Quantification and characterization of microplastics ingested by mangrove oysters across West Africa.

Microplastic ingestion by marine organisms presents a challenge to both ecosystem functioning and human health. We characterized microplastic abundance, shape, size, and polymer types ingested by the West African mangrove oyster, Crassostrea tulipa (Lamarck, 1819) sampled from estuaries and lagoons from the Gambia, Sierra Leone, Ghana, Benin, and Nigeria using optical microscopy and Fourier transform infrared (FTIR) techniques. A total of 780 microplastics were isolated in the whole tissues of the 250 oysters (n = 50 oysters per country). The abundance and distribution of microplastics in the oysters followed the pattern: the Gambia > Ghana > Sierra Leone > Nigeria > Benin. The Tanbi wetlands in the Gambia recorded the highest average of 10.50 ± 6.69 per oyster while the Ouidah lagoon in Benin recorded the lowest average of 1.80 ± 1.90 per oyster. Overall, microplastic numbers varied significantly (p < 0.05) among the five countries. Microfibers, particularly those within 1001-5000 µm size, dominated the total microplastic count with a few fragments and films. No spherical microplastics were isolated in the oysters. In the Sierra Leone and Benin oysters, fragments and films were absent in the samples. Microplastic between the 1001 and 5000 µm size class dominated the counts, followed by 501-1000 µm, 101-500 µm, and 51-100 µm. Five polymer groups namely polyethylene, polyester, nylon, polypropylene, and polyamide were identified across the five countries, with polyethylene occurring in oysters from all five countries and polyester occurring in all but the oysters from Nigeria. This diversity of polymers suggests varied sources of microplastics ingested by the studied oysters. The absence of microspheres across the five supports findings from other studies that they are the least ingested and highly egested by the oysters.

Microplastics in the Volta Lake: Occurrence, distribution, and human health implications.

Pollution of plastic waste in aquatic ecosystems in Ghana is of significant concern with potential adverse effects on food safety and ecosystem function. This study examined the abundance and distribution of microplastics (MPs) in freshwater biota samples namely: the African river prawn (Macrobrachium vollenhovenii), the Volta clam (Galatea paradoxa), Nile tilapia (Oreochromis niloticus), and sediment from the Volta Lake. Both biota and sediment samples were subjected to microscopic identification and FTIR analysis. In biota samples, the highest mean microplastic abundance of 4.7 ± 2.1 items per individual was found in the prawn, while the Nile tilapia recorded the least (2.8 ± 0.6 items per individual). A total of 398 microplastic particles were observed in sediment samples from the Volta Lake. Microfibers were the major plastic shapes identified in biota and sediment samples. We examined the relationship between microplastic abundance, biota size, and sediment properties. Despite the lack of statistical significance, microplastic shape, size, and polymer composition in assessed organisms mirrored those in the benthic sediment. Polyethylene, polypropylene, polyester, and polystyrene were the four dominant polymer types identified in the organisms and sediments. Although the estimated human exposure was relatively low compared with studies from other regions of the world, the presence of microplastics raises concern for the safety of fisheries products consumed by the general populace in the country. This research is essential for developing effective mitigation measures and tackling the wider effects of microplastic contamination on Ghana's freshwater ecosystems, particularly the Volta Lake.

Distal Limb Ischaemia in Association With Takotsubo Cardiomyopathy.

Raynaud's phenomenon (RP) is a common clinical condition associated with digital ischaemia. A 73-year-old woman with a history of RP presented with bilateral distal lower limb ischaemia. Although no chest pain was reported, her serum troponin was greater than 25,000 ng/ml with lateral lead ST-segment elevation on ECG. Her coronary angiogram was normal, but echocardiography revealed a hypokinetic apical region consistent with Takotsubo cardiomyopathy. She was treated with iloprost, but her toes became necrotic, mummified and auto-amputated over six months. It is hypothesised that a surge in serum catecholamines may link the two processes.

Plastic waste and fish landed by beach seine fishers in coastal Ghana.

