Flow-Through Cell for Ion-selective Electrodes

This research work describes a novel flow-through all-solid-state potentiometric device that consists of solid-contact ion-selective electrodes and a solid-state planar reference electrode. The device is capable of measuring ionic concentrations in small sample volumes. Planar potassium ion-selective electrodes (K-ISEs) and chloride ion-selective electrodes (Cl-ISEs) were made using carbon cloth (CC) as ion-to-electron signal transducer (CC-ISEs). Polyvinyl butyral/sodium chloride (PVB/NaCl)-based and polyvinyl acetate/potassium chloride (PVAc/KCl) composite-based reference electrodes were prepared using silver/silver chloride disk electrodes and characterized. The PVAc/KCl composite-based reference electrode showed superior performance and was selected for use in the flow-through device. Carbon cloth and polycarbonate (PC) were tested as substrates for the fabrication of the planar PVAc/KCl composite-based reference electrode. The reference electrode made using the CC substrate (CC-RE) performed well when used with either an external commercial reference electrode or a chloride ion-selective electrode. However, the construction and assembly of the CC-RE made it perform poorly when combined with a CC-ISE in one cell. The PC-based reference electrode (PC-RE) solved the issues associated with the CC-RE and performed well when combined with CC-ISEs in the complete flow-through potentiometric device. When measured against the PC-RE, the potassium and chloride CC-ISEs (K- and Cl-ISEs) consistently showed fast and stable near-Nernstian responses, good R2 values, and high within-day repeatability in the 10–3 M to 10–1 M KCl concentration range. The use of valinomycin as ionophore in the studied K-ISEs resulted in excellent selectivity for the electrodes in the presence of interfering ions such as Na+, Mg+, and Ca2+. Whereas the Cl-ISEs based on the ion exchanger tridodecylmethylammonium chloride (TDMAC) showed relatively poor selectivity in the presence of interfering ions such as bicarbonate (HCO3–) and lactate (C3H5O3–). These ions were selected for the selectivity measurements due to their significant presence in sweat samples that are meant to be measured using the flow-through device. The standard potentials of both potassium and chloride CC-ISEs demonstrated poor reproducibility in between-electrode and between-day measurements. Results from the electrochemical impedance spectroscopy measurements, carried out using the K-ISEs, showed that the resistance of the valinomycin-based potassium ion-selective membrane (ISM) is relatively high in these electrodes compared to the values reported in the literature. In addition, electrodes made in a similar way and are supposed to be identical exhibited different values of ISM resistance. This can be attributed to errors in the manual fabrication of the electrodes. Despite the high (charge transfer) resistance values of the ISMs, the CC-ISEs showed fast and relatively stable potentiometric responses

New Technologies: Catalysts for Business Models and Finance Function

To bridge performance gap, improve operational efficiency, enhance competitive advantage and secure corporate assets, business entities have continued to embrace new technologies with profound positive impact on their bottom-line.As new technologies replace humans through automation in the emerging business models, the demand for professionals, including chartered accountants, who are not IT-savvy is fast declining, taking with it, wages, salaries and a high percent of income taxes. These problems are compounded by the huge costs of technology acquisition and inevitable investment inhuman capacity building in the face of increasingly mobile staff.Using secondary information, the study observed that many professional accountants dread the transition from manual to automation as it would eliminate repetitive finance-related jobs in the midst of high unemployment rate in the country, dissuade new entrants into the accounting profession and alter the human side of enterprise.It therefore recommends that the training curricula of professional accountancy organisations should be rejigged and skewed towards technology while existing professional accountants should hone their IT skills to leverage technology to deliver value online, real time to their diverse stakeholders. Keywords: Technology, Internet of things, automation, business models, artificial intelligence, robotics, machine learning, finance function

Market risk and returns: Evidence from the Nigerian capital market

No Abstract. Global Journal of Social Sciences Vol. 6 (2) 2007: pp. 125-12

Intestinal Parasitic Infections in Primary School Children in Rural Communities in Edo State, Nigeria

Background: Intestinal parasitic infections are a major public health problem in developing countries where majority of the affected persons are children. This study is aimed at determining the prevalence of intestinal parasitic infections and the effect of socio-demography in some rural primary schools in Ovia Northeast Local Government Area (LGA), Edo State, Nigeria. Materials and Methods: A total of 675 school children from rural settings were recruited. The faecal samples were processed using standard technique. Results: A total of 96 (14.2%) out of the 675 children had asymptomatic intestinal parasitic infection. Male gender and walking barefooted were significantly associated with asymptomatic intestinal parasitic infection (P<0.0001). Children within the ages of 14 – 16 years (P=0.0008), defaecate in nearby bushes (P=0.042), that use well/rain water (P<0.0001), don’t wash their hands (P<0.0001) and children whose fathers were bricklayers (P<0.0001) have higher prevalence of asymptomatic intestinal parasitic infections. The parasites recovered were E. histolytica, A. lumbricoides, T. trichiura, hookworm and Taenia species. A. lumbricoides had the highest prevalence (69.2%). A. lumbricoides was the most prevalent parasitic agent recovered in all age groups and the only parasitic agent that was significantly associated with gender, particularly the male gender. Conclusion: Effective treatment of infected school children as well as improved sanitary habits for prevention of soil pollution and contamination is advocated. Keywords: Intestinal parasites, primary school children Running title: Intestinal parasites in Primary School childre

Semantic Annotation of Experimental Methods in Analytical Chemistry

A major obstacle for reusing and integrating existing data is finding the data that is most relevant in a given context. The primary metadata resource is the scientific literature describing the experiments that produced the data. To stimulate the development of natural language processing methods for extracting this information from articles, we have manually annotated 100 recent open access publications in Analytical Chemistry as semantic graphs. We focused on articles mentioning mass spectrometry in their experimental sections, as we are particularly interested in the topic, which is also within the domain of several ontologies and controlled vocabularies. The resulting gold standard dataset is publicly available and directly applicable to validating automated methods for retrieving this metadata from the literature. In the process, we also made a number of observations on the structure and description of experiments and open access publication in this journal

Semantic Annotation of Experimental Methods in Analytical Chemistry

A major obstacle for reusing and integrating existing data is finding the data that is most relevant in a given context. The primary metadata resource is the scientific literature describing the experiments that produced the data. To stimulate the development of natural language processing methods for extracting this information from articles, we have manually annotated 100 recent open access publications in Analytical Chemistry as semantic graphs. We focused on articles mentioning mass spectrometry in their experimental sections, as we are particularly interested in the topic, which is also within the domain of several ontologies and controlled vocabularies. The resulting gold standard dataset is publicly available and directly applicable to validating automated methods for retrieving this metadata from the literature. In the process, we also made a number of observations on the structure and description of experiments and open access publication in this journal.Proteomic