Effectiveness evaluation of contingency sum as a risk management tool for construction projects in Niger Delta, Nigeria

Construction managers in a bid to effectively manage risks prone projects have adopted several methods, one of which is contingency sum. This study aims at evaluating the effectiveness of contingency sum as a risk management tool for construction projects in Niger Delta region of Nigeria. The objectives are to establish the level of awareness and utilization of contingency estimating methods among construction stakeholders, evaluate their perceptions of the percentage allowed for contingency in construction projects and determine whether there is a relationship between initial project cost, cost overrun and percentage allowed for contingency. Structured questionnaire served as the research instrument and the data were analysed using simple percentage, mean score and correlation. The findings of the study show that the most used contingency estimating method in the region is traditional percentage and that the three most important factors that affect the sum or percentage allowed as contingency for projects are complexity of the project, experience of the estimator and location of the project. The percentage allowed for projects as contingency by consultants and contractors in this study ranges between 5- 20 while the average contingency allowed is 10.4 (%). Furthermore, there is no relationship between initial project cost and the percentage allowed for contingency(p=0.294> 0.05).It was concluded that the contingencies allowed for projects in Niger Delta are based on the discretions of the consultants and contractors and not a function of the estimated contract value and it is not adequate. The study therefore recommends that contingency sum or percentage allowed should not be limited to complexity of the project , experience of the estimator, location of the project or the total contract sum but should be based on a comprehensive assessment of all factors that generate risk in each particular project. Key Words: Construction project, Contingency sum, Evaluation, Management tool, Ris

Evaluation of Causes of Construction Material Waste: Case of River State, Nigeria

This research paper evaluates the causes of construction waste generation on building sites in Rivers State, Nigeria. The methods employed to collect data include review of relevant literature and structured questionnaire. The statistical techniques used to analyse the data collected are Mean score method, ranking method and Man-Whitney U test. The results of analysis showed that the three most important factors contributing to construction material waste generation on building sites in Rivers State, Nigeria are ‘’rework contrary to drawing and specification”, “design changes and revision” and “waste from uneconomical shapes” respectively. It was also discovered that inappropriate equipment contributed least to waste generation on site and there is little “bottle neck” in obtaining work permit by contractors in Rivers State, Nigeria. The study revealed that all the 74 factors were considered important by the respondents. The study showed that there is no significant difference between the consultants and contractors perception about the factors affecting construction waste generation on building sites in Rivers State, Nigeria. This study therefore recommended that construction stakeholders should consider the studied factors at every level of the construction processes and in their waste management plan.Key words: Building Sites, Construction Waste, Evaluation, Factors, Nigeri

Effects of Project-Related Factors on Construction Labour Productivity in Bayelsa State of Nigeria

Construction labour productivity has continued to be researched into because of its importance in nations’ economy. This study assesses and compares the relative effects of project-related factors on construction labour productivity in Bayelsa State of Nigeria from the perspectives of building craftsmen and project supervisors/engineers. A field survey involving a stratified random sample of 146 building craftsmen and 81 project supervisors/engineers was conducted. Data were collected through structured questionnaires and analysed using Mean Item Score and Mann-Whitney U-test. The result shows that there is no significant difference between building craftsmen’ and project supervisors’/engineers’ perceptions of the relative effects of project-related factors on construction labour productivity (p = 0.646 > 0.05). In addition, the selected project team members ranked specification and standardisation, availability of material, project goals and milestones, high quality of required works and availability of drawings as the first five significant project-related factors affecting construction labour productivity respectively. The study therefore, recommends that construction managers should make more explicit projectspecifications; address the effects of availability of materials, high quality of required works and nonavailability of project documents on construction labour productivity with clients and motivate craftsmen with realisable goals and milestones.Keywords: Construction, craftsmen, effects, labour, factors, productivit

Coincident Tick Infestations in the Nostrils of Wild Chimpanzees and a Human in Uganda

