bluuebunny/crossref_metadata_2025 huggingface dataset:
Permanent magnet machine design trade-offs to achieve sensorless control at high load
Authors: Caner Murat , Gerada Chris , Asher Greg
Published: January 2015

Purpose

– The purpose of this paper is to introduce a new design optimization technique for a surface mounted permanent magnet (SMPM) machine to increase sensorless performance at high loadings by compromising with torque capability.

Design/methodology/approach

– An SMPM parametric machine model was created and analysed by finite element analysis (FEA) software by means of the Matlab environment. Eight geometric parameters of the machine were optimized using genetic algorithms (GAs). The outer volume of the machine, namely copper loss per volume, was kept constant. In order to prevent sensorless performance loss at high loading, an optimization process was realized using two loading stages: maximum torque with minimum ripple at nominal load and maximum self-sensing capability at twice load. In order to show the effectiveness of the proposed technique, the obtained results were compared with the classical one-stage optimization realized for each loading condition separately.

Findings

– With the proposed technique, fairly good performance results of the optimization were obtained when compared with the one-stage optimizations. Using the proposed technique, sensorless performance of the motor was highly increased by compromising torque capability for high loading. Additionally, this paper shows that the self-sensing properties of a SMPM machine should be considered at the design stage of the machine.

Originality/value

– In related literature, design optimization studies for the sensorless capability of SMPM motor are very few. By increasing optimization performance, new proposed technique provides to achieve good result at high load for sensorless performance compromising torque capability.
Machine design and control strategy for wide-speed-range PMSG systems
Authors: Shen Jianxin , Miao Dong-Min
Published: January 2015

Purpose

– The purpose of this paper is to focus on the machine design and control strategy of the permanent magnet synchronous generator (PMSG) system, especially utilized in variable speed applications, in order to stabilize the output voltage on the dc link over a wide speed range.

Design/methodology/approach

– Different ac/dc power converter topologies are comparatively studied, each with an accordingly designed PMSG, so as to investigate the influence of the armature winding inductance as well as the relationship between the PMSG and power converter topologies.

Findings

– Pulse width modulation (PWM) rectifier is preferable for the said application due to its good performance and controllability. Moreover, by employing the PWM rectifier, relatively large inductance of the PMSG is considered for both short-circuit current reduction and field regulation.

Originality/value

– Field-regulating control is realized with a space vector PWM (SVPWM) rectifier, which can weaken the PMSG magnetic field during high-speed operation, while even properly enhance the field at low speed, ensuring a small change of the PMSG output voltage and a stable dc voltage.
Study of the temperature uniformity of aluminium billets heated by superconducting DC induction heaters
Authors: Wang Yawei , Gao Hao , Li Zhuyong , Ping Yang , Jin Zhijian , Hong Zhiyong
Published: January 2015

Purpose

– The purpose of this paper is to analyse and improve the temperature uniformity of aluminium billets heated by superconducting DC induction heaters.

Design/methodology/approach

– A 3D electromagnetic model coupled with a heat transfer model is developed to calculate the heating process of the billets which are rotated in uniform transverse DC magnetic field. A laboratory-scale DC induction heater prototype has been built to validate the model. The results from simulation and measurement have a good agreement. The model is used to investigate the factors affecting the temperature uniformity of aluminium billets.

Findings

– The results from simulation show that lower rotation speeds always mean better temperature uniformity along the radial direction, due to the increase in power penetration. However, the situation is very different for the temperature distribution along the axial direction. When the rotation speed is low, the temperature at the ends is lower than other parts. The situation reverses as the rotation speeds increase. This phenomenon is referred to as the “ending effect” in this paper.

Research limitations/implications

– Because of the ending effect, a lower rotation speed does not always result in better overall temperature uniformity, especially for billets of smaller sizes.

Practical implications

– There is an optimal rotation speed that yields the best overall temperature uniformity. Lower rotation speeds are not always preferred. The results and numerical model developed are very useful in the design of a superconducting DC induction heater.

Originality/value

– The temperature uniformity of aluminium billets heated by DC induction heaters is investigated and optimized.
Microcontroller-based inverter topology integrated in PV systems
Authors: Bouzguenda Mounir , Selmi Tarek , Gastli Adel , Masmoudi Ahmed
Published: January 2015

Purpose

– The purpose of this paper is to study the problem of the leakage currents in transformerless inverter topologies. It proposes a novel topology and how important the adopted control strategy on the power quality produced by the inverter.

Design/methodology/approach

– The paper presents an investigation of a novel transformerless inverter topology. It adopted a control strategy in which the DC source is disconnected from the inverter when the zero vectors of the control are applied. By using such control strategy, the electrical efficiency of the whole system was improved and the leakage current was significantly reduced.

Findings

– The paper provides a solution to minimize the leakage current in transformerless inverter topologies. Besides, the problem of zero-crossing distortions was totally eliminated.

