Addressing Accra's urban water challenges within a sustainable development context

Like most major cities in Africa, Accra is undergoing a rapid pace of urbanization fueled by economic development, population growth and rural to urban migration. The city faces major challenges with the provision of adequate and effective urban water infrastructure. The challenges associated with perennial flooding in Accra are reviewed in the context of recommended policy, institutional and organizational changes that are deemed to provide a more sustainable and holistic approach to urban water service provision. These have the potential of increasing the interactions of multiple stakeholders including the public, system designers, urban planners, entrepreneurs, activists, etc. and fostering an even closer link between professional practice and community participation providing the scope for spurning innovation, capacity building and job creation at a local level

Effects of Stress on the Work Attitude of Staff of College of Distance Education, University of Cape Coast

The study sought to find out how the staff of the College of Distance Education react to stressful conditions at the work place. The cross-sectional survey design was adopted for the study. Responses of 77 lecturers and administrators of the College of Distance Education to a self-administered questionnaire were analyzed using descriptive and inferential statistics. The study found among others that pressure to meet deadlines on students’ related issues and task of bringing lots of feedback from study centres, unpleasant office environment and unavailability of work schedule cause stress on staff of the college. It was again revealed that the stress from the work environment make staff delegate task, report to work late, make mistakes, dislike going to work, get nervous, easily irritated and close before the closing time. Among the recommendations made were the institutionalization of free health screening/ care as well as health and safety seminars particularly on stress management, organisation of recreational activities, re-introduction and increment in number of day-offs and  ergonomically arranging offices. Keywords: Stress, Work stress, Work attitude, Staff attitude, College of Distance Educatio

Classical literature gives life to business paradox and systems integration

Professors bemoan the great difficulty students have understanding the complexity of their disciplines or functional specializations. Many non-traditional students have work and family commitments that limit the time needed to reflect professionally and to master these concepts. This disconnect has persisted despite decades of work developing more integrated, interdisciplinary curricula. One potential, partial solution is to simply start sooner and partner with liberal arts courses to introduce business students to complexity and paradox before they arrive at the business school. Grounding these concepts in the Classics embeds them in great stories of passion, betrayal, commitment, and emotion normally absent in business courses. Business textbooks and cases are usually sanitized, simplified, and quantified, stripping them of the chaos normally experienced in reality. These classical tales are captivating and compelling, making the business concepts used to analyze them more memorable and hopefully retained until encountered again in the business curriculum. The classics deal with real and raw emotions, with powerful prose more likely to capture and engage students on a very personal level. This article explores how economics can be used to analyze Jane Austen’s Pride and Prejudice, how multi-stakeholder theory can be used to analyze Sophocles’ Antigone, and how business contract law can be used to analyze William Shakespeare’s The Merchant of Venice. Liberal Arts programs will gain additional relevance, commanding further student respect; business schools will stand a better chance of meeting AACSB gold-standard, interdisciplinary learning outcomes when students are exposed to these concepts before arriving at the business school

Insights Into Auditory Cortex Dynamics From Non-invasive Brain Stimulation

Non-invasive brain stimulation (NIBS) has been widely used as a research tool to modulate cortical excitability of motor as well as non-motor areas, including auditory or language-related areas. NIBS, especially transcranial magnetic stimulation (TMS) and transcranial direct current stimulation, have also been used in clinical settings, with however variable therapeutic outcome, highlighting the need to better understand the mechanisms underlying NIBS techniques. TMS was initially used to address causality between specific brain areas and related behavior, such as language production, providing non-invasive alternatives to lesion studies. Recent literature however suggests that the relationship is not as straightforward as originally thought, and that TMS can show both linear and non-linear modulation of brain responses, highlighting complex network dynamics. In particular, in the last decade, NIBS studies have enabled further advances in our understanding of auditory processing and its underlying functional organization. For instance, NIBS studies showed that even when only one auditory cortex is stimulated unilaterally, bilateral modulation may result, thereby highlighting the influence of functional connectivity between auditory cortices. Additional neuromodulation techniques such as transcranial alternating current stimulation or transcranial random noise stimulation have been used to target frequency-specific neural oscillations of the auditory cortex, thereby providing further insight into modulation of auditory functions. All these NIBS techniques offer different perspectives into the function and organization of auditory cortex. However, further research should be carried out to assess the mode of action and long-term effects of NIBS to optimize their use in clinical settings

