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INTRODUCTION: Improvements in computed tomography (CT) technology in terms of image quality and reduction in absorbed dose have increased its applications in medical imaging. Diagnostic reference levels (DRLs) help to identify high radiation doses that are unusually delivered to patients undergoing exposure to ionising radiation. The aim of this review was to provide an overview of published studies by African researchers towards establishing paediatric CT DRLs in Africa. METHODS: The search for articles was conducted using some relevant literature search engines including PubMed, Scopus, Science Direct, Google Scholar and Web of Science. Two reviewers were involved in the article selection process which involved a three-stage screening process of identifying; article titles, abstracts and full-test reading. RESULTS: One hundred and seventy-four articles were identified from the database, PubMed (30), Scopus (21), Google Scholar (53), Web of Science (25) and Science Direct (45). Fifty duplicated articles were excluded before screening. Twelve peer-reviewed articles were included in this study based on the inclusion criteria. DRL values in terms of computed tomography dose index volume of head for the age groupings 0-1, 1-5, 5-10 and 10-15 were 27, 36.6, 39.5 and 47.5 mGy while the dose length product values were 461.6, 664, 872 and 978 mGy.cm respectively. The DRLs were calculated as 75th percentile of the local DRLs reported by the 12 articles included in this review. CONCLUSION: This review has shown that only few of the African countries (19%) have published studies on paediatric CT DRLs. There were variations in the DRLs published by the various authors which indicate that harmonisation and standardisation of paediatric CT protocols is essential for the optimisation of paediatric doses.

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Magnetic Resonance Imaging (MRI) employs a radiofrequency electromagnetic field to create pictures on a computer. The prospective biological consequences of exposure to radiofrequency electromagnetic fields (RF EMFs) have not yet been demonstrated, and there is not enough evidence on biological hazards to offer a definite response concerning possible RF health dangers. Therefore, it is crucial to research the health concerns in reaction to RF EMFs, considering the entire exposure in terms of patients receiving MRI. Monitoring increases in temperaturein-vivothroughout MRI scan is extremely invasive and has resulted in a rise in the utilization of computational methods to estimate distributions of temperatures. The purpose of this study is to estimate the absorbed power of the brain exposed to RF in patients undergoing brain MRI scan. A three-dimensional Penne's bio-heat equation was modified to computationally analyze the temperature distributions and potential thermal effects within the brain during MRI scans in the 0.3 T to 1.5 T range (12.77 MHz to 63.87 MHz). The instantaneous temperature distributions of thein-vivotissue in the brain temperatures measured at a time, t = 20.62 s is 0.2 °C and t = 30.92 s is 0.4 °C, while the highest temperatures recorded at 1.03 min and 2.06 min were 0.4 °C and 0.6 °C accordingly. From the temperature distributions of thein-vivotissue in the brain temperatures measured, there is heat build-up in patients who are exposed to electromagnetic frequency ranges, and, consequently, temperature increases within patients are difficult to prevent. The study has, however, indicated that lengthier imaging duration appears to be related to increasing body temperature.

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The impact of invasive species on biodiversity, food security and economy is increasingly noticeable in various regions of the globe as a consequence of climate change. Yet, there is limited research on how climate change affects the distribution of the invasive Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera:Liviidae) in Ghana. Using maxnet package to fit the Maxent model in R software, we answered the following questions; (i) what are the main drivers for D. citri distribution, (ii) what are the D. citri-specific habitat requirements and (iii) how well do the risk maps fit with what we know to be correctly based on the available evidence?. We found that temperature seasonality (Bio04), mean temperature of warmest quarter (Bio10), precipitation of driest quarter (Bio17), moderate resolution imaging spectroradiometer land cover and precipitation seasonality (Bio15), were the most important drivers of D. citri distribution. The results follow the known distribution records of the pest with potential expansion of habitat suitability in the future. Because many invasive species, including D. citri, can adapt to the changing climates, our findings can serve as a guide for surveillance, tracking and prevention of D. citri spread in Ghana.

