110 research outputs found

    A review on the potential of aquaculture development in Kenya for poverty alleviation and food security

    Get PDF
    On the global scene, aquaculture accounts for about 50% of total fish production amounting to about 80 million metric tonnes. It is estimated that another 40 million metric tonnes of aquatic food will be required by the year 2030. Today, fish farming represents the fastest growing sector of food production. Moreover, aquaculture has a major role to play in the achievement of the first three Sustainable Development Goals on poverty, hunger, food security and healthy lives of people from developing countries. This is significant especially in the developing countries where poverty and malnutrition are a reality. However, in sub-Saharan Africa, per capita fish production from aquaculture is still below world production levels. In Kenya, inland capture fisheries accounted for over 90% of the total national fish production while marine capture fisheries contributed about 5% in the last decade. Kenya has one of the fastest growing human populations in the world indicating that the demand for fish and fish products will continue to rise, increasing the gap between supply and demand. Currently, aquaculture only produces about 24,000 metric tonnes of fish annually compared to an annual average of 178,000 metric tonnes from natural fisheries. The dominant cultured species include: Nile tilapia (Oreochromis niloticus), African catfish (Clarias gariepinus), rainbow trout (Onchorhynchus mykis) and common carp (Cyprinus carpio). Culture systems commonly used are static ponds and raceway systems. In addition, the country is endowed with numerous aquaculture resources ranging from favorable climatic conditions to vast water resources. In the year 2009, the Kenyan government took steps to enhance aquaculture production through an Economic Stimulus Programme. This has increased the contribution of aquaculture in Kenya to 11.0% of the total fish production. This paper discusses the growth and development of aquaculture in Kenya during the last 50 years and the impact of government support to the sub-sector. The paper also proposes strategies for ensuring that Kenya becomes one of the leading producers of fish from aquaculture in Africa.Key words: Fish production, capture fisheries, culture systems, Economic Stimulus Programme, aquacultur

    Mechanisms for the Association between Traditional Masculine Ideologies and Rape Myth Acceptance among College Men

    Get PDF
    We explored mechanisms for the relationship between traditional masculine ideologies and rape myth acceptance. We hypothesized that locus of control would serve as a mediator for victim precipitation rape myths, while negative attitudes toward women would serve as a mediator for victim masochism and victim fabrication rape myths. Using a sample of 100 male college students, the results indicated that negative attitudes toward women mediated the relationship between traditional masculine ideologies and all three types of rape myths, but locus of control did not serve as a mediator for any. Implications and directions for future research are discussed

    One versus two eyes makes a difference! Early face perception is modulated by featural fixation and feature context

    Get PDF
    The final publication is available at Elsevier via https://doi.org/10.1016/j.cortex.2018.08.025 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The N170 event-related potential component is an early marker of face perception that is particularly sensitive to isolated eye regions and to eye fixations within a face. Here, this eye sensitivity was tested further by measuring the N170 to isolated facial features and to the same features fixated within a face, using a gaze-contingent procedure. The neural response to single isolated eyes and eye regions (two eyes) was also compared. Pixel intensity and contrast were controlled at the global (image) and local (featural) levels. Consistent with previous findings, larger N170 amplitudes were elicited when the left or right eye was fixated within a face, compared to the mouth or nose, demonstrating that the N170 eye sensitivity reflects higher-order perceptual processes and not merely low-level perceptual effects. The N170 was also largest and most delayed for isolated features, compared to equivalent fixations within a face. Specifically, mouth fixation yielded the largest amplitude difference, and nose fixation yielded the largest latency difference between these two contexts, suggesting the N170 may reflect a complex interplay between holistic and featural processes. Critically, eye regions elicited consistently larger and shorter N170 responses compared to single eyes, with enhanced responses for contralateral eye content, irrespective of eye or nasion fixation. These results confirm the importance of the eyes in early face perception, and provide novel evidence of an increased sensitivity to the presence of two symmetric eyes compared to only one eye, consistent with a neural eye region detector rather than an eye detector per se.Natural Sciences and Engineering Research Council of Canada || NSERC #418431 Canada Foundation for Innovation || CFI # 213322 Canada Research Chair program || CRC #213322 and 23040

    Variation in size frequency distribution of coral populations under different fishing pressures in two contrasting locations in the Indian Ocean

    Get PDF
    This study aimed to assess how the size-frequency distributions of coral genera varied between reefs under different fishing pressures in two contrasting Indian Ocean locations (the Maldives and East Africa). Using generalized linear mixed models, we were able to demonstrate that complex interactions occurred between coral genera, coral size class and fishing pressure. In both locations, we found Acropora coral species to be more abundant in non-fished compared to fished sites (a pattern which was consistent for nearly all the assessed size classes). Coral genera classified as ‘stress tolerant’ showed a contrasting pattern i.e. were higher in abundance in fished compared to non-fished sites. Site specific variations were also observed. For example, Maldivian reefs exhibited a significantly higher abundance in all size classes of ‘competitive’ corals compared to East Africa. This possibly indicates that East African reefs have already been subjected to higher levels of stress and are therefore less suitable environments for ‘competitive’ corals. This study also highlights the potential structure and composition of reefs under future degradation scenarios, for example with a loss of Acropora corals and an increase in dominance of ‘stress tolerant’ and ‘generalist’ coral genera.USAi

