Control methods for Dermanyssus gallinae in systems for laying hens: results of an international seminar

This paper reports the results of a seminar on poultry red mite (PRM), Dermanyssus gallinae. Eighteen researchers from eight European countries discussed life cycle issues of the mite, effects of mites on hens and egg production, and monitoring and control methods for PRM in poultry facilities. It was determined that PRM probably causes more damage than envisaged, with the cost in The Netherlands alone reaching 11 million euro per annum. However a great deal is still unknown about PRM (e.g. reproduction, survival methods, etc.) and that PRM monitoring is an important instrument in recognising and admitting the problem and in taking timely measures. Currently, the most promising control method combines heating the hen house in combination with chemical treatments. Future areas of development which show promise include the use of entomopathogenic fungi, vaccination and predatory mites. The final aim is to solve the problem of D. gallinae in housing systems for laying hens

Challenges in stakeholders self-organising to enhance disaster communication

Purpose - This paper combines disaster risk reduction (DRR) and communication management literature to investigate the challenges and opportunities encountered when stakeholders spontaneously self-organise communication efforts during a disaster. The 2017 Knysna Fire Disaster in South Africa is used as context. Research methodology - The qualitative, exploratory research was supported by data obtained through thematic analysis of qualitative in-depth interviews and the Facebook page created by the community. Information from the disaster debrief was also included. Findings - The findings suggest that disaster information needs to be sent every 30 seconds to a minute to coordinate rescue and relief efforts. The challenges for disaster management teams to manage this mammoth task and the role that the self-organising community played in assisting the communication process was found not to be recognised in disaster management policies or systems. This adversely affected the work of the disaster management team and stakeholder relationship. Research limitations - This study focussed on one disaster. Future studies could possibly compare various disaster examples to provide even greater insight into the self-organising communicative behaviour of those affected by disasters. Originality/value - The research gives one of the first clear indications of the scope of disaster communication needed during a disaster. It also highlights the community’s ability to contribute to communication management during a disaster, and which is not catered for in the practice, guidelines, or management systems used for disaster management

PERCEIVED EFFECTIVENESS OF THE LEADERSHIP STYLES OF DEANS IN ETHIOPIAN GOVERNMENTAL TECHNICAL AND VOCATIONAL EDUCATION AND TRAINING (TVET) COLLEGES

The Industrial Development Strategy of 2003 has shown that considerable human resource deficits in Ethiopia are the major reason for the low rate of industrial development. This strategy confirms in its statement: “...education and a training system that is capable of producing the manpower that is both professionally and ethically capable of carrying and sustaining the responsibility of seeing to it that our industrial development program will have achieved its goals” (MOFED, 2003). Therefore, it called for efforts towards quality improvement of the workforce, to reverse the marginalisation of the industrial professions in the TVET system, and to build a culture of entrepreneurship and self-employment (MOFED, 2010). In 2009, the Southern Nations, Nationalities People’s Region (SNNPR) Centre of Competence (COC) conducted standard exams for those who graduated from TVETs. The results were disappointing, as only 12.2% of the TVET graduates and 34.9% of the TVET instructors passed the examinations (SNNPR TVET, 2010). Hence, to solve this chronic problem, high calibre deans should be appointed. In line with this idea, in the year 2003, the World Bank designed a training project to produce and assign skilled leaders in higher education in Ethiopia (World Bank, 2003). Although it failed, it was also the plan of the Ethiopian government that the percentage of TVET leaders trained in leadership would reach 100% in the year 2014 (MOFED, 2010). The TVET sector has particular significance for the reduction of poverty and for the promotion of gender equity because it stresses certain dimensions such as opportunities, skills, human resources development and empowerment. However, in Ethiopia, the Ministry of Finance and Economic Development (MOFED) has introduced an emphasis on developing TVET skills only since the turn of the 21st century. As a result, the MOE has required TVET practitioners not only to link up their knowledge and skills with the past in order to understand the present situation, but also to prompt them to look beyond the present to cope with this dynamic world (MOFED, 2006). The present study assumes importance in finding out perceived effectiveness of the leadership styles of deans in Ethiopian governmental technical and vocational education and training (TVET) colleges.  Article visualizations

Assessment of factors that impact on the viability of contract farming: A case study of maize and soya beans in Mashonaland West and central provinces in Zimbabwe

