DEVELOPMENT OF ONCHOCERCA VOLVULUS (FILARIOIDEA: ONCHOCERCIDAE) IN THE WEST AFRICAN BLACK FLY SIMULIUM YAHENSE (DIPTERA: SIMULIIDAE) IN LIBERIA

2001 ◽  
Vol 87 (6) ◽  
pp. 1265-1272 ◽  
Author(s):  
M. Trpis ◽  
W. P. Wergin ◽  
ChA. Murphy
2006 ◽  
Vol 77 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Khady Diouf ◽  
Jacques Panfili ◽  
Maylis Labonne ◽  
Catherine Aliaume ◽  
Javier Tomás ◽  
...  

Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 302
Author(s):  
Taline D. Kazandjian ◽  
Arif Arrahman ◽  
Kristina B. M. Still ◽  
Govert W. Somsen ◽  
Freek J. Vonk ◽  
...  

Bites from elapid snakes typically result in neurotoxic symptoms in snakebite victims. Neurotoxins are, therefore, often the focus of research relating to understanding the pathogenesis of elapid bites. However, recent evidence suggests that some elapid snake venoms contain anticoagulant toxins which may help neurotoxic components spread more rapidly. This study examines the effects of venom from the West African black-necked spitting cobra (Naja nigricollis) on blood coagulation and identifies potential coagulopathic toxins. An integrated RPLC-MS methodology, coupled with nanofractionation, was first used to separate venom components, followed by MS, proteomics and coagulopathic bioassays. Coagulation assays were performed on both crude and nanofractionated N. nigricollis venom toxins as well as PLA2s and 3FTx purified from the venom. Assays were then repeated with the addition of either the phospholipase A2 inhibitor varespladib or the snake venom metalloproteinase inhibitor marimastat to assess whether either toxin inhibitor is capable of neutralizing coagulopathic venom activity. Subsequent proteomic analysis was performed on nanofractionated bioactive venom toxins using tryptic digestion followed by nanoLC-MS/MS measurements, which were then identified using Swiss-Prot and species-specific database searches. Varespladib, but not marimastat, was found to significantly reduce the anticoagulant activity of N. nigricollis venom and MS and proteomics analyses confirmed that the anticoagulant venom components mostly consisted of PLA2 proteins. We, therefore, conclude that PLA2s are the most likely candidates responsible for anticoagulant effects stimulated by N. nigricollis venom.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Clovis Bessong Tanyi ◽  
Raymond Ndip Nkongho ◽  
Justin Nambangia Okolle ◽  
Aaron Suh Tening ◽  
Christopher Ngosong

African farmers are currently grappling with potential control measures for the invasive fall armyworm (FAW) (Spodoptera frugiperda), which has recently emerged as an important economic pest that is ravaging maize fields across the continent. We evaluated the efficacy of the West African black pepper extract and beans intercropping systems as viable FAW control measures and the implication on maize yields. The experiment comprised five treatments (control-no input, dwarf beans intercrop, climbing beans intercrop, West African black pepper extract, and insecticide) with three replications each. FAW severity was assessed at three to seven weeks after planting (WAP), while maize infestation was assessed at seven WAP. FAW severity increased significantly (P<0.05) across WAP for the control and dwarf beans intercrop, with the highest at four and six WAP, respectively. FAW severity also differed (P<0.05) significantly across treatments at four to seven WAP, with the lowest recorded in the extract of West African black pepper (Piper guineense) and the highest in control treatments. Maize infestation ranged from 13 to 93%, with the lowest in the West African black pepper extract and synthetic insecticide, followed by both dwarf and climbing beans intercrops and then the control. The maize yield determined at physiological maturity ranged from 2.2 to 6.3 t ha−1 across treatments and differed significantly, with the highest in the West African black pepper extract and synthetic insecticide, followed by both the dwarf and climbing beans intercrops, as compared to the control. Overall, the West African black pepper extract and beans push cropping systems demonstrated efficacy as viable sustainable alternative control measures for the invasive fall armyworm in maize fields.


2020 ◽  
Vol 28 (Supplement) ◽  
pp. 86-109
Author(s):  
Kehinde Ibrahim

The judgments of the ECOWAS Court, which are final and immediately binding, are vital for the realisation of ECOWAS aims and objectives. The enforcement of its judgments is particularly important in the case of individuals whose enjoyment of fundamental human rights, as guaranteed under the ECOWAS Community laws, is dependent on effective enforcement. Yet, an existential puzzling paradox emanates through a poor record in the implementation of the ECOWAS Court's judgments. This problem, which is not limited to the West African region deserves scrutiny and concrete proposals. Legal and political considerations surface in assessing the existence of this paradox, and despite the lack of a consistent political will, to implement the decisions of ECOWAS Court relevant judicial actors have roles to play. National courts could take a bolder approach in complementing the work of the ECOWAS Court. The ECOWAS Court itself could put in place concrete mechanisms and adopt certain practices to address this poor record of non-implementation. It is yet to be seen how substantive mechanisms would work in practice.


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