Trophic interrelationships and food-webs among the fishes in ecosystems of the Victoria and Kyoga lake basin

The Victoria and Kyoga lake basins had a high fish species diversity with many fish species that were found only in these lakes. Two Tilapiines species Oreochromis esculentus and Oreochromis variabilis were the most important commercial species in these lakes and were found nowhere else on earth except in the Victoria and Kyoga lake basins (Graham 1929, Worthington 1929). Lakes Kyoga and Nabugabo also had endemic haplochromine species (Worthington 1929, Trewavas 1933, Greenwood 1965, 1966). As stocks of introduced species increased, stocks of most of the native species declined rapidly or disappeared altogether. The study was carried out on Lakes Victoria and Kyoga, River Nile, some selected satellite lakes from the two basins namely Lakes Mburo, Kachera, Wamala, Kayanja, Kayugi, Nabugabo, Victoria, Victoria nile and River Sio(Victoria lake basin). Lakes Kyoga (Iyingo), Nawampasa, Nakuwa, Gigati, Nyaguo, Agu, Kawi and Lemwa (Kyoga lake basin). Species composillon and relative abundance of fishes were estimated by detennining the overall average total number of each species encountered. A trophic consists of species using the same food category. Shannon-Weaver Index of diversity H (Pielou, 1969) and number of trophic groups, were used to estimate the Trophic diversity of various fish species in the lakes. Food analysis has been done on some fishes in some of the sampled lakes and is still going on, on remaining fishes and in some lakes. Generally fish ingested detritus, Spirulina, Melosira, filamentous algae, Planktolyngbya, Microcysists, Anabaena, Merismopedia, Spirogyra, higher plant material, rotifers, Ostracodes, Chironomid larvae and pupae, Choaborus larvae, Odonata, Povilla, Insect remains, Caridina, fish eggs and fish. Eight trophic groups were identified from thes food items ingestes. These included detritivores, algae eaters, higher plant eaters, zooplanktivores, insectivores, molluscivores, prawn eaters, paedophages and piscivores. Trophic diversity by number of trophic groups was highest in Lake Kyoga (6) followed by lakes Kayugi, Nabugabo, River Nile and Mburo (3) and the lowest number was recorded in kachera (2)

Chloramphenicol Pharmacokinetics in African children with severe malaria

Article published in Journal of tropical pediatricsThe objective of this study was to determine if the current dosage regimen for chloramphenicol (CAP) administered to children with severe malaria (SM) for presumptive treatment of concomitant bacterial meningitis achieves steady state plasma CAP concentrations within the reported therapeutic range of 10–25 mg/l. Fifteen children (11 male, 4 female) with a median age of 45 months (range: 10–108 months) and having SM, were administered multiple intravenous doses (25 mg/kg, 6 hourly for 72 h) of chloramphenicol sodium succinate (CAPS) for presumptive treatment of concomitant bacterial meningitis. Blood samples were collected over 72 h, and plasma CAPS, CAP and CSF CAP concentrations determined by high performance liquid chromatography. Average steady state CAP concentrations were approximately 17 mg/l, while mean fraction unbound (0.49) and CSF/plasma concentration ratio (0.65) were comparable to previously reported values in Caucasian children. Clearance was variable (mean^4.3 l/h), and trough plasma concentrations during the first dosing interval were approximately 6 mg/l. Simulations indicated that an initial of loading dose of 40 mg/kg CAPS, followed by a maintenance dose of 25 mg/kg every 6 h would result in trough CAP concentrations of approximately 10 mg/l and peak concentrations _25 mg/l throughout the treatment period. The current dosage regimen for CAP needs to include a loading dose of 40 mg/kg CAPS to rapidly achieve plasma CAP concentrations within the reported therapeutic range.The objective of this study was to determine if the current dosage regimen for chloramphenicol (CAP) administered to children with severe malaria (SM) for presumptive treatment of concomitant bacterial meningitis achieves steady state plasma CAP concentrations within the reported therapeutic range of 10–25 mg/l. Fifteen children (11 male, 4 female) with a median age of 45 months (range: 10–108 months) and having SM, were administered multiple intravenous doses (25 mg/kg, 6 hourly for 72 h) of chloramphenicol sodium succinate (CAPS) for presumptive treatment of concomitant bacterial meningitis. Blood samples were collected over 72 h, and plasma CAPS, CAP and CSF CAP concentrations determined by high performance liquid chromatography. Average steady state CAP concentrations were approximately 17 mg/l, while mean fraction unbound (0.49) and CSF/plasma concentration ratio (0.65) were comparable to previously reported values in Caucasian children. Clearance was variable (mean=4.3 l/h), and trough plasma concentrations during the first dosing interval were approximately 6 mg/l. Simulations indicated that an initial of loading dose of 40 mg/kg CAPS, followed by a maintenance dose of 25 mg/kg every 6 h would result in trough CAP concentrations of approximately 10 mg/l and peak concentrations <25 mg/l throughout the treatment period. The current dosage regimen for CAP needs to include a loading dose of 40 mg/kg CAPS to rapidly achieve plasma CAP concentrations within the reported therapeutic range

