3,991 research outputs found

    The rise of peri-urban aquaculture in Nigeria

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    The paper traced aquacultural development in Nigeria to the colonial period in 1950s with fish farming in tilapias during which more than 200 small scale subsistence level ponds were built with some growth continuing in the rural areas. There was a bloom in farming of catfishes in 2000. The interest shown by private fish farmers has been identified as a propelling factor for aquacultural development in Nigeria. The development of private fish hatcheries has been another factor leading to the growth of aquaculture. The paper noted that social capital and its development either directly or indirectly can be identified as contributing to the success of the sectors. The increasing profit from aquaculture has led to fish farmers increasing beyond 5000 tonnes in 2009. The paper highlighted the numerous advantages which led to the expansion of the industry in Nigerian villages

    Increased plasma markers of oxidative stress are associated with coronary heart disease in males with diabetes mellitus and with 10-year risk in a prospective sample of males

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    Background: Increased oxidative stress is associated with coronary heart disease (CHD). We examined the association between plasma markers of oxidative stress and CHD in a cross-sectional sample of patients with diabetes and prospective CHD risk in a sample of men predominantly without diabetes. Methods: Plasma total antioxidant status (TAOS) and the ratio of oxidized LDL (Ox-LDL) to LDL-cholesterol (LDL-C) were determined in a cross-section of 761 Caucasian individuals with diabetes (UDACS study). Plasma TAOS was also determined in 310 baseline samples from a 10-year prospective cohort of 3012 healthy males (NPHSII). Results: Within UDACS, males with CHD had lower mean (SD) plasma TAOS [no CHD, 43.4 (13.2)%; CHD, 40.3 (13.8)%; P = 0.04]. The prevalence of CHD was higher in the lowest compared with the upper quartiles (32.7% vs 19.7%; P = 0.004). We observed a significant association between plasma Ox-LDL:LDL-C and CHD status [no CHD vs CHD, 16.9 (3.1) vs 19.3 (5.0) units/mmol; P = 0.04], with the prevalence of CHD being higher among men in the upper compared with lower quartiles (18.4% vs 35.1%; P = 0.003). No association was observed in females. In NPHSII, TAOS was lower in those who developed CHD [35.1 (8.0)% vs 37.1 (7.9)%; P = 0.04]. The odds ratio for CHD in the lowest compared with the upper quartile was 1.91 (95% confidence interval, 0.99–3.70; P = 0.04). This remained unchanged after adjustment for classic risk factors. Conclusions: A cross-sectional and prospective association exists between baseline plasma measures of oxidative stress and CHD risk. The association with prospective CHD risk remained after adjustment for "traditional" risk factors, implying an independent role for oxidative stress in CHD risk

    Assessment of Gerio Lake Fishery for Enhanced Management and Improved Fish Production

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    The highlights of the Fisheries Assessment Survey conducted on Gerio Lake, Yola in Adamawa State, North-eastern Nigeria in February, 2005 is presented in this paper. There were 22 fish species found in fishermen\u2019s landings during the survey period. About 30 fishermen were found using undersized nets to catch the juveniles of these species. Fishing pressure was found to be very high. For an optimum catch, about 10 fishermen ought to have engaged in full time fishing activities if, the fisheries of the lake is to be managed on a sustainable basis. However, a surplus of over 80 fishermen was recorded actively fishing during the period of the assessment. All these have a depleting effect on the abundance and sizes of fish harvested from the lake. A community based fisheries management system, which establishes a participatory involvement of fishermen in the conservation and rational exploitation of fisheries resources for the well being of the stakeholders is recommended for the Lake

    NEUTRON LOSSES TO Pasup233sup 233 IN THE AQUEOUS HOMOGENEOUS BREEDER REACTOR

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    Neutron losses to Pa/sup 2//sup 3//sup 3/ in the blanket of the AHBR were computed and compared for two cases: (1) concentration of Pa/sup 2//sup 3// sup 3/ is maintained uniform by continuous mixing, and (2) batches of fertile material are shifted periodically from high- to low-flux regions of blanket. It was found that, if the fertile material is cycled through three radial positions in three days, the loss of neutrons to Pa/sup 2//sup 3//sup 3/ is no more than one per cent greater than if it is mixed continuously. (auth

    A molecular phylogenetic reappraisal of the Hysteriaceae, Mytilinidiaceae and Gloniaceae (Pleosporomycetidae, Dothideomycetes) with keys to world species