This research analyses factors that affect the viability of contract farming in the Zimbabwean maize and soya sector. The objective was to analyse how sustainability factors (social, ethical, environmental and economic factors) were integrated to ensure the viability and sustainability of contract ventures. A sample of 70 farmers and 4 contracting firms involved in the contract farming production of maize and soya were used. A questionnaire survey and focus group interviews were used as data gathering tools. Quantitative and qualitative data analysis techniques were used and a probit regression model was applied to identify the factors that impacts significantly on the viability of the enterprises. The farmer’s scale, years of experience, availability of inputs, crop grown, production area and access to finances were all identified as the significant factors affecting contract farming viability. It was recommended that farmers refrain from side marketing and contractors stick to contractual agreements in terms of payments and timely provision of inputs.Keywords: contract farming; viability; sustainabilit

Control methods for Dermanyssus gallinae in systems for laying hens: results of an international seminar

This paper reports the results of a seminar on poultry red mite (PRM), Dermanyssus gallinae. Eighteen researchers from eight European countries discussed life cycle issues of the mite, effects of mites on hens and egg production, and monitoring and control methods for PRM in poultry facilities. It was determined that PRM probably causes more damage than envisaged, with the cost in The Netherlands alone reaching 11 million euro per annum. However a great deal is still unknown about PRM (e.g. reproduction, survival methods, etc.) and that PRM monitoring is an important instrument in recognising and admitting the problem and in taking timely measures. Currently, the most promising control method combines heating the hen house in combination with chemical treatments. Future areas of development which show promise include the use of entomopathogenic fungi, vaccination and predatory mites. The final aim is to solve the problem of D. gallinae in housing systems for laying hen

Being well, being musical: Music composition as a resource and occupation for older people

Introduction: Participatory music making for older people has tended to focus on singing and performance. In a community music project undertaken by Manchester Camerata (a chamber orchestra), Blacon Community Trust and a small group of older adults, participants were given the opportunity to compose individual pieces of music interactively with professional musicians. This paper reports the findings of the research project. Method: An arts-based research method was adopted and incorporated action research and interpretive interactionism to articulate the experiences and perceptions of participants. Participants and Manchester Camerata musicians also worked together to represent the thematic findings of the research in a group composition. Findings: The findings demonstrate that individual and group music composition contributed to a sense of wellbeing through control over musical materials, opportunities for creativity and identity making, validation of life experience and social engagement with other participants and professional musicians. Conclusion; The results emphasised occupation as essential to health and wellbeing in the later stages of life. The findings also highlight the particularly innovative aspects of this research: (i) the use of music composition as a viable arts-in-health occupation for older people and (ii) the arts-based research method of group composition. (PsycINFO Database Record (c) 2016 APA, all rights reserved

Extending the BASE architecture for complex and reconfigurable cyber-physical systems using Holonic principles.

