Studies in virus diseases

In any approach to this subject it is essential first to review the relevant literature, and secondly to examine and discuss the physical, chemical and physico-chemical principles upon which instruments such as the ultra violet light, electron, and fluorescence microscopes are constructed. Only in this way can one interpret the significance of published research and correlate them with one's own deductions.The following pages contain a comprehensive description of apparatus used, their mode of operation, scope of usefulness and methods of interpreting data. The text is subdivided into sections dealing with rnicroscopy, staining , filtration and centrifugation, in which are contained personal observations on the morphology of the elementary bodies of myxoma and their centrifugalisation, also an account of the existence of elementary bodies in Rift Valley fever

Neurodevelopmental evaluation and referral practices in children with congenital heart disease in central South Africa

Introduction: Children with congenital heart disease (CHD) are at higher risk for developmental delays than the general population. The American Heart Association (AHA) published a guideline to address these concerns in 2012. This study determined the neurodevelopmental evaluation and referral practices of practitioners in central South Africa.Method: An online survey was administered to practitioners (n=45) including paediatric cardiologists (n=4), cardiothoracic surgeons (n=4) and general paediatricians (n=37). Information on practitioner characteristics, awareness of the 2012 AHA guideline; and neurodevelopmental evaluation and referral practices was collected.Results: Twenty-one practitioners responded, including paediatric cardiologists (n=4), cardiothoracic surgeons (n=2) and paediatricians (n=15). Data for 20 practitioners was included. Despite most practitioners (n=18) indicating guidelines for the management of development were important, the majority (n=16; 80%) were unaware of the guideline. Most practitioners (n=18; 90%) failed to risk stratify children to identify those to be evaluated. Children with developmental delays were referred for formal developmental evaluation (n=11; 55%) and to intervention therapies (n= 15; 75%).Conclusion: Most practitioners are unaware of the 2012 AHA guideline. Awareness of the developmental risks associated with CHD and implementation of the guideline could promote early identification of developmental delays with referral to intervention therapies

Cooperation between Referees and Authors Increases Peer Review Accuracy

Peer review is fundamentally a cooperative process between scientists in a community who agree to review each other's work in an unbiased fashion. Peer review is the foundation for decisions concerning publication in journals, awarding of grants, and academic promotion. Here we perform a laboratory study of open and closed peer review based on an online game. We show that when reviewer behavior was made public under open review, reviewers were rewarded for refereeing and formed significantly more cooperative interactions (13% increase in cooperation, P = 0.018). We also show that referees and authors who participated in cooperative interactions had an 11% higher reviewing accuracy rate (P = 0.016). Our results suggest that increasing cooperation in the peer review process can lead to a decreased risk of reviewing errors

Spirotetramat resistance in Myzus persicae (Sulzer) (Hemiptera: Aphididae) and its association with the presence of the A2666V mutation

This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.BACKGROUND: Chemicals are widely used to protect field crops against aphid pests and aphid-borne viral diseases. One such species is Myzus persicae (Sulzer), a global pest that attacks a broad array of agricultural crops and transmits many economically damaging plant viruses. This species has evolved resistance to a large number of insecticide compounds as a result of widespread and repeated chemical use in many parts of the world. In this study, we investigated the evolution of resistance to a new plant protection product, spirotetramat, following reported chemical control failures. RESULTS: Our study provides clear phenotypic and genotypic evidence of spirotetramat resistance in populations of M. persicae from Australia. We show there is cross-resistance to other insecticides within the same chemical group, namely spiromesifen and spirodiclofen. We also demonstrate that resistance is associated with the previously reported mutation, A2226V in the target site of spirotetramat, acetyl-CoA carboxylase. Our genetic analysis found all resistant M. persicae populations belong to the same multi-locus clonal type and carry the A2226V mutation, which appears to be inherited as a dominant trait in this species. CONCLUSION: Our findings provide new insight into the resistance conferred by A2226V and have implications for the control of M. persicae in Australia and worldwide. A diagnostic assay developed in this study should serve as a valuable tool for future resistance monitoring and to support the implementation of pest management strategies. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.Grains Research and Development CorporationBayer CropScienceBiotechnology and Biological Sciences Research Council (BBSRC

Sustainability transitions for smallholder farmers: How can government, research and development programs support profitable goat markets in Tete?

