Recovery of Zn2+, Fe2+ and Mn2+ from Some Selected Edible Vegetables and Pumpkin using Modified Maize Cobs

This study reports on the pre-concentration of some essential trace elements from vegetables using modified maize cobs by sorption. This was enabled by some functional groups anchored within the chemical structure of the material. Modification was achieved by treating the dry powdered material with thionylchloride (SOCl2) which was dispersed in dimethylformaldehyde (DMF) then reacting with ethylenediamine air drying the resultant for 24 hours. The presence of the anchored group was confirmed by FT-IR and it was used for Batch sorption experiments. The effect of pH, concentration, and dosage on the adsorption of zinc, iron and manganese ion by the parent and modified materials were carried out. Using the optimal parameters, the modified material was used for the pre-concentration of the trace metal ions from solutions of some selected vegetables samples. Pre-concentration of nutrients from fermented samples showed significantly high levels than non-fermented samples. This new method of pre-concentrating metal ions shows promising results and can improve the nutrition value in the preparation of dietary supplements. The method is effective and is of low cost

A Comparative Study of Modified and Unmodified Algae (Pediastrum boryanum) for Removal of Lead, Cadmium and Copper in Contaminated Water

The presence of heavy metals in water is of concern due to the risk toxicity. Thus there is need for their removal for the safety of consumers. Methods applied for removal of heavy metals include adsorption, membrane filtration and co-precipitation. However, studies have revealed adsorption is highly effective technique. Most adsorbents are expensive or require extensive processing before use and hence need to explore for possible sources of inexpensive adsorbents. This research work investigated the use an algal biomass (pediastrum boryanum) as an adsorbent for removal of Lead, Cadmium and Copper in waste water in its raw and modified forms. The samples were characterized with FTIR and was confirmed a successful modification with tetramethylethlynediamine (TMEDA). Sorption parameters were optimized and the material was finally applied on real water samples. It was found that the sorption was best at lower pH values (4.2-6.8). Sorption kinetics was very high as more that 90% of the metals were removed from the solution within 30 minutes. The adsorption of copper fitted into the Langmuir adsorption isotherm indicating a monolayer binding mechanism. Cadmium and lead fitted best the Freundlich adsorption mechanism. Sorption of lead and cadmium was of pseudo-second order kinetics, confirming a multisite interaction whereas copper was pseudo-first order indicating a single site adsorption. The adsorption capacity did not improve upon modification but the stability of the material was improved and secondary pollution of leaching colour was alleviated. This implies that the modified material is suitable for application on the removal of metals from water

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Copper extraction by wet chemical method

In many countries large deposits of copper with no locally established copper based industries occur because known methods for extraction are prohibitively expensive and unaffordable. This study reports on an affordable and sustainable method for the extraction of copper. This was achieved through the use of a wet chemical method which makes use of hydrazones prepared in situ from chicken dung leached solution. The method involves the reduction of copper (II) ions leached from copper ore to zero valence using chlorine treated solution prepared from chicken droppings at a temperature range of 60–70 °C. The ore samples were pulverized to 250 micro millimetres and leached with hydrochloric acid to obtain leachate containing copper ions. The dissolved copper was reduced to copper metal and obtained by filtration. It was confirmed by XRFS analysis that, the metal purity was found to range between 60 and 80% depending on the ore used. In another experiment, chicken waste solution was used to extract copper from the ore. To the mixture, chlorine gas was then bubbledthrough a glass delivery tube to prepare the hydrazone in situ at a temperature range of 60–70 °C and a pure copper metal was obtained. The findings from this study have shown that there is great potential for the production of copper at low cost and this could be applied in both small-scale cottage industries and large industries using readily available resources such as chicken dung. Keywords: Hydrazones, In situ, Reduction, Zero valence, Chicken dun

Dietary aflatoxin exposure of lactating mothers of children 0–6 months in Makueni County, Kenya

Abstract The southeastern region of Kenya is prone to aflatoxin outbreaks, yet maternal and infant aflatoxin intake levels remain unclear. We determined dietary aflatoxin exposure of 170 lactating mothers breastfeeding children aged 6 months and below in a descriptive cross‐sectional study involving aflatoxin analysis of maize‐based cooked food samples (n = 48). Their socioeconomic characteristics, food consumption patterns and postharvest handling of maize were determined. Aflatoxins were determined using high‐performance liquid chromatography and enzyme‐linked immunosorbent assay. Statistical analysis was conducted using Statistical Package Software for Social Sciences (SPSS version 27) and Palisade's @Risk software. About 46% of the mothers were from low‐income households, and 48.2% had not attained the basic level of education. A generally low dietary diversity was reported among 54.1% of lactating mothers. Food consumption pattern was skewed towards starchy staples. Approximately 50% never treated their maize, and at least 20% stored their maize in containers that promote aflatoxin contamination. Aflatoxin was detected in 85.4% of food samples. The mean of total aflatoxin was 97.8 μg/kg (standard deviation [SD], 57.7), while aflatoxin B1 was 9.0 μg/kg (SD, 7.7). The mean dietary intake of total aflatoxin and aflatoxin B1 was 7.6 μg/kg/b.w.t/day (SD, 7.5) and 0.6 (SD, 0.6), respectively. Dietary aflatoxin exposure of lactating mothers was high (margin of exposure < 10,000). Sociodemographic characteristics, food consumption patterns and postharvest handling of maize variably influenced dietary aflatoxin exposure of the mothers. The high prevalence and presence of aflatoxin in foods of lactating mothers are a public health concern and calls for the need to devise easy‐to‐use household food safety and monitoring measures in the study area

