Magnetoelastic Coupling and Possibility of Spintronic Electromagnetomechanical Effects

Nanoelectromangetomechanical systems (NEMMS) open up a new path for the development of high speed autonomous nanoresonators and signal generators that could be used as actuators, for information processing, as elements of quantum computers etc. Those NEMMS that include ferromagnetic layers could be controlled by the electric current due to effects related with spin transfer. In the present paper we discuss another situation when the current-controlled behaviour of nanorod that includes an antiferro- (instead of one of ferro-) magnetic layer. We argue that in this case ac spin-polarized current can also induce resonant coupled magneto-mechanical oscillations and produce an oscillating magnetization of antiferromagnetic (AFM) layer. These effects are caused by \emph{i}) spin-transfer torque exerted to AFM at the interface with nonmagnetic spacer and by \emph{ii}) the effective magnetic field produced by the spin-polarized free electrons due to $sd$-exchange.The described nanorod with an AFM layer can find an application in magnetometry and as a current-controlled high-frequency mechanical oscillator.Comment: 8 pages, 2 figures, submitted to Low Temp. Physic

High level of treatment failure with commonly used anthelmintics on Irish sheep farms

peer-reviewedBackground: In 2013 a Technology Adoption Program for sheep farmers was established to encourage the implementation of best management practices on sheep farms in Ireland. There were 4,500 participants in this programme in 2013. As part of this programme, farmers had the option to carry out a drench test to establish the efficacy of their anthelmintic treatment. Results: Flock faecal samples were collected before and after treatment administration and gastrointestinal nematode eggs enumerated. In total there were 1,893 participants in the task, however only 1,585 included both a pre- and post-treatment faecal sample. Of those, 1,308 provided information on the anthelmintic product that they used with 46%, 23% and 28% using a benzimidazole (BZ), levamisole (LEV) and macrocyclic lactone (ML) product respectively. The remaining farmers used a product inapplicable for inclusion in the task such as a flukicide or BZ/LEV combination product. Samples were included for analysis of drench efficacy if the pre-treatment flock egg count was ≥200 eggs per gram and the interval post-sampling was 10–14 days for BZ products, 4–7 days for LEV products and 14–18 days for ML products. These criteria reduced the number of valid tests to 369, 19.5% of all tests conducted. If the reduction post-treatment was ≥95% the treatment was considered effective. Only 51% of treatments were considered effective using this criterion. There was a significant difference in efficacy between the anthelmintic drug classes with BZ effective in only 30% of treatments, LEV effective in 52% of cases and ML effective in 76% of cases. Conclusions: Gastrointestinal nematode anthelmintic treatments, as practiced on Irish farms, have a high failure rate. There was a significant difference between the efficacies of the anthelmintic classes with BZ the least effective and ML the most effective

The Potential of an Enhanced Cooperation Measure in the EAFRD (2014-2020): the case of Ireland

This report was funded by the Department of Agriculture, Food and the Marine (DAFM) through the National Rural Network (February-May, 2012).The current Proposal for a Regulation of the European Parliament and of the Council on support for Rural Development by the European Agricultural Fund for Rural Development (EAFRD) includes Article (36) Cooperation that is potentially instrumental for realising the objectives of FOOD HARVEST 20204. The purpose of this report is to assess the scope and potential of Article 36 in the context of Irish agriculture and its findings have four key aspects. First, the main areas of confluence between Article 36 and primary policy objectives as set out in Food Harvest 2020 are identified. Second, a range of cooperation categories and types relevant to Article 36, many of which are operational in Ireland, are profiled. Third, drawing from case-studies of these co-operation types5, the operational characteristics of each type are presented, focusing on compatibility with Article 36. Possible supports that would encourage and assist the formation and operation of the cooperation types on a broad scale into the future, and also any possible constraints that would prevent success, are indicated. Fourth, a brief discussion of some key implementation considerations arising from the analysis overall is presented.Department of Agriculture, Food and the Marin

Distribution and incidence of viruses in Irish seed potato crops

peer-reviewedVirus diseases are of key importance in potato production and in particular for the production of disease-free potato seed. However, there is little known about the frequency and distribution of potato virus diseases in Ireland. Despite a large number of samples being tested each year, the data has never been collated either within or across years. Information from all known potato virus testing carried out in the years 2006–2012 by the Department of Agriculture Food and Marine was collated to give an indication of the distribution and incidence of potato virus in Ireland. It was found that there was significant variation between regions, varieties, years and seed classes. A definition of daily weather data suitable for aphid flight was developed, which accounted for a significant proportion of the variation in virus incidence between years. This use of weather data to predict virus risk could be developed to form the basis of an integrated pest management approach for aphid control in Irish potato crops

Reaping the rewards of learning within agricultural knowledge systems: An account of a PhD learning system

