911 resultados para East Central African Expedition (1878-1880)


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Scientific work of the organization covered in the Annual Report include: Commercial fisheries of Lake Victoria, Nile Perch investigations , Fisheries surveys in Kenya and Tanzania, Studies on anadromous fishes, Studies on mormyrid fishes , Studies on Tilapia species and Studies on Halplochromis species

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To test the hypotheses of modern human origin in East Asia, we sampled 12,127 male individuals from 163 populations and typed for three Y chromosome biallelic markers (YAP, M89, and M130). All the individuals carried a mutation at one of the three sites.

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The regional distribution of an ancient Y-chromosome haplogroup C-M130 (Hg C) in Asia provides an ideal tool of dissecting prehistoric migration events. We identified 465 Hg C individuals out of 4284 males from 140 East and Southeast Asian populations. We genotyped these Hg C individuals using 12 Y-chromosome biallelic markers and 8 commonly used Y-short tandem repeats (Y-STRs), and performed phylogeographic analysis in combination with the published data. The results show that most of the Hg C subhaplogroups have distinct geographical distribution and have undergone long-time isolation, although Hg C individuals are distributed widely across Eurasia. Furthermore, a general south-to-north and east-to-west cline of Y-STR diversity is observed with the highest diversity in Southeast Asia. The phylogeographic distribution pattern of Hg C supports a single coastal 'Out-of-Africa' route by way of the Indian subcontinent, which eventually led to the early settlement of modern humans in mainland Southeast Asia. The northward expansion of Hg C in East Asia started similar to 40 thousand of years ago (KYA) along the coastline of mainland China and reached Siberia similar to 15 KYA and finally made its way to the Americas. Journal of Human Genetics (2010) 55, 428-435; doi:10.1038/jhg.2010.40; published online 7 May 2010

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East African sun-dried fish infested by Dermestes maculatus were exposed to tropical sunlight at ambient temperature and analysed for insect mortality and weight losses. Solar treatment for 6 to 8 lo was highly effective for one layer of split sun-dried fish and 100% insect mortality was toted, while pest species were still present in the four layer batch. Weight losses between 1.2% and 10.2% were recorded, the top layer suffering the highest loss. The high surface temperature of 60°C caused fish to become brittle and quality losses occurred. A reduction in length of exposure/temperature is probably a presupposition for application of the method to local conditions.

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East African sun-dried fish dipped for 4 seconds in different solutions of pyrethrum and piperonyl butoxide were analysed for insecticide residue limits. All analyses showed residues above the FAO/WHO MRL; exceeding factors of between 7.6 (22.9 ppm) and 1.6 (5.3 ppm) were found for pyrethrum while exceeding factors between 5.1 (102 ppm) and 1.7 (33.1 ppm) were common for piperonyl butoxide after 6 months storage at ambient temperature. All insecticide treated fish, regardless of dip concentration, were observed to be less susceptible to infestation by Dermestes maculatus than samples of untreated fish. No dry weight losses due to insect infestation were recorded, however moisture evaporation caused weight losses between 6 and 8% during the period. Further investigations showed that careful handling and a dip concentration more in accordance with FAO/WHO MRL than the commercial practice will reduce the cost of insecticides from K.sh. 0.72 to K.sh. 0.23 per kg pyrethrum treated fish.

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The Annual report covers activities of the organization during the reporting period. It explains the scientific work carried out by the organization, the establishment of the Lake Victoria Fisheries Commission and the African Journal of Tropical Hydrobiology and Fisheries.

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The Annual report presents activities carried out by the Organization during the period 1973. It presents scientific work of the Organization which include: Tissue specificity of malate dehydrogenase in Astatoreochromis and two species of haplochromis, report on LaKe Babati Fishery, Observations on Engraulicypris orgenteus (PELLEGRIN) 1904 from Lake Victoria, Commercial trawl fishing on Lake Victoria: Fisheries development and conservation, Lunar periodicity and the breeding of Tilapia nilotica in the Northern part of Lake Victoria.

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The Annual report presents activities carried out by the Organization during the reporting period 1970. It explains the scientific work carried out by the Organization which includes: bottom trawl survey, a limnological survey of Lake Victoria for the period January to December 1970, maturity, sex ration and fecundity of lung fish (protopterus aethiopicus Heckel) from Lake Victoria, On the fish species of Lake Baringo, identification of organisms in Lake Victoria responsible for ecosounder traces, further observations on the ecology of the Nile perch (Lates niloticus Linne) in Lake Victoria and Lake Kioga, fishery economics studies, The African journal of Tropical Hydrobiology and fisheries and observation on fish marketing experiments in Tanzania

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The annual report present activities carried out by the different organizations that make up the East African Agricultural & Fisheries Research Council which covers reports from the following Organisations: I. Report of the East African Agriculture and Forestry Research Organization 2. Report of the East African Fishery Research Organization 3. Report of the East African Marine Fisheries Research Organization 4. Report of the East African Trypanosomiasis Research Organization 5. Report of the East African Veterinary Research Organization The activities reported are for the period 1958

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The annual report present activities carried out by the different organizations that make up the East African Agricultural & Fisheries Research Council which included: 1. Report of the East African Agriculture & Forestry Research Organization 2. Report of the East African Veterinary Research Organization 3. Report of the East African Fishery Research Organization 4. Report of the East African Marine Fisheries Research Organization The activities reported are for the period 1954-55.

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The annual report present activities carried out by the different organizations that make up the East African Agricultural & Fisheries Research Council which included: 1. Report of the East African Agriculture & Forestry Research Organization 2. Report of the East African Veterinary Research Organization 3. Report of the East African Fishery Research Organization 4. Report of the East African Marine Fisheries Research Organization and 5. Report of the East African Trypanosomiasis Research Organisation. The activities reported are for the period 1955-56.

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The annual report present activities carried out by the different organizations that make up the East African Agricultural & Fisheries Research Council which covers reports from the following Organisations: I. Report of the East African Agriculture and Forestry Research Organization 2. Report of the East African Fishery Research Organization 3. Report of the East African Marine Fisheries Research Organization 4. Report of the East African Trypanosomiasis Research Organization and 5. Report of the East African Veterinary Research Organization The activities reported are for the period 1956-57

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Quality changes during storage were investigated for several commercially important East African freshwater fish. Lates, Bagrus, Protopterus, Tilapia esculenta and T. nilotica were examined during storage in ice and at ambient temperature (250•C). After 24 hours at ambient temperature Lates and Bagrus were completely spoilt but Protopterus was still edible. In iced storage most fish were acceptable for at least 20 days. Organoleptic examination showed that T. nilotica was acceptable after 22 days storage in ice and that gutting was only marginally beneficial. Changes in physical appearance, which could form the basis of a fish inspection system, were recorded during storage. Possible chemical quality control indices were also investigated. It was found that total volatile bases and hypoxanthine are unlikely to be useful quality indices for the species studied with the possible exception of Lates. The bacterial counts of the flesh and skin of T. esculenta and T. niloticus were found to be low (a maximum of 10 organisms per sq cm of skin or per g of flesh) after 22 days storage in ice.

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The present study was under taken to provide further and more detailed information on the apparent seasonal and relative abundance of the species, food and feeding habits. Spawning season and size composition. The incidence of parasites, in relation to the month of the year and the fish length, was also examined.

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The paper provides key for the identification of the East African marine fishes. Just like in most determination keys this one is based on the "either-or" principle, i.e. there is a single alternatIve at each point. A specimen either fits all the characters recorded, or fails to conform to one or more characters and you should then proceed to the next number, keeping this up until the fish to be identified does fit all the characters.