Possible antimicrobial activity of Morinda lucida stem bark, leaf and root extracts

Inhibitory activities of both aqueous and methanolic extracts of the root, stem bark, and leaf of Morinda lucida on Escherichia coli, Salmonella typhi, Salmonella paratyphi, and Salmonella typhorium was investigated in vitro. In vitro experiment was carried out using the agar well diffusion and disc diffusion methods with Gram-negative enterobacteria. M. lucida extracts were more active against all the tested bacteria than the standard antibiotics, chloramphenicol and ciprofloxacin even at the same concentrations of 5, 10 and 20 mg/ml. The results of this study show that the extracts of M. lucida has the potentials of inhibiting the growth of E. coli and Salmonella species, thereby suggesting its potency in the treatment of infections in which E. coli and Salmonella species are implicated.Keywords: Gram-negative, inhibitory activity, Escherichia coli, Salmonella species, enterobacteria, infections, antibioticsAfrican Journal of Biotechnology, Vol. 13(3), pp. 471-475, 15 January, 201

Evolution of Biomass Burning Aerosol Properties During Transport in the Southeast Atlantic Region

Biomass burning (BB) is a major source of absorbing aerosols globally and accounts for about 40% of black carbon in the atmosphere. The Southern African region contributes approximately 35% of the planet’s BB aerosol emissions. During the austral winter and spring, smoke is transported westward towards the southeast Atlantic Ocean, where it overlies and interacts with a quasi-permanent stratocumulus (Sc) cloud deck. Aerosol-cloud-climate interactions contribute the largest uncertainty to model estimates of anthropogenic forcing. The SEA region thus exhibits a large model-to-model divergence of climate forcing due to aerosols. This makes studies in the region particularly valuable for understanding these interactions. Previous studies focusing on Southern Africa BB have explored the distribution of aerosol loading. However, changes in aerosol optical properties during transport are not well documented. This study aims to use remotely sensed observations to investigate the evolution of BB aerosol optical properties after emission within continental Africa, during transport over land, and over the Atlantic Ocean. Measurements taken from a collection of remote-sensing instruments during the ORACLES campaign are combined with results from two regional models, the WRF-AAM and WRF-CAM5, to explore the changes in the optical properties of smoke plumes as they age. The aerosol age is modeled using tracers from the WRF-AAM configured over the region’s spatial domain (14 ºN – 41 ºS, 34 ºW – 51 ºE). The study conducted an analysis of extinction, single scattering albedo (SSA), and extinction Angstrom exponent (EAE) in relation to aerosol age. Additionally, observations from airborne 4STAR, ground-based AERONET were compared with model results using WRF-CAM5. The analysis revealed that aerosol age varied distinctly with longitude and the physical and chemical processes associated with the transport drive changes in the optical properties. The aerosols sampled closest to the source exhibited lower SSA values relative to particles sampled along the coastline. Along the coastline, free tropospheric SSA peaked at about 5-6 days, before gradually decreasing over the ocean, with a minimum value observed after approximately 12 days. SSA was underestimated by WRF-CAM5, and the modeled values are constrained to a narrower range than observations highlighting the importance of improving the representation of mass absorption and extinction in regional climate models

Comparative histopathology of gladiator swimming crab (Callinectes pallidus) from two coastal areas in Lagos, Nigeria

Callinectes pallidus is an economically important species of crab which inhabits both inshore and estuaries often susceptible to contamination from anthropogenic sources. The present study examined histopathology of the tissues of Callinectes pallidus from two coastal areas in Lagos, Nigeria, as a possible measure of degree of susceptibility to environmental stress.Tissues (hepatopancreas, gill, ovary, intestine and flesh) of samples of 30 crabs from each coastal site were processed for histological examination using standard method. The histopathological results in this study showed no structural alteration in gills, intestine and flesh in crabs from both sites, but there was a great structural degeneration and lesion in the hepatopancreas and ovaries of C. pallidus from Agbara (site 2). The environmental stressors identified in Agbara based on documented literatures includes Brewery effluents- that contains high carbohydrate, nitrogen and washing reagents; high concentration of heavy metals such as Cu, Zn and Fe and pharmaceutical effluents. The present study thereby revealed that hepatopancreas and ovaries of C.pallidus from Agbara (site 2) are more susceptible to these environmental stressors. Thus, it could be concluded that C.pallidus from site 2 are more susceptible to environmental stress than those from site 1.The present study also provide a fundamental information on the well being of C.pallidus from the two sites. Therefore, efforts should be intensified to avert future deleterious effect of the environmental stressors on the studied species in Agbara water body.Keywords: Susceptibility, hepatopancreas, ovary,stress, alteration and cra

