The study has generated visible aerosols with the diameter of 11 to 35 µm from the kenaf cellulose nanofiber (KCNF) impregnated with the temephos (KCNF+T) in water suspension. The study aimed to determine whether the KCNF+T aerosols are capable to elicit neurotoxicity in the adult mosquitoes via the respiratory exposure route by observing their behavioural response and measuring its body acetylcholine esterase (AChE) activity. Adult Aedes aegypti mosquitoes were assigned to one negative control group and three treatment groups namely, distilled water (vehicle control), KCNF and KCNF+T. The study adopted the MS1911 whereby the aerosols generated are released into the insecticide bioassay glass chamber (IBGC) separately to achieve four different aerosols concentrations of 6.4 ml/m3, 12.8 ml/m3, 19.2 ml/m3, and 25.6 ml/m3. Then the 20 sugar-fed mosquitoes were released free-flying into each IBGC to observe its behavioural response (knockdown) at 30, 60, 120, 180, 240, 300 minutes intervals and 24th hour mortality. Results showed that only mosquitoes exposed to KCNF+T aerosols exhibited persistent knockdown. There was significant difference (p< 0.05) between observation intervals with the cumulative knockdown of 84.8%, 92.8%, 99.0%, 100.0%, 100.0%, 100.0% compared with the KCNF aerosols. Further, it was distinctive that only KCNF+T is capable to cause the female mosquitoes moribund/mortality at the 24th hour with 90% at the lowest aerosol concentration of 6.4 ml/m3. The neuroenzyme assay on the mosquito that died from the KCNF+T exposure verified to have reduced AChE enzyme activity. The behavioural response and reduction of the AChE activity strongly suggests the temephos from the KCNF+T aerosols has been released into the mosquito body causing the neurotoxicity but KCNF alone is not neurotoxic.
Ostrich oil has been used extensively in the cosmetic and pharmaceutical industries. However, rancidity causes undesirable chemical changes in flavour, colour, odour and nutritional value. Bleaching is an important process in refining ostrich oil. Bleaching refers to the removal of certain minor constituents (colour pigments, free fatty acid, peroxides, odour and non-fatty materials) from crude fats and oils to yield purified glycerides. There is a need to optimize the bleaching process of crude ostrich oil prior to its use for therapeutic purposes. The objective of our study was to establish an effective method to bleach ostrich oil using peroxide value as an indicator of refinement. In our study, we showed that natural earth clay was better than bentonite and acid-activated clay to bleach ostrich oil. It was also found that 1 hour incubation at a 150 °C was suitable to lower peroxide value by 90%. In addition, the nitrogen trap technique in the bleaching process was as effective as the continuous nitrogen flow technique and as such would be the recommended technique due to its cost effectiveness.