Antibacterial and Antifungal Activity of Dombeya torrida (J.F. Gmel) and Hydnora abyssinica (A. Braun)

Background: The decoction of Dombeya torrida bark is used to treat indigestion while its roots are used for treatment of chest pains and colds. Hydnora abyssinica decoction is used as a cure for throat complaints, as an astringent in dysentery, for treatment of typhoid, anthrax, and East Coast Fever. Objectives: The present study was aimed at investigating the antibacterial and antifungal activities of D. torrida and H. abyssinica. Methodology: The D. torrida stem-bark and leaves and H. abyssinica whole plant were collected from Kiambu County and Embu County, respectively. Extraction of the plants was carried out using chloroform, methanol and water. The extracts were screened for activity against Staphylococcus aureus, Staphylococcus epididermis, Bacillus pumilus, Escherichia coli, Saccromyces cerevisiae and Candida albicans using agar diffusion assay and autobioassay. Results: Dombeya torrida bark decoction had the highest activity against S. aureus with an inhibition zone diameter of 16.91 mm. Hydnora abyssinica macerate had least activity against S. aureus with a zone diameter of 8.86 mm. Dombeya torrida bark decoction had the highest activity against S. Epididermis with a diameter of 17.05 mm with Hydnora abyssinica macerate having the least activity. Activity against E. coli was highest for D. torrida bark decoction with zone diameter of 16.56 mm. Hydnora abyssinica chloroform extract had the highest activity against B. pumilus with a zone diameter of 17.04 mm. The highest activity observed against S. cerevisiae was with D. torrida chloroform extract with a zone diameter of 17.69 mm with H. abyssinica macerate having the least activity (7.70 mm). Dombeya torrida chloroform extract was the most active extract against C. albicans with a zone diameter of 20.09 mm. Conclusion: The plants under study, D. torrida and H. abyssinica were chosen on the basis of folklore. Above results support the folklore that H. abyssinica is used as a cure for throat complaints, as an astringent in dysentery, treatment of diarrhoea and amoebic dysentery. Results of D. torrida extracts also supports its folklore use to treat chest pains and colds as many of these conditions are usually caused by bacterial infections. Keywords: antibacterial, antifungal, Dombeya torrida, Hydnora abyssinica, autobioassa

Essential oils composition of Ocimum basilicum L. and Ocimum gratissimum L. from Kenya and their inhibitory effects on growth and fumonisin production by Fusarium verticillioides

This work investigated the constituents and the efficacy against Fusarium verticillioides infection and fumonisin production of essential oils of Ocimum basilicum L. and Ocimum gratissimum L. from different locations in Kenya. The oil of leaves and flowering tops of O. basilicum from Sagana contained mainly linalool (95%). The flowering tops and leaves from Yatta contained mainly camphor (32.6 and 31.0%, respectively) and linalool (28.2 and 29.3, respectively). Eugenol was the main constituent in the oil of O. gratissimum leaves from both Sagana (95.5%) and Yatta (70.1%). The oil of the flowering tops had significantly less eugenol. The main component of the oil of flowering tops from Yatta was Z-â-ocimene (34.1%). Oil from both species had some antifungal activity. The oils of O. basilicum and O. gratissimum from different locations showed chemical variation, antifungal activity, free radical scavenging capacity and antimycotoxicogenic property. These properties are attributed to the phenolic compound eugenol. Industrial relevance: This manuscript gives the chemical composition and some biological effects of essential oil of two Ocimum species in Kenya namely Ocimum basilicum L. and Ocimum gratissimum L. The work reveals that there are chemovarieties of these plants in different locations in the country. Of significance is the presence of very high amounts of linalool in one chemovariety of O. basilicum while geranial and neral are major in another. The third variety contains almost equal amounts of camphor and linalool. The first two containing high quantities of linalool, geranial and neral could be cultivated after agronomic studies to provide essential oils useful in perfumery, soap or food industry while that containing camphor and linalool may find use in medicine. Proper seed selection and good agricultural practice for O. gratissimum containing high amount of eugenol could serve as good substitute for cloves which grows best only in a few islands in East Africa. Clove oil due to its high eugenol content has many biological activities including those demonstrated in the present work, and many applications in medicine and commercial world. There is need for more research on these plants especially on cultivation and commercial exploitation of the herbs.Fil: Dambolena, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Zunino, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: López, Abel Gerardo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; ArgentinaFil: Rubinstein, Héctor Ramón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Zygadlo, Julio Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Mwangi, Julius W.. University of Nairobi; KeniaFil: Thoithi, Grace N.. University of Nairobi; KeniaFil: Kibwage, Isaac O.. University of Nairobi; KeniaFil: Mwalukumbi, Josphat M.. University of Nairobi; KeniaFil: Kariuki, Samuel T.. Egerton University; Keni