Long read: what Joe Biden’s Supreme Court comments tell us about who he may pick as vice president

With the 2020 presidential primary now all but over, attention has now turned to who the Democratic nominee – former Vice President Joe Biden – will likely choose to be his running mate. While California Senator Kamala Harris currently tops many commentators’ lists of contenders, Garikai Chimuka suggests that Joe Biden’s past statement that he will appoint the first Black woman to the US Supreme Court likely means that he will not similarly choose a Black woman to be his Vice President

A study of the Development of the Leasing Industry in Zambia

Access to credit is critical to businesses and individuals. This is because access to financing is crucial to their survival, sustainability, growth and ultimately to a country’s economic growth, employment and asset formation In Zambia, productive sectors, which are vital to economic development, face-increasing difficulty in accessing long-term finance. Leasing is an alternative to traditional forms of financing; unfortunately, the industry has not taken a prominent role in financing initiatives in Zambia. The aim of the study was to get insight of the development and challenges of leasing market in Zambia. Further, the study would provide an assessment of the contribution of the current legal and regulatory infrastructure in developing the leasing industry in Zambia. The study used primary data from nine non-bank leasing companies, Bank of Zambia officials and Ministry of Finance officials. Secondary data was gathered from various financial sector and leasing publications, reports and dissertations. The findings of the study reveal that the prudential performance of the sector has been unsatisfactory. The study revealed that the industry performed average in capital adequacy, but performed poorly in asset quality, earnings and liquidity performance. The regulatory system was still fragmented and operating in an environment with insufficient legislation. The study further revealed that the regulatory body had not yet put enough effort in promoting the leasing markets in Zambia. The main regulator, Bank of Zambia, lacked technical and supervisory capacity to adequately, supervise the industry. The industry faced a number of challenges that inhibited it from fully participating in the financial sector. In addition to regulatory infrastructure reforms that were needed to expand the industry, other factors such as access to long-term low cost funding needed to be attracted, the leasing market needed to be educated on the availability of lease finance and strengthened supply-chain relationships are necessary. The Zambian leasing market may not develop fully if banks and big corporate companies did not take active part in these modern financial products

Identification and expression analysis of peroxisome-targeted defence proteins mediating innate immunity in the model plant Arabidopsis thaliana

Master's thesis in Biological ChemistryPeroxisomes are single-membrane organelles that have oxidative metabolic functions. Peroxisomes carry out major functions such as lipid degradation, photorespiration and glyoxylate cycle. However, new functions have been recently reported such as peroxisome mediation in plant innate immunity. To elucidate more on peroxisomal roles in pathogen defence in plants, identification and expression analyses of both new and established peroxisome-targeted pathogen defence proteins in plants was investigated in this study. Subcellular localization analysis of four PTS1 carrying proteins with a pathogen annotation was done. In addition, gene expression analysis of established peroxisomal pathogen defence was carried out using Real-Time Quantitative PCR (qPCR). The four PTS1 carry proteins that whose subcellular localization was studied are NUDT7, NUDT15, CHAT homolog and ATP-BP. NUDT15 and CHAT homolog targeted punctuate subcellular structures, which were later confirmed to be peroxisomes in double labelling experiment with a peroxisomal marker. NUDT7 and ATP-BP failed to target any subcellular structures, were therefore, putatively reported to be cytosolic in this study. Expression analyses were done on three NHL proteins (NHL4, NHL6 and NHL25) and also on three IAN proteins (IAN8, IAN11 and IAN12) using wild type Arabidopsis Col 0 plants, by mimicking pathogen attack with exogenously applied defence hormone-salicylic acid. All the NHL and IAN genes were induced after salicylic acid treatment. In addition, co-expression analyses were done on the aforementioned NHL and IAN proteins (except for NHL25). NHL6 and IAN8 were co-expressed with other Arabidopsis defence proteins. Whereas NHL4, IAN11 and IAN12 were found not be co-expressed in the dataset generated. In conclusion, in this study, two new peroxisomal pathogen defence proteins were identified namely NUDT15 and CHAT homolog, and also NHL6 and NHL25 were induced by salicylic acid treatment

