Environmental drivers of Culicoides phenology: how important is species-specific variation when determining disease policy?

Since 2006, arboviruses transmitted by Culicoides biting midges (Diptera: Ceratopogonidae) have caused significant disruption to ruminant production in northern Europe. The most serious incursions involved strains of bluetongue virus (BTV), which cause bluetongue (BT) disease. To control spread of BTV, movement of susceptible livestock is restricted with economic and animal welfare impacts. The timing of BTV transmission in temperate regions is partly determined by the seasonal presence of adult Culicoides females. Legislative measures therefore allow for the relaxation of ruminant movement restrictions during winter, when nightly light-suction trap catches of Culicoides fall below a threshold (the ‘seasonally vector free period’: SVFP). We analysed five years of time-series surveillance data from light-suction trapping in the UK to investigate whether significant inter-specific and yearly variation in adult phenology exists, and whether the SVFP is predictable from environmental factors. Because female vector Culicoides are not easily morphologically separated, inter-specific comparisons in phenology were drawn from male populations. We demonstrate significant inter-specific differences in Culicoides adult phenology with the season of Culicoides scoticus approximately eight weeks shorter than Culicoides obsoletus. Species-specific differences in the length of the SVFP were related to host density and local variation in landscape habitat. When the Avaritia Culicoides females were modelled as a group (as utilised in the SFVP), we were unable to detect links between environmental drivers and phenological metrics. We conclude that the current treatment of Avaritia Culicoides as a single group inhibits understanding of environmentally-driven spatial variation in species phenology and hinders the development of models for predicting the SVFP from environmental factors. Culicoides surveillance methods should be adapted to focus on concentrated assessments of species-specific abundance during the start and end of seasonal activity in temperate regions to facilitate refinement of ruminant movement restrictions thereby reducing the impact of Culicoides-borne arboviruses

The occurrence of Culicoides species, the vectors of arboviruses, at selected trap sites in Zimbabwe

A study of the distribution of Culicoides species was conducted by establishing 12 light trap sites over five rainy seasons between 1998 and 2003 covering all the geo-climatic natural regions of Zimbabwe. In total, 279 919 specimens of Culicoides were trapped over a total of 163 trapping nights. The highest median counts of Culicoides per trapping night were recorded in natural region III, which has climatic conditions conducive to the successful development of the larvae. Culicoides imicola, the major vector of bluetongue and African horse sickness viruses in Africa, was found to be the most abundant species (80.4%), followed by Culicoides enderleini (5.9%) and Culicoides milnei (5.2%). This study identified 10 species of Culicoides that had not been previously described in Zimbabwe, including Culicoides loxodontis and Culicoides miombo, which are members of the C. imicola complex. A total of 23 994 Culicoides midges were collected from five trap sites in Harare, Zimbabwe, with the dominant species, C. imicola, representing 91.6% of the total collection. Seventeen arboviruses were isolated from these midges, 15 of which were bluetongue virus. The predominant bluetongue virus serotype was serotype 11, followed by serotypes 1, 8, 12 and 15. Bluetongue virus serotypes 1, 2, 8, 10, 12, 15, 16 and 18, detected in this study, had not been previously reported in Zimbabwe.http://www.ojvr.org/am201

A critical engagement with theological education in Africa

The higher education landscape has arguably become one of the most arduous to traverse. More so in the African context, where a host of variables continiously challenge educators to reflect critically on their philosophies and practices as they engage an ever-changing audience. In this book, a critical engagement with theological education in Africa is offered. As the book originates from South Africa, it is presented as a South African perspective, although contributors are situated accross the African continent and abroad. The common denominator is that all contributers are, in some way or another, invested in theological education in Africa. The main contribution of this collaborative work is to be sought in the insights it offers on four main areas of theological education: A historical and current orientation on theological edcuation in Africa, some paradigm shifts in theological education in Africa, ministerial formation needs versus theological education challenges, and a critical reflection on elective models and methods. The book presents the original and innovative research of scholars for fellow scholars involved in theological higher education as it is grounded in the respective fields of interest of each contributor. It contributes to a better understanding of the complex African theological higher education landscape that is also mindful of post-COVID-19 realities. Methodologically the work draws on a combination of methods, including literature studies, empirical work, and in some cases sectional offerings from doctoral studies, as indicated in the various chapters

A critical engagement with theological education in Africa

The higher education landscape has arguably become one of the most arduous to traverse. More so in the African context, where a host of variables continiously challenge educators to reflect critically on their philosophies and practices as they engage an ever-changing audience. In this book, a critical engagement with theological education in Africa is offered. As the book originates from South Africa, it is presented as a South African perspective, although contributors are situated accross the African continent and abroad. The common denominator is that all contributers are, in some way or another, invested in theological education in Africa. The main contribution of this collaborative work is to be sought in the insights it offers on four main areas of theological education: A historical and current orientation on theological edcuation in Africa, some paradigm shifts in theological education in Africa, ministerial formation needs versus theological education challenges, and a critical reflection on elective models and methods. The book presents the original and innovative research of scholars for fellow scholars involved in theological higher education as it is grounded in the respective fields of interest of each contributor. It contributes to a better understanding of the complex African theological higher education landscape that is also mindful of post-COVID-19 realities. Methodologically the work draws on a combination of methods, including literature studies, empirical work, and in some cases sectional offerings from doctoral studies, as indicated in the various chapters

