Insecticidal Activity of Crude Extracts of Hyptis suaveolens (Bush Mint) on Anopheles Mosquitoes Collected from Lafia, Nasarawa State, Nigeria

Anopheles gambiae is a vector that is responsible for the transmission of malaria parasites which causes high morbidity and mortality in Nigeria and the world at large. Human-vector contact can be reduced by the use of conventional repellents being sold in the market, though some of these repellent are not environmentally friendly and An. gambiae have developed resistance to some of these repellents. To this end, the phytochemical constituents and insecticidal activity of crude extracts of Hyptis suaveolens (bush mint) was determined on adult An. gambiae mosquitoes collected from Lafia, Nasarawa State, Nigeria to evaluate its effect in controlling them. Here, 70% ethanolic and diethyl ether fat crude extracts were made from H. suaveolens dried leaves and used to carry out the experiment. The phytochemical screening of the ethanol extract revealed the presence of alkaloids, flavonoid, saponins, tannins, steroids and reducing sugar. Glycoside was not detected in the ethanol extract. Only steroids was detected in diethyl ether extract the rest of the phytochemical tested were absent. An. gambiae larvae were collected from the field and were raised to F1 progeny adults that were used for the study. WHO protocol for carrying out human bait repellency cage test was used. Human hand treated with the extracts was exposed to a cage containing 30 female mosquitoes for each of the extracts respectively. The ethanolic crude extract treatment proved to be more effective in repelling mosquitoes with 0% (0/30) mosquito landing than diethyl ether extract which had 40% (12/30) mosquitoes landing and the control hand (untreated left hand) had the highest landing rate 63.3% (19/30) which showed very high significant difference (χ2 = 27.2619, df = 2, P <0.00001) in relation to the treatments. After 24 hours holding period, the mortality rate of exposed mosquitoes was observed to be highest in the ethanolic treatment 73.3% (22/30). In conclusion, H. suaveolens extracts have repellency potential in controlling adult An. gambiae

Anti-trypanosomal Activity of Bufonidae (Toad) Venom Crude Extract on Trypanosoma brucei brucei in Swiss Mice

Trypanosomiasis afflicts about 6 ~ 7 million people globally and to a large extent impedes livestock production in Africa. Naturally, trypanosomal parasites undergo genetic mutation and have developed resistance over a wide range of therapies. The utilization of animals and plants products has presented therapeutic potential for identifying novel anti-trypanosomal drugs. This study evaluated toad venom for anti-trypanosomal potency invivo in Swiss mice. Toads were collected from July to August 2019. The acute oral toxicity and biochemical characterization of the toad venom were determined. The experimental mice were administered various doses (130 mg/kg, 173 mg/kg and 217 mg/kg) of the toad venom crude extract and 0.75 mg/mL of Diamizan Plus standard drug for the treatment of trypanosomiasis, once daily for 3 days. The in-vivo anti-trypanosomal activity was evaluated by a curative test, after infecting the mice with Trypanosoma brucei brucei. The pre-patent period was 72 hours before treatment commenced. The overall results showed that trypanosomal load was highest in the control group while the group treated with Diamizan drug had the least trypanosomal load. As such, the mean trypanosomal load in relation to treatments showed a very high significant difference (P0.05) across treatment groups. The over 50% reduction in the trypanosomal load in the 130 mg/kg group in comparison with the control group brings to bare the anti-trypanosomal potency of the toad venom. The anti-trypanosomal activity demonstrated by the toad venom has provided basis for development of new therapeutic agents from different toad species. The study recommends further studies (both in-vivo and invitro) followed by the characterization of the active compounds present in the toad venom responsible for the anti-tyrpanosomal activity observed alongside the management and conservation of these species

Spoilage of freshly harvested mango fruits (Mangifera indica) stored using different storage methods

No Abstract. Global Journal of Agricultural Sciences Vol. 6 (2) 2007: pp. 145-14

Synthesis, spectral characterization, and theoretical investigation of the photovoltaic properties of (E)-6-(4-(dimethylamino)phenyl)diazenyl)-2-octyl-benzoisoquinoline-1, 3-dione

Abstract This research work focuses on the synthesis, characterization through spectra (FT-IR, UV–vis, and 1H-NMR) investigations, and the use of density functional theory (DFT) along with time-dependent density functional theory (TD-DFT) to investigate the electronic, structural, reactivity, photophysical properties, and the photovoltaic properties of a novel (E)-6-(4-(dimethylamino)phenyl)diazenyl)-2-octyl-benzoisoquinoline-1,3-dione. The structure of the synthesized compound was modeled using the Gaussian09W and GaussView6.0.16 softwares employing B3LYP and 6–31 + G(d) basis set. The DFT studies was performed in order to investigate the Frontier Molecular Orbital (FMO), Natural Bond Orbital (NBO), charge distribution, Nonlinear Optics (NLO), and stability of the titled molecule. The HOMO–LUMO energy gap which corresponds to the difference between HOMO and LUMO energies of the studied compound was found to be 2.806 eV indicating stiff and smooth nature of the titled molecule. This accounts for the less stability and high chemical reactivity of the compound. The photovoltaic properties were conducted to evaluate the light harvesting efficiency (LHE), short circuit current density (JSC), Gibbs free energy of injection ( $$\Delta {G}_{inj}$$ Δ G inj ), open cycled voltage (VOC) and Gibbs free energy regeneration ( $$\Delta {G}_{reg}$$ Δ G reg ) and solar cell conversion efficiency. Interestingly, the results obtained were found to be in good agreement with other experimental and computational findings

Performability Analysis Methods for Clustered WSNs as Enabling Technology for IoT

The Internet of Things (IoT) where sensors are used to couple the physical infrastructure with information and communication technologies is the main concept enabling applications such as smart homes, smart cities and intelligent transportation. The distributed sensor networks are used for interconnecting devices to transmit measured information, and control instructions. Therefore, energy efficiency and performability of wireless sensor networks (WSNs) are critical for IoT applications. It is possible to combine WSN nodes into smaller groups and set one of the nodes as cluster head (CH) in order to increase the energy efficiency and decrease transmission delay. This approach of combining sensor nodes is known as clustering. Clustering is a technique that has been widely applied for achieving goals such as prolonging the network lifetime, improving scalability and balancing the residual energy of all nodes. Development of algorithms using equal and unequal clustering techniques has been a popular topic in recent studies. Most of these techniques use residual energy of nodes and distance to base station as parameters for selecting cluster heads. This chapter considers analytical modelling approaches of homogeneous clustered WSNs with a centrally located CH responsible for coordinating cluster communication. Unlike most of the existing studies, the performance and energy efficiency of the cluster head are considered together. Furthermore, potential failure of WSN nodes is considered and performance and availability models are integrated as well as the potential repair or replacement of sensor nodes. Existing techniques used in performance evaluation of multiserver systems in general are investigated and analysed in detail. Similarly, pure availability modelling approaches are also analysed. Pure performance modelling techniques, pure availability models and performability models are considered critically for WSN configurations. Since the pure performance models tend to be too optimistic and pure availability models are too conservative, performability models are used in turn for the evaluation. The two-dimensional continuous-time Markov chains (CTMC) which are popularly used in performability analysis are considered together with queuing theory, in order to merge the performance and reliability processes which are relatively mutually independent. The possible use of open queuing networks to model the behaviour of the CH which is expecting intra-cluster as well as inter-cluster traffic while in various operative states is discussed. Among the possible operative conditions, we have states where the servers are broken, fully operational states, states with degraded service facilities and states where sleep scheduling mechanisms are also incorporated to extend the proposed energy models