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

Acute and chronic toxicity of pawpaw (Carica papaya) seed powder to adult Nile tilapia (Oreochromis niloticus Linne 1757)

This experiment determined the toxicity of pawpaw seed powder to adult tilapia, Oreochromis niloticus, the most cultivable fish species in Africa. The 96 h static bioassay experiment was conducted todetermine the median lethal concentration (LC50) for adult Nile tilapia, to pawpaw seed, Carica papaya. Two hundred live, and apparently healthy O. niloticus measuring 11.5 - 14.6 cm total length and 65.6 -112.4 g were used for the experiment. Eighteen (75 x 45 x 45 cm) glass tanks of 121.5 litres capacity each were filled with 50 litres aerated unchlorinated well water. The toxicant was introduced at different concentrations in triplicate per treatment. The 96-h LC50 of pawpaw seed powder to adult tilapia is 4.2 mg/l with 95% confidence limit of 31.86 – 93.81 mg/l and the maximum admissible toxicantconcentrations ranges between 0.042 - 0.42 mg/l, while the total mortality occurred in the concentration of 8 mg/l within 24 h exposure period. Toxic reaction exhibited by the fish includes erratic movement,air gulping, loss of reflex, discolouration, molting, loss of scale, and haemorrhage. The pathologic lesion of gill, skin, liver and kidney includes different level of degeneration of cells, lamellar hyperemia,hyperthrophy of gill arch, shrinkages and dermal erosion and necrosis of skin, while hyperplasia, disarrangement of hepatic cell, necrosis and vacuolation occurred in liver and kidney of adult tilapia O.niloticus. Damages became severe with increasing concentration of C. papaya to fish and time of exposure. There was no significant changes in the water quality during the experiment; the result obtained before the test, during the test and after the test were found close to the water quality parameters of the control. Results of the tests provided baseline information and established safe limits of using C. Papaya seed powder as an antifertility agent in controlling excessive breeding of tilapia infish farm

Conservation Of Biodiversity In Central Cross River State: The Role Of Indigenous Communities

The central zone of Cross River State is alarmingly being taken over by secondary vegetation as a result of over cultivation of the land, since the communities there are largely agrarian. There are some forms of traditional religious practices and beliefs typified by shrines, evil forests, sacred water and so on that have direct bearing on the conservation and management of environmental resources. This is because they lead to the conservation of fauna and flora. It is worthy to note that these practices enable forest and wildlife species to multiply and wild animals to move about freely in the forest and other habitats. This has helped the new generation to know some of the important species. In this study, a total of two hundred and six and half (206.5) hectares of land is protected under traditional way, which is divided into one hundred and twenty seven (127.7) hectares, and seventy eight (78.8) hectares of forest and aquatic areas respectively, in the Central Cross River State. This large zone of forest and aquatic areas are indirectly conserved in the Central Cross River State by the inhabitants without realizing their contribution to natural resources conservation. The groups of animals and plants involved are fully discussed in this paper

Some aspect of the physico-chemical and biological properties of Cross river, an inland water body in South-eastern Nigeria