Research limitations/implications

– Because of the high conversion ratio of the boost converter, the efficiency of the whole system needs to be enhanced.

Practical implications

– The paper includes the experimental results of the proposed topology which are in good match with the simulation results.

Originality/value

– This paper identifies a need to study the leakage current phenomena in transformerless inverter topologies.
Investigation of magnet segmentation techniques for eddy current losses reduction in permanent magnets electrical machines
Authors: Zoubida Belli , Mekideche Mohamed Rachid
Published: January 2015

Purpose

– Reducing eddy current losses in magnets of electrical machines can be obtained by means of several techniques. The magnet segmentation is the most popular one. It imposes the least restrictions on machine performances. This paper investigates the effectiveness of the magnet circumferential segmentation technique to reduce these undesirable losses. The full and partial magnet segmentation are both studied for a frequency range from few Hz to a dozen of kHz. To increase the efficiency of these techniques to reduce losses for any working frequency, an optimization strategy based on coupling of finite elements analysis and genetic algorithm is applied. The purpose of this paper is to define the parameters of the total and partial segmentation that can ensure the best reduction of eddy current losses.

Design/methodology/approach

– First, a model to analyze eddy current losses is presented. Second, the effectiveness of full and partial magnet circumferential segmentation to reduce eddy loss is studied for a range of frequencies from few Hz to a dozen of kHz. To achieve these purposes a 2-D finite element model is developed under MATLAB environment. In a third step of the work, an optimization process is applied to adjust the segmentation design parameters for best reduction of eddy current losses in case of surface mounted permanent magnets synchronous machine.

Findings

– In case of the skin effect operating, both full and partial magnet segmentations can lead to eddy current losses increases. Such deviations of magnet segmentation techniques can be avoided by an appropriate choice of their design parameters.

Originality/value

– Few works are dedicated to investigate partial magnet segmentation for eddy current losses reduction. This paper studied the effectiveness and behaviour of partial segmentation for different frequency ranges. To avoid eventual anomalies related to the skin effect an optimization process based on the association of the finite elements analysis to genetic algorithm method is adopted.
Unified model of temperature dependence of core losses in soft magnetic materials exposed to non-sinusoidal flux waveforms and DC bias condition
Authors: Ruszczyk Adam , Sokalski Krzysztof
Published: January 2015

Purpose

– The purpose of this paper is to present modelling of power losses dependences on temperature in soft magnetic materials exposed to non-sinusoidal flux waveforms and DC bias condition.

Design/methodology/approach

– Scaling theory allows the power loss density to be derived in the form of a general homogeneous function, which depends on the peak-to-peak of the magnetic inductance ΔB, frequency f, DC bias HDC and temperature T. The form of this function has been generated through the Maclaurin expansion with respect to scaled frequency, which suit very much for the Bertotti decomposition. The parameters of the model consist of expansion coefficients, scaling exponents, parameters of DC bias mapping, parameters of temperature factor and tuning exponents. Values of these model parameters were estimated on the basis of measured data of total power density losses.

Findings

– The main finding of the paper is a unified methodology for the derivation of a mathematical model which satisfactorily describes the total power density losses versus ΔB, f, HDC, and T in soft magnetic devices.

Research limitations/implications

– Still the derived method does not describe dependences of the power density loss on shape and size of considered sample.

Practical implications

– The most important achievement is of the practical use. The paper is useful for device designers.

Originality/value

– This paper presents the algorithm which enables us to calculate core losses while the temperature is changing. Moreover, this method is effective regardless of soft magnetic material type and the flux waveforms as well as the DC bias condition. The application of scaling theory in the description of energy losses in soft magnetic materials justifies that soft magnetic materials are scaling invariant systems.
Simple nonlinear MEC-based model for sensitivity analysis and genetic optimization of permanent-magnet
Authors: Mohammadi Sajjad , Vahidi Behrooz , Mirsalim Mojtaba , Lesani Hamid
Published: January 2015

Purpose

– The purpose of this paper is to develop an effective, yet simple analytical framework for optimization of permanent-magnet synchronous machines. Also, single/multi-objective optimizations are performed for a case-study machine with surface-mounted permanent magnets.

Design/methodology/approach

– First, an accurate magnetic equivalent circuit is developed which takes all the material such as iron saturation and PM parameters into account. Then, through a Fourier analysis, it is combined with the d-q model of PM synchronous machines to achieve an optimization framework including the developed torque, back-EMF and a number of design considerations. Finally, a genetic algorithm (GA) is employed in the single/multi-objective design optimizations, which offers several design characteristics upon different desired outcomes.