Study on the deformation behavior of the cathode collector bar at high temperature and low levels

L'étude de la déformation de la barre collectrice dans les conditions subies au sein de la cellule de réduction d'aluminium est d'une grande importance pour l'optimisation de l'efficacité et l'augmentation de la durée de vie de la cellule. Ce mémoire nous informe des résultats d'un programme expérimental réalisé sur une barre de collectrice en acier. Le but, est d' étudier son comportement en tenant compte de ses propriétés thermiques, mécaniques et de fluage. Des essais ont été effectués en compression à de basses tensions, de 0,5 à 2MPa et à une température élevée, de 900°C. Différents comportements ont été observés à de faibles contraintes, jusqu'à 2MPa, cela peut être justifié par le temps et le niveau de pression appliqué. L'inspection métallographique a montré l'apparition d'oxydation et de la corrosion sur des échantillons testés, ceci est dû à l'environnement agressif des conditions du test. D'importants efforts et modifications ont été fournis pour éradiquer cet effet et pour améliorer l'exactitude des données de test de fluage obtenus.The study of the deformation behaviour of the collector bar at conditions experienced within the aluminium reduction cell is of great importance to optimizing the efficiency and increasing the life span of the cell. This mémoire communicates the results of an experimental program carried out on the steel collector bar material (AISI 1006) to investigate its behaviour in relation to its thermal, mechanical and the creep properties. Tests were carried out in compression at low stresses, 0.5 to 2 MPa and high temperature, 900 °C. Different behaviour was observed at low stresses up to 2 MPa, which can be characterised by time and applied stress level. Metallographic inspection showed effect of oxidation and corrosion on tested samples due to the aggressive environment of the test condition, major efforts and modification were made to eradicate this effect and to improve the accuracy of obtained creep test data

Effect of Corporate Environmental Investments on Financial Performance in Mining and Manufacturing Companies Listed on the Johannesburg Stock Exchange Social Responsibility Index

This article investigates the relationship between corporate environmental investment and financial performance. The article examines the effect of carbon emission reduction and hazardous solid waste disposal on company’s return on assets. The paper adopts a quantitative research design by analyzing secondary data from the financial statements of companies listed on the Social Responsibility Index consecutively from 2008 to 2017.   Panel data analysis consisting of the random and fixed effects models was used to analyze the data. The study adopted the Hausman test to determine the most appropriate model. Data was also tested for multi-collinearity and heteroscedasticity in order to enhance the reliability of the regression results. The results produced a mixed result showing positive gains between carbon emissions reduction and return on assets while hazardous solid waste reduction was negatively related to return on assets. Our results have crucial managerial implications as it was established that corporate environmental investment to reduce carbon emissions is vital as they result in different cost savings. Conversely, investments to reduce hazardous solid waste disposal are equally important to establish and maintain a sustainable operational environment and to enhance stakeholder relations but have no direct influence on return on assets

The Role of Affinity Group Membership For Marginalized Music Therapy Students and Professionals

Little research has been done exploring the significance of affinity group membership in the profession of music therapy. In this study, 48 music therapy students and professionals who identified as a part of an affinity group connected to their marginalized identities were surveyed, answering open- and closed-ended questions related to their experiences of a sense of belongingness, acculturative stress, and burnout in professional environments. Quantitative data were analyzed using cross-tabulation descriptive statistics through Google Forms and qualitative data were analyzed through thematic analysis. The quantitative data highlighted how affinity group membership plays a significant role in the sense of belongingness for marginalized music therapy students and professionals. They also suggested that many participants experienced similar challenges and feelings in differing spaces (e.g., work, school) related to their marginalized identities. Thematic findings revealed that affinity group membership promoted feelings of belongingness, confidence in expressing one’s marginalized identity, increased comfort in advocacy for self and others, reduced inclination to assimilate to dominant societal norms, and increased cultural sensitivity in music therapy practice. This research suggests that music therapy educational and professional environments should be more intentional about providing affinity spaces and access to resources for marginalized students and professionals. More research can be done to explore the relationship between the sense of belongingness among marginalized music therapy students and professionals and job satisfaction, higher education, burnout levels, and sociocultural location