Ticks in the nostrils of humans visiting equatorial African forests have been reported sporadically for decades, but their taxonomy and natural history have remained obscure. We report human infestation with a nostril tick in Kibale National Park, Uganda, coincident with infestation of chimpanzees in the same location with nostril ticks, as shown by high-resolution digital photography. The human-derived nostril tick was identified morphologically and genetically as a nymph of the genus Amblyomma, but the mitochondrial 12S ribosomal RNA or the nuclear intergenic transcribed spacer 2 DNA sequences of the specimen were not represented in GenBank. These ticks may represent a previously uncharacterized species that is adapted to infesting chimpanzee nostrils as a defense against grooming. Ticks that feed upon apes and humans may facilitate cross-species transmission of pathogens, and the risk of exposure is likely elevated for persons who frequent ape habitats.Human Evolutionary BiologyLibraries/Museum

Confronting ethical challenges in long-term research programs in the tropics

Ecologists and conservation biologists conducting long-term research programs in the tropics must confront serious ethical challenges that revolve around economic inequalities, cultural differences, supporting the local communities as much as possible, and sharing the knowledge produced by the research. In this collective article, researchers share their experiences and perspectives in dealing with the ethical issues that arise during research activities and cannot be ignored.Accepted manuscrip

Wild chimpanzees modify modality of gestures according to the strength of social bonds and personal network size

Primates form strong and enduring social bonds with others and these bonds have important fitness consequences. However, how different types of communication are associated with different types of social bonds is poorly understood. Wild chimpanzees have a large repertoire of gestures, from visual gestures to tactile and auditory gestures. We used social network analysis to examine the association between proximity bonds (time spent in close proximity) and rates of gestural communication in pairs of chimpanzees when the intended recipient was within 10 m of the signaller. Pairs of chimpanzees with strong proximity bonds had higher rates of visual gestures, but lower rates of auditory long-range and tactile gestures. However, individual chimpanzees that had a larger number of proximity bonds had higher rates of auditory and tactile gestures and lower rates of visual gestures. These results suggest that visual gestures may be an efficient way to communicate with a small number of regular interaction partners, but that tactile and auditory gestures may be more effective at communicating with larger numbers of weaker bonds. Increasing flexibility of communication may have played an important role in managing differentiated social relationships in groups of increasing size and complexity in both primate and human evolution

Level Of Adoption Of Sustainability Practice Among Locally And Foreign Owned Construction Firm In Nigeria Delta

The quest to have sustainable development by different stakeholders in the construction industry cannot be overemphasised. Hence the aim of this research is to assess the  level of adoption of sustainability practices among locally owned and foreign owned construction firms in Niger- Delta, Nigeria.  Data were obtained using 1179 copies of structured questionnaire, administered through random sampling technique. The methods of data analysis were simple percentage, mean score and Mann- Whitney test. The average mean scores of 2.89 and 3.39 for locally and foreign owned construction firms respectively, indicate that the overall level of adoption of sustainability practices among locally and foreign owned firms is moderate.  The P-value of 0.001 is less than 0.05 significance level, hence the hypothesis was rejected. This indicates that there is a significant difference in the level of adoption of sustainability practices among locally owned and foreign owned construction firms in Niger Delta, Nigeria. This study concluded that firms’ ownership has significant impact on the level of adoption of sustainability practices by the construction firms in Niger Delta. This study recommends government should pass into law, legislations that would encourage the adoption of sustainability practices by the construction firms in Niger - Delta, Nigeria. This study also recommends that construction firms should improve on their level of adoption of sustainability practices in Niger Delta by increasing top management support, human resource management, employee empowerment, training and educating employees on sustainability practices and increasing the amount of resources allocated to sustainability. Government should pass into law, legislation that would promote the interest of the government and the citizens in the Niger Delta, Nigeria. These Legislations would make the firms to improve their level of adoption of sustainability practice in Niger Delta, Nigeria