108 research outputs found
The impact of low erythrocyte density in human blood on the fitness and energetic reserves of the African malaria vector Anopheles gambiae
Background
Anaemia is a common health problem in the developing world. This condition is characterized by a reduction in erythrocyte density, primarily from malnutrition and/or
infectious diseases such as malaria. As red blood cells are the primary source of protein for haematophagous mosquitoes, any reduction could impede the ability of mosquito vectors to transmit malaria by influencing their fitness or that of the parasites they transmit. The aim of this study was to determine the impact of differences in the density of red blood cells in human blood on malaria vector (Anopheles gambiae sensu stricto) fitness. The hypotheses tested are that mosquito vector energetic reserves and fitness are negatively influenced by reductions in the red cell density of host human blood meals commensurate with those expected from severe anaemia.
Methods
Mosquitoes (An. gambiae s.s.) were offered blood meals of different packed cell volume(PCV) of human blood consistent with those arising from severe anaemia (15%) and normalPCV (50%). Associations between mosquito energetic reserves (lipid, glucose and glycogen)and fitness measures (reproduction and survival) and blood meal PCV were investigated.
Results
The amount of protein that malaria vectors acquired from blood feeding (indexed by
haematin excretion) was significantly reduced at low blood PCV. However, mosquitoes
feeding on blood of low PCV had the same oviposition rates as those feeding on blood of normal PCV, and showed an increase in egg production of around 15%. The long-term survival of An. gambiae s.s was reduced after feeding on low PCV blood, but PCV had no significant impact on the proportion of mosquitoes surviving through the minimal period required to develop and transmit malaria parasites (estimated as 14 days post-blood feeding). The impact of blood PCV on the energetic reserves of mosquitoes was relatively minor.
Conclusions
These results suggest that feeding on human hosts whose PCV has been depleted due to severe anaemia does not significantly reduce the fitness or transmission potential of malaria vectors, and indicates that mosquitoes may be able exploit resources for reproduction more
efficiently from blood of low rather than normal PCV
Mathematical model of the point kinetic equations of a fast reactor in LabVIEW
The reactor point kinetics equations have been subjected to intense research in an effort to find simple yet accurate numerical solution methods. Many solution techniques have been presented on the point kinetics equations with varying degrees of complexity including Power Series Solutions, CORE, PCA, Ganapol and Taylor series methods. In this paper, fast and simple algorithms were developed based on the first and second order Taylor series expansion and simulated in LabVIEW to solve the Reactor Point Kinetics. Simulations for a fast reactor are presented. At 1× 10-8 s the neutron population was 1.000220 neutrons / cm3, at 1× 10-2 s it was 2.007681 neutrons / cm3 and at 1× 10-1 s it was 2.075317 neutrons / cm3. Keywords: reactor point kinetics equations, taylor series approximations, neutron population density, fast reacto
Promoting radio astronomy in Ghana through school visits and Astronomy Clubs
The Promoting Radio Astronomy in Ghana through School visits and Astronomy Clubs (PRAGSAC) project was an intervention to promote astronomy education in schools in Ghana. It was initiated by a group of enthusiastic students who were trained in radio astronomy and astrophysics under a Royal Society/Newton Fund UK project termed Development in Africa with Radio Astronomy. The team's aim is to expose school children to astronomy and to increase their interest in the sciences. Approximately 800 school children from seven junior high schools were positively impacted by this project. Astronomy clubs were formed in the selected schools with practical astronomy lessons taught. The kids visited the largest single radio telescope in Africa at Kuntunse in Accra and were amazed about the engineering and the science that it undertakes. For the patrons of the clubs, a teacher training workshop was organised for them, so as to equip them to manage the clubs. The feedback from students and teachers was exceptionally positive, implying that the PRAGSAC project has helped inspire more students to pursue courses and consider careers within the sciences
Tissue and serum markers of inflammation during the follow-up of patients with giant-cell arteritis—a prospective longitudinal study
Objective. To evaluate the association between inflammatory markers and relapse in GCA patients longitudinally assessed in a clinical trial of infliximab and glucocorticosteroids
Steroid-sparing agents in giant cell arteritis
Background:
Giant cell arteritis is the commonest form of medium-to-large vessel vasculitis, requiring long-term corticosteroid therapy. The short- and long-term side effects of corticosteroids are many, including weight gain, psychological effects, osteoporosis, cardiometabolic complications, and infections.
Materials and Methods:
Various agents used in place of or in combination with corticosteroids to reduce corticosteroid-related side effects were reviewed. However, considerable variation in practice was identified giving unclear guidance. This review included the most recent evidence on methotrexate, mycophenolate mofetil, azathioprine, cyclophosphamide, abatacept, and tocilizumab
Results and Discussion:
Also discussed are encouraging results with tocilizumab in GCA patients. Amongst the agents available for steroid-sparing effects, tocilizumab demonstrated the most robust data and is consequently recommended as the agent of choice for steroid-sparing, for remission induction, remission maintenance, and treating relapsing and refractory cases of GCA.Published versio
Recent updates on the Maser Monitoring Organisation
The Maser Monitoring Organisation (M2O) is a research community of telescope operators, astronomy researchers and maser theoreticians pursuing a joint goal of reaching a deeper understanding of maser emission and exploring its variety of uses as tracers of astrophysical events. These proceedings detail the origin, motivations and current status of the M2O, as was introduced at the 2021 EVN symposium
Recent updates on the Maser Monitoring Organisation
The Maser Monitoring Organisation (M2O) is a research community of telescope operators, astronomy researchers and maser theoreticians pursuing a joint goal of reaching a deeper understanding of maser emission and exploring its variety of uses as tracers of astrophysical events. These proceedings detail the origin, motivations and current status of the M2O, as was introduced at the 2021 EVN symposium
Inositol 1,4,5-trisphosphate supports the arrhythmogenic action of endothelin-1 on ventricular cardiac myocytes
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