Department of Biological Sciences
https://karuspace.karu.ac.ke/handle/20.500.12092/1953
2024-03-28T05:02:54Z
2024-03-28T05:02:54Z
Green synthesis of copper oxide nanoparticles and its efficiency in degradation of rifampicin antibiotic.
Nzilu, Dennis Mwanza
Madivoli, Edwin Shigwenya
Makhanu, David Sujee
Wanakai, Sammy Indire
Kiprono, Gideon Kirui
Kareru, Patrick Gachoki
https://karuspace.karu.ac.ke/handle/20.500.12092/3020
2023-12-14T00:00:28Z
2023-08-28T00:00:00Z
Green synthesis of copper oxide nanoparticles and its efficiency in degradation of rifampicin antibiotic.
Nzilu, Dennis Mwanza; Madivoli, Edwin Shigwenya; Makhanu, David Sujee; Wanakai, Sammy Indire; Kiprono, Gideon Kirui; Kareru, Patrick Gachoki
In recent ages, green nanotechnology has gained attraction in the synthesis of metallic nanoparticles due to their cost-effectiveness, simple preparation steps, and environmentally-friendly. In the present study, copper oxide nanoparticles (CuO NPs) were prepared using Parthenium hysterophorus whole plant aqueous extract as a reducing, stabilizing, and capping agent. The CuO NPs were characterized via UV–Vis Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), powder X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Dynamic Light Scattering (DLS). The UV–Vis spectra of CuO NPs showed a surface plasmonic resonance band to occur at 340 nm. FTIR analysis revealed the presence of secondary metabolites on the surface of CuO NPs, with a characteristic Cu–O stretching band being identified at 522 cm−1. Scanning electron micrographs and transmission electron micrographs showed that CuO NPs were nearly spherical, with an average particle of 59.99 nm obtained from the SEM micrograph. The monoclinic crystalline structure of CuO NPs was confirmed using XRD, and crystallite size calculated using the Scherrer-Debye equation was found to be 31.58 nm. DLS showed the presence of nanoparticle agglomeration, which revealed uniformity of the CuO NPs. Furthermore, the degradation ability of biosynthesized nanoparticles was investigated against rifampicin antibiotic. The results showed that the optimum degradation efficiency of rifampicin at 98.43% was obtained at 65℃ temperature, 50 mg dosage of CuO NPs, 10 mg/L concentration of rifampicin solution, and rifampicin solution at pH 2 in 8 min. From this study, it can be concluded that CuO NPs synthesized from Parthenium hysterophorus aqueous extract are promising in the remediation of environmental pollution from antibiotics. In this light, the study reports that Parthenium hysterophorus-mediated green synthesis of CuO NPs can effectively address environmental pollution in cost-effective, eco-friendly, and sustainable ways.
Green synthesis of copper oxide nanoparticles
2023-08-28T00:00:00Z
Functional response of Orius albidipennis (Hemiptera: Anthocoridae) to Megalurothrips sjostedti (Thysanoptera: Thripidae)
Gitonga (a), Linus M.
Löhrb (b), B.
Magambo (a), J. K.
Mueke (c), J. M.
https://karuspace.karu.ac.ke/handle/20.500.12092/2856
2023-04-25T00:00:10Z
2002-05-02T00:00:00Z
Functional response of Orius albidipennis (Hemiptera: Anthocoridae) to Megalurothrips sjostedti (Thysanoptera: Thripidae)
Gitonga (a), Linus M.; Löhrb (b), B.; Magambo (a), J. K.; Mueke (c), J. M.
A locally available anthocorid predator, Orius albidipennis Reuter, was evaluated as a candidate biocontrol agent for Megalurothrips sjostedti Trybom, a major pest of French beans, Phaseolus vulgaris (L), in Kenya. The functional response of adult O. albidipennis to larval and adult M. sjostedti was studied at 15, 25, and 28 °C and densities of 5, 10, 20, and 30 larval and adult M. sjostedti per cage, over 24 h. More larvae and adult M. sjostedti were killed at the higher densities and with an increase in temperature. The data provided good fit to both type I and II functional response models. Attack rates increased with temperature for both the second instar larva and adult M. sjostedti. Handling times for the larvae decreased with an increase in temperature while those for the adults increased with increase in temperature. The implications of these results are discussed.
