POPULATION POLICIES : FORMULATION,IMPLEMENTATION AND PROSPECTS KEY ISSUES IN NIGERIA’S POPULATION POLICY IN THE 1990S

This paper reviews Nigeria's population policy which was adopted during the first quarter of 1988. The policy has been adopted at a time of social and economic stress. The policy document is divided into eight sections, each section highlights demographic and socio-economic aspects of the society. The major constraints to the realisation of the policy objectives are mentioned and the future prospects to the year 2000 are appraised

Evaluation of Water Infiltration Equations on Fadama Soils of Jos – North, Plateau State, Nigeria

The main purpose of this study is to obtain water infiltration parameters of the Fadama Soils on the Jos Plateau. Estimation of water infiltration on a soil is a major constraint due to its variability depending on local soil characteristics. This could be used in simulating infiltration for the Fadama soils when designing agricultural projects. Field measurement of infiltration were made using the double ring infiltrometer at the three locations (Rizek, Kerker and Shen – du) on the Jos Plateau. Readings were taken at intervals of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 65,70, 75, 80, 85, 90, 95, 100,105,  110, 115 and 120minutes. A set of field measured cumulative infiltration depths were used for the estimation of the model parameters for the five models, while the other set was used in simulating the infiltration equations. At Rizek, Horton and NCRS model performed better (0.997) followed by Philip’s model (0.973) while Kostiakov and modified Kostiakov’s model have the least value of 0.923 each. Philip’s model has the best fit (1.00) followed by the NCRS’s model (0.999) at Kerker while the Kostiakov and modifiedKostiakov’smodel had 0.997 each and Horton with the least value (0.986). At Shen – du, Kostiakov and modified Kostiakov performed better (0.997), then, Horton with (0.986), NCRS has 0.993 with Philip’s model having the least value (0.991).The study indicate that Kostiakov, Philip, Horton, NCRS and Modified Kostiakov’s models were capable of simulating infiltration for the Fadama soils (Rizek, Kerker and Shen – du) on the Jos, Plateau. Keywords: Infiltration Equations, Fadama Soils, Kostiakov Equation, Infiltartion Model

Implications of Geographic Information System in Mapping Solid Waste Collection Points in New Owerri, Imo State

The unsanitary condition in which solid waste is temporarily dumped and disposed of has generated environmental concern through pollutions and health hazards. This calls for a need to map out suitable collection points and disposal point for effective and efficient management of solid waste to promote hygienic environment. Therefore, GIS offers solution in this regard as a decision support system for most suitable site selection. Consequently, different layers (roads, stream and land use) were created to serve the purpose of manipulation and analyses to procure most suitable site for collection point of solid waste generated in New Owerri, Imo State using Arc view 3.2a software

Classical multivariate Hermite coordinate interpolation on n-dimensional grids

In this work, we study the Hermite interpolation on n-dimensional non-equally spaced, rectilinear grids over a field k of characteristic zero, given the values of the function at each point of the grid and the partial derivatives up to a maximum degree. First, we prove the uniqueness of the interpolating polynomial, and we further obtain a compact closed form that uses a single summation, irrespective of the dimensionality, which is algebraically simpler than the only alternative closed form for the n-dimensional classical Hermite interpolation [1]. We provide the remainder of the interpolation in integral form; moreover, we derive the ideal of the interpolation and express the interpolation remainder using only polynomial divisions, in the case of interpolating a polynomial function. Finally, we perform illustrative numerical examples to showcase the applicability and high accuracy of the proposed interpolant, in the simple case of few points, as well as hundreds of points on 3D-grids using a spline-like interpolation, which compares favorably to state-of-the-art spline interpolation methods

A correlation between the heavy element content of transiting extrasolar planets and the metallicity of their parent stars

Nine extrasolar planets with masses between 110 and 430M are known to transit their star. The knowledge of their masses and radii allows an estimate of their composition, but uncertainties on equations of state, opacities and possible missing energy sources imply that only inaccurate constraints can be derived when considering each planet separately. Aims: We seek to better understand the composition of transiting extrasolar planets by considering them as an ensemble, and by comparing the obtained planetary properties to that of the parent stars. Methods: We use evolution models and constraints on the stellar ages to derive the mass of heavy elements present in the planets. Possible additional energy sources like tidal dissipation due to an inclined orbit or to downward kinetic energy transport are considered. Results: We show that the nine transiting planets discovered so far belong to a quite homogeneous ensemble that is characterized by a mass of heavy elements that is a relatively steep function of the stellar metallicity, from less than 20 earth masses of heavy elements around solar composition stars, to up to 100M for three times the solar metallicity (the precise values being model-dependant). The correlation is still to be ascertained however. Statistical tests imply a worst-case 1/3 probability of a false positive. Conclusions: Together with the observed lack of giant planets in close orbits around metal-poor stars, these results appear to imply that heavy elements play a key role in the formation of close-in giant planets. The large masses of heavy elements inferred for planets orbiting metal rich stars was not anticipated by planet formation models and shows the need for alternative theories including migration and subsequent collection of planetesimals.Comment: Astronomy and Astrophysics 0 (2006) in pres

Implicit STEM ability beliefs predict secondary school students’ STEM self-efficacy beliefs and their intention to opt for a STEM field career