    From eye to face: The impact of face outline, feature number, and feature saliency on the early neural response to faces

    Get PDF
    The final publication is available at Elsevier via https://doi.org/10.1016/j.brainres.2019.146343. © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The LIFTED model of early face perception postulates that the face-sensitive N170 event-related potential may reflect underlying neural inhibition mechanisms which serve to regulate holistic and featural processing. It remains unclear, however, what specific factors impact these neural inhibition processes. Here, N170 peak responses were recorded whilst adults maintained fixation on a single eye using a gaze-contingent paradigm, and the presence/absence of a face outline, as well as the number and type of parafoveal features within the outline, were manipulated. N170 amplitudes and latencies were reduced when a single eye was fixated within a face outline compared to fixation on the same eye in isolation, demonstrating that the simple presence of a face outline is sufficient to elicit a shift towards a more face-like neural response. A monotonic decrease in the N170 amplitude and latency was observed with increasing numbers of parafoveal features, and the type of feature(s) present in parafovea further modulated this early face response. These results support the idea of neural inhibition exerted by parafoveal features onto the foveated feature as a function of the number, and possibly the nature, of parafoveal features. Specifically, the results suggest the use of a feature saliency framework (eyes > mouth > nose) at the neural level, such that the parafoveal eye may play a role in down-regulating the response to the other eye (in fovea) more so than the nose or the mouth. These results confirm the importance of parafoveal features and the face outline in the neural inhibition mechanism, and provide further support for a feature saliency mechanism guiding early face perception.This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC #418431), the Canada Research Chair program (CRC #213322 and 230407) and the Canada Foundation for Innovation (CFI # 213322), awarded to RJI. KBP was supported by an NSERC Alexander Graham Bell Canada Graduate Scholarship Master’s Award and a Canadian Institutes of Health Research (CIHR) Charles Best and Frederick Banking Doctoral Research Award for the course of this work

    DNA species surveillance: Monitoring bushmeat poaching and trading in Kenya using partial cytochrome b gene

    Get PDF
    DNA species identification has applications in such areas as forensic science, systematics, conservation genetics and agriculture. One key anthropogenic activity threatening large wildlife fauna is illegal exploitation. In Kenya, species identification of raw and processed meat products remains a constraint to effective enforcement of illegal trade in game meat (bushmeat) and products. We tested the reliability of a 321 bp mitochondrial cytochrome b (cyt b) region as a species identification tool for application in wildlife forensics. Query sequences were generated from known specimens of 14 Eastern African wildlife species, 13 representing commonly poached ungulates, and three domesticated species. These were compared, using Basic Local Alignment Search Tool (BLAST) algorithm, with NCBI GenBank reference sequences for species identity. These query sequences were subsequently deposited on Genbank. They represent a contribution to a diagnostic internal East African Wildlife reference cyt b database. The test species comprised: Cape buffalo, bushbuck, Guenther’s dik-dik, common duiker, common eland, Grant’s gazelle, hartebeest, impala, lesser kudu, plains zebra, Thomson’s gazelle, common warthog, wildebeest, Maasai ostrich, cattle, goat and sheep. Additionally, cooked beef and pork samples were analyzed. The results show that, when conspecific sequences were available in the database, species discrimination was 100%. Phylogeny clustering of the species by maximum likelihood supported the species determination by BLAST. The second part of the study carried out a preliminary survey of the prevalence of illegal game meat sold in the dispersal area of Tsavo National Park, Kenya. Sixty two raw meat samples were randomly collected from small roadside retail outlets along the Nairobi-Mombasa highway (A109), a major transnational highway that transverses Tsavo National Park. The results indicate a 9.7% (n = 6) illegal game meat sale, comprising five Guenther’s dik-diks and a Beisa oryx. A 2 km radius hotspot, with 83% (n = 5) of the bushmeat sales was identified just south of Tsavo East National Park.Key words: East Africa, Kenya, bushmeat, poaching, wildlife conservation, species identification, mitochondrial cytochrome b gene

    Effect of C/N ratio levels and stocking density of Labeo victorianuson pond environmental quality using maizeflour as a carbon source