For Mozambique the goat sector provides huge opportunities for reducing rural poverty levels, improving food security and contributing to the national economy. Mozambique has a huge demand for goat meat and products. Large and medium size buyers fail to source enough goats of the right quality and supply consistently to feed the growing demand in urban markets. Despite its potential, the goat sector is not fully developed. Improved goat production can provide an additional annual income of US$50 million at the national level. In the short term farmers can double their income from goats. Though farmers realize the critical role of goats as source of saving and possible source of investment, they do not invest much in goats and are not able to make an adequate profit from selling their goats. Mortality rates of around 15%, poor quality of goats being sold to markets, and livestock theft are losses to entire rural economies. There are many causes for the low productivity, the primary reasons being: a) Lack of a market structure through which farmers and the private sector can interact; b) Absence of a grading system that rewards farmers for their investments in quality production; and c) Livestock theft that destroys community trust, and eventually hampers collective action among farmers..

Women in wage labour: A systematic review of the Effectiveness and Design Features of Interventions Supporting Women’s Participation in Wage Labour in Higher-growth and/or Male-dominated Sectors in Low- and Middle-income Countries

In low- and middle-income countries (LMICs), women’s participation in wage labour is significantly lower than that of men. In addition, women’s participation is often clustered in particular sectors of the economy that are not well-remunerated and have lower prestige. Higher growth economic sectors such as ICT and finance are dominated by men, excluding women from lucrative opportunities for social and economic development. Even where women have equal access to wage labour opportunities, they often suffer from vertical occupational segregation, earning significantly less than men and being less likely to be promoted. This horizontal and vertical occupational segregation of wage labour markets in LMICs for women hinders both economic and social development. In response to this challenging gendered nature of wage labour markets in LMICs, a range of interventions and policies have been proposed to increase women’s employment. These interventions aim to overcome a range of barriers to women’s wage labour employment in highergrowth/male-dominated sectors, such as discrimination against women by markets and work institutions, or a lack of access to credit and assets and of technical and soft skills. However, these labour market programmes to increase women’s wage employment vary greatly, as do the barriers to women’s wage labour participation. Different programme designs assume different pathways to support women’s employment and it is not clear what programme approaches and design features are most effective

New ecosystems in the deep subsurface follow the flow of water driven by geological activity

Eukarya have been discovered in the deep subsurface at several locations in South Africa, but how organisms reach the subsurface remains unknown. We studied river-subsurface fissure water systems and identified Eukarya from a river that are genetically identical for 18S rDNA. To further confirm that these are identical species one metazoan species recovered from the overlying river interbred successfully with specimen recovered from an underlying mine at -1.4 km. In situ seismic simulation experiments were carried out and show seismic activity to be a major force increasing the hydraulic conductivity in faults allowing organisms to create ecosystems in the deep subsurface. As seismic activity is a non-selective force we recovered specimen of algae and Insecta that defy any obvious other explanation at a depth of -3.4 km. Our results show there is a steady flow of surface organisms to the deep subsurface where some survive and adapt and others perish. As seismic activity is also present on other planets and moons in our solar system the mechanism elucidated here may be relevant for future search and selection of landing sites in planetary exploration

Cardiometabolic markers to identify cardiovascular disease risk in HIV-infected black South Africans

Background. The prevalence of HIV is the highest in sub-Saharan Africa; South Africa (SA) is one of the most affected countries with the highest number of adults living with HIV infection in the world. Besides the traditional risk factors for cardiovascular disease (CVD) in the general population, in people living with HIV there are specific factors – chronic inflammation, metabolic changes associated with the infection, therapy, and lipodystrophy – that potentially increase the risk for developing CVD. Objective. This study proposes a screening discriminant model to identify the most important risk factors for the development of CVD in a cohort of 140 HIV-infected black Africans from the North West Province, SA.Methods. Anthropometric measures, systolic blood pressure, diastolic blood pressure and the carotid-dorsalis pedis pulse wave velocity were determined. Blood was analysed to determine the levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, triglycerides (TGs) and glucose. Partial least squares discriminant analysis was performed as a supervised pattern recognition method. Independent Student’s t-tests were further employed to compare the means of risk factors on interval scales; for comparison of categorical risk factors between groups, χ2 tests were used. Results. A TG:HDL-C ratio ≥1.49, TC:HDL-C ratio ≥5.4 and an HDL-C level ≤0.76 mmol/l indicated CVD risk in this cohort of patients living with HIV.Conclusion. The results have important health implications for black Africans living with HIV as these lipid levels may be a useful indicator of the risk for CVD.