Improvements in vortex flow control design to increase sewer network flood resistance

Copyright © 2013 IWA7th International Conference on Sewer Processes and Networks (SPN7), Sheffield, UK, 28-30 August 2013Flow controls are used within the water industry to manage the flow through sewer networks by attenuating flows at convenient or critical locations. Many sewer networks, regardless whether the systems have a flow control installed, are predicted to become stressed in the future due to the effects of climate change, population growth and urbanisation. This issue is compounded by the age of the Britain’s sewerage infrastructure as well as the cost and difficulty of replacing and upgrading the infrastructure. Statutory ‘Catchment Flood Management Plans’ have been introduced within the United Kingdom to tackle this issue by better understanding the flow path of flood water on a catchment scale. This paper discusses a method to maximise the use of the current sewerage infrastructure by installing flow controls, meaning a greater volume of the sewer network can be used for stormwater storage. This paper continues by describing a method of increasing a sewer network’s flood resistance by using vortex flow controls with a lower design flow-rate compared to an orifice plate. This paper then concludes by describing three case studies demonstrating the use vortex flow controls when retrofitting sewer networks as well as the impact of implementing the retrofit design method.EPSRCSTREAM IDCHydro Internationa

Performance evaluation of a chimney solar dryer for Habanero pepper (Capsicum chinense Jacq)

Habanero pepper (Capsicum chinense Jacq) is cultivated predominantly in the Volta, Central and Ashanti regions of Ghana and commonly utilised in  most local dishes. Majority of consumers prefer the dried form of the pepper. However, farmers are usually confronted with the challenge of  obtaining low-cost, locally fabricated dryers that can efficiently dry agricultural produce while mitigating quality and safety concerns. In this study, a model of the newly designed chimney solar dryer by the Horticulture Innovation laboratory of the University of California, Davis, in the United States of America, for crop drying in developing countries was constructed and its performance evaluated in comparison to open sun drying. Habanero pepper was used as a test crop. Subsequently, microbial analysis was carried out on the dried products. The mean chimney dryer temperature (46.4°C) was found to be higher than the ambient temperature (36.2°C). The relative humidity in the chimney solar dryer and the ambient ranged from 25% to 68% and 26% to 83%, respectively. During the period of the drying experiment, mean maximum solar insolation of 823.18 W/m2 was  recorded at 11.30 am while a mean minimum solar insolation of 107.84 W/m2 was recorded at 4.30 pm. The solar-dried and sun-dried pepper  recorded total drying time of 35 h and 55 h respectively. The mean performance coefficient of the chimney solar dryer was determined to be 1.21 which gives an indication of a high dryer performance. The mean yeasts and moulds counts of the solar-dried and sun-dried pepper were 4.30 x 104 cfu/g and 2.52 x 105 cfu/g, respectively. Also, the Staphylococcus aureus and Escherichia coli counts were <10 cfu/g for samples in both drying media. In conclusion, the chimney solar dryer was found to have performed better than open sun drying with shorter drying time and better qualityof the dried product. Key words: chimney, habanero pepper, open sun drying, performance, quality, solar drye

3D Finite Element Model Simulating the Behaviour of Filling Soils Used to Set Up a New Placement Method for Separate Sewer Systems

The use of a finite element (FE) method and selection of the appropriate model to simulate soil elastoplastic behaviour has confirmed the importance and sensitivity of the soil properties on the accuracy when compared with experimental data. The properties of the filling soil play a significant role in determining levels of deformation and displacement of both the soil and subterranean structures when using the FE model simulation. This paper investigates the impact of the traffic load on the filling soil deformation when using the traditional method, one pipe in a trench, and a new method, two pipes in a single trench one over the other, for setting up a separate sewer system. The interaction between the buried pipes and the filling soils has been simulated using an elastoplastic FE model. A modified Drucker-Prager cap constitutive model was used to simulate the stress-strain behaviours of the soil. A series of laboratory tests were conducted to identify the elastoplastic properties of the composite soil used to bury the pipes. The FE models were calibrated using a physical lab model for testing the buried pipes under applied load. This allows the FE model to be confidently upgraded to a full-scale model. The pipe-soil interactions were found to be significantly influenced by the soil properties, the method of placing the pipes in the trench and the diameters of the buried pipes. The deformation of the surface soil was decreased by approximately 10% when using the new method of setting up the separate sewer