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As significant threats to global citrus production, Diaphorina citri (Kuwayama; Hemiptera: Psyllidae) and Trioza erytreae (Del Guercio; Hemiptera: Triozidae) have caused considerable losses to citrus trees globally. Diaphorina citri vectors "Candidatus Liberibacter asiaticus" and "Ca. L. americanus", whereas T. erytreae transmits "Ca. L. africanus" and "Ca. L. asiaticus", the pathogens responsible for citrus greening disease or Huanglongbing (HLB). Though HLB is a destructive disease of citrus wherever it occurs, information on the occurrence and geographical distribution of its vectors in Africa is limited. In recent surveys to determine if HLB vectors are present in Ghana, we observed eggs, nymphs, and adults of insects suspected to be D. citri and T. erytreae. Using morphological traits and DNA analyses, the identity of the suspected insects was confirmed to be D. citri and T. erytreae. Individuals of D. citri and T. erytreae were examined using qPCR for CLaf, CLam, and CLas, but none of them tested positive for any of the Liberibacter species. Herein we report, for the first time, the presence of D. citri and T. erytreae in Ghana (West Africa). We discuss the implications of this new threat to the citrus industry to formulate appropriate management strategies.

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Pesticide residues historically represent a severe threat to public health and the environment. Several species worldwide are still in danger from pesticide residues, despite efforts to mitigate the adverse health effects of these pollutants. As agricultural output has increased and scientific understanding has advanced, new methods have emerged for degrading pesticide traces. The remarkable effectiveness of ozone as a broad-spectrum disinfectant and its potential to destroy pesticide residues have led to its widespread use as a residue-free method for improving soil quality, disinfecting food, and treating water, among other benefits. Ozone is cheap to manufacture, making it an affordable option for treating harmful pesticide residues. Its capacity to degrade pesticides without negatively impacting the environment has increased its adoption as a tool for cleaning up after pesticide use. This review extensively provides an overview of ozonation for pesticide residues removal in different settings and applications. Ozone treatment of pesticide residues in the soil, water and food is effective in removing pesticides residues. We highlight recent advances in methods of removing pesticide residues. We discuss several challenges related to the ozone treatment of pesticide residues. Whether used alone or in conjunction with other processes, ozone is highly effective at removing pesticide residues from the environment. Therefore, we recommend this holistic and environmentally friendly strategy to reduce pesticide residues.

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INTRODUCTION: In Ghana, Corchorus olitorius, Solanum macrocarpon and Amaranthus cruentus are green leafy vegetables that are customarily eaten together with a starchy staple food. The present study aimed at assessing the ethanolic leaf extract of C. olitorius, S. macrocarpon and A. cruentus for antioxidant capacity, phytochemical property, nutritional and anti-nutrient content. METHOD: Phytochemical constituent and proximate analysis were determined using standard protocols. The DPPH scavenging activity was used to determine the antioxidant activity of the ethanolic leaf extracts from the three vegetables. The antinutrients phytate and oxalate were determined by titrimetric methods of analysis. RESULTS: Pytochemical screening revealed the presence of tannins and flavonoids in C. olitorius, S. macrocarpon and A. cruentus. Alkaloids and saponins were present in C. olitorius and S. macrocarpon but not in A. cruentus. Terpenoids, steroids, carotenoids and coumarins were absent in all the three vegetables. Proximate analysis revealed varying levels of moisture, fat, protein, ash, crude fibre and carbohydrates in the three leafy vegetables. The DPPH scavenging showed 86.71%, 71.72% and 38.86% activity for S. macrocarpon, C. olitorius and A. cruentus respectively. The antinutrient results revealed an oxalate level of 2.7 ± 0.13% for C. olitorius, 6.43 ± 0.06% for A. cruentus and 12.32 ± 0.13% for S. macrocarpon. For levels of phytates, our results revealed a 3.084 ± 0.54%, 1.14 ± 0.26% and 1.71 ± 0.27% for C. olitorius, A. cruentus and S. macrocarpon, respectively. CONCLUSION: The current study has shown that C. olitorius, A. cruentus and S. macrocarpon possess important phytochemicals, nutrients and significant antioxidant activity, suggesting a potential of these vegetables against diverse disease, if eaten by humans.