The pragmatic import of ‘Orí’ in Yorùbá conversational discourse

Among the Yorùbá of Nigeria, of all the parts of the human body, Orí [English: head] features most frequently in linguistic thought and action, but although numerous researchers have considered its spiritual values, orí’s conversational worth has been greatly overlooked. While acknowledging the spiritual associations of this top part of the body, this paper uses fragments of naturally occurring speech-in-context – surreptitiously collected among several Yorùbá interlocutors – to generate a tentative typology for Orí and concludes that the invocation of the head, whether in reference to one’s own or to that of another, has socio-pragmatic significance, and can serve various discourse functions, e.g., as a strategy for opening, commenting on, marking, and closing talk sequences. The discussion identifies perspectives – other than spiritual – from which this vital detail of the human frame could be ex-amined, given its frequency in much Yorùbá conversational discourse

Library usage by university accounting students : a comparison of contact and open distance learning institution in South Africa

This study examines the current level of library patronage among accounting students both in the distance and a contact learning institution in South Africa. There is a relative absence of studies of academic library usage by accounting students. The low level of library usage, that is, low level of library visits and poor research skills of undergraduate accounting students has been attributed to the difficulty in integrating accounting curriculum with information literacy. However, the challenge facing academic librarians is persuading both academic faculty and accounting students to integrate information literacy into their curriculum and to convince individual students to make time in their schedules for library usage. In South Africa, this problem is compounded when it is a requirement of the accreditation body, The South African Institute of Chartered Accountants (SAICA), which requires academic departments to integrate library usage into the accounting curriculum for their programme to be accredited. The study examines the current level of library patronage among accounting students both in a distance and a contact learning institution in South Africa. The sub-objectives of the study were to investigate the reasons for low level of library patronage among accounting students in South African Universities; to determine what features would make the use of a library for locating information that is relevant and attractive to university accounting students in a contact and a distance learning institution in South Africa; and to investigate what, if any, improvements to library service can be made to make the use of the library of significant importance. Using a survey research method that utilises a structured questionnaire, this study gathered data from a sample of 500 accounting students from a distance and a contact learning institution in South Africa, out of which 379 returned completed questionnaire, representing 76%. The finding indicates that as with most accounting students across the world, South African students are no exception because of the peculiarity and design of their programme curriculum that provides recommended texts for students’ usage. The findings further show that the apathy of library services patronage among university accounting students in South Africa is exacerbated by lecturers who seldom give assignments or tasks that require the students to search for information beyond the recommended textbooks. Findings indicate that the most significant factor that influences accounting students of universities to patronise library resources are the expertise and interaction of the library staff. This is supported by the Expectation-Confirmation Theory framework which posits that patrons will continue to use library services only if their perceived perception of the usefulness of the services are satisfied. In this case, accounting students from both institutions examined in this study confirm the Expectation-Confirmation Theory framework of satisfaction being based on the perception of the library services they receive. The study recommends that in motivating accounting students to patronise library services, library management needs to understand the discipline-specific teaching and learning practices and collaborate with curriculum developers in the accounting discipline to incorporate the use of library services in their programme. Further study is encouraged to include all universities that offer accounting programmes in South Africa for a more robust finding.Information ScienceM. Inf. (Information Science

Trophic ecology of fishes: consolidating the basic (traditional) methods

Studies of food and feeding ecology are important to investigate trophic interrelationships of fishes in their resident water bodies. These are usually achieved using various important methods. However because no single measure gives an overall representation of the feeding habits of fish, best results are achieved only when methods are used to complement one another. This paper reviews various methods used in studying trophic fish ecology and suggests consolidation of the traditional or basic methods with relevant statistical indices and local ecological knowledge. More advanced methods are also proposed as valuable tools because they compensate for some possible errors that may arise from the use of quantitative methods