1,859 research outputs found

    Investment prospects in the production of the common carp (Cyprinus carpio) fingerlings in freshwater ponds

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    Since the introduction of Common carp Cyprinus carpio in Oyo State (Nigeria) from Israel in 1964, various local breeding methods have been employed in carp rearing to improve the survival rate at all stages of development during breeding. The physico-chemical parameters of the ponds which were simultaneously investigated for carp rearing in this study includes temperature (t), dissolved oxygen (DO) and hydrogen-ion concentration (pH). However, high rates of water displacement in the breeding ponds were unfavourable to the development of zooplankton which play important role in the food web of C. carpio. The survival rates of 15.88-69.50% and 19.60-33.83% obtained for the egg-hatchling and hatchling-fingerling stages respectively were encouraging. A breeding performance of this magnitude was found to be viable, breaking even in the fourth year. However, an increase in size of this trial project would be more profitable and increase fingerling supply as well as provide employment opportunities. This study thereby provides some baseline information on some local techniques and progress in the propagation of C. carpio and scope for further improvemen

    Ocean climate data for user community in West and Central Africa: Needs, opportunities, and challenges

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    The urgent need to improve data delivery systems needed by scientists studying ocean role in climate and climate characteristics has been manifested in recent years because of the unprecedented climatic events experienced in many parts of the world. Indeed, there has been a striking and growing realization by governments and the general public indicating that national economies and human welfare depend on climate and its variability. In West and Central Africa, for instance climatic events, which have resulted in floods and droughts, have caused a lot of concern to both governments and people of the region. In particular, the droughts have been so widespread that greater awareness and concern have become generated for the need to find solutions to the problems created by the consequences of the climatic events. Particularly in the southern border regions of the Sahara Desert as well as in the Sahel region, the drought episodes considerably reduced food production and led to series of socioeconomic problems, not only in the areas affected by the droughts, but also in the other parts of West Africa. The various climatic variabilities which have caused the climatic events are no doubt related to the ocean-atmosphere interactions. Unfortunately, not much has been done on the understanding of these interactions, particularly as they affect developing countries. Indeed, not much has been done to develop programs which will reflect the general concerns and needs for researching into the ocean-atmosphere systems and their implications on man-environmental systems in many developing countries. This is for example, true of West and Central Africa, where compared with the middle latitude countries, much less is known about the characteristics of the ocean-atmosphere systems and their significance on man-environmental systems of the area

    Global Financial and Macroeconomic Fluctuations: Implications for African Economic Development

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    In the light of dampening effects of the global financial melt-down, the paper examines the trends in financial flows, particularly foreign direct investment (FDI) and the possible effects of the global financial crisis and macroeconomic fluctuations on economic development in Africa. The paper employs simple panel data approach which links panel data methodology that allows for individual heterogeneity, while the method of estimation is the Fixed and Random Effects regression. The method of panel VAR is also used in the paper with a view to capturing the dynamic effects of FDI inflows for policy analysis using the impulse response functions. The number of countries (27) included in the paper and the period of estimation, 1987-2007, are informed by data availability. With some suggestions on the direction of policy to stimulate increased financial flows, the paper opines that there is the need for comparative dynamics of African economies in order to return to the path of sustainable growth and development

    Evaluation of QSAR and ligand enzyme docking for the identification of ABCB1 substrates

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    P-glycoprotein (P-gp) is an efflux pump that belongs to ATP-binding cassette (ABC) transporter family embedded in the membrane bilayer. P-gp is a polyspecific protein that has demonstrated its function as a transporter of hydrophobic drugs as well as transporting lipids, steroids and metabolic products. Its role in multidrug resistance (MDR) and pharmacokinetic profile of clinically important drug molecules has been widely recognised. In this study, QSAR and enzyme-ligand docking methods were explored in order to classify substrates and non-substrates of P-glycoprotein. A set of 123 compounds designated as substrates (54) or non-substrates (69) by Matsson et al., 2009 was used for the investigation. For QSAR studies, molecular descriptors were calculated using ACD labs/LogD Suite and MOE (CCG Inc.). P-glycoprotein structures available in the Protein data bank were used for docking studies and determination of binding scores using MOE software. Binding sites were defined using co-crystallised ligand structures. Three classification algorithms which included classification and regression trees, boosted trees and support vector machine were examined. Models were developed using a training set of 98 compounds and were validated using the remaining compounds as the external test set. A model generated using BT was identified as the best of three models, with a prediction accuracy of 88%, Mathews correlation coefficient of 0.77 and Youden’s J index of 0.80 for the test set. Inclusion of various docking scores for different binding sites improved the models only marginally

    The development of high-voltage technique in NTU "KhPI"

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    Expanded Criteria Donors: Process and Outcomes

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    Expanded criteria donor (ECD) kidneys are transplantable deceased donor (DD) kidneys for which the average patient, graft survival, and renal function are inferior when compared to standard criteria DD kidneys. Although the term ECD kidneys has been used since the early 1990s to describe kidneys with various characteristics associated with poorer outcomes, the concept has been formally implemented in U.S. organ allocation. A DD kidney is considered to be an ECD organ if the estimated adjusted risk of graft failure is ≥ 70% (RR ≥ 1.70) compared to DD kidneys with standard characteristics of transplant suitability. The donor characteristics that define an ECD kidney include age ≥ 60 years, or age 50–59 years plus two of the following: cerebrovascular accident as the cause of death, preexisting hypertension, or terminal serum creatinine greater than 1.5 mg/dl. In the aggregate, recipients of ECD kidneys have improved survival compared to end-stage renal disease (ESRD) patients on the kidney transplant waiting list. Patient survival is 5% lower at 1 year and 8–12% lower at 3–5 years for ECD kidney recipients. Adjusted graft survival in ECD kidneys is 8% lower at 1 year and 15–20% lower at 3–5 years after transplantation compared to standard criteria donor kidneys. However, patients less than 40 years of age, African Americans, Asians for whom the median waiting time is less than 1350 days receive no survival benefit from ECD kidney transplantation. Informed choice by the potential recipient is a prominent feature of the allocation policy regarding ECD kidneys. Since there are recipient characteristics associated with no survival benefit following ECD transplantation, nephrologists who refer patients for kidney transplantation should be familiar with the combination of donor and recipient factors that are likely to yield detrimental results.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74587/1/j.1525-139X.2005.00090.x.pd

    The politics of revenue allocation and resource control in Nigeria: implications for federal stability

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    No doubt, one of the perennial problems which has not only defied all past attempts at permanent solution, but has also evoked high emotions on the part of all concerned is the issue of equitable revenue allocation in Nigeria. Thus, the thrust of this paper is an in-depth analysis of the politics of revenue allocation cum resource control. The paper takes a cursory look at virtually all previous attempts at arriving at equitable formula. The paper however, infers that in a deeply plural and divided society like Nigeria a polity that ‘robs Peter to pay Paul’ may eventually be both counter-productive and dysfunctional. The clarion call however is a federal system with fiscal policy that can imbue in the citizenry sense of justice, equity and fairness visà-vis revenue allocation. To do otherwise according to the findings of this paper is to jeopardize all efforts at national cohesion and integration
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