Effective toxicity of pH to embryonic development of the banded lampeye killifish (Duméril, 1861).

The banded lampeye killifish, feeds on larvae of the anopheles mosquito, which makes the fish a good candidate for biological control of malaria. Aquatic organisms require optimal hydrogen ion concentration (pH) for healthy aquatic life, but the impact of pH alteration on . reproductive potential is not known.

Benthic macroinvertebrates as indicators of water quality: A case study of estuarine ecosystems along the coast of Ghana.

Increasing human activities in coastal areas of Ghana have led to the degradation of many surface waterbodies, with significant consequences for the ecosystems in the affected areas. Thus, this degradation extremely affects the health of ecosystems and disrupts the essential services they provide. The present study explored the use of benthic macroinvertebrates as an indicator of estuarine degradation along the coast of Ghana.

H-NMR Determination of Organic Compounds in Municipal Wastewaters and the Receiving Surface Waters in Eastern Cape Province of South Africa.

Surface water is the recipient of pollutants from various sources, including improperly treated wastewater. Comprehensive knowledge of the composition of water is necessary to make it reusable in water-scarce environments. In this work, proton nuclear magnetic resonance (H-NMR) was combined with multivariate analysis to study the metabolites in four rivers and four wastewater treatment plants releasing treated effluents into the rivers.

Evaluating the responses of taxa in the orders Ephemeroptera, Plecoptera and Trichoptera (EPT) to sediment stress in the Tsitsa River and its tributaries, Eastern Cape, South Africa.

Excessive delivery of fine sediment has been implicated as the main water quality stressor in the Tsitsa River catchment. This study evaluates the responses of the taxa Ephemeroptera, Plecoptera and Trichoptera (EPT) to suspended sediment and grain size distribution in eight selected study sites in the Tsitsa River catchment. The sampling of macroinvertebrates took place seasonally from August 2016 to April 2017 and EPT identified to either genus or species level.

Development of a procedure for determining the mixing ratios in ecotoxicological experiments and its application in binary salt mixture experiments.

Although a plethora of models exist to describe the characteristics and risk assessment of chemical mixtures in ecotoxicology, there is no specific procedure to decide on the mixing ratios (i.e. proportions of the individual chemical substances that form the mixture) at any desired level of concentration in an ecotoxicological mixture experiment.

Derivation of South African water quality guidelines for Roundup(®) using species sensitivity distribution.

Glyphosate-based herbicides are among the leading products used in South Africa to control weeds and invading alien plant species. Although these herbicides ultimately find their way into aquatic ecosystems, South Africa has no water quality guideline based on indigenous species to protect the country's aquatic biota against these biocides. In this study, South African water quality guidelines (SAWQGs) for Roundup(®) based on species sensitivity distribution (SSD) using indigenous aquatic biota were developed.

Chronic myeloid leukemia in an adult ghanaian with sporadic neurofibromatosis 1.

Patients with neurofibromatosis type 1 (NF1), a common, progressive, autosomal dominant neurocutaneous disorder, are predisposed to malignancies. Several types of hematologic malignancies have been described in them. However, to date there has been no report to the best of our knowledge of a patient with NF1 developing chronic myeloid leukemia (CML).

Binding and elution behavior of proteins on strong cation exchangers.

This work provides a broad survey of binding and elution behavior of proteins on strong cation exchangers. Four proteins comprising two monoclonal antibodies, lysozyme, and cytochrome c were used as models in the investigation. Seven chromatography resins with different base matrices were compared.

Comparison of agarose and dextran-grafted agarose strong ion exchangers for the separation of protein aggregates.

The control of aggregate levels in recombinant protein based drugs is a primary concern during process development and manufacture. In recent years, a novel class of dextran-grafted ion exchange matrices has gained popularity for process scale protein purification due to increased mass transfer rates and higher dynamic binding capacity compared to conventional matrices. Using bovine serum albumin and a monoclonal antibody as model proteins, we studied Sepharose FF and Sepharose XL ion exchangers for the separation of protein aggregates.

Separation of protein charge variants with induced pH gradients using anion exchange chromatographic columns.

This work concerns the chromatographic separation of protein charge variants using pH gradients generated by step changes in buffer composition with weak base anion exchange columns. A local equilibrium model is first developed to describe pH transitions occurring in the column using buffers comprising neutral, zwitterionic or positively charged species. Model predictions, based solely on the resins' titration curves and obtained with the method of characteristics, show, in excellent agreement with experiments, that induced pH gradients of varying durations and shapes can be obtained with a broad range of buffer systems including Tris, Bis-Tris propane, histidine, and their mixtures and ethanolamine.