Quantifying carbon cycle feedbacks under negative CO2 emissions

Land and ocean carbon sinks play a major role in regulating atmospheric CO2 concentration and climate. However, their future efficiency depends on feedbacks in response to changes in atmospheric CO2 concentration and climate. Since negative CO2 emissions technologies (NETs) are a key mitigation measure in emission scenarios consistent with global climate targets, understanding carbon cycle feedbacks under negative CO2 emissions is essential. This thesis investigates carbon cycle feedbacks under positive and negative CO2 emissions using an Earth system model driven with idealized scenarios of increasing and decreasing atmospheric CO2 concentration. Results suggest that carbon cycle feedbacks differ under positive and negative emissions, independently of the specific approach chosen for their quantification. The findings of this thesis provide insights into the approach best suited to quantify carbon cycle feedbacks under negative CO2 emissions, and into the role of these feedbacks in determining the effectiveness of NETs in reducing CO2 levels

Synthesis of bulk ion-imprinted polymers (IIPs) embedded with oleic acid coated Fe3O4 for selective extraction of hexavalent uranium

A selective and reliable method for the extraction of trace quantities of U(VI) by the use of a magnetic U(VI) ion-imprinted polymer (IIP) was developed. In this study, oleic acid (OA) coated magnetite nano-particles were incorporated into the cross-linked polymeric matrix of the selective sorbent, in order to gain the physical advantages of separating the polymers. Many physico-chemical factors influence the adsorption process; uranyl ion uptake ability based on these parameters was investigated. The optimum parameters obtained were sample pH 4,50 mg of the magnetic polymer, a contact time of 45 min and an initial U(VI) concentration of 2 mg·ℓ-1. The adsorption capacities for the magnetic NIP and IIP were found to be 0.95 mg·g1 and 1.21 mg·g-1, respectively. The adsorption behaviour of U(VI) in the presence of other competing metal ions onto the cross-linked magnetic polymers was also examined in binary mixtures and the order of selectivity was found to be U(VI) > Pb(VI) > Ni(II). The resulting magnetic nano-composite polymers were found to be stable up to the sixth cycle of use and reuse. The Freundlich adsorption model was used for the mathematical description of the adsorption equilibrium and the adsorption kinetic data fitted the pseudo-first-order model with R2 > 0.92.Keywords: Bulk, magnetic imprinted polymers, oleic acid, uraniu

Fatty acids composition in South African freshwater fish as indicators of food quality

Lipid classes and fatty acid composition of three commercially important freshwater fish species Oreochromis mossambicus (Mozambique tilapia), Clarias gariepinus (African catfish) and Cyprinus carpio (carp) obtained from an aquaculture, different river systems and fish markets from different provinces in South Africa were investigated. Fatty acids were extracted from the fish fillets through the Folch extraction method (using chloroform: methanol at the ratio of 2:1). Generally, tilapia fish species was found to be the richest in fatty acid composition. In all fish species analysed, palmitic acid (16:0) was found to be the most abundant fatty acid ranging from 18.24 to 21.84%. Appreciable quantities of essential polyunsaturated fatty acid such as docosahexaenoic (DHA) (22:6 n-3, 3.92 to 6.16%), eicosapentaenoic acid (EPA) (20:5 n-3, 1.91 to 2.92%) and arachidonic acid (20:4 n-6, 7.19 to 8.50%) were also found. Observations show that fish species obtained from Gauteng Province are richer in fatty acids compared to those in Limpopo Province. The study points out that all fish species investigated contain appreciable levels of Omega-3 (n-3) polyunsaturated fatty acids (PUFA) and are therefore suitable for an unsaturated low-fat diet. This is important especially for poor communities who cannot afford to get a balanced diet, rich in some essential fatty acids.Therefore, it is important to determine the nutritional value of local fish, since it significantly contribute to a healthy diet in rural communities.Keywords: fatty acid composition, lipids, freshwater fish, Omega -3 and Omega-6, polyunsaturated fatty acids, EPA, DH

Determination of Phenols in Water Samples using a Supported Liquid Membrane Extraction Probe and Liquid Chromatography with Photodiode Array Detection

A simple, selective and inexpensive miniaturized sample preparation method based on a supported liquid membrane extraction probe is described for the extraction and preconcentration in a single step of phenols in water samples. The phenols were extracted from 5 mL aqueous water samples into 0.4 mL aqueous acceptor  phase through the organic membrane. The organic membrane consisted of a porous PTFE membrane impregnated with undecane. In order to obtain a selective  extraction and enrichment of the phenols, the conditions were kept such that the phenols were non-ionized in the sample and ionized in the acceptor phase. This was achieved by pH adjustments in the sample and acceptor phases. The method was optimized for its extraction time, depth of the probe in the sample and   stirring speed. The detection limit ranged from about 4 μg L–1 for 2-chlorophenol and 2,4-dichlorophenol to 10 μg L–1 for 4-chlorophenol. The resulting enrichment  factors were about eight times for 2-chlorophenol and  2,4-dichlorophenol and four times for 4-chlorophenol. The sample preparation method was tested for the determination of phenols in river water samples and landfill leachate. Concentrations of phenols in river water were found to be in the range 4.2 μg L–1 for   2-chlorophenol to 50 μg L–1 for 4-chlorophenol. In landfill leachate, 4-chlorophenol was detected at a concentration of 80 μg L–1.KEYWORDS: Supported liquid membrane extraction probe, selectivity, chlorophenols, water samples

