182 research outputs found

    Smallholder irrigation productivity for sustainable intensification: Water balances for high value crops in northern Ghana

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

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    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

    Investigation of the structure and microhardness of Mo-Fe-C coatings obtained by the electron beam injected in the atmosphere

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    In this work 'Mo-Fe-C' coatings fabricated on medium carbon steel by non-vacuum electron beam cladding were investigated. The structure of coatings and transition zones were studied by scanning electron microscopy (SEM). It was shown that an increase of Fe percentage in the cladding mixture led to a decrease of the eutectic volume fraction in the coating and was accompanied by the formation of the gradient structure between the coating and a substrate material. Measurements of microhardness in the cross section of samples revealed that the cladding of a 'Mo-C powder mixture contributed to a 4.5-fold increase of microhardness

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

    Get PDF
    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

    Poultry red mite (Dermanyssus gallinae) infestation:A broad impact parasitological disease that still remains a significant challenge for the egg-laying industry in Europe

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    Abstract The poultry red mite, Dermanyssus gallinae, has been described for decades as a threat to the egg production industry, posing serious animal health and welfare concerns, adversely affecting productivity, and impacting public health. Research activities dedicated to controlling this parasite have increased significantly. Their veterinary and human medical impact, more particularly their role as a disease vector, is better understood. Nevertheless, red mite infestation remains a serious concern, particularly in Europe, where the prevalence of red mites is expected to increase, as a result of recent hen husbandry legislation changes, increased acaricide resistance, climate warming, and the lack of a sustainable approach to control infestations. The main objective of the current work was to review the factors contributing to this growing threat and to discuss their recent development in Europe. We conclude that effective and sustainable treatment approach to control poultry red mite infestation is urgently required, included integrated pest management

    Investigation of the structure and microhardness of Mo-Fe-C coatings obtained by the electron beam injected in the atmosphere

    Get PDF
    In this work 'Mo-Fe-C' coatings fabricated on medium carbon steel by non-vacuum electron beam cladding were investigated. The structure of coatings and transition zones were studied by scanning electron microscopy (SEM). It was shown that an increase of Fe percentage in the cladding mixture led to a decrease of the eutectic volume fraction in the coating and was accompanied by the formation of the gradient structure between the coating and a substrate material. Measurements of microhardness in the cross section of samples revealed that the cladding of a 'Mo-C powder mixture contributed to a 4.5-fold increase of microhardness

    Climate Smart Agriculture in the African Context

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    Agriculture remains vital to the economy of most African countries and its development has significant implications for food security and poverty reduction in the region. Increase in agricultural production over the past decades has mainly been due to land area expansion, with very little change in production techniques and limited improvement in yields. Currently one in four people remains malnourished in Africa. CSA integrates all three dimensions of sustainable development and is aimed at (1) sustainably increasing agricultural productivity and incomes; (2) adapting and building resilience to climate change from the farm to national levels; and (3) developing opportunities to reduce greenhouse gas emissions from agriculture compared with past trends. It is an approach to identify the most suitable strategies according to national and local priorities and conditions to meet these three objectives. There is no such thing as an agricultural practice that is climate smart per se. Whether or not a particular practice or production system is climate smart depends upon the particular local climatic, biophysical, socio-economic and development context, which determines how far a particular practice or system can deliver on productivity increase, resilience and mitigation benefits. For Africa to reap the potential benefits CSA, concrete actions must be taken to: enhance the evidence base to underpin strategic choices, promote and facilitate wider adoption by farmers of appropriate technologies; develop institutional arrangements to support, apply and scale-out CSA from the farm level to the agricultural landscape level; manage tradeoffs in perspectives of farmers and policymakers; strengthen technical, analytical and implementation capacities; ensure policy frameworks and public investments are supportive of CSA; develop and implement effective risk-sharing schemes