The biology and ecology of native non-cichlids in the Victoria and Kyoga lake basins

An overview of the biology and ecology of some of the constantly less important commercial species is given below. These included Bagrus docmac, Clarias gariepinus, Protopterus aethiopicus, Labeo victorianus, Barbus spp, Mormyrids, Synodontis spp, and Schilbe intermedius. The stocks of most of these species declined due to over-exploitation and introduction of non-native fishes especially Nile perch. A few of these taxa still survive in the main lake and others in satellite lakes. The current status of these species in the Victoria lake basin is not known but the available information provided some information on some habitat and other requirements of some of these originally important species of the Victoria lake basin

Fish species diversity and the role of Kyoga satellite lakes in conservation of fish species diversity

Lakes Victoria and Kyoga had many fish species, which were important as food for local population and valuable in scientific studies. Over the past twenty years, the diversity of fish in these lakes had declined due to over-exploitation, introduction of new fish species including the piscivorous Nile perch and degradation of fish habitat. This study examined fish species diversity in the seven small lakes in the Kyoga lake basin and compaired this with the main lake Kyoga (Iyingo) and historical data from Lake Victoria which have had high anthropogenic impacts. A total of 68 fish species were recorded of which 41 were haplochromines. Almost all the native non-cichlids which occurred in the main lakes (Victoria and Kyoga) before the Nile perch upsurge were recorde

Group Cohesion and Strategic Context On The Relationship Between Top Management Team Composition And Performance Of Family Firms: A Critical Review Of Literature

According to the upper echelons theory, TMT composition impacts on organizationalperformance. However, empirical studies have found contradictory results with somereplication studies being unable to duplicate any previous findings. Theseinconsistencies in empirical findings have led to the conclusion that the relationshipbetween TMT composition and firm performance is not a direct and straightforwardone as envisaged by the upper echelons theory. This has led to the search for thevariables that mediate or moderate this relationship. This study focused on family firmsand studied family firm specific variables of TMT composition namely family ratio,number of generations in the TMT and number of nuclear units within the TMT. Thisstudy established that the impact of TMT composition on firm performance in familyfirms is mediated by group cohesion. This is because the family firm is fraught withmany dynamics among the family members some of which are not related to thebusiness. Due to this, it was concluded that whether or not the TMT composition in thefamily firm impacted performance positively or not, was dependent upon the family’sability to pull in the same direction that is how cohesive the family was. In addition, itwas established that family firms pursuing complex strategies in terms of their productsor markets were likely to benefit the most from TMT composition. This is because thestrategic context triggered deliberations and information sharing which harnessed thediverse skills availed by the TMT composition. Thus the strategy context moderated therelationship between TMT composition and firm performance. It was also noted that acomplex strategic context was capable of triggering conflict and disagreements thusnegating the impact of TMT composition on firm performance. The study thereforeconcluded that the impact of strategic context needed to be reviewed in light of thegroup cohesiveness. Further it was noted that to fully understand the impact of TMTcomposition on family firm performance, the moderating effect of strategic context andthe intervening effect of group cohesion needed to be considered. Due to the uniquenessof the characteristics of family firms and the convergence of ownership andmanagement in family firms, the resource based view, stewardship and agency theoriesneeded to be considered in addition to the upper echelons theory when explaining theimpact of TMT composition on family firm performance. It was observed that thestrategic management field had lagged behind in research on family firms despite thegrowing importance of family firms in modern day economies. In line with this it wassuggested that policy makers needed to design policies and legal frameworks that areappropriate to family firms. The study encouraged families to get involved in themanagement of their firms and foster cohesiveness among TMTs in order to deriveoptimal results for their businesses