Thesis (MEng)--Stellenbosch University, 2021.ENGLISH ABSTRACT: ndustry 4.0 (I4.0) represents the newest technological revolution aimed at optimising industries using drivers such as Cyber-Physical Systems (CPSs), the Internet of Things (IoT) and many more. In the past two decades, the holonic paradigm has become a major driver of intelligent manufacturing systems, making it ideal to advance I4.0. The objective of this thesis is to extend an existing holonic reference architecture, the Biography-Attributes-Schedule-Execution (BASE) architecture, for complex and reconfigurable CPSs. In the context of this thesis, complex and reconfigurable systems are considered to be systems that are comprised of many diverse, autonomous and interacting entities, and of which the functionality, organization or size is expected to change over time. The thesis applies the principles of holonic systems to manage complexity and enhance reconfigurability of CPS applications. The BASE architecture is extended for two reasons: to enable it to integrate many diverse entities, and to enhance its reconfigurability. With regards to research on holonic systems, this thesis aims to address two important functions for systems implemented using holonic principles, namely cooperation and cyber-physical interfacing The most important extensions made to the architecture were to enable scalability, refine the cooperation between holons, and integrate cyber-physical interfacing services as Interface Holons. These extensions include platform management components (e.g. a service directory) and standardised plugins (e.g. cyber-physical interfacing plugins). The extended architecture was implemented on an educational sheep farm, because of the many heterogeneous resources (sheep, camps, sensors, humans, etc.) on the farm that need to be integrated into a BASE architecture implemented CPS. This case study implementation had to integrate data from different sensors, provide live analysis of observed data and, when required, notify the physical world of any problems in the CPS. At the end of the implementation, an evaluation was done using the requirements of a complex, reconfigurable CPS as evaluation criteria. This evaluation involved setting up quantitative and qualitative evaluation metrics for the evaluation criteria, doing the evaluations, and discussing what the results from the different evaluations indicate about the effectiveness and efficiency of the extensions made to the BASE architecture. The extensions made to the BASE architecture were found to improve robustness and resilience. The use of Erlang was found to play a very important role in the resulting reliability. The extensions also helped to fully address the original BASE architecture’s scalability shortcomings and to increase development productivity. Lastly, the extensions show the benefits of using service orientation to enable cooperation between holons and how extracting all cyber-physical interfacing of a system into dedicated Interface Holons reduces development time, improves reusability and enhances diagnosability of interfacing problems.AFRIKAANSE OPSOMMING: ndustrie 4.0 (I4.0) is die nuutste tegnologiese revolusie en dit is daarop gemik om industrieë te optimiseer deur middel van drywers soos Kuber-Fisiese Stelsels (KFSs), die Internet of Things (IoT) en vele meer. In die afgelope twee dekades het die holoniese paradigma ʼn belangrike drywer van intelligente vervaardigingstelsels geword, wat dit ideaal maak om I4.0 te bevorder. Die doel van hierdie tesis is om ‘n bestaande holoniese verwysings argitektuur, die Biography-Attributes-Schedule-Execution (BASE-) argitektuur, uit te brei vir komplekse, herkonfigureerbare KFSs. In die konteks van hierdie tesis, word komplekse en herkonfigureerbare stelsels gesien as stelsels wat bestaan uit menige diverse, outonome entiteite wat met mekaar interaksie het en waarvan die funksionaliteit, organisasie en grootte verwag is om te verander met verloop van tyd. Hierdie tesis pas die beginsels van holoniese stelsels toe om die kompleksiteit van KFSs te bestuur en om herkonfigureerbaarheid van KFSs te verbeter. Die BASE-argitektuur word uitgebrei om twee redes, naamlik om die integrasie van menige diverse entiteite te ondersteun en om die argitektuur se herkonfigureerbaarheid te verbeter. Die studie sal ‘n navorsingsbydrae lewer oor holoniese stelsels deur twee belangrike funksionaliteite van stelsels wat geïmplementeer is deur middel van holoniese stelsels aan te spreek – samewerking tussen holons en kuber-fisiese koppeling. Die belangrikste uitbreidings wat gemaak is aan die argitektuur was om skaleerbaarheid moontlik te maak, samewerking tussen holons te verfyn en om kuber-fisiese koppelingsdienste te integreer as holons. Hierdie uitbreidings sluit nuwe platformbestuurkomponente en gestandaardiseerde plugins in. Die uitgebreide argitektuur is geïmplementeer op ʼn opvoedkundige skaapplaas, omdat die skaapplaas baie heterogene hulpbronne (skape, kampe, sensors, mense, ens.) insluit wat in die BASE-argitektuur geïmplementeerde KFS geïntegreer kon word. v Hierdie gevallestudie-implementering moes data van verskillende sensors integreer, intydse analises doen van die waargeneemde data en wanneer nodig, ‘n entiteit in die fisiese wêreld inlig van enige probleme in die KFS. Aan die einde van die implementering is ʼn evaluering gedoen deur die vereistes van ʼn komplekse, herkonfigureerbare KFS as evalueringskriteria te gebruik. Die evaluering het bestaan uit die opstel van kwantitatiewe en kwalitatiewe evalueringsmaatreëls, die uitvoer van die evaluerings en ʼn bespreking van wat die evalueringsresultate aandui oor die effektiwiteit en doeltreffendheid van die uitbreidings wat aan die BASE- argitektuur gemaak is. Dit is bevind dat die uitbreidings wat gemaak is aan die BASE-argitektuur robuustheid en veerkragtigheid verbeter het. Die gebruik van Erlang het ʼn groot rol gespeel in die gevolglike betroubaarheid. Die uitbreidings aan die BASE- argitektuur het ook gehelp om die argitektuur volledig skaleerbaar te maak en om ontwikkelingsproduktiwiteit te verbeter. Laastens, bewys die uitbreidings die voordele van diensoriëntasie in die samewerking tussen holons en hoe die gebruik van Koppelings Holons (Interface Holons) ontwikkelingstyd verminder, die herbruikbaarheid van programbronkode verbeter en diagnoseerbaarheid van koppelingsprobleme versterk.Master

Brushless direct current motor efficiency characterization

Abstract: The use of a compact lightweight efficient propulsion system is one of the main technological requirements for a long endurance electric Unmanned Aerial Vehicle (UAV). Currently the most popular trend is to use a permanent magnet brushless direct current (BLDC) model motor. This type of motor is used because of its efficiency which can be greater than 90% when optimally driven. However the majority of manufacturers do not provide adequate performance response profiles throughout the specified motor applied voltage range. This paper presents a methodology to characterize the BLDC efficiency

Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR

New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100x larger than during its dormant state. The X-ray flux one month after reactivation was at least 800x larger than during quiescence, and has been decaying exponentially on a 111+/-19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation.Comment: Published in ApJ (2018 April 5); 13 pages, 4 figure