Findings

– An analytical design framework for the optimization of permanent-magnet synchronous machines is developed in this paper that can effectively account for all material properties such as iron saturation and PM characteristics, and take into account the design considerations, all of which are shown as superiorities of the proposed approach over the existing method. In addition, the proposed framework is relatively simpler in terms of implementing. The model is verified by employing finite element method. Moreover, sensitivity analysis is carried out to investigate the influence of the design parameters on the machine performance, which provides valuable information for the designer of such devices. Finally, a GA is utilized to perform single/multi-objective optimization schemes whose objectives are minimizing the torque ripples, back-EMF total harmonic distortion and PM volume.

Originality/value

– The proposed framework is new approach that could be employed in the design optimization of PM synchronous machines. Contrary to existing method, it is simpler and more effective in taking the material properties such as iron saturation and PM characteristics into account.
Exploring the creative climate in an open innovation arena
Authors: Yström Anna , Aspenberg Hedvig , Kumlin Annika
Published: January 2015

Purpose

– By increasing connectivity between multiple partners, the new paradigm of open innovation has been argued to stimulate creativity. However, there are still few empirical studies exploring what influence this new form of organizing for innovation has on the creative climate. The purpose of this paper is to start filling that knowledge gap by exploring the creative climate in an open innovation arena called SAFER, where 26 partner organizations meet to innovate together.

Design/methodology/approach

– The paper is based on a mixed method consisting of a quantitative creative climate questionnaire complemented by qualitative data gathering through interviews.

Findings

– The findings suggest that the networking and cross-functional meetings within the arena are beneficial to facilitate a creative climate, but there are challenges in handling uncertainties such as work identities, information sharing and knowledge transparency.

Practical implications

– The arena is found to be rather dependent on interaction with the outside environment, implying that a well-constructed arena from an organizational point of view is in itself not enough to ensure a creative climate. The project organization of the arena makes the general perception of SAFER fragmented, and it is questioned whether such an arena could or should strive for only one creative climate.

Originality/value

– The paper presents an interesting example of how introducing open innovation affects the creative climate, and discusses the difficulty of using established methods for assessing the creative climate in the new, emerging forms of organizing for innovation.
Breather-type kink wave of the (2+1)-dimensional BKP equation
Authors: Chen Wei , Chen Hanlin , Dai Zhengde
Published: January 2015

Purpose

– The purpose of this paper is to find solutions for the (2+1)-dimensional B-type Kadomtsev-Petviashvili equation and to research the quality of B-type Kadomtsev-Petviashvili equation.

Design/methodology/approach

– The authors apply the extended three-wave approach and the homoclinic test technique to solve the B-type Kadomtsev-Petviashvili equation.

Findings

– The authors obtain breather type of cross-kink solutions, doubly breather type of kink solitary solutions and the breather type of kink wave solutions for B-type Kadomtsev-Petviashvili equation.

Research limitations/implications

– As nonlinear evolution equations are characterized by rich dynamical behaviors, the authors have just found some of them and others are still to be found.

Originality/value

– These results may help us to investigate the local structure and the interaction of waves in high-dimensional models.
Solitons and other solutions of the long-short wave equation
Authors: Ebadi Ghodrat , Mojaver Aida , Kumar Sachin , Biswas Anjan
Published: January 2015

Purpose

– The purpose of this paper is to discuss the integrability studies to the long-short wave equation that is studied in the context of shallow water waves. There are several integration tools that are applied to obtain the soliton and other solutions to the equation. The integration techniques are traveling waves, exp-function method,G′/G-expansion method and several others.

Design/methodology/approach

– The design of the paper is structured with an introduction to the model. First the traveling wave hypothesis approach leads to the waves of permanent form. This eventually leads to the formulation of other approaches that conforms to the expected results.

Findings

– The findings are a spectrum of solutions that lead to the clearer understanding of the physical phenomena of long-short waves. There are several constraint conditions that fall out naturally from the solutions. These poses the restrictions for the existence of the soliton solutions.

Originality/value

– The results are new and are sharp with Lie symmetry analysis and other advanced integration techniques in place. These lead to the connection between these integration approaches.
Rhetoric or reality? A case study into how, if at all, practical work supports learning in the classroom
Authors: Martindill David , Wilson Elaine
Published: January 2015

Purpose

– The purpose of this paper is to study the use and value of practical work in the secondary school science classroom. Informed by the findings of a large survey of students from a wide variety of schools, a case study of pupils in the middle secondary range sought to investigate the precise role of practical work in the learning of a specific topic over a series of lessons.

Design/methodology/approach

– Qualitative and quantitative assessment of academic progress of two classes of pupils revealed that students who undertook practical tasks made greater gains in knowledge and understanding than those who undertook non-practical alternatives. In order to explore students’ views about the practical tasks and whether they found them to be an affective and effective aid for their learning, data were collected using questionnaires, lesson observations and interviews of focus groups.

Findings

– The data suggest three reasons why practical work supported pupils’ learning. First, practical work supported their visualisation of abstract concepts and provided a stimulus for the recall of key facts later. Second, it provided a distinctive opportunity for pupils to work collaboratively, with associated gains. Finally, hands-on tasks promoted a classroom atmosphere rich in variety, semi-autonomous learning and self-discovery, which pupils found intrinsically motivational.