    Get PDF
    The main obstacle in developing intensive fish culture is waste management which is detrimental to the environment. To mitigate environmental impacts associated with effluent discharge, measures should be put in place to avoid deterioration of the pond environment. The addition of carbon materials into culture facilities while manipulating the levels of carbon and nitrogen ratios is one of the best strategies of controlling ammonia and nitrite in ponds. This study was carried out in 18 hapas suspended in six, 150 m 2 earthen ponds to investigate the effects of C/N ratios (10 and 20) and stocking density (10, 15 and 25 fish m ) on water quality, sediment quality and growth of Labeo victorianus. All treatments were carried out in triplicate during a time period of 72 days. A locally formulated and prepared feed containing 30% crude protein with a C/N ratio of 10 was applied. Maize flour was used as the carbohydrate source for manipulating C/N ratio and applied to the water column separately from the feed. Increasing C/N ratio from 10 to 20 reduced (P b 0.001) the total ammonia nitrogen (TAN), nitrite-nitrogen (NO 2 -N) and nitrate-nitrogen (NO 3 -N) in the water column and total nitrogen in the sediment (P b 0.001). It also raised sediment pH, organic matter and total phosphorus (P b 0.001). The lowest protein efficiency ratio (PER), specific growth rate (SGR) and the highest food conversion ratio for the feed were recorded with a C/N ratio of 10 (P b 0.05). Based on highest growth, survival, production and net benefits, C/N ratio of 20 and a stocking density of 25 fish m −2 are optimal. Therefore, carbohydrate addition in L. victorianus culture is a promising option for sustainable aquaculture

    NUTRITIVE VALUE AND AVAILABILITY OF COMMONLY USED FEED INGREDIENTS FOR FARMED NILE TILAPIA (OREOCHROMIS NILOTICUS L.) AND AFRICAN CATFISH (CLARIAS GARIEPINUS, BURCHELL) IN KENYA, RWANDA AND TANZANIA

    Get PDF
    ABSTRACT Commonly utilized feed ingredients for culture of Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) from Kenya, Tanzania and Rwanda were collected over a period of six months (January -June 2010) and evaluated for their nutritive composition through proximate analysis. Most of the fish feed ingredients were found in all the three countries except a few that were unique to one or two countries as detailed in the results. Feed ingredients of animal origin exhibited significantly (P<0.05) higher crude protein levels (407 -635 g/kg DM) compared to the feed ingredients of plant based origin. Freshwater shrimps (Caridina nilotica) contained the highest crude protein levels of 635 g/kg DM. Feed ingredients of animal origin had low ether extracts (EE) with an exception of Omena fish (Rastrineobola argentea). Crude fibre (CF) was generally higher on feed ingredients of plant origin and ranged between 55-368 g/kg DM while Nitrogen Free Extracts (NfE) and ash content were higher in the feedstuffs of plant origin with an exception of maize bran which had the lowest value. Omena fish and freshwater shrimp had higher ash content of 182 and 228g/kg DM compared to other feed ingredients of animal origin, which may indicate contamination with soil particles during drying process. Based on the feed ingredient availability, potential competition with other human uses, content of crude protein and crude fibre and the feasibility of removal of anti-nutritional factors, C. nilotica, blood meal, meat and bone meal, were identified as most promising sources of animal based protein. Cotton (Gossypium spp) and sunflower (Helianthus annuus) seed cakes provided the best option as source of processed plant based protein. Leaves of gallant soldier (Galisonga parviflora), sweet potato (Ipomoea batatus), cassava (Manihot esculenta) and papaya (Papaya carica) were identified as high potential feedstuffs of plant origin either processed or in raw form for small-scale fish farming. We recommend that in well fertilized semiintensive ponds, maize (Zea mays), wheat (Triticum aestivum) and rice (Oryza sativa) bran may be utilized where available to supplement natural pond food

    Computed Tomography of the Mandibles of a Stranded Offshore Killer Whale (Orcinus orca)

    Get PDF
    A mature, adult female, offshore killer whale (Orcinus orca) was stranded deceased in Portage Bay, Alaska, in October 2015. Full necropsy examination with histopathology was performed. Consistent with previous studies of offshore killer whales, and thought to be a result of their unique elasmobranch diet, all the teeth were significantly abraded and almost flush with the gingival margin. Age was estimated at 30–35 years based on annuli and growth arrest lines in a remaining tooth. The dentate portion of the mandibles were excised en bloc and frozen until imaging could be completed. Radiography and computed tomography revealed lesions consistent with severe abrasion, pulp exposure and evidence of endodontic and/or periodontal disease in nine of the 15 mandibular teeth present (60.0%). Only five (33.3%) teeth were suspected to have been vital at the time of death based on imaging. Lesions were more severe rostrally, with the caudal teeth less affected. Autolysis precluded gingival histopathology and no teeth were analyzed histologically. Necropsy examination revealed a likely multifactorial cause of death, with most significant lesions including the severe chronic periodontal/endodontic disease with abrasion, inanition and emaciation with possible cardiovascular disease. This case highlights the importance of imaging in evaluating periodontal and endodontic status, especially post mortem when other tissues are no longer available, and demonstrates that periodontal and endodontic disease occur naturally in this species and can be a significant cause of morbidity in mature free-ranging killer whales of the offshore ecotype
    • …
    corecore