, while individual lifetime reproductive success (R0), optimized in native populations, is near constant over a large range of intermediate maturation sizes. We suggest that high variability in reproductive tactics in native populations is an underappreciated determinant of invasiveness, acting as substrate upon which selection can act during the invasion process.