Coronavirus Disease 2019 (COVID-19) spreads rapidly and is easily contracted by individuals who come near infected persons. With this nature and rapid spread of the contagion, different types of research have been conducted to investigate how non-pharmaceutical interventions can be employed to contain and prevent COVID-19. In this review, we analyzed the key elements of digital contact tracing strategies developed for the prevention and containment of the dreaded epidemic since its outbreak. We carried out a scoping review through relevant studies indexed in three databases, namely Google Scholar, PubMed, and ACM Digital Library. Using some carefully defined search terms, a total of 768 articles were identified. The review shows that 86.32% (n = 101) of the works focusing on contact tracing were published in 2020, suggesting there was an increased awareness that year, increased research efforts, and the fact that the pandemic was given a very high priority by most journals. We observed that many (47.86%, n = 56) of the studies were focused on design and implementation issues in the development of COVID-19 contact tracing systems. In addition, has been established that most of the studies were conducted in 41 countries and that contract tracing app development are characterized by some sensitive issues, including privacy-preserving and case-based referral characteristics.

Aims: A study was carried out to determine the effect of replacing fishmeal with Leucaena leucoephala leaf meal in the diet of Tilapia zilli fingerlings. Study Design: Three hundred (300) Tilapia zilli fingerlings (9.5±0.5 g/fish, mixed sex) fed with diet containing Leucaena leucoephala leaf meal for 10 weeks at 0%, 2.5%, 5.0%, 7.5% and 10.0% level of inclusion, representing the replacement of fish meal at 0%, 25% 75% and 100% respectively. Place and Duration of Study:  A study was carried out in the wet laboratory of Fisheries Technology department of Lagos State Polytechnic, Ikorodu between July 2017 and October 2017. Methodology: Tilapia sp. fingerlings were treated with five diets including a control experiment of which each treatment was replicated thrice, the total number of replicates was fifteen and the experiment was laid out in a completely randomized design. Results: Statistical analyses revealed that there was no significant difference (P=05) in weight gain, feed conversion ratio and protein efficiency ratio. Conclusion: L. leucocephala can be recommended in the diet of Tilapia zilli because of its economic in terms of cheapness and abundance especially in the tropical region and its nutritional values as a good source of plant protein.

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Aim:  To evaluate the polycyclic aromatic hydrocarbons (PAHs) concentrations in fresh and smoked Clarias geriepinus. Study Design: Fifty numbers of fresh Clarias geriepinus which range in weight between 200.5g and 655.2g were collected from selected clustered farmers and categorized based on their weight into five groups. The tissues were collected from each fresh fish for analysis of PAHs before smoking. Place and Duration of Study: The sampled fish were collected from government assisted clustered fish farm estate. The analyses for PAHs were conducted for two weeks in year 2022 at the central laboratory of Nigeria Institute for Oceanography and Marine Research Methodology: The laboratory procedures and analyses for the detection of sixteen PAHs in the muscles of fresh and smoked on each five grouped of C. geriepinus were carried out using Gas Chromatography (Model HP 6890A). Results: The results shows presence of PAHs in both locally smoked and fresh Clarias geriepinus therefore, there is no significant difference in the means concentrations of PAHs in both tissues but significant difference occurs (p=.05) in the grouped smoked fish with Indeno (1, 2, 3-c, d) Pyrene mean concentrations higher in both fresh and smoked fish. Conclusion: PAHs concentrations from both fresh and smoked C. geriepinus muscles are below the FAO/WHO threshold limit. It is therefore safe for human consumption but a gas or electric powered smoking kiln is hereby recommended to prevent further accumulation of PAHs in smoked fish which could be carcinogenic to human consumers.