    Inside-Out Regulation of ICAM-1 Dynamics in TNF-Ξ±-Activated Endothelium

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    Background: During transendothelial migration, leukocytes use adhesion molecules, such as ICAM-1, to adhere to the endothelium. ICAM-1 is a dynamic molecule that is localized in the apical membrane of the endothelium and clusters upon binding to leukocytes. However, not much is known about the regulation of ICAM-1 clustering and whether membrane dynamics are linked to the ability of ICAM-1 to cluster and bind leukocyte integrins. Therefore, we studied the dynamics of endothelial ICAM-1 under non-clustered and clustered conditions. Principal Findings: Detailed scanning electron and fluorescent microscopy showed that the apical surface of endothelial cells constitutively forms small filopodia-like protrusions that are positive for ICAM-1 and freely move within the lateral plane of the membrane. Clustering of ICAM-1, using anti-ICAM-1 antibody-coated beads, efficiently and rapidly recruits ICAM-1. Using fluorescence recovery after photo-bleaching (FRAP), we found that clustering increased the immobile fraction of ICAM-1, compared to non-clustered ICAM-1. This shift required the intracellular portion of ICAM-1. Moreover, biochemical assays showed that ICAM-1 clustering recruited beta-actin and filamin. Cytochalasin B, which interferes with actin polymerization, delayed the clustering of ICAM-1. In addition, we could show that cytochalasin B decreased the immobile fraction of clustered ICAM-1-GFP, but had no effect on non-clustered ICAM-1. Also, the motor protein myosin-II is recruited to ICAM-1 adhesion sites and its inhibition increased the immobile fraction of both non-clustered and clustered ICAM-1. Finally, blocking Rac1 activation, the formation of lipid rafts, myosin-II activity or actin polymerization, but not Src, reduced the adhesive function of ICAM-1, tested under physiological flow conditions. Conclusions: Together, these findings indicate that ICAM-1 clustering is regulated in an inside-out fashion through the actin cytoskeleton. Overall, these data indicate that signaling events within the endothelium are required for efficient ICAM-1-mediated leukocyte adhesio

    Should the poultry red mite Dermanyssus gallinae be of wider concern for veterinary and medical science?

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    The poultry red mite Dermanyssus gallinae is best known as a threat to the laying-hen industry; adversely affecting production and hen health and welfare throughout the globe, both directly and through its role as a disease vector. Nevertheless, D. gallinae is being increasingly implemented in dermatological complaints in non-avian hosts, suggesting that its significance may extend beyond poultry. The main objective of the current work was to review the potential of D. gallinae as a wider veterinary and medical threat. Results demonstrated that, as an avian mite, D. gallinae is unsurprisingly an occasional pest of pet birds. However, research also supports that these mites will feed from a range of other animals including: cats, dogs, rodents, rabbits, horses and man. We conclude that although reported cases of D. gallinae infesting mammals are relatively rare, when coupled with the reported genetic plasticity of this species and evidence of permanent infestations on non-avian hosts, potential for host-expansion may exist. The impact of, and mechanisms and risk factors for such expansion are discussed, and suggestions for further work made. Given the potential severity of any level of host-expansion in D. gallinae, we conclude that further research should be urgently conducted to confirm the full extent of the threat posed by D. gallinae to (non-avian) veterinary and medical sectors

    Evaluation of sleep, puberty and mental health in children with long-term melatonin treatment for chronic idiopathic childhood sleep onset insomnia

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    OBJECTIVES: To establish whether long-term use of melatonin influences pubertal development, sleep quality and mental health development in children as compared with the normal Dutch population of the same age. METHODS: This follow-up research study was conducted in children included in a previous melatonin dose-finding trial. Outcomes were measured using questionnaires (Strength and Difficulties Questionnaire (SDQ), Children's Sleep Habits Questionnaire (CSHQ) and Tanner Stages) adopted for Dutch children. Mean duration of therapy, persistence of effect, adverse events and (other) reasons leading to cessation of therapy were additional objectives of this study. RESULTS: Mean years of usage (n = 51) was 3.1 years (min 1.0 year, max 4.6 years), mean dose 2.69 mg (min 0.3 mg, max 10 mg). Mean SDQ score, mean CSHQ score and Tanner Stages standard deviation scores did not differ in a statistically significant way from published scores of the general Dutch population of the same age and sex. CONCLUSIONS: This follow-up study demonstrates that melatonin treatment in children can be sustained over a long period of time without substantial deviation of the development of children with respect to sleep quality, puberty development and mental health scores, as compared with the general Dutch population
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