Constituents of the Essential Oil of Suregada zanzibariensis Leaves are Repellent to the Mosquito, Anopheles gambiae s.s.

In traditional African communities, repellent volatiles from certain plants generated by direct burning or by thermal expulsion have played an important role in protecting households against vectors of malaria and other diseases. Previous research on volatile constituents of plants has shown that some are good sources of potent mosquito repellents. In this bioprospecting initiative, the essential oil of leaves of the tree, Suregada zanzibariensis Verdc. (Angiospermae: Euphobiaceae) was tested against the mosquito, Anopheles gambiae s.s. Giles (Diptera: Culicidae) and found to be repellent. Gas chromatography (GC), GC-linked mass spectrometry (GC-MS) and, where possible, GC-co-injections with authentic compounds, led to the identification of about 34 compounds in the essential oil. About 56% of the constituents were terpenoid ketones, mostly methyl ketones. Phenylacetaldehyde (14.4%), artemisia ketone (10.1%), (1S)-(-)-verbenone (12.1%) and geranyl acetone (9.4%) were the main constituents. Apart from phenylacetaldehyde, repellent activities of the other main constituents were higher than that of the essential oil. The blends of the main constituents in proportions found in the essential oil were more repellent to An. gambiae s.s. than was the parent oil (p < 0.05), and the presence of artemisia ketone in the blend caused a significant increase in the repellency of the resulting blend. These results suggested that blends of some terpenoid ketones can serve as effective An. gambiae s.s. mosquito repellents

Contactless Palm Vein Authentication security technique for better adoption of e-commerce in developing countries

E-commerce has been contributing immensely to the economic development of the developed countries and the main catalyst to this could be attributed to the total adoption of e-commerce by the citizens. In order word, e-commerce could also be an economic driver in developing countries. Moreover, security has been identified as major barrier that prevents citizens from adopting e-commerce in developing countries. This paper examines Security Authentication Techniques (SAT) of Digital Signature (DF) and Fingerprint System (FPS) the limitations of these architectures and then propose Contactless Palm Vein Authentication (CPVA). The architecture of this new CPVA will be discussed in relation to Security, privacy, trust and reliability