Originality/value

– This study, which responds to the criticism practical work has received in recent years, sheds some light on the mechanisms through which the strategy supports learning in certain contexts. Moreover it argues that practical work needs to be effectively planned to maximise the learning gains made by pupils.
The prospects of lesson study in the US
Authors: Gero Greg
Published: January 2015

Purpose

– Lesson study has emerged as an approach to improving the quality of teaching in the USA. The purpose of this paper is to provide an investigation into teachers’ attitudes toward lesson study. Evidence suggests that lesson study may increase teachers’ content knowledge and their ability to anticipate student misconceptions during lessons. Nevertheless, certain issues have surfaced in the literature. Teachers may struggle with the demands of collaboration, critique of their lessons, and observation of their teaching. Moreover, lesson study may conflict with the existing mandate-monitor culture within many school districts. Understanding how teachers perceive lesson study is vital to gauging the effectiveness of the process.

Design/methodology/approach

– In all, 55 teachers at two elementary schools in urban Los Angeles participated in the researcher-designed survey. For the teachers in this study, participation in lesson study was mandatory, and most had participated in a version of lesson study that emphasized following the established curriculum and district-approved strategies. Data were analyzed using correlational analysis.

Findings

– Results yielded significant associations between teachers’ comfort levels with collaboration, lesson observation, lesson critique, and their support for lesson study. Higher degrees of control by the district over the lesson study process were linked to teachers feeling less responsible for student learning.

Practical implications

– The findings from this study have important implications for the prospects of lesson study as a model of teacher development in the USA.

Originality/value

– This paper fulfils a need to investigate factors that impede and promote the effective implementation of lesson study in the USA.
Cooperative research. A critical strategy in university teacher training. A case study of Lesson and Learning Studies
Authors: Soto Gómez Encarna , Serván Núñez Maria J , Pérez Gómez Angel I
Published: January 2015

Purpose

– The purpose of this paper is to present the possibilities offered by Lesson and Learning Studies (LLS) for training and for improving and generating knowledge by reconstructing the practical knowledge of teachers in university training through joint design, observation and reflection. In short, the research aims to show how merging LLS contributes to developing fundamental teaching skills in new, uncertain contexts and to recreating processes of research and analysis of complex situations from critical and creative perspectives by involving university teachers and student teachers in disciplined, informed reflection on their own practice through shared, narrative productions in a dual spiral which promotes the contrasting of experiences and perspectives in an ongoing manner.

Design/methodology/approach

– A case study of own practice in a university master’s degree, the aim of which is to develop a training improvement process by following the stages of LLS.

Findings

– The case study shows the need to reverse the theory-practice sequence and to increase the importance of experience, the relevance of tutoring in the role of teachers, and the significance of cooperation and contrast as learning strategies. The evidence presented shows that LLS can be an extremely useful resource and procedure to reconstruct practical knowledge, facilitating internal contrast between the different espoused theories of the members of the group of teachers, and also between their espoused theories and their practical knowledge, in other words their theories-in-use.

Originality/value

– The paper explores the value of LLS to reconstruct the practical knowledge of university teachers.
Application and limitation of axiomatic design complexity in quality engineering
Authors: Sharma Naresh K. , Cudney Elizabeth A.
Published: January 2015

Purpose

– Complexity is an important element in axiomatic design theory. The current method for calculating complexity for a system following normal distribution is unbounded and approximate. The purpose of this paper is to present a detailed bounded solution for complexity using design and system ranges on a single function requirement.

Design/methodology/approach

– This paper discusses the complexity measure for a system following a uniform distribution. The complexities of two types of systems, a system performing with a uniform distribution and a system performing on target according to a normal distribution are then considered and compared. The research proposes a complexity measure for a system performing within specification limits with a uniform distribution. In addition, a new concept of relative complexity is proposed.

Findings

– A bounded solution for complexity for a normal distribution based on the existing assumptions was given which includes bias in addition to variance. The bounded solution was then compared to the existing approximate solution from the variance as well as bias standpoint. It was found that bias has an inappropriately reverse relationship with the bounded solution of complexity. Therefore, complexity cannot be used to approximate the system improvement when the improvement is based on a reduction in bias.

Originality/value

– The current method for calculating complexity for a system following normal distribution is unbounded and approximate. This paper proposed a complexity measure for a system performing within specification limits with a uniform distribution.
Quality management in the global brewing industry
Authors: Vrellas Charisis G. , Tsiotras George
Published: January 2015

Purpose

– The purpose of this paper is to stimulate interest in the use of quality management methods and tools and to provide a basis and direction for further improvement in the global brewing industry.

Design/methodology/approach

– The methodology that is followed in the paper is based on the study of quality management tools and best practices in global brewing companies.