Some aspect of Physico-Chemical and Biological properties of Cross River was investigated once every month from May 2001-May 2002, measurements were made from the surface water at three locations, Ikot Okpora in Biase, Obubra, and Ikom. The temperature of the river varied from27.38±0.74°C at Ikot Okpora to 27.79 ± 0.49°C at Ikom, the highest temperature of 29.3°C was recorded in the month of December at Obubra, while the lowest temperature of 25.9oC was recorded at Ikot Okpora in March, The Biochemical oxygen demand fluctuate widely and varied from 1.23±0.35mg/l at Ikot Okpora to1.21 ±0.26mg/l at Ikom, the highest BOD of 1.80mg/l was recorded at Ikot Okpora, in the month of April, while the lowest BOD of 0.70mg/l was recorded at Ikom in May. The pH varied from 6.63 ± 0.31 at Ikot Okpora to 6.79±0.56 at Ikom, the highest pH of 7.89 was recorded at Ikom, in the month of September, while the lowest pH of 5.17 was recorded at Obubra in November. Dissolved oxygen concentration varied from 4.8±0.02 at Ikot Okpora to 5.02±0.50 at Ikom, the highest DO2 of 5.9mg/l was recorded at Ikom and Obubra, in the month of March and November respectively, while the lowest DO2 of 4.3mg/l was recorded at Ikom and Obubra in December and January respectively. The electrical conductivity varied from 69.13±18.37µS/cm at Ikot Okpora to 322.28 ±248.40µS/cm at Ikom, the highest Conductivity 710.4µS/cm was recorded at Ikom, in the month of February, while the lowest conductivity of 20.01µS/cm was recorded at Ikot Okpora in September. TSS varied from 18.62 ±6.12mg/l at Ikot Okpora to 39.85±23.66mg/l at Ikom, the highest TSS of 75.0mg/l was recorded at Ikom, in the month of November, while the lowest TSS of 11.0mg/l was recorded at Ikot Okpora in January. Turbidity varied from 20.31 ±5.31 FTU at Ikot Okpora to 21.12±14.31 FTU at Ikom, the highest turbidity of 29.0FTU, was obtained during June at Obubra, while the lowest of 10.0FTU occurred in Ikom in April, Total Alkalinity varied from100.68±22.93 at Ikot Okpora to 119.38± 27.05 at Ikom, the highest alkalinity of 181.0mg/l was obtained during February at Obubra, while the lowest of 10.8mg/l occurred at Ikom in June. Total hardness varied from 52.25 ± 18.92 at Ikot Okpora to 47.48 ± 23.02 at Ikom, the highest value of 91.06mg/l was recorded at Ikom in the month of March while the lowest value of 12.83mg/l was recorded at Ikot Okpora in the month of April. The river had high level of nutrients, phosphate varied from 0.11±0.08mg/l at Ikot Okpora to 0.202±0.13mg/l, the highest value of 0.362mg/l was recorded at Ikom in the month of September, while the lowest level of 0.006mg/l was recorded at the three stations in April. Nitrate varied from 0.37±0.39mg/l to at Ikot Okpora to 1.01±0.69mg/l the highest value of 3.14mg/l was recorded at Obubra in March, while the lowest value of 0.8mg/l was recorded at Biase in the month of June. Silicate varied from 1.60 ±0.71mg/l at Ikot Okpora to 2.39±1.38mg/l at Ikom, colour (89.0-247.0, 78.0-199.0, 87.0-287.0) mg/l, at Ikom, Obubra and Ikot Okpra respectively. The major ions fluctuate widely between February and May, highest value was recorded in February and lowest in May, Cacium varied from14.06±5.27 at Ikot Okpora to 24.28 ±4.0 at Ikom, the highest value of 30.78mg/l was recorded at Obubra during the month of February, while the smallest value of 9.17mg/l was recorded at Ikot Okpora during the month of May. Chloride varied from 24.77±0.0 at Ikot Okpora to 93.92 ±62.30mg/l at Ikom, the highest value of 40.65mg/l was recorded at Obubra during the month of January, while the smallest value of 10.65mg/l was recorded at Ikom during the month of May. Sulphate varied from4.53 ±0.0mg/l at Ikot Okpora to 10.54 ±9.78mg/l at Ikom, the highest value of 38.34mg/l was recorded at Ikom during the month of February, while the smallest value of 0.9mg/l was recorded at Ikom during the month of May. Ammonium varied from 0.42±0.14mg/l at Ikot Okpora to 0.84 ± 0.47mg/l at Ikom, the highest value of 1.89mg/l was recorded at Ikom during the month of July, while the smallest value of 0.287mg/l was recorded at Ikot Okpra during the month of April. Metal fluctuated widely in the river, Copper varied from 0.71 ±1.0mg/l at Ikot Okpora to 2.06±2.36mg/l at Ikom, the highest value of 6.28mg/l was recorded at Obubra during the month of February, while the smallest value of 0.02mg/l was recorded at Obubra during the month of April. Iron varied from 10.54 ±1.92mg/l at Ikot Okpora to 0.202±0.13mg/l at Ikom, the highest value of 13.15mg/l was recorded at Ikot Okpora during the month of February, while the smallest value of 0.196mg/l was recorded at Obubra during the month of April. Phytoplankton was represented by five families, Chlorophyceae, Dinophyceae, Cyannophyceae, and Chrysophyceae. Dictyosphaeriun sp in the family Chyptophyceae dominated the Phytoplankton with value of 17,780cells/ml at Obubra, 213,815cells/ml at Ikot Okpora and 295,185cells/ml at Ikom, and the lowest number recorded was Tetraedron sp with 580cells/ml at Obubra, 567cells/ml at Ikot Okpora, and 956cells/ml at Ikom. Zooplankton was dominated by ciliata, Tintinnopisis sp, with value of 4,65,00cells/ml, 2,500,650cells/ml, and 5,356,000cells/ml for Obubra, Ikot Okpora, and Ikom respectively and the Zooflagellate, Collodictyon tricilliatum with value of 2,330,000cells/ml, 678,000cells/ml, and 4,105,000cells/ml for Obubra, Ikot Okpora, and Ikom respectively, while the copepod,(Naupili). with value of 400cells/ml, 567cells/ml, 875cells/ml for Obubra, Ikot Okpora, and Ikom respectively represent the least zooplankton species, Ten bacterial species, Aeromonas sp., Vibrio sp., Acinetobacter sp., Moraxella sp., Streptococi sp., Corynebacterium sp., Bacillum sp., Neisseria sp., Pseudomonas sp, and Micrococcus sp., were enumerated . Corynebacterium sp and Vibrio sp are the most dominant species with value of 9.6x10104cells/ml each. Biase is the most endemic area. Keywords: physico-chemical studies, biological studies, Cross River, inland water, Nigeria Global Journal of Agricultural Sciences Vol. 4(2) 2005: 139-15