Baseline data on plastic landing by fishers and monitoring of this is important in evaluating the success of plastic waste management efforts. This study investigated plastic and fish landed by beach seine fishers in Ghana together with the rate of plastic deposition on an adjoining beach. Plastic constituted 31.6% of the total catch and 41.7% of the fish landed by weight. There were significant differences between the average weight of fish (139.58 ± 53.6 kg) and plastic (65.73 ± 14.6 kg) landed per fishing session and the catch per unit effort of fish (183.4 ± 76.7 kg/day) and plastic (88.4 ± 35.2 kg/day). The mean weight of plastic landed per fishing session was higher than the mean weight of each of the 26 species of fisheries. The rate of plastic deposition on the beach was 8.1 ± 2.5 plastic items per m2 per tidal cycle or 0.35 ± 0.11 kg plastic per m2 per tidal cycle with food packs and tableware dominating the deposited plastic. The results suggested ongoing water sachets and plastic bottle recycling in Ghana are yielding results and calls for targeted efforts in plastic food packs and tableware management.

Potential human health risks associated with ingestion of heavy metals through fish consumption in the Gulf of Guinea.

Heavy metal pollution of the marine environment has toxic implications for both the aquatic biota and human health. We examined the levels of Zinc (Zn), Lead (Pb), Copper (Cu), Cadmium (Cd), Arsenic (As) and Mercury (Hg) in muscles of Sardinella maderensis, Dentex angolensis, Sphyraena sphyraena and Penaeus notialis caught from the coastal waters of Ghana using inductively coupled plasma mass spectrometry method. Penaeus notialis recorded the highest concentrations of all the metals (Cu:12.08 ± 1.46 µg/g, Zn: 19.20 ± 2.27 µg/g, As: 8.46 ± 2.42 µg/g, and Cd: 0.03 ± 0.01 µg/g) except Hg. Mercury was relatively high in D. angolensis (0.14 ± 0.03 µg/g). Apart from As, all metals were within globally permissible daily limits for consumption by human per meal. The estimated Target Hazard Quotient due to the intake of Hg through D. angolensis consumption exceeded the threshold value across all age categories. Carcinogenic risks due to As intake through P. notialis consumption far exceeded the 10-6 threshold for all age groups in Ghana. It is recommended that the consumption of these fish species particularly, the shrimp P. notialis be done cautiously to avoid possible future health challenges.

Optimal zinc level and uncertainty quantification in agricultural soils via visible near-infrared reflectance and soil chemical properties.

Zinc (Zn) is a vital element required by all living creatures for optimal health and ecosystem functioning. Therefore, several researchers have modeled and mapped its occurrence and distribution in soils. Nonetheless, leveraging model predictive performances while coupling information derived from visible near-infrared (Vis-NIR) and soils (i.e. chemical properties) to estimate potential toxic elements (PTEs) like Zn in agricultural soils is largely untapped. This study applies two methods to rapidly monitor Zn concentration in agricultural soil. Firstly, employing Vis-NIR and machine learning algorithms (MLAs) (Context 1) and secondly, applying Vis-NIR, soil chemical properties (SCP), and MLAs (Context 2). For the Vis-NIR information, single and combined pretreatment methods were applied. The following MLAs were used: conditional inference forest (CIF), partial least squares regression (PLSR), M5 tree model (M5), extreme gradient boosting (EGB), and support vector machine regression (SVMR) respectively. For context 1, the results indicated that M5-MSC (M5 tree model-multiplicative scatter correction) with coefficient of determination (R2) = 0.72, root mean square error (RMSE) = 21.08 (mg/kg), median absolute error (MdAE) = 13.69 and ratio of performance to interquartile range (RPIQ) = 1.63 was promising. Regarding context 2, CIF with spectral pretreatment and soil properties [CIF-DWTLOGMSC + SCP (conditional inference forest-discrete wavelet transformation-logarithmic transformation-multiplicative scatter correction-soil chemical properties)] yielded the best performance of R2 = 0.86, RMSE = 14.52 (mg/kg), MdAE = 6.25 and RPIQ = 1.78. Altogether, for contexts 1 and 2, the CIF-DWTLOGMSC + SCP approach (context 2) was the best Zn model outcome for the agricultural soil. The uncertainty map revealed a low to high error distribution in context 1, and a low to moderate distribution in context 2 for all models except CIF, which had some patches with high uncertainty. We conclude that a multiple optimization approach for modeling Zn levels in agricultural soils is invaluable and may provide fast and reliable information needed for area-specific decision-making.

Abnormal Driving Detection using GPS Data.