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    A reappraisal of the phylogenetic integrity of bitunicate ascomycete fungi belonging to or previously affiliated with the Hysteriaceae, Mytilinidiaceae, Gloniaceae and Patellariaceae is presented, based on an analysis of 121 isolates and four nuclear genes, the ribosomal large and small subunits, transcription elongation factor 1 and the second largest RNA polymerase II subunit. A geographically diverse and high density taxon sampling strategy was employed, including multiple isolates/species from the following genera: Anteaglonium (6/4), Encephalographa (1/1), Farlowiella (3/1), Gloniopsis (8/4), Glonium (4/2), Hysterium (12/5), Hysterobrevium (14/3), Hysterographium (2/1), Hysteropatella (2/2), Lophium (4/2), Mytilinidion (13/10), Oedohysterium (5/3), Ostreichnion (2/2), Patellaria (1/1), Psiloglonium (11/3), Quasiconcha (1/1), Rhytidhysteron (8/3), and 24 outgroup taxa. Sequence data indicate that although the Hysteriales are closely related to the Pleosporales, sufficient branch support exists for their separation into separate orders within the Pleosporomycetidae. The Mytilinidiales are more distantly related within the subclass and show a close association with the Gloniaceae. Although there are examples of concordance between morphological and molecular data, these are few. Molecular data instead support the premise of a large number of convergent evolutionary lineages, which do not correspond to previously held assumptions of synapomorphy relating to spore morphology. Thus, within the Hysteriaceae, the genera Gloniopsis, Glonium, Hysterium and Hysterographium are highly polyphyletic. This necessitated the transfer of two species of Hysterium to Oedohysterium gen. nov. (Od. insidens comb. nov. and Od. sinense comb. nov.), the description of a new species, Hysterium barrianum sp. nov., and the transfer of two species of Gloniopsis to Hysterobrevium gen. nov. (Hb. smilacis comb. nov. and Hb. constrictum comb. nov.). While Hysterographium, with the type Hg. fraxini, is removed from the Hysteriaceae, some of its species remain within the family, transferred here to Oedohysterium (Od. pulchrum comb. nov.), Hysterobrevium (Hb. mori comb. nov.) and Gloniopsis (Gp. subrugosa comb. nov.); the latter genus, in addition to the type, Gp. praelonga, with two new species, Gp. arciformis sp. nov. and Gp. kenyensis sp. nov. The genus Glonium is now divided into Anteaglonium (Pleosporales), Glonium (Gloniaceae), and Psiloglonium (Hysteriaceae). The hysterothecium has evolved convergently no less than five times within the Pleosporomycetidae (e.g., Anteaglonium, Farlowiella, Glonium, Hysterographium and the Hysteriaceae). Similarly, thin-walled mytilinidioid (e.g., Ostreichnion) and patellarioid (e.g., Rhytidhysteron) genera, previously in the Mytilinidiaceae and Patellariaceae, respectively, transferred here to the Hysteriaceae, have also evolved at least twice within the subclass. As such, character states traditionally considered to represent synapomorphies among these fungi, whether they relate to spore septation or the ascomata, in fact, represent symplesiomorphies, and most likely have arisen multiple times through convergent evolutionary processes in response to common selective pressures

    Food security and poverty alleviation under the National Special Programme for Food Security: a preliminary socio-economic assessment of Yamama Lake, Kebbi state, Nigeria

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    The World Food Summit in its meeting in Rome in 1999 estimated that 790 million people in the developing world do not have enough food to eat. This is more than the total populations of North America and Europe combined. Nigeria is one of the developing countries affected by hunger, deprivation and abject poverty by its citizenry inspite of its enormous natural and human resources. To reduce poverty and increase food supplies to the masses the Federal Government of Nigeria embarked on a programmed-tagged National Special Programme for Food Security (NSPFS) in the year 2002. The programme's broad objectives are to attain food security in the broadest sense and alleviate rural poverty in Nigeria. One of the areas of the programme's intervention is in the aquaculture and inland fisheries development because Nigeria imported 681mt of fish in 2003 with a total cost of about N50 million. The paper assesses the socio-economic conditions of one of the selected water bodies (Yamama Lake) with a view to introducing community-based fisheries management plan for the rational exploitation and management of the fishery and other aquatic resources of the water body thereby increasing fish supply and improving the living standard of the fisherfolk in the area. Data were collected using Participatory Rural Appraisal (PRA) tools and questionnaire administratio

    Assessment of inland waters fisheries in Nigeria with implications for improved freshwater fish production, poverty alleviation and food security

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    Rapid Appraisals of the current fisheries situations of some selected inland water bodies in Nigeria were carried out within the framework of Aquaculture and Inland Fisheries Project (AIFP) Annex II of the National Special Programme for Food Security (NSPFS). This paper presents the results of the fishery assessment of one of the selected inland water bodies (Sabke Lake) in Nigeria with a view to optimizing the fish yield through the adoption of improved culture based fishery techniques and community-based fisheries management. The lake is unmanaged and the fishing pressure was found to be very high. Also a number of fishermen were found using small mesh size nets to crop the juveniles of highly valued fish species for an optimum catch. About 14 fishermen ought to have been engaged in full time fishing activities if the fisheries of this lake is to be managed on a sustainable basis. However, a surplus of over 100 fishermen was recorded actively fishing during the period of the study. The results further revealed that Fisheries Rules and Regulations were not established for the national exploitation and proper management of the fisheries of many inland water bodies including Sabke Lake. All these have a depilatory effect on the abundance and sizes of fish harvested from the nigerian inland water bodies especially Sabke Lake. A community based management system that establishes a participatory involvement of fishermen in the conservation and national exploitation of fisheries resources for their own well being is recommended for Sabke Lake and other inland water bodies in Nigeri
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