Continent-wide genomic analysis of the African buffalo (<i>Syncerus caffer</i>)

AbstractThe African buffalo (Syncerus caffer) is a wild bovid with a historical distribution across much of sub-Saharan Africa. Genomic analysis can provide insights into the evolutionary history of the species, and the key selective pressures shaping populations, including assessment of population level differentiation, population fragmentation, and population genetic structure. In this study we generated the highest qualityde novogenome assembly (2.65 Gb, scaffold N50 69.17 Mb) of African buffalo to date, and sequenced a further 195 genomes from across the species distribution. Principal component and admixture analyses provided surprisingly little support for the currently described four subspecies, but indicated three main lineages, in Western/Central, Eastern and Southern Africa, respectively. Estimating Effective Migration Surfaces analysis suggested that geographical barriers have played a significant role in shaping gene flow and the population structure. Estimated effective population sizes indicated a substantial drop occurring in all populations 5-10,000 years ago, coinciding with the increase in human populations. Finally, signatures of selection were enriched for key genes associated with the immune response, suggesting infectious disease exert a substantial selective pressure upon the African buffalo. These findings have important implications for understanding bovid evolution, buffalo conservation and population management

Supercritical antisolvent co-precipitation of rifampicin and ethyl cellulose

International audienc

State of the art and future directions in nanomedicine for tuberculosis.

Research Article published by Expert Opinion on Drug Delivery Volume 10, Issue 1220 -13Introduction: Tuberculosis (TB) ranks the second leading cause of death from an infectious disease worldwide. However, treatment of TB is affected by poor patient compliance due to the requirement for daily drug administration, for lengthy periods of time, often with severe drug-induced side effects. Nanomedicines have the potential to improve treatment outcomes by providing therapies with reduced drug doses, administered less frequently, under shortened treatment durations. Areas covered: In this article, we present the pathophysiology of the disease, focusing on pulmonary TB and the characteristics of drugs used in treatment and discuss the application of nanomedicines within this scope. We also discuss new formulation approaches for TB nanomedicines and directions for future research. Expert opinion: Nanomedicines have the potential to improve TB treatment outcomes. New approaches such as nanoparticle systems able to impact the immune response of macrophages and deliver drug intracellularly, as well as the use of polymer–drug conjugates for drug delivery, are likely to play an important role in TB nanomedicines in future. However, further research is required before TB nanomedicines can be translated to the clinic

Microencapsulation of eucalyptol in polyethylene glycol and polycaprolactone using particles from gas-saturated solutions

Eucalyptol is the natural cyclic ether which constitutes the bulk of terpenoids found in essential oils of Eucalyptus spp. and is used in aromatherapy for treatment of migraine, sinusitis, asthma and stress. It acts by inhibiting arachidonic acid metabolism and cytokine production. Chemical instability and volatility of eucalyptol restrict its therapeutic application and necessitate the need to develop an appropriate delivery system to achieve extended release and enhance its bioactivity. However, the synthesis method of the delivery system must be suitable to prevent loss or inactivation of the drug during processing. In this study, supercritical carbon dioxide (scCO2) was explored as an alternative solvent for encapsulation and co-precipitation of eucalyptol with polyethylene glycol (PEG) and/or polycaprolactone (PCL) using the particles from gas-saturated solution (PGSS) process. Polymers and eucalyptol were pre-mixed and then processed in a PGSS autoclave at 45 °C and 80 bar for 1 h. The mixture in scCO2 was micronized and characterized. The presence of eucalyptol in the precipitated particles was confirmed by infrared spectroscopy, gas chromatography and mass spectrometry. The weight ratios of PEG–PCL blends significantly influenced loading capacity and encapsulation efficiency with 77% of eucalyptol encapsulated in a 4 : 1 composite blend of PEG–PCL. The particle size distribution of the PGSS-micronized particles ranged from 30 to 260 μm. ScCO2 assisted microencapsulation in PEG and PCL reduced loss of the volatile drug during a two-hour vaporization study and addition of PCL extended the mean release time in simulated physiological fluids. Free radical scavenging and lipoxygenase inhibitory activities of eucalyptol formulated in the PGSS-micronized particles was sustained. Findings from this study showed that the scCO2-assisted micronization can be used for encapsulation of volatile drugs in polymeric microparticles without affecting bioactivity of the drug.National Research Fund, South Africahttp://pubs.rsc.org/en/journals/journalissues/rahj2020Zoology and Entomolog

Managing cultivated pastures for improving soil quality in South Africa: challenges and opportunities

Loss of productive agricultural land due to soil degradation poses a serious threat to agricultural output and sustainability. Soil degradation of cultivated pastures manifests as a long-term decline in production potential. There are concerns that soils under pastures in certain regions of South Africa are degrading as a result of mismanagement, which include practising continuous tillage, improper grazing management, injudicious application of fertilisers and poor irrigation management. Soil quality indicators, which include physical, chemical and biological parameters in soil, are science-based methods to monitor sustainability and protect soil. Soil quality data informs the land manager in the decision-making process to address practices that degrade agro-ecological systems and mitigate any loss of function. The aim of this paper is to provide a synthesis of the challenges and opportunities in soil management of pastures. The value of assessing soil chemical, physical and biological indicators to monitor soil quality is stressed.Keywords: fertilisation, grazing management, irrigation management, soil degradation, tillag