Given a GPS dataset comprising driving records captured at one-second intervals, this research addresses the challenge of Abnormal Driving Detection (ADD). The study introduces an integrated approach that leverages data preprocessing, dimensionality reduction, and clustering techniques. Speed Over Ground (SOG), Course Over Ground (COG), longitude (lon), and latitude (lat) data are aggregated into minute-level segments. We use Singular Value Decomposition (SVD) to reduce dimensionality, enabling K-means clustering to identify distinctive driving patterns. Results showcase the methodology's effectiveness in distinguishing normal from abnormal driving behaviors, offering promising insights for driver safety, insurance risk assessment, and personalized interventions.

Occurrence of microplastics in wild oysters (Crassostrea tulipa) from the Gulf of Guinea and their potential human exposure.

The high dependence on plastics in Ghana has resulted in the generation of large quantities of plastic waste which are poorly managed and improperly disposed into the aquatic environments. This study assessed the spatial distribution and abundance of microplastics in mangrove oysters (Crassostrea tulipa): a major fishery resource of commercial importance in Ghana. The results showed that 84.0% of all individuals examined had ingested microplastics. A total of 276 microplastic items were recovered from the 120 individual oysters. Densu (100%) and Volta (93%), two estuaries situated in urban areas, had a greater incidence of microplastics than Whin (77%) and Nakwa (66%), estuaries situated in peri-urban and rural settlements, respectively. The mean microplastic abundance ranged from 1.4 to 3.4 items/individual and 0.34 to 1.7 items/g tissue wet weight. Fiber accounted for 69% of microplastic shapes, followed by fragments (27%) and films (4%). Polymer analysis showed polyethylene (PE), polypropylene (PP) and polystyrene (PS) as the most common types in oysters. The estimated microplastic intake per capita per year was one magnitude higher than the mean for other countries. This high rate of human exposure to microplastics requires an eminent policy formulation to guide the use, management and disposal of plastic waste in Ghana.

Occurrence of microplastics in gastrointestinal tract of fish from the Gulf of Guinea, Ghana.

Over the past decades, there has been a growing concern about microplastics pollution in global aquatic habitats and its potential impact on human health. This study was carried out to determine the presence of microplastics in fish of economic importance in Ghana. Microplastics were found to be abundant in all investigated samples, with 68 % of the fishes contaminated with microplastics and a total of 133 plastic items identified in the fish. The presence of fibers, black coloured particles, and microplastics in the size range of 0.5-1.0 mm was the most abundant in the samples examined. Three polymers specifically, polyethylene, polyvinyl acetate, and polyamide were identified in the study. The presence of microplastics in the fishes investigated may pose severe ecological and health concerns, and hence comprehensive policies targeted at preventing plastic pollution of Ghana's maritime environment is warranted.

'Attorneys of the poor': Training physicians to tackle health inequalities.

The stellar gains in life expectancy and health over the past century have been accompanied by an increase in societal and health inequalities. This health gap between the most and least fortunate in our society is widening, driven by complex social determinants of health, as well as healthcare systems themselves. Physicians are not just well-qualified and well-placed to act as advocates for change, but have a moral duty to do so: to stand by silently is to be complicit. Following a workshop on health inequalities and medical training at the Royal College of Physicians Trainees Committee, we sought to examine how health inequalities could be addressed through changes to the medical education system. We discuss the arguments for reform in recruitment to medicine, and changes to undergraduate, postgraduate and continuing medical education in order to equip the profession to deliver meaningful improvements in health inequalities. We propose a population health credential as a mechanism by which specialists can gain additional skills to take on leadership roles addressing health inequalities, allowing them to support colleagues in public health and bring in specialty-specific knowledge and experience.

Artery of Percheron infarct: hiding in plain sight.

A 54-year-old woman presented to the emergency department with fluctuating consciousness without localising signs and non-specific neurology. Urgent computed tomography (CT) was unremarkable and differentials of opioid overdose or post-ictal state were considered. Magnetic resonance imaging of the brain demonstrated an artery of Percheron (AOP) infarct; resulting from occlusion of an uncommon anatomical variant in the thalamic and midbrain circulation. This should be considered in patients presenting with fluctuating consciousness and normal CT.

Ascorbate and ferritin interactions: Consequences for iron release in vitro and in vivo and implications for inflammation.

