13 research outputs found
Phagocytosis of Plasmodium falciparum ring-stage parasites predicts protection against malaria.
Ring-infected erythrocytes are the predominant asexual stage in the peripheral circulation but are rarely investigated in the context of acquired immunity against Plasmodium falciparum malaria. Here we compare antibody-dependent phagocytosis of ring-infected parasite cultures in samples from a controlled human malaria infection (CHMI) study (NCT02739763). Protected volunteers did not develop clinical symptoms, maintained parasitaemia below a predefined threshold of 500 parasites/ÎŒl and were not treated until the end of the study. Antibody-dependent phagocytosis of both ring-infected and uninfected erythrocytes from parasite cultures was strongly correlated with protection. A surface proteomic analysis revealed the presence of merozoite proteins including erythrocyte binding antigen-175 and -140 on ring-infected and uninfected erythrocytes, providing an additional antibody-mediated protective mechanism for their activity beyond invasion-inhibition. Competition phagocytosis assays support the hypothesis that merozoite antigens are the key mediators of this functional activity. Targeting ring-stage parasites may contribute to the control of parasitaemia and prevention of clinical malaria
A synthesis of past, current and future research for protection and management of papyrus (Cyperus papyrus L.) wetlands in Africa
Papyrus wetlands (dominated by the giant
sedge Cyperus papyrus L.) occur throughout eastern,
central and southern Africa and are important for
biodiversity, for water quality and quantity regulation
and for the livelihoods of millions of people. To draw
attention to the importance of papyrus wetlands, a
special session entitled ââThe ecology of livelihoods in
papyrus wetlandsââ was organized at the 9th INTECOL
Wetlands Conference in Orlando, Florida in June
2012. Papers from the session, combined with additional
contributions, were collected in a special issue
of Wetlands Ecology and Management. The current
paper reviews ecological and hydrological characteristics
of papyrus wetlands, summarizes their ecosystem
services and sustainable use, provides an
overview of papyrus research to date, and looks at
policy development for papyrus wetlands. Based on
this review, the paper provides a synthesis of research
and policy priorities for papyrus wetlands and introduces
the contributions in the special issue. Main
conclusions are that (1) there is a need for better
estimates of the area covered by papyrus wetlands.
Limited evidence suggests that the loss of papyrus
wetlands is rapid in some areas; (2) there is a need for a
better understanding and modelling of the regulating
services of papyrus wetlands to support trade-off
analysis and improve economic valuation; (3) research
on papyrus wetlands should include assessment of all
ecosystem services (provisioning, regulating, habitat,
cultural) so that trade-offs can be determined as the
basis for sustainable management strategies (âwise
useâ); (4) more research on the governance, institutional
and socio-economic aspects of papyrus wetlands
is needed to assist African governments in
dealing with the challenges of conserving wetlands in
the face of growing food security needs and climate
change. The papers in the special issue address a
number of these issues