Findings

– From all evidence found by this research, the conclusion is that quality management can dramatically improve certain operations and reduce cost or increase profit as well. All of the global brewing companies examined in this paper have their quality policies and each one of them uses what fits best to its business profile.

Research limitations/implications

– This study refers to some of the largest brewing companies in the world. Future research could be addressed toward the analysis of other smaller brewing companies, which are characterized by the concepts of quality management.

Practical implications

– The analysis of quality management in the global brewing industry may cause the interest of other brewing companies and other stakeholders affected by this industry. Quality tools can be very useful for dealing with problems and improving procedures in a brewery. Furthermore, the extension of this work with detailed references to these tools could produce a quality guide for brewing companies.

Originality/value

– The value of this paper lies in the identification and presentation of tools and quality policies which have been successfully developed by global brewing companies and may as well be implemented by others.
Reliability based source maintenance scheduling using nature inspired algorithm
Authors: Abirami M. , Subramanian S. , Ganesan S. , Anandhakumar R.
Published: January 2015

Purpose

– The purpose of this paper is to solve the realistic problem of source maintenance scheduling (SMS) based on reliability criterion. A novel effective optimization technique is proposed to solve the problem at hand.

Design/methodology/approach

– The problem has been formulated as a combinatorial optimization task, with the goal of maximizing reliability by minimizing the sum of squares of the reserve loads while satisfying unit and system constraints. This paper employs a nature inspired algorithm known as Teaching Learning Based Optimization (TLBO) for solving the SMS problem based on reliability.

Findings

– The results reveal that optimal maintenance schedules of generating units has been obtained using TLBO algorithm with minimized values of sum of squares of reserve loads while satisfying system and operational constraints. It is also found that the inclusion of resource constraints (RC) in the model have significant effects on the objective function value which provides a deep insight of the proposed methodology.

Originality/value

– The contribution of this paper is that an efficient nature inspired algorithm has been applied to solve source maintenance scheduling problem in viewpoint of the planning for future system capacity expansion. The incorporation of exclusion and RC in the model makes the analysis about the impact of SMS on the system reliability more reasonable.
Open access awareness, use, and perception: a case study of AAU faculty members
Authors: Kaba Abdoulaye , Said Raed
Published: January 2015

Purpose

– The purpose of this paper is to report the findings of a survey undertaken at Al Ain University of Science and Technology (AAU) to investigate and understand faculty awareness, use and perception of Open Access (OA) resources.

Design/methodology/approach

– Using a Web-based survey questionnaire, data were collected from full-time faculty members teaching at AAU, United Arab Emirates (UAE).

Findings

– The study found that faculty members possess a good knowledge and a positive perception of OA resources. They frequently use OA resources for teaching, learning and research activities. However, the findings indicate that female faculty members are more likely to use OA resources than male faculty members. Faculty members with a high level of awareness or use are found to have a highly positive perception of OA resources. Presenting research reports at conferences and seminars or publishing research papers is weakly associated with the level of awareness and use of OA resources. The study revealed no association between the faculty member and their use of OA resources.

Research limitations/implications

– It is essential for scientific communities to understand the importance of OA resources and how to use them effectively in teaching, learning and research activities.

Originality/value

– This kind of research is new to the Gulf Cooperation Council countries in general and the UAE in particular. The findings of the study may help to improve the awareness and the use of OA resources among scientific communities not only in the Arab countries but also around the world.
Learning to work in asymmetric relationships: insights from the computer software industry
Authors: Pérez Lourdes , Cambra-Fierro Jesús
Published: January 2015

Purpose

– This paper aims to provide guidance for managers so that they may develop advanced supply chain management (SCM) capabilities in the context of asymmetric alliances. These alliances, generally characterised by large dissimilarities between the partners, often facilitate value-creating opportunities.

Design/methodology/approach

– Using case studies, the paper analyses similarities and differences in SCM between symmetric and asymmetric alliances within supply networks. It focusses on the key dimensions of complementarity, value distribution, relational management and specialisation.

Findings

– It was found that the question of complementarity, although important, should not be equated to the need for symmetry but to the ability of the firms in the supply network to learn to work together. For small firms who seek co-creation with large partners, this means collaboration, specialisation through relation-specific investments, flexibility and understanding the overall value system in which their business relationships compete is important.

Practical implications

– Small firms seeking to develop advanced SCM capabilities have to accept responsibility for selecting a reduced number of key partners and managing relationships. Firms should proactively use the contractual process to learn about partners' expectations and goals and to identify committed champions. These factors play an important role in developing communications and trust, as small firms do not have easy access to senior managers in large corporations.

Originality/value

– This paper discovered a novel concept – dual value appropriation – where partners do not divide the total value generated as frequently proposed in the literature, but that it is fully appropriated, as it represents a different value proposition for each of them.
Categories of incubator success: a case study of three New York incubator programmes
Authors: Al-Mubaraki Hanadi Mubarak , Muhammad Ali Husain , Busler Michael
Published: January 2015

Purpose

– The purpose of this paper is to investigate and identify three categories of incubators in the USA located in New York (NY). The incubator categories are: technology commercialisation; economic development; and entrepreneurship.