Functional response of Orius albidipennis (Hemiptera: Anthocoridae) to Megalurothrips sjostedti (Thysanoptera: Thripidae)
2002-05-02T00:00:00Z
Current Status of Soil-Transmitted Helminths among School Children in Kakamega County, Western Kenya Prevalence and Intensity of Intestinal Parasites in School age Children in Thika District, Kenya
Ngonjo, Teresia
Okoyo, Collins
Andove, Julius
Simiyu, Elses
Lelo, Agola Eric
Kabiru, Ephantus
Kihara, Jimmy
Mwandawiro, Charles
https://karuspace.karu.ac.ke/handle/20.500.12092/2803
2023-03-09T00:00:14Z
2016-02-17T00:00:00Z
Current Status of Soil-Transmitted Helminths among School Children in Kakamega County, Western Kenya Prevalence and Intensity of Intestinal Parasites in School age Children in Thika District, Kenya
Ngonjo, Teresia; Okoyo, Collins; Andove, Julius; Simiyu, Elses; Lelo, Agola Eric; Kabiru, Ephantus; Kihara, Jimmy; Mwandawiro, Charles
Background. School age children are at high risk of soil-transmitted helminth (STH) worldwide. In Kenya, STH infections in children remain high despite the periodic administration of anthelmintic drugs. Our study assessed the prevalence and intensity of STH in primary school-aged children in Kakamega County, western Kenya. Methodology. We carried out a cross-sectional study on a population of 731 children attending 7 primary schools in March 2014. Children aged 4–16 years were examined for STH by the quantitative Kato-Katz technique. Infection intensities were expressed as eggs per gram (epg) of faeces. Findings. Among 731 school children examined for STH, 44.05% were infected. Highest prevalence of STH was in Shitaho primary school where 107 participants were examined and 62.6% were infected with mean intensity of 11667 epg. Iyenga had the least prevalence where 101 participants were examined and 26.7% were infected with mean intensity of 11772 epg. A. lumbricoides was the most prevalent STH species with 43.5% infected, while hookworm infections were low with 1.8% infected. Conclusion. Prevalence of STHs infections in Kakamega County remains high. We recommend guidelines and other control strategies to be scaled up to break transmission cycles.
Current Status of Soil-Transmitted Helminths among School Children
2016-02-17T00:00:00Z
A new mite IPM strategy: predator avoidance behaviour resulting from the synergetic effects of predator release and acaricide‐treated nets
Kungu, Miriam
Deletre, Emilie
Subramanian, Sevgan
Fiaboe, Komi Km
Gitonga, Linus
Lagat, Zipporah Osiemo
Thibaud, Martin
https://karuspace.karu.ac.ke/handle/20.500.12092/2762
2023-01-13T00:00:15Z
2018-10-26T00:00:00Z
A new mite IPM strategy: predator avoidance behaviour resulting from the synergetic effects of predator release and acaricide‐treated nets
Kungu, Miriam; Deletre, Emilie; Subramanian, Sevgan; Fiaboe, Komi Km; Gitonga, Linus; Lagat, Zipporah Osiemo; Thibaud, Martin
Background: Tetranychus evansi and T. urticae spider mites are known major pests of Solanaceae. Smallholders in Africa rely heavily on pesticide treatments. However, farmers claim that pesticides are generally ineffective despite high-frequency sprays. New management solutions are thus urgently needed. This study assessed the efficacy of using acaricide-treated nets combined with predatory mite release for controlling spider mites.
Results: The results showed the acaricide-treated net alone was more effective at reducing numbers of T. urticae than T. evansi. We observed the opposite for release of the predatory mite Phytoseiulus longipes. This difference could be explained by the specific dispersion strategies of the two spider mite pests; T. evansi is gregarious, whereas T. urticae dispersed rapidly. Joint application of both techniques resulted in a synergetic effect that reduced T. evansi and T. urticae spider mite numbers close to zero. The synergetic effect could be explained by predator avoidance behaviour of the prey spider mites, resulting in higher prey trapping and killing rates on acaricide-treated nets, while P. longipes fed on spider mite eggs.
Conclusion: These techniques are profitable for smallholders as they are not expensive and avoid residues on the crop. © 2018 Society of Chemical Industry.
A new mite IPM strategy
2018-10-26T00:00:00Z