Determination of naproxen, ibuprofen and triclosan in wastewater using the polar organic chemical integrative sampler (POCIS): A laboratory calibration and field application

In this study, the occurrence in wastewater of two non-steroidal  anti-inflammatory drugs (NSAIDs), naproxen and ibuprofen, and one  personal care product, triclosan, was assessed using the polar organic  chemical integrative sampler (POCIS). The samplers were initially  calibrated in the laboratory to obtain sampling rates (Rs) for each target compound followed by deployment in the influent and effluent of  Goudkoppies and Northern Wastewater Treatment Plants (WWTPs), South Africa. Exposure was done for 14 days in 2012. High performance liquid chromatography (HPLC) system with ultraviolet (UV) and fluorescence (FLD) detectors was used to analyse POCIS extracts. Laboratory calibration of POCIS yielded Rs values for the three compounds that were between 0.087 and 0.383l.d-1 in quiescent conditions, and 0.125 and 0.936 l.d-1 in  stirred conditions. From the accumulated amounts in field-deployed  samplers, estimated freely dissolved concentrations of the studied compounds in wastewater influent ranged from 55.0 to 78.4 µg.l-1 and 52.3 to 127.7 µgl.-1 in Goudkoppies and Northern WWTPs, respectively. Average concentrations of these compounds in the treated effluent ranged from 10.7 to 13.5 µgl.-1 in Goudkoppies WWTP, and 20.4 to 24.6 µgl.-1 in Northern WWTP. Analyte removal efficiencies varied between 68 and 86% in Goudkoppies WWTP and 61 and 82% in Northern WWTP. Grab samples processed by SPE method yielded higher analyte concentrations (up to three-fold) as compared to POCIS-derived estimates. This  discrepancy was attributed to SPE's ability to extract both the free  dissolved, and particle sorbed fractions of the contaminants.Keywords: Polar organic chemical integrative sampler, pharmaceuticals and personal care products, wastewater, wastewater treatment plant

Selective adsorption of uranium (VI) on NaHCO3 leached composite γ-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerization

Ion imprinted nano-magnetic composite polymers for selective removal of hexavalent uranium were prepared by a precipitation polymerization technique in the presence of γ-methacryloxypropyltrimethoxysilane (γ-MPS) coated magnetite and other pre-polymerization reagents. The synthesized magnetic polymers were then leached with NaHCO3 to produce magnetic ion imprinted polymers (IIPs) with fabricated adsorption sites complementary to the uranyl ions in terms of size and shape. Several parameters were investigated to obtain conditions which gave the optimum adsorption of the uranyl onto the magnetic IIPs and their corresponding controls, magnetic ion non-imprinted polymers (NIPs). The optimum amount of magnetic sorbent, initial concentration and contact time were 50 mg, 2.5 mg L-1 and 45 min, respectively. The adsorption capacity of the magnetic IIP (1.15 ± 0.01 mg g-1) was higher than that of the magnetic NIP (0.93 ± 0.02 mg g-1). This indicated that the former had a somewhat higher affinity for U(VI) than the later. The magnetic polymers also displayed good selectivity of the order: U(VI) > Ni(II) > Mg(II). After six cycles of use, the magnetic polymers illustrated good stability and reusability.SP201

Sample preparation using liquid membrane extraction techniques

A brief review is given of membrane extraction techniques that are seen as suitable for the extraction of various chemicals in water samples. Membrane-based extraction methods have now gained popularity as methods of choice in the extraction of both ionisable and non-ionisable molecules from different samples. The main attractive features for these techniques include the use of minimal organic solvents, high selectivity and clean-up efficiency, with high enrichment factors. In most cases the overall cost involved is low due to the simplicity of the techniques which normally involve relatively fewer steps and handling procedures as compared to many other sample-preparation techniques. The various forms and the configurations of membrane-based techniques are another attractive feature which allows the possibility of hyphenation with separation instruments such as gas/liquid chromatographs and even capillary electrophoresis.Keywords: liquid membrane extraction techniques, sample preparation, water monitoring, organic and inorganic compound