Design/methodology/approach

– The study uses a qualitative approach based on interviews concerning three incubator programmes selected for their successful outcomes.

Findings

– The research findings suggest four priorities for incubators: to be dynamic models of self-sustainable, efficient business development; to provide helpful tools for generating jobs; to foster and support enterprise and innovation to create the best environment for the start-up and smart growth of businesses; and to support value-added businesses through various means, such as developing the region’s science parks and R&D centres, improving collaboration between universities, and supporting business investment and growth.

Originality/value

– The research adds value to academicians and practitioners such as government, funded organisations, institutions and policy makers.
Sustainable soil management practices
Authors: Shrestha Shiva Kumar
Published: January 2015

Purpose

– Temporary and permanent decline in the productive capacity of the land due to natural and human-induced activities such as soil erosion, changing cropping practices and less use of organic matter (OM) has been the greatest challenge faced by mankind in recent years, particularly in the hills and mountains of Nepal. Hence, the purpose of this paper is to examine the effectiveness of sustainable soil management practices to mitigate desertification process in the hills of Nepal.

Design/methodology/approach

– Promotion of sustainable soil management (SSM) practices through a decentralised agriculture extension approach by involving all the stakeholders in a participatory way.

Findings

– SSM practices mainly: OM management, fodder and forage promotion, increased biomass production systems, integrated plant nutrition systems, and bioengineering for soil and water conservation are identified as the most appropriate and relevant technologies in mitigating the desertification process without deteriorating land quality, particularly conserving the top-soils effectively and efficiently in the hills and mountains of the country.

Research limitations/implications

– This research is focus on the overall effect of SSM practices due to time and budget constraints. There is scope for doing research on the different aspects of SSM practices and the extent of their effect on different soil parameters (chemical, biological and physical).

Practical implications

– SSM interventions clearly indicated that there is significant impact in increasing soil fertility, conserving fertile top-soils and mitigating physical, chemical and biologic desertification processes. These are possible through maintaining and improving the soil organic matter, which is the most important indicator for soil health. SSM practices have resulted in an increase of up to 30 per cent in crop yield compared to yields without SSM practices. This might be due to the improvement in SOC which improves soil texture, increases nutrient supply from organic source and conserves water quality, thus, improving soil quality.

Social implications

– This has created awareness among farmers. Hence, farmers are mitigating pH through increased use of organic manures, where there is less availability of agriculture lime and they are far from road access.

Originality/value

– SSM practices significantly contributes to combat soil desertification in the hills of Nepal.
Margarine and the origins and timing of microeconomic reform in Australia
Authors: Abbott Malcolm
Published: January 2015

The production of margarine in Australia was for a long time the subject of strict quotas designed to limit the output of the industry in order to protect the dairy industry. The industry was effectively deregulated by the Whitlam, Dunstan (South Australia) and Wran (New South Wales) governments in the years 1975 and 1976. This move was effectively the first measure designed to deregulate an industry in modern Australian economic history and aimed to promote competition in order to improve efficiency and community welfare. It also began the long process of eliminating government intervention in the Australian dairy industry, which was not to be completed until 2000.
Re/creating entrepreneurs of the self: discourses of worker and employee ‘value’ and current vocational rehabilitation practices
Authors: Fadyl Joanna , McPherson Kathryn , Nicholls David
Published: January 2015

Vocational rehabilitation for people experiencing work disability is a social practice often situated within health services, but the social and political drivers and effects of this practice are rarely critically analysed in health research or policy. In this study we used a Foucauldian theoretical perspective to analyse the ways in which current vocational rehabilitation practices in New Zealand re/produce notions of worker and employee ‘value’, and how different approaches to vocational rehabilitation deploy current discourses about value. We also consider the subject positions produced through these different approaches and the identities and actions they make possible for people experiencing work disability. The analysis showed that notions about the importance of worker and employee value in a job market are pervasive in vocational rehabilitation, and reflect wider societal discourses. However, the deployment of those discourses in different approaches to vocational rehabilitation practice are diverse, producing different opportunities and constraints for people experiencing disability. We argue that an examination of these various opportunities and constraints at the level of practice approaches is important, as considerable time and resources are allocated to developing solutions to help those who do not thrive in the current systems, yet we rarely critique the premises on which the systems are based.
Mast cell activation is involved in stress‐induced epithelial barrier dysfunction in the esophagus
Authors: Zhong Chan Juan , Wang Kun , Zhang Lu , Yang Chang Qing , Zhang Kuo , Zhou Shu Pei , Duan Li Ping
Published: January 2015

Objective

We aimed to investigate the role of mast cell in stress‐induced barrier dysfunction in the esophagus and its possible pathway involved using mast cell‐deficient (Ws/Ws) rats.

