187 research outputs found

    Potentials of cellulosic wastes in media formulation

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    Potential use of cellulosic wastes as carbon and energy sources in selective media formulations was investigated. Two agar media, Czapek-Dox and Sabouraud’s agar, were modified by substituting their carbon sources with cellulose, sawdust and sugarcane pulps. Then, two fungi; Aspergillus niger ANL301 and Penicillium chrysogenum PCL501, newly isolated from wood-wastes, were transferred to the unmodified and modified media and their growth was monitored for 120 h. Growth of the organisms on modified media containing sawdust and sugarcane pulp compared favorably with that obtained for the unmodified equivalents. Modified Czapek-Dox agar containing 2% (w/v) sawdust (Wood agar) and sugarcane pulps (Cane agar) gave 78.9 – 93.3% of the maximum growth obtained on Sabouraud’s agar. The modified Sabouraud’s agar containing sawdust (Wood-Pep agar) and sugarcane pulps (Cane-Pep agar) yielded 84.4 – 100% of the maximum growth on Sabouraud’s agar. Cellulose-containing media gave a lower level of growth (60.0 – 66.7%) of that obtained for the unmodified media

    Effects of Soil Properties and Operational Variables on the Compactibility of a Sandy Loam Soil

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    The evaluation of an empirical equation for the determination of degree of compaction of a sandy loam soil was carried out using seven soil physical properties and four compaction operational variables. The soil used was obtained from a borrow pit in Gombe. Five levels of compactive effort, E/A, using a drop-weight type compactor varying from 107.91 to 539.55 Nm was used to compact each of seven pairs of embankment and slice thicknesses (Z, z respectively) with Z varying from 210 to 450 mm and z from 30 to 210 mm. The developed empirical equation, π1 = Gπ2k in which π1 is the dimensionless degree of compaction and π2 is a dimensionless combination of the soil properties and the compaction operational variables, has a very high coefficient of determination, r2 varying from 98.8% to 98.9%. G and k are each polynomial functions of compactive effort per loading, eL. that is, G = αGeL2+βG eL + λG and k=αkeL2+βkeL+ λk. The values of the respective α, β and λ are highly statistically significant at 99.95 confidence level. The “dependent” variables (G and k) are highly correlated at 99.95% confidence level of statistical significance with the “independent” variable (eL). The multivariate expression of the degree of compaction obtained in this study shows that compaction depends, not only on cumulative compactive effort, E/A, but also on the compactive effort per loading (eL), embankment and slice thicknesses (Z and z respectively) as well as on easy-to-measure soil properties (i.e. soil texture, soil uniformity coefficient, antecedent soil moisture and antecedent bulk density)

    A design proposer on policy framework in IPV6 network

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    Networked systems are increasingly driven by changing business needs, their management becomes even more complex. In order to adapt to changing business requirements, distributed systems switch from the traditional client-server model to a service-driven model: The internet service driven network is a new approach to the provision of network computing that concentrates on the services you want to provide. These services range from the low-level services that manage relationships between networked devices to the value-added services provided to the end-users. The requirements for management systems identified above, can be facilitated with policy-based management approach where the support for distribution, automation and dynamic adaptation of the behaviour of the managed system is achieved by using policies. IPV6 is one of the useful delivery protocols for future fixed and wireless/mobile network environment while multihoming is the tools for delivering such protocol to the end users. This paper proposed interface selection mechanism while the study presents a policy framework in IPv6 multihomed mobile network, policy Framework Architecture, and a case study for the framework

    An approach design and analysis of resource management software for multihoming in-vehicle of IPv6 network

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    The resource management of Multihoming in nested mobile network raises new issues in the host mobility of ipv6 network. Multihoming facilitates the possibility of switching over to the network path offering better performance. However the key factor in attaining the benefit of multihoming is to ensure that the handoff switches over from one network interface to the other interface with minimal interruption. The aim of mobility support is to make mobile nodes keep connectivity without modification when roaming. The contribution of this paper is to simulate a policy based routing protocol framework that focuses on session preservation by redundancy and Load balancing by selecting the best available interface or enabling multiple interfaces simultaneously, since their management is critical for mobile communication. To manage these two critical resources, we identify the mobility characteristics and hardware configurations of in vehicle networks. The study then proposed a policy based routing protocol using two adaptive session preservation schemes in multihoming, which is refer to as best-connected MR selections based on location and path based type to support nested network of MIPV6 which was simulated using network simulator (NS2)

    Potentials of cellulosic wastes in media formulation

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    Potential use of cellulosic wastes as carbon and energy sources in selective media formulations was investigated. Two agar media, Czapek-Dox and Sabouraud’s agar, were modified by substituting theircarbon sources with cellulose, sawdust and sugarcane pulps. Then, two fungi; Aspergillus niger ANL301 and Penicillium chrysogenum PCL501, newly isolated from wood-wastes, were transferred to the unmodified and modified media and their growth was monitored for 120 h. Growth of the organisms on modified media containing sawdust and sugarcane pulp compared favorably with that obtained for the unmodified equivalents. Modified Czapek-Dox agar containing 2% (w/v) sawdust (Wood agar) and sugarcane pulps (Cane agar) gave 78.9 – 93.3% of the maximum growth obtained on Sabouraud’s agar. The modified Sabouraud’s agar containing sawdust (Wood-Pep agar) and sugarcane pulps (Cane-Pep agar) yielded 84.4 – 100% of the maximum growth on Sabouraud’s agar. Cellulose-containing media gave a lower level of growth (60.0 – 66.7%) of that obtained for the unmodified media