This review discusses the chemical mechanisms of ascorbate-dependent reduction and solubilization of ferritin's ferric iron core and subsequent release of ferrous iron. The process is accelerated by low concentrations of Fe(II) that increase ferritin's intrinsic ascorbate oxidase activity, hence increasing the rate of ascorbate radical formation. These increased rates of ascorbate oxidation provide reducing equivalents (electrons) to ferritin's core and speed the core reduction rates with subsequent solubilization and release of Fe(II). Ascorbate-dependent solubilization of ferritin's iron core has consequences relating to the interpretation of 59Fe uptake sourced from 59Fe-lebelled holotransferrin into ferritin. Ascorbate-dependent reduction of the ferritin core iron solubility increases the size of ferritin's iron exchangeable pool and hence the rate and amount of exchange uptake of 59Fe into ferritin, whilst simultaneously increasing net iron release rate from ferritin. This may rationalize the inconsistency that ascorbate apparently stabilizes 59Fe ferritin and retards lysosomal ferritinolysis and whole cell 59Fe release, whilst paradoxically increasing the rate of net iron release from ferritin. This capacity of ascorbate and iron to synergise ferritin iron release has pathological significance, as it lowers the concentration at which ascorbate activates ferritin's iron release to within the physiological range (50-250 µM). These effects have relevance to inflammatory pathology and to the pro-oxidant effects of ascorbate in cancer therapy and cell death by ferroptosis.

The therapeutic role of ivabradine in heart failure.

Heart failure represents a major global cause of morbidity and mortality. Ivabradine is a selective funny current (If) inhibitor, which acts on the sinoatrial node, resulting in a reduction in heart rate. Ivabradine is currently licensed for use in patients with symptomatic heart failure with reduced ejection fraction and a heart rate persistently at least 70 beats per minute in spite of otherwise optimal prognostic heart failure pharmacotherapy. In this review article, we examine the mechanism of action of ivabradine, evaluate the clinical trials underpinning its application in heart failure and discuss its current recommended clinical use in this capacity.

Labile iron potentiates ascorbate-dependent reduction and mobilization of ferritin iron.

Ascorbate mobilizes iron from equine spleen ferritin by two separate processes. Ascorbate alone mobilizes ferritin iron with an apparent Km (ascorbate) ≈1.5mM. Labile iron >2µM, complexed with citrate (10mM), synergises ascorbate-dependent iron mobilization by decreasing the apparent Km (ascorbate) to ≈270µM and raising maximal mobilization rate by ≈5-fold. Catalase reduces the apparent Km(ascorbate) for both ascorbate and ascorbate+iron dependent mobilization by ≈80%. Iron mobilization by ascorbate alone has a higher activation energy (Ea=45.0±5.5kJ/mole) than when mediated by ascorbate with labile iron (10µM) (Ea=13.7±2.2kJ/mole); also mobilization by iron-ascorbate has a three-fold higher pH sensitivity (pH range 6.0-8.0) than with ascorbate alone. Hydrogen peroxide inhibits ascorbate's iron mobilizing action. EPR and autochemiluminescence studies show that ascorbate and labile iron within ferritin enhances radical formation, whereas ascorbate alone produces negligible radicals. These findings suggest that iron catalysed single electron transfer reactions from ascorbate, involving ascorbate or superoxide and possibly ferroxidase tyrosine radicals, accelerate iron mobilization from the ferroxidase centre more than EPR silent, bi-dentate two-electron transfers. These differing modes of electron transference from ascorbate mirror the known mono and bidentate oxidation reactions of dioxygen and hydrogen peroxide with di-ferrous iron at the ferroxidase centre. This study implies that labile iron, at physiological pH, complexed with citrate, synergises iron mobilization from ferritin by ascorbate (50-4000µM). This autocatalytic process can exacerbate oxidative stress in ferritin-containing inflamed tissue.

Industrial noise pollution and its effects on the hearing capabilities of workers: A study from saw mills, printing presses and corn mills.

The purpose of this study was to ascertain industrial noise pollution and its effects on the hearing capabilities of workers. The procedure adopted included noise measurements, otoscopy, audiometric evaluation and assessment of medical history. The results showed that noise levels in corn mills and saw mills exceed 85dBA. The average noise level measured in the printing industry was 85dBA. It was also found that 23 %, 20 % and 7.9 % of workers in corn mills, saw mills and the printing industry have evidence of noise-induced hearing loss (NIHL). A highly significant correlation was found between noise exposure level, duration of exposure and the development of NIHL in corm mills and saw mills but not in the printers. Hearing - impairment was also observed at the speech frequencies among some of the workers exposed to hazardous noise. These findings suggest that more specific intervention is required to protect workers exposed to such hazards at the work places employed in this study.