Comparative study of hatching rates of African catfish (Clarias gariepinus Burchell 1822) eggs on different substrates

The hatching rates of African catfish (Clarias gariepinus) eggs on four natural substrates: the roots of Nile cabbage (Pistia stratiotes), water hyacinth (Eichhornia crassipes), pond weed (Ceratophyllum dermasum) and green grass leaves (Commelina sp.), and four artificial substrates: sisal mats, nylon mats, papyrus mats and kakaban mats, was assessed. Concrete slabs were used as control. The natural substrates performed better than the artificial ones. Pistia roots gave the best mean hatching rate of 66.2 ± 3.62%. Green grass leaves were second with a mean rate of 54.0 ± 3.46%, water hyacinth was third with 49.7 ± 3.16% and Ceratophyllum fourth with a mean of 13.0 ± 2.37%. Concrete slabs gave a mean rate of 18.6 ± 2.8%, sisal mats 18.6 ± 2.0%, papyrus 12.2 ± 1.2% and kakaban 11.8 ± 1.9%. Nylon mats were the last, with a mean rate of 4.0 ± 0.7%. The best performing natural substrates were those with the ability to float and thin fibrous roots that seemed to allow higher aeration of the eggs during incubation. The cost of using natural substrates was minimal

Wireless Inductive Charging for Low Power Devices

Currently wireless charging for most consumer electronics is still evolving in the mainstream market. This technology has taken a slow adoption. I n a world faced with variety of handheld devices demand for a shorter charging time is constantly being explored. Wireless charging has its challenges and successes The goal of this project was to design a prototype through research and design that would critically address and analyze the major design challenges that bring about longer charging periods of the new inductive wireless charging compared to the old fashioned, wired charging method and provide probable solutions. All the sections of the prototype namely transmitter, receiver and coil arrangement were designed and tested. The entire circuit was finally simulated and later fabricated on a PCB to come up with a prototype. Results were compared. This study showed that proper choice of coils must be made during design in order to minimize power losses and therefore increase efficiency

Queering African Studies

African Intimacies: Race, Homo- sexuality, and Globalization by Neville Hoad. (Minneapolis: University of Minnesota Press, 2007. Pp. 187. $60.00 cloth,$20.00 paper.

Estimating Hypothetical Bias in Economically Emergent Africa: A Generic Public Good Experiment

This paper reports results from a contingent valuation based public good experiment conducted in the African nation of Botswana. In a sample of university students, we find evidence that stated willingness to contribute to a public good in a hypothetical setting is higher than actual contribution levels. However, results from regression analysis suggest that this is true only in the second round of the experiment, when participants making actual contributions have learned to significantly lower their contribution levels. As globalization expands markets, and economies such as Botswana’s continue to modernize, there is a growing need to understand how hypothetical bias will influence the valuation of public goods.hypothetical bias, public good, willingness to pay, Botswana, Environmental Economics and Policy,

Demonstration of Self-Updating Landslide Hazard Maps with Dynamic Crowd-Sourced Data in Rwanda

No abstract availabl

Comparative study of hatching rates of African catfish (Clarias gariepinus Burchell 1822) eggs on different substrates

The hatching rates of African catfish (Clarias gariepinus) eggs on four natural substrates: the roots of Nile cabbage (Pistia stratiotes), water hyacinth (Eichhornia crassipes), pond weed (Ceratophyllum dermasum) and green grass leaves (Commelina sp.), and four artificial substrates: sisal mats, nylon mats, papyrus mats and kakaban mats, was assessed. Concrete slabs were used as control. The natural substrates performed better than the artificial ones. Pistia roots gave the best mean hatching rate of 66.2 ± 3.62%. Green grass leaves were second with a mean rate of 54.0 ± 3.46%, water hyacinth was third with 49.7 ± 3.16% and Ceratophyllum fourth with a mean of 13.0 ± 2.37%. Concrete slabs gave a mean rate of 18.6 ± 2.8%, sisal mats 18.6 ± 2.0%, papyrus 12.2 ± 1.2% and kakaban 11.8 ± 1.9%. Nylon mats were the last, with a mean rate of 4.0 ± 0.7%. The best performing natural substrates were those with the ability to float and thin fibrous roots that seemed to allow higher aeration of the eggs during incubation. The cost of using natural substrates was minimal.Hatching, Seed production, Fish eggs, Africa, Kenya, Clarias gariepinus

Economic Evaluation of Organic and Inorganic Resources for Recapitalizing Soil Fertility in Smallholder Maize-based Cropping Systems of Central Kenya

Structural adjustments programs (SAPs) in the last two decades have eliminated all farm-support programs leading to low usage of fertilizers by Kenyan smallholders. One way of addressing this problem is use of organic nutrient resources. This paper examines their cost-effectiveness as capital investments in replenishment of Nitrogen (N), Phosphorus (P), Potassium (K) and soil organic matter (SOM) in smallholder, Maize-based cropping systems. On-farm trials were established in Maragwa and Kirinyaga Districts in 2003/04. Maize was planted in 3 replicates in randomised complete block design (RCBD) using different levels of organic and inorganic fertilizer resources. A blanket rate of 40kg P/ha was applied in all treatment except the control to increase organic N-utilization efficiency. The test crop was harvested, oven-dried and weighed. Net Present Values (NPV) were computed using Partial Budgeting Analysis Model. Increasing levels of inorganic N increased maize yields significantly (P<0.05). However, higher yields were necessary but not sufficient criteria to determine profitability of different treatments. Manure + 60 kg N/ha gave highest NPV (USD 564), Manure + 40kg N/ha gave second highest NPV (USD 511) in Maragwa District while Manure + 60kg N/ha gave highest NPV (USD 633) and Manure + 40kg N/ha second highest NPV (USD 618) in Kirinyaga District. These results suggested that higher N-levels were not necessarily the most economical. Use of organic resources with modest amounts of mineral fertilizers seemed more profitable and held the key to enhancement of nutrient budgets, food security and rural livelihoods.Natural resource capital, Net present values (NPV), Nutrient budgets, Smallholder farmers, Soil organic matter (SOM), Structural adjustment programs (SAPs), Crop Production/Industries, Land Economics/Use,

Burkina Faso women empowerment and welfare project

It has been proven that the poor have the desire and motivation to do something to change their situation. They may be short of ideas of how to wiggle themselves out of an uncomfortable situation but they surely have the inner resource when they are gently nodded in the right direction. This was proven in a project that was carried out in Burkina Faso among poor urban women. The project further revealed that sustainable development cannot be attained without integration. To address the root causes of poverty; gender inequities, HIV/AIDS and the environment should be addressed together. Activities that provide and permit access to basic necessities like education and health should be integrated in the project too. To assure sustainability of the project CED practitioner should avoid introducing complex technology or financially unattainable practices but should, to the extent possible, use local resources and build on the local knowledge. In this project local resource persons, locally available material - mostly recycled - were utilized. The project drew largely from local knowledge and values will ensure continuity of the activities even after external support has ceased. Finally, following the principle of subsidiarity the management of the project activities should to the extent feasible be left to the beneficiaries. The targeted women in this project managed the savings and loan project, using the self help group model, to improve their personal businesses. (Author abstract)Macharia, D. G. (2007). Burkina Faso women empowerment and welfare project. Retrieved from http://academicarchive.snhu.eduMaster of Science (M.S.)School of Community Economic Developmen