Despite the widely-accepted view that low self-efficacy beliefs negatively influence students’ intention to opt for a STEM field oriented study or career path, it remains unclear how to effectively stimulate these beliefs in students who do seem to have the ability and motivation to opt for a STEM career. A suggestion from previous literature is that students’ implicit beliefs about the malleability of their learning ability can have a major impact on their self-efficacy beliefs, and, importantly, that these implicit beliefs are malleable themselves. Even though this relation between implicit beliefs, self-efficacy, and STEM field aspirations has been suggested multiple times, there is no empirical evidence to support this claim. The goal of the current study was to examine whether implicit beliefs about the malleability of STEM ability are associated with secondary school students’ intention to opt for a STEM field bachelor’s degree, using a Structural Equation Modelling approach. Furthermore, we examined the mediating role of STEM-oriented self-efficacy beliefs on the relationship between implicit ability beliefs and STEM intention. We used a Likert-type questionnaire, consisting of subscales to measure ability beliefs, self-efficacy, and intention to opt for a STEM degree of secondary school students in their fifth grade (n = 483). Results showed that there is a positive relation between implicit STEM ability beliefs and the intention to opt for a STEM field bachelor degree, and that this relation is partly mediated by self-efficacy beliefs. Incremental STEM ability beliefs predicted positive self-efficacy beliefs and increased STEM intention. These findings provide a foundation for a novel approach to stimulate and motivate students for the STEM field, namely by stimulating incremental beliefs about their STEM ability

Fluctuations and criticality (dedicated to Reinhard Folk on his 60th birthday)

It is our pleasure and honour to present a collection of papers dedicated to Reinhard Folk on the occasion of his 60th birthday. With this Festschrift, colleagues and friends of the jubilee pay tribute to his long lasting and fruitful work in the field of condensed matter physics

An Analyses of Onion Marketing in Toro District of Toro Local Government Area in Bauchi State, Nigeria

The broad objective of the study was to determine the profitability and marketing efficiency of onion marketing in Toro District of Toro local government area in Bauchi State. Questionaire was the main instrument of data collection from a sample of fourty (40) onion traders in the study area. Analytical tools used were; descriptive statistics, gross margin, marketing margin and market efficiency. Majority (67.5%) of the respondents were males. Also, majority (55%) of onion Traders falls within the age bracket of 41 - 50 years of age, the result indicates high proportions (85.00%) of the respondents were educated. The years of Onion marketing experience of the respondents indicates that half of the respondents (50%) had 11 - 20 years of marketing experience in onion trading and the study also indicates that majority (52.50%) went into onions marketing with money between ₦21,000:00 - ₦30,000:00. Greater proportion (87.50%) of the respondents belongs to cooperative associations. Major problems of onion marketing identified were those of transportation, storage facilities, starting capital, market information and low price. Result of the costs and returns analysis revealed that onion marketing was profitable to the turn of N1,315.00 per bag for wholesale and N2,020.00 per bag for retail traders of onion marketers respectively. This finding also indicated that marketing of onion is efficient with total efficiency of 141.28% for wholesalers and 150.80% for retailers. Proper functional programmes and policies should be made to improve onion production and marketing in the study area

Species diversity and distribution of ruderal flora on landfills in Maradi city, Niger

Waste management continues to be a critical environmental issue in cities. It impacts on the well being of the population, the environment and the biodiversity. In the city of Maradi, in Niger, more interest is given to the problem in order to understand the whole waste management system. It is in this context that this study is carried out to investigate on the role of ruderal flora on the municipal solid wastes dumpsites and landfill sites in Maradi city. The specific objectives are to determine the floristic diversity and distribution of ruderal flora on the municipal solid waste disposal sites, and to identify potential species that can play an important role in the phytoremediation of these sites. In total, 65 species belonging to 52 genera and 24 families were recorded. These species can be categorised into two groups containing anthropic and nitrophilic species according to the ascending Hierarchical Classification (AHC) at 25% similarity. Characteristic species of the first group G1 are Amaranthus viridis and Cucurbita pepo, and Datura innoxia and Cucumis melo for the second group G2. Other ruderal species, namely Amaranthus spinosus L., Amaranthus viridis L., Celosia trygina L., Datura innoxia Mill., and an introduced woody species, Cuphea hyssopifolia Kunth., found are not included in the Maradi city list of species. Datura innoxia, Amaranthus viridis and Amaranthus spinosus are species known to tolerate different degrees of pollution and their ecology should be further study to better understand how they can be used for phytoremediation on this kind of sites

Effect of structural defects on anomalous ultrasound propagation in solids during second-order phase transitions

The effect of structural defects on the critical ultrasound attenuation and ultrasound velocity dispersion in Ising-like three-dimensional systems is studied. A field-theoretical description of the dynamic effects of acoustic-wave propagation in solids during phase transitions is performed with allowance for both fluctuation and relaxation attenuation mechanisms. The temperature and frequency dependences of the scaling functions of the attenuation coefficient and the ultrasound velocity dispersion are calculated in a two-loop approximation for pure and structurally disordered systems, and their asymptotic behavior in hydrodynamic and critical regions is separated. As compared to a pure system, the presence of structural defects in it is shown to cause a stronger increase in the sound attenuation coefficient and the sound velocity dispersion even in the hydrodynamic region as the critical temperature is reached. As compared to pure analogs, structurally disordered systems should exhibit stronger temperature and frequency dependences of the acoustic characteristics in the critical region.Comment: 7 RevTeX pages, 4 figure