Biodiversity values of different aquatic systems, habitats and organisms in relation to restoration and sustaining of biodiversity

Biodiversity values provide objective data and advice from which policy makes could assess the conservation options and determine optimal policies that would balance the needs of conservation with the socia-economic needs of the people in the area

Question Typology in Kenyan TV Argumentative Talk Shows

The argumentative talk on radio and TV has become a popular feature of media discourse in Kenya. Question-answer sequences as the talk unfolds through the joint participation of co-participants in the talk have emerged as a means to put argumentative talk into effect. Yet, the nature of questions and their categorization remain little understood. Given the recursive nature of question-answer sequences, this paper investigates question typology that sets apart argumentative talk shows from other types of talk. The data consists of transcripts from two Kenyan TV argumentative talk shows: Checkpoint on KTN and Opinion Court on Citizen TV. A question classification scheme by Schirm [2008] was used to discuss the incidence and usage of questions in argumentative talk shows. Findings revealed that clashing, rhetorical, classic clarifying, and opinion-eliciting questions were the most frequently used types in the data sets. It was also noted that different question types served unique rhetorical purposes leading to the conclusion that argumentative talk shows on TV exhibit recursive interactional resources qualifying it as a genre

A comparison of random forests, boosting and support vector machines for genomic selection

Genomic selection (GS) involves estimating breeding values using molecular markers spanning the entire genome. Accurate prediction of genomic breeding values (GEBVs) presents a central challenge to contemporary plant and animal breeders. The existence of a wide array of marker-based approaches for predicting breeding values makes it essential to evaluate and compare their relative predictive performances to identify approaches able to accurately predict breeding values. We evaluated the predictive accuracy of random forests (RF), stochastic gradient boosting (boosting) and support vector machines (SVMs) for predicting genomic breeding values using dense SNP markers and explored the utility of RF for ranking the predictive importance of markers for pre-screening markers or discovering chromosomal locations of QTLs

A randomized, open-label, comparative efficacy trial of artemether-lumefantrine suspension versus artemether-lumefantrine tablets for treatment of uncomplicated Plasmodium falciparum malaria in children in western Kenya

<p>Abstract</p> <p>Background</p> <p>Artemether/lumefantrine (AL) has been adopted as the treatment of choice for uncomplicated malaria in Kenya and other countries in the region. Six-dose artemether/lumefantrine tablets are highly effective and safe for the treatment of infants and children weighing between five and 25 kg with uncomplicated <it>Plasmodium falciparum </it>malaria. However, oral paediatric formulations are urgently needed, as the tablets are difficult to administer to young children, who cannot swallow whole tablets or tolerate the bitter taste of the crushed tablets.</p> <p>Methods</p> <p>A randomized, controlled, open-label trial was conducted comparing day 28 PCR corrected cure-rates in 245 children aged 6–59 months, treated over three days with either six-dose of artemether/lumefantrine tablets (Coartem^®) or three-dose of artemether/lumefantrine suspension (Co-artesiane^®) for uncomplicated falciparum malaria in western Kenya. The children were followed-up with clinical, parasitological and haematological evaluations over 28 days.</p> <p>Results</p> <p>Ninety three percent (124/133) and 90% (121/134) children in the AL tablets and AL suspension arms respectively completed followed up. A per protocol analysis revealed a PCR-corrected parasitological cure rate of 96.0% at Day 28 in the AL tablets group and 93.4% in the AL suspension group, p = 0.40. Both drugs effectively cleared gametocytes and were well tolerated, with no difference in the overall incidence of adverse events.</p> <p>Conclusion</p> <p>The once daily three-dose of artemether-lumefantrine suspension (Co-artesiane^®) was not superior to six-dose artemether-lumefantrine tablets (Coartem^®) for the treatment of uncomplicated malaria in children below five years of age in western Kenya.</p> <p>Trial registration</p> <p>ClinicalTrials.gov NCT00529867</p