Methods

Ws/Ws rats and normal (+/+) rats were submitted to chronic restraint stress (CRS) 2 h/day for 7 days. Tissues were obtained from distal esophagus. Mast cells were counted under Alcian blue‐safranin O stain. Activation of mast cells was assessed using transmission electron microscope. Esophageal epithelial barrier dysfunction was evaluated by measuring intercellular spaces (ICS) and by quantifying tight junction (TJ) proteins. The localization and expression of mast cell‐derived tryptase and proteinase activated receptor 2 (PAR‐2) were assessed.

Results

A higher number of mast cells and higher proportion of activated mast cells were observed in CRS +/+ rats compared with non‐stress controls. Increased ICS and decreased expression of some TJ proteins were observed in the CRS +/+ rats but not in the CRS Ws/Ws rats. Tryptase and its receptor PAR‐2 were found elevated concomitantly by nearly 100% in CRS +/+ rats, but not in CRS Ws/Ws rats.

Conclusions

Mast cells play an important role in stress‐induced epithelial barrier dysfunction in esophagus. The mechanism may involve the activation of PAR‐2 by mast cell‐derived tryptase, causing proinflammatory responses and the subsequent disruption of the epithelial TJ proteins and a disturbed cytoskeleton function, resulting in dilated intercellular spaces.
Dipeptidyl peptidase‐4 inhibition improves cardiac function in experimental myocardial infarction: Role of stromal cell‐derived factor‐1α
Authors: Connelly Kim A. , Advani Andrew , Zhang Yanling , Advani Suzanne L. , Kabir Golam , Abadeh Armin , Desjardins Jean‐Francois , Mitchell Melissa , Thai Kerri , Gilbert Richard E.
Published: January 2015

Background

In addition to degrading glucagon‐like peptide‐1 (GLP‐1), dipeptidyl peptidase‐4 (DPP‐4) inactivates several chemokines, including stromal cell‐derived factor‐1α (SDF‐1α), a pro‐angiogenic and cardiomyocyte protective protein. We hypothesized that DPP‐4 inhibition may confer benefit following myocardial infarction (MI) in the diabetic setting as a consequence of enhanced SDF‐1α availability rather than potentiating GLP‐1. To test this we compared the effects of saxagliptin with those of liraglutide and used the SDF‐1α receptor (CXCR4) antagonist plerixafor.

Methods

Studies were conducted in streptozotocin‐diabetic rats. Rats were randomized to receive saxagliptin (10 mg/kg per day), liraglutide (0.2 mg/kg, s.c., b.i.d.), plerixafor (1 mg/kg per day, s.c.), saxagliptin plus plerixafor or vehicle (1% phosphate‐buffered saline). Two weeks later, rats underwent experimental MI, with cardiac function examined 4 weeks after MI.

Results

Glycemic control and MI size were similar in all groups. Four weeks after MI, mortality was reduced in saxagliptin‐treated rats compared with vehicle treatment (P < 0.05). Furthermore, rats receiving saxagliptin had improved cardiac function compared with vehicle‐treated rats (P < 0.05). Antagonism of CXCR4 prevented the improvement in cardiac function in saxagliptin‐treated rats and was associated with increased mortality (P < 0.05).

Conclusion

Saxagliptin‐mediated DPP‐4 inhibition, but not liraglutide‐mediated GLP‐1R agonism, improved cardiac function after MI independent of glucose lowering. These findings suggest that non‐GLP‐1 actions of DPP‐4 inhibition, such as SDF‐1α potentiation, mediate biological effects.
Role of Mig‐6 in hepatic glucose metabolism
Authors: Yoo Jung‐Yoon , Kim Tae Hoon , Kong Sieun , Lee Ju Hee , Choi Wonseok , Kim Koon Soon , Kim Hyun Jin , Jeong Jae‐Wook , Ku Bon Jeong
Published: January 2015

Background

Mitogen‐inducible gene 6 (Mig‐6) has an important role in the regulation of cholesterol homeostasis and bile acid synthesis. However, the physiological functions of Mig‐6 in the liver remain poorly understood.

Methods

To investigate Mig‐6 functioning in the liver, we used conditionally ablated Mig‐6 using the Albumin‐Cre mouse model (Albcre/+Mig‐6f/f; Mig‐6d/d). Male mice were killed after a 24‐h fast and refed after 24 h fasting. Fasting glucose and insulin levels were measured and western blot analyses were performed to determine epidermal growth factor receptor (EGFR), extracellular signal‐regulated kinase (ERK) 1/2, AKT, mammalian target of rapamycin (mTOR), c‐Jun N‐terminal kinase (JNK), and Insulin receptor substrate‐1 (IRS‐1) in liver tissue samples. In addition, human hepatocellular carcinoma HepG2 cells were transfected with Mig‐6 short interference (si) RNA before western blot analysis.