Improving STEM Education in Research: Preliminary Report on the Development of a Computer-Assisted Student-Mentor Research Community

Research education in STEM disciplines currently suffers from 1) The inability to feasibly collect highly detailed data on both the student’s and mentor’s activities; 2) The lack of tools to assist students and mentors in organizing and managing their research activities and environments; and 3) The inability to correlate a student’s assessment results with their actual research activities. Together these three problems act to impede both the improvement and educational quality of student research experiences. We propose a computer-assisted student-mentor research community as a solution to these problems. Within this community setting, students and their mentors are provided tools to make their work easier, much like a word processor makes writing a letter easier. Through their use of these tools, details of student-mentor activities are automatically recorded in a relational database, without burdening users with the responsibility of archiving data. Equally important, student assessments of outcome can be directly related to student activity, allowing educators to identify practices resulting in successful research experiences. Community tools also facilitate the use of labor-intensive teaching laboratories involving real inquiry-based research. The community structure has the added benefit of allowing students to see, communicate and interact more freely with other students and their projects, thus enriching the student’s research experience. We provide herein a preliminary report on the development and testing of a prototype, student-mentor research community, and present its tools, an assessment of student interest in participating in the community, and discuss its further development into a nationally-available student-mentor research community

Modelling of vortex flow controls at high drainage flow rates

A number of vortex flow control (VFC) devices for urban drainage systems are investigated computationally at high flow rates, for which a confined vortex dominates the flow regime. A range of turbulence models, including both eddy viscosity and Reynolds stress closures, are compared with in-house experimental measurements of head loss and internal pressure measurements. Single-phase and multi-phase (free surface) calculations are also compared. Very good agreement with the experimental data was obtained when the swirl parameter of the device was below 3.14 for predictions made using the Reynolds stress closure formulations. For devices with swirl parameters above this value, the computational methodology was found to under-predict the head loss of the device. This was attributed to poor calibration of the turbulence model for swirling flow scenarios in which the pressure gradient and diffusive (turbulent) forces in the flow are comparable

Effects of the combination of camptothecin and doxorubicin or etoposide on rat glioma cells and camptothecin-resistant variants

From the rat C6 glioma cell line in culture, we selected camptothecin-resistant variants by growth in the presence of increasing amounts of this drug (C6CPT10, C6CPT50 and C6CPT100, growing respectively with 10, 50 and 100 ng ml–1camptothecin). The degree of resistance to camptothecin ranged between 15-fold (C6CPT10) and 30-fold (C6CPT50and C6CPT100). The C6CPT10cell line presented a collateral sensitivity to etoposide (3.6-fold), while the C6CPT50 and C6CPT100 cell lines were cross-resistant to etoposide (1.8-fold) The resistant lines were characterised by a two-fold reduced content and catalytic activity of topoisomerase I, and C6CPT50 and C6CPT100 presented a significant increase in topoisomerase IIα content and catalytic activity and a marked overexpression of P-glycoprotein. We explored the cytotoxicity of combinations of a topoisomerase I inhibitor (camptothecin) and a topoisomerase II inhibitor (doxorubicin or etoposide) at several molar ratios, allowing the evaluation of their synergistic or antagonistic effects on cell survival using the median effect principle. The simultaneous combination of camptothecin and doxorubicin or etoposide was additive or antagonistic in C6 cells, slightly synergistic in the C6CPT10 line and never more than additive in the C6CPT50 and C6CPT100 cell lines. The sequential combination of doxorubicin and camptothecin gave additivity in the order camptothecin → doxorubicin and antagonism in the order doxorubicin → camptothecin. Clinical protocols combining a topoisomerase I and a topoisomerase II inhibitor should be considered with caution because antagonistic effects have been observed with combinations of camptothecin and doxorubicin.© 2001 Cancer Research Campaign http://www.bjcancer.co