Despite the existence and application of mandatory agri-environmental policy for many decades, significant environmental sustainability problems remain attributable to the agricultural sector. Participatory types of extension practices are believed to have a potential to enable extension organisations to enhance the supports provided to farmers to help meet the requirements and objectives of these policies. To test this proposition, the PhD researcher used a learning systems approach for exploring the interplay between farmer subjectivities, the European Union’s policy of cross compliance and the extension practices of Teagasc, the Irish Agriculture and Food Development Authority. Three learning sub-systems were employed in the investigation. The first used the principles of Participatory Action Research for revealing stakeholders’ perceptions of Teagasc’s cross compliance extension service. This process resulted in the attainment of rich insights about extension practices, however it also revealed that a significant number of farmers were experiencing socio-cultural difficulties with the application and enforcement of cross compliance. To better understand the implications of these subjectivities, a second sub-system was created to learn about farmers’ experiences of the policy. This process surfaced diverse insights about farmers’ personal experiences of cross compliance. A final sub-system employed systems thinking and practice for appraising the utility of the learning arising from the previous sub-systems for improving interactions between farmers, extension organisations and cross compliance. The combined findings of the thesis indicate that there is considerable potential for extension organisations to use participatory practices for developing rich understandings of farmers’ preferences for mandatory agri-environmental policy and its related extension practices. However, a limitation in realising participant preferences is that extension organisations appear to have little influence over the application and enforcement of mandatory agri-environmental policy. Overcoming this participatory barrier will require sustained collective learning targeted at understanding how stakeholders can work together to develop agri-environmental policies that are socially, financially and environmentally sustainable. This paper explores how this ‘sustained collective learning’ may be realised taking a specific account of the learnings developed within and following the completion of the PhD Learning System. The insights elucidated will be of interest to scholars and extension practitioners involved in similar learning endeavours

The multiferroic phase of DyFeO3_{3}:an ab--initio study

By performing accurate ab-initio density functional theory calculations, we study the role of $4f$ electrons in stabilizing the magnetic-field-induced ferroelectric state of DyFeO$_{3}$. We confirm that the ferroelectric polarization is driven by an exchange-strictive mechanism, working between adjacent spin-polarized Fe and Dy layers, as suggested by Y. Tokunaga [Phys. Rev. Lett, \textbf{101}, 097205 (2008)]. A careful electronic structure analysis suggests that coupling between Dy and Fe spin sublattices is mediated by Dy-$d$ and O-$2p$ hybridization. Our results are robust with respect to the different computational schemes used for $d$ and $f$ localized states, such as the DFT+$U$ method, the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional and the GW approach. Our findings indicate that the interaction between the $f$ and $d$ sublattice might be used to tailor ferroelectric and magnetic properties of multiferroic compounds.Comment: 6 pages, 4 figures-Revised versio

Maps of Organic Agriculture in Australia

Australia is the world leader in organic agriculture, based on certified organic hectares. This has been the case since global organic statistics were first published (in 2000). Australia now accounts for more than half of the world’s certified organic hectares (54%). Australia has 35,645,000 certified organic hectares which is 8.8% of Australia’s agricultural land. In the present paper, three maps (cartograms, ‘maps with attitude’) of organic agriculture in Australia are presented. These three maps illustrate the data, at the state and territory level, for (a) certified organic hectares (35,645,037 hectares) (b) certified organic producers (n = 1,998), and (c) certified organic operators (producers + handlers + processors) (n = 4,028). States and territories are resized according to their measure for each attribute. The base-map for Australia, with states and territories coloured according to their state colours (or a variation thereof), is the standard cartographic representation of the country. The three organics maps are density-equalising cartograms (area cartograms) where equal areas on the map represent equal measures (densities) of the parameter under consideration. This mapping protocol creates distorted yet recognisable new maps that reveal where there is a high presence of the parameter under consideration (and the state or territory is ‘fat’), or a low presence (and the state or territory is ‘skinny’). These three maps visually reveal the uneven distribution of the metrics of organics across Australia, and, on a state by state basis, they suggest unrealised opportunities and potentials

Experience and evaluation of colony loss monitoring in Scotland : survey methodology, response rates and degree of success

Surveys of beekeepers in Scotland have been running since 2006, with Scotland joining COLOSS Working Group 1 in 2010. Since 2008 these surveys have been based on stratified random sampling of the membership records of the Scottish Beekeepers’ Association (SBA), and have used a postal questionnaire with a covering letter. The surveys have run in late spring, after a small scale pilot run, and allowing 3 to 4 weeks for response to the main survey. Late returns are accepted and included where possible in the COLOSS return. A small prize draw has been possible in recent surveys as an incentive to participate, and a postal reminder is issued. The SBA has approximately 1100 members. Sample sizes were 100 beekeepers approached directly in the 2006 survey, 119 SBA members in 2008, and 200 hobbyist SBA members in the 2010 survey (plus 26 bee farmers), 200 SBA members in 2011 and 250 in 2012. Response rates were 77% in 2006, 42.0% (50; 44 beekeepers) in 2008, 68.5% (137, of which 116 were beekeepers; plus 9 bee farmers) in 2010, 47.0% (94; 64 beekeepers) in 2011, and 41.6% (104; 91 beekeepers) in 2012. Our main observation regarding the success of the questions is that questions relating to bee management lead to illogical results in a large proportion of cases. Our attempts to allow for all possibilities in the answers to these questions have not reduced the incidence of such unreliable results. We therefore use stated colony numbers at the start of winter and stated losses to calculate overall loss rates. As bee management is rare in Scottish winters, this should have little impact on conclusions. Summer losses are very low. For future surveys, we plan to operate an online questionnaire based on LimeSurvey (http://www.limesurvey.org/), for speed and ease of data collection and lower costs, possibly with a larger scale sample