Results

Serum fasting glucose levels were significantly higher in Mig‐6d/d versus Mig‐6f/f mice. On an insulin tolerance test, insulin sensitivity was decreased in Mig‐6d/d versus Mig‐6f/f mice. Furthermore, hepatic expression of the glucokinase (Gck), glucose‐6‐phosphatase (G6pc), and phosphoenolpyruvate carboxykinase 1 (Pck1) genes was decreased significantly in Mig‐6d/d mice. Phosphorylation of EGFR, ERK1/2, AKT, mTOR, JNK, and IRS‐1 was increased in Mig‐6d/d compared with Mig‐6f/f mice.

Conclusion

Liver‐specific ablation of Mig‐6 caused hyperglycemia by hepatic insulin resistance. Increased EGFR signaling following Mig‐6 ablation activated JNK and eventually induced insulin resistance by increasing phosphorylation of IRS‐1 at serine 307. This is the first report of Mig‐6 involvement in hepatic insulin resistance and a new mechanism that explains hepatic insulin resistance.
Determinants of adherence to diabetes treatment
Authors: Larkin Amy T. , Hoffman Christina , Stevens Adrienne , Douglas Andrew , Bloomgarden Zachary
Published: January 2015

Background

Understanding and improving medication adherence is crucial in diabetes management. Adherence to a diabetes regimen can improve glucose control and limit the development of complications. The aim of the present study was to evaluate the extent to which a variety of factors influence diabetes medication adherence.

Methods

A medication adherence survey was made available on WebMD, a medical information website for patients and/or consumers. Respondents were residents of the US, ≥18 years old, and diagnosed with either type 1 or type 2 diabetes mellitus (self‐reported).

Results

Behavioral adherence (self‐reported doses missed per week) correlated with perceived adherence (patients' self‐report of their overall impression of medication adherence, ranked 0–5; P < 0.001). Adherent patients (very few [0%–10%] issues with adherence) were more likely to report having received information from their physician. Mostly adherent patients (few [11%–26%] issues with adherence) were less likely to obtain information from their physician, but reported more medication self‐titration. Somewhat non‐adherent patients (some [27%–46%] adherence issues) reported more “self‐consciousness factors” and hypoglycemia. Non‐adherent patients (many [47%–88%] adherence issues) were more likely to report worries about medication side effects.

Conclusions

Receiving information from a healthcare provider is associated with greater diabetes medication adherence, suggesting the importance of clinicians making time to provide patient education.
Microsnare‐assisted microcatheter navigation for flow diversion of a challenging giant intracerebral aneurysm: A novel technique
Authors: O'Grady Alan , Denton John , Laing Andrew
Published: January 2015

Giant cerebral aneurysms are associated with a poor prognosis, with 2‐year survival rates reported as low as 20% (Sundt et al.; Syman et al.). Morbidity is largely associated with haemorrhage, local compressive effects and thrombosis. While endovascular coiling has been acknowledged as a safe treatment in small to medium size aneurysms (Molyneux et al.; Pierot, Spelle & Vitry), the safety of this technique is more questionable in giant aneurysms due to the unknown stability of the coiling mesh and the need for retreatment. Parent vessel remodelling with the use of flow diverters is an evolving technique with promising results (Pierot et al.). However, navigation of microcatheters within the parent artery across giant aneurysms may be challenging due to tortuous anatomy. To improve microcatheter trackability and stability across a giant aneurysm neck, we describe a novel microsnare‐assisted support technique.
Resistant Hypertension and Renal Denervation Where to Now?
Authors: Shaw James A. , Warren Josephine L.
Published: January 2015

Treatment resistant hypertension (TRH) is a major clinical problem with limited treatment options. Renal denervation (RDN) arose as a safe and very effective treatment for TRH with early studies showing dramatic blood pressure reductions however subsequent studies have not shown such a benefit. This review discusses the pathophysiology of TRH and the results of the published studies in RDN for TRH. The initial symplicity (1 and 2) studies using the Ardian RDN catheter showed that office blood pressures were significantly reduced 6 months following the procedure. However these initial studies were limited by a lack of a true control group and inadequate blinding. Subsequent studies (symplicity 3 and simplicity flex) included patients with elevated blood pressures on 24 hr ambulatory blood pressure monitor as well as office measurements. Furthermore, both included a sham arm where patients were randomized to undergo renal angiography alone or RDN, patients were blinded to whether they were in the treatment or sham arm. These more recent studies showed that in both the control and treatment group while there was a significant BP reduction from baseline there was no difference between the groups. Thus RDN appears to have no benefit in blood pressure reduction in those with TRH. RDN currently should only be used in patients with TRH as part of a properly designed clinical study. Pre clinical data suggests that renal sympathetic overactivity is an issue in younger hypertensive patients and this may be the group in which future studies using RDN should focus.