An assessment of the levels of phthalate esters and metals in the Muledane open dump, Thohoyandou, Limpopo Province, South Africa

<p>Abstract</p> <p>Background</p> <p>This work reports the determination of the levels of phthalate esters (dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diethyl hexyl phthalate (DEHP)) and metals (lead, cadmium, manganese, zinc, iron, calcium) in composite soil samples. The soil samples were collected randomly within the Muledane open dump, Thohoyandou, Limpopo province, South Africa. Control samples were collected about 200 m away from the open dump. The phthalate esters were separated and determined by capillary gas chromatography with a flame ionization detector, whilst the metals were determined by atomic absorption spectrophotometry.</p> <p>Results</p> <p>Open dump values for the phthalate esters and metals to be generally higher in comparison to control samples for DMP, DEP, DBP and DEHP – the mean values calculated were 0.31 ± 0.12, 0.21 ± 0.05, 0.30 ± 0.07, and 0.03 ± 0.01 mg/kg, respectively, for the open dump soil samples. Nonetheless, the mean open dump values for lead, cadmium, manganese, zinc, iron and calcium were 0.07 ± 0.04, 0.003 ± 0.001, 5.02 ± 1.92, 0.31 ± 0.02, 11.62 ± 9.48 and 0.12 ± 0.13 mg/kg, respectively. The results were compared statistically.</p> <p>Conclusion</p> <p>Our results revealed that the discarding of wastes into the open dump is a potential source of soil contamination in the immediate vicinity and beyond, <it>via </it>dispersal. Increased levels of phthalate esters and metals in the soil pose a risk to public health, plants and animals. Sustained monitoring of these contaminants is recommended, in addition to upgrading the facility to a landfill.</p

The Burden of Influenza-Associated Hospitalizations in Oman, January 2008-June 2013

Acute respiratory infections (ARI), including influenza, comprise a leading cause of morbidity and mortality worldwide. Influenza surveillance provides important information to inform policy on influenza control and vaccination. While the epidemiology of influenza has been well characterized in western countries, few data exist on influenza epidemiology in the Eastern Mediterranean Region. We describe the epidemiology of influenza virus in Oman.Using syndromic case definitions and protocols, patients from four regional hospitals in Oman were enrolled in a descriptive prospective study to characterize the burden of severe acute respiratory infections (SARI) and influenza. Eligible patients provided demographic information as well as oropharyngeal (OP) and nasopharyngeal (NP) swabs. Specimens were tested for influenza A and influenza B; influenza A viruses were subtyped using RT-PCR.From January 2008 through June 2013, a total of 5,147 cases were enrolled and tested for influenza. Influenza strains were detected in 8% of cases for whom samples were available. Annual incidence rates ranged from 0.5 to 15.4 cases of influenza-associated SARI per 100,000 population. The median age of influenza patients was 6 years with children 0-2 years accounting for 34% of all influenza-associated hospitalizations. By contrast, the median age of non-influenza SARI cases was 1 year with children 0-2 years comprising 59% of SARI. Compared to non-influenza SARI cases, a greater proportion of influenza cases had pre-existing chronic conditions and underwent ventilation during hospitalization.Influenza virus is associated with a substantial proportion of SARI in Oman. Influenza in Oman approximately follows northern hemisphere seasonality, with major peaks in October to December and a lesser peak around April. The burden of influenza was greatest in children and the elderly. Future efforts should examine the burden of influenza in other potential risk groups such as pregnant women to inform interventions including targeted vaccination

Socio-Technical Interplay in a Two-Sided Market: The Case of Learning Platforms

The rise of the platform era changes the way interactions are structured and enables transactions at a distance. The platform phenomena also enables co-creation of content, shifting the way services are delivered across diverse boundaries. This is especially apparent in workplaces, where the developments change roles, relationships and conditions for teaching and learning, creating the possibility of a two-sided market. From a socio-technical and socio-cultural learning perspective, this study primarily aims for a better understanding of platforms in higher educational settings. Using a learning platform as an illustrative case, we argue for platform context transactions that are not monetary transactions. The main contribution of the paper is to offer a discussion where we problematize the transactional concept in two-sided markets. The findings shed new light on emerging challenges and tensions in the interplay between the constant change of technology and what it means to work in such change. This has implications for both teaching and learning and offers insights that can be valuable for understanding the shift to online learning during the recent pandemic of covid-19.</p

Role of Mineral Nutrients in Plant Growth Under Extreme Temperatures

Food productivity is decreasing with the drastic increase in population, while it is expected that the global population will be nine to ten billion in 2050. Growth, production, and development on whole plant, cell, and subcellular levels are extremely affected by environmental factors particularly with the extreme temperature events (high- or low-temperature stress). Increase in the fluidity of lipid membrane, protein accumulation, and denaturation are the direct effects of high temperature on a plant. Membrane integrity loss, protein deprivation, protein synthesis inhabitation, and inactivation of mitochondrial and chloroplast enzymes are the indirect effects of high temperature. Similarly, the oval abortion, alteration of the pollen tube, reduction in fruit set, pollen sterility, and flower abscission are the consequences of low temperature at the time of product development, which in turn lowers the yield. The judicious nutrient management is essential for improving the plant nutrition status to mitigate the drastic effects of temperature stress as well as for sustainable plant yield under extreme temperature events, because nutrient deficiency results in growth and development problems in 60% cultivars worldwide. Additionally, effective nutrient management increases the temperature stress tolerance in plants. Therefore, the appropriate nutrient application rates and timings are imperative for alleviating the heat stress in plants and can serve as an effective and decent strategy. To minimize the contrasting effects of the environmental stresses, particularly heat stress, several examples of the supplemental applications of N, P, K, Ca, Mg, Se, and Zn are given in detail in this study, to observe how these nutrients reduce the effects of temperature stress in plants. This study concluded that judicious nutrient management minimizes the heat stress and increases the growth and yield of plants