    Assessment of Charcoal Production and Its Impact on Deforestation and Environment in Borgu Local Government Area of Niger State, Nigeria

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    Commercial charcoal production is gradually becoming one of the major sources of sustenance and currently plays a major role in promoting entrepreneurial development in Borgu Local Government Area of Niger State. The study was carried out to assess charcoal production and its impact on deforestation and environment in the study area. Data for the study were generated from a structured questionnaire administered to charcoal producers in the study area. Data obtained revealed that majority (83%) were male with 56% within the age class of 21-40, majority (67%) were married and about (51%) attained primary education. Majority of the producers (82%) used traditional earth mound kiln method for charcoal production and about 56% of the producers obtained their raw material from free area. Most preferred tree species for charcoal production was Prosopis africana and accounted for 61%. Loss of biodiversity ranked 1st as regards impact of charcoal production on deforestation and environment in the study area, closely followed by forest degradation and soil degradation respectively. This study will enable forestry policy makers, charcoal producers, and farmers in the study area to be better informed about the implications of charcoal production on deforestation and environment and seek innovative means and ways to combat its menace

    Challenges of Decentralized, Farmer-Led and Fee-For-Service Extension

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    Agricultural extension services are crucial for the rapid spread of research results to farmers and for transmitting information about farmers’ needs, circumstances, and problems to researchers. In developing countries, public extension organizations are dominant. These public extension systems are often inadequately funded, have high costs, and their effectiveness is limited by many administrative and design deficiencies and challenges. Chief among these are the large scale and complexity of extension operations, the weak links between extension and research, problems of accountability, weak political commitment and support, weak management systems, severe difficulties of fiscal unsustainability, and difficulties of tracing extension impact. Disenchantment with the traditional, public extension programmes has led to the emergence of other approaches aimed at overcoming some of the weaknesses inherent in the public extension systems. This paper reviews the challenges of decentralized, farmer-led and fee-for-service extension

    Challenges of Decentralized, Farmer-Led and Fee-For-Service Extension

    Get PDF
    Agricultural extension services are crucial for the rapid spread of research results to farmers and for transmitting information about farmers’ needs, circumstances, and problems to researchers. In developing countries, public extension organizations are dominant. These public extension systems are often inadequately funded, have high costs, and their effectiveness is limited by many administrative and design deficiencies and challenges. Chief among these are the large scale and complexity of extension operations, the weak links between extension and research, problems of accountability, weak political commitment and support, weak management systems, severe difficulties of fiscal unsustainability, and difficulties of tracing extension impact. Disenchantment with the traditional, public extension programmes has led to the emergence of other approaches aimed at overcoming some of the weaknesses inherent in the public extension systems. This paper reviews the challenges of decentralized, farmer-led and fee-for-service extension

    Discovery of Potent, Selective, and Orally Bioavailable Small-Molecule Modulators of the Mediator Complex-Associated Kinases CDK8 and CDK19.

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    The Mediator complex-associated cyclin-dependent kinase CDK8 has been implicated in human disease, particularly in colorectal cancer where it has been reported as a putative oncogene. Here we report the discovery of 109 (CCT251921), a potent, selective, and orally bioavailable inhibitor of CDK8 with equipotent affinity for CDK19. We describe a structure-based design approach leading to the discovery of a 3,4,5-trisubstituted-2-aminopyridine series and present the application of physicochemical property analyses to successfully reduce in vivo metabolic clearance, minimize transporter-mediated biliary elimination while maintaining acceptable aqueous solubility. Compound 109 affords the optimal compromise of in vitro biochemical, pharmacokinetic, and physicochemical properties and is suitable for progression to animal models of cancer

    Challenges of accountability and development in Nigeria: An auto-regressive distributed lag approach

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    Purpose The purpose of this paper is to examine the challenges of accountability and development in Nigeria. In the literature, corruption is seen as an indicator of a lack of political accountability in most countries of the world, especially in less developed countries such as Nigeria. The Nigerian Government has taken several actions to address the problems of bad governance and corruption that have impeded economic development, but unfortunately these measures have not yielded the desired results. Design/methodology/approach Thus, this study examined accountability and developmental issues in Nigeria using secondary data and then made use of the auto-regressive distributed lag econometric technique to analyze the data. Findings The results from the study found that a rise in total government expenditure poses a danger of reducing Nigeria’s economic development in the long run and that control of corruption and political (the institutional variables) has a direct and significant effect on Nigeria’s economic development. Originality/value Therefore, upon these findings, this paper recommended that for Nigeria to experience development, corruption should be eliminated, and the Nigerian Government should spend on viable projects and economic activities that will be beneficial to the populace and the society at large and hence bring about economic development. Accountability is the hallmark of a prudent government that ensures efficient management of resources and transparency in the utilization of funds by the government. The absence of accountability mechanism allows corruption to thrive, which hinders the developmental process
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