Association between thrombocytes count and Plasmodium falcipurum infection among children under five years attending Kombewa Sub-County Hospital

Malaria is a leading cause of morbidity and mortality especially among children, expectant women and continues to be a global health burden. Haematological changes mark some of the most common complications in malaria as they play a major role in malaria pathology. Thrombocytes in particular, have been shown to bind infected erythrocytes and kill intracellular malaria parasites thereby indicating a protective function of platelets in the early stages. However, the mechanism that leads to low thrombocytes count in malaria infected individuals is not clear. Understanding the mechanism of platelet reduction during pathogenesis of malaria infection will be fundamental in malaria severity classification, monitoring of platelet count during infection and prompt initiation of anti-malarial therapy. In trying to understand these facts, this study sort to establish the association between platelet count and P. falciparum infection amongst children less than five years. This was a retrospective case-control study, n=549. Children below the age of five years that attending Kombewa Sub -County Hospital were recruited. Study participants were identified using the inclusion criteria and followed horizontally to retrieve platelet count from complete blood count results. The respective malaria blood film reads were then recorded, stratified to give case and control from which random sampling was done. Chi-square test and Tukey’s multiple comparison tests from Graph pad prism 5 were used in the analysis. The odds of exposure to low platelet count were then established with a confidence level of 95%. We found significant difference between the cases and controls in regard to parasite density (Chi square=157.5, p value <0.05), mean parasite density in controls =2042.1/?l compared to cases= 142880/?l. The odds of cases being exposed to malaria was 12 times more than controls (OR=12.382, 95%). We also found no variation in thrombocytes counts in relation to gender, children with thrombocytopenia were having higher parasite density, parasite density as a result of P.falciparum infection is not dependent on gender and children that suffered malarial infection were twelve times likely to develop thrombocytopenia. Further studies are then recommended to establish the effects of incorporation of platelet aggregation inhibitors such as aspirin in malaria treatment.Key Words: Plasmodium falciparum, thrombocytopenia, infectio

Leveraging Signatures of Plant Functional Strategies in Wood Density Profiles of African Trees to Correct Mass Estimations From Terrestrial Laser Data

peer reviewedWood density (WD) relates to important tree functions such as stem mechanics and resistance against pathogens. This functional trait can exhibit high intraindividual variability both radially and vertically. With the rise of LiDAR-based methodologies allowing nondestructive tree volume estimations, failing to account for WD variations related to tree function and biomass investment strategies may lead to large systematic bias in AGB estimations. Here, we use a unique destructive dataset from 822 trees belonging to 51 phylogenetically dispersed tree species harvested across forest types in Central Africa to determine vertical gradients in WD from the stump to the branch tips, how these gradients relate to regeneration guilds and their implications for AGB estimations. We find that decreasing WD from the tree base to the branch tips is characteristic of shade-tolerant species, while light-demanding and pioneer species exhibit stationary or increasing vertical trends. Across all species, the WD range is narrower in tree crowns than at the tree base, reflecting more similar physiological and mechanical constraints in the canopy. Vertical gradients in WD induce significant bias (10%) in AGB estimates when using database-derived species-average WD data. However, the correlation between the vertical gradients and basal WD allows the derivation of general correction models. With the ongoing development of remote sensing products providing 3D information for entire trees and forest stands, our findings indicate promising ways to improve greenhouse gas accounting in tropical countries and advance our understanding of adaptive strategies allowing trees to grow and survive in dense rainforests. © 2020, The Author(s)

Natural honey pre-treatment protect against immune suppression in cyclophospamide exposed wistar rats

Background: Honey is a natural compound with numerous therapeutic functions ranging from anti-inflammatory, antioxidant, anti-microbial, anti-hypertensive and hypoglycemic activities. The aim of this study was to investigate the immunomodulatory activity of natural honey on cyclophosphamide induced suppression of humoral immunity in Wistar rats. Methods: Wistar rats with mean body weight of 125+25g were divided into 5 groups (1-5;n- 5)G.ro up 1 (control) received only saline, while groups 2-5 were treated with 30mg/kg bw of Cyclophosphamide (Cyp)in traperitoneally on days 19, 20 and 21. Groups 3-5 received 1.0g, 2.0g and 4.0g per kg bw natural honey orally for 21days in addition to the Cyp injections. Rats were weighed pre-treatment and post-treatment respectively. Blood samples were collected for measurements of hematological parameters and serum immunoglobulin G and M concentrations. Spleen were harvested, weighed and measured respectively. Results: Compared to the Control group, group 2 had significant reduction in haemoglobin concentration (10.6g/dl), lymphocytes (0.4x109/L) and total white blood cells (0.4x109/L) counts. IgG and IgM concentrations were equally reduced at 960.4 + 37.3mg/dL and 173.6+1.2mg/dL respectively. Body and spleenic weights, heamatological parameters and IgG concentrations were increased in groups 3-5 on a dose dependent manner; the highest increase been observed in group 5. IgM concentration was significantly increased in groups 3-5 relative to group 2, but in reverse dose dependent style. Conclusion: Natural honey pre-treatment with Cyp treatment improves haematological and leucocytic parameters as well as serum IgG and IgM concentrations, thereby potentially protecting tissues from the deleterious effects of short term Cyp treatment

Socio-economic Aspects of Fisheries Management in Lake Naivasha

A survey on Lake Naivasha identified and delineated critical breeding and nursery areas for fish which were to be protected in order to assist in the recovery of its fish stocks. Crescent Island, Oserian Bay, the river Malewa mouth and Kamere and its wetlands were identified as critical areas. A questionnaire revealed that most fishermen come from the Rift Valley and Nyanza provinces with a mean age of 36 years. Most boats operating on the lake are about 23.5 m in length and are each limited to a maximum of 10 gill nets of 112 mm (4.5 inches) mesh size. Most fishermen indicated that they know of others using illegal fishing gears. Regular patrols were identified as important (52%) and suggested that buoys be placed in the delineated areas. Respondents suggested that awareness be created to the people who depend directly on the fisheries and an all-inclusive patrol by all stakeholders including Fisheries Department and the Kenya Wildlife Services to enforce laws was recommended.Key words: Lake Naivasha, species change, critical areas, stakeholder opinions, fishery management

Logging rules in tropical rainforests need considering the environmental context to limit their impact on biodiversity - Evidence from the CoForChange project in Central Africa

CoForChange projec

Tracking land-cover changes with sedimentary charcoal in the Afrotropics

Fires have played an important role in creating and maintaining savannas over the centuries and are also one of the main natural disturbances in forests. The functional role of fires in savannas and forests can be investigated through examining sedimentary charcoal in order to reconstruct long-term fire history. However, the relationship between charcoal and vegetation structure in tropical grassy ecosystems remains to be elucidated. Here, we compared recent charcoal records from lake sediments in three tropical ecosystems (forest, savanna, and forestsavanna mosaic) with land cover inferred from remote-sensing images. Charcoal width-to-length (W/L) ratio is a good proxy for changes in fuel type. At one of the lakes, a significant W/L modification from values >0.5 (mainly wood) to <0.5 (grass) was recorded simultaneously with changes in land cover. Indeed, a significant deforestation was recorded around this lake in the remote-sensing imagery between 1984 and 1994. The results also indicate that a riparian forest around a lake could act as a physical filter for charcoal accumulation; we used the mean charcoal size as a proxy to evaluate this process. Charcoal Accumulation Rates (CHAR), a burned biomass proxy, were combined with W/L ratio and the mean charcoal size to investigate the land-use history of the landscapes surrounding the study sites. This combined approach allowed us to distinguish between episodic slash-and-burn practices in the forest and managed fields or pastures burning frequently

Tropical tree allometry and crown allocation, and their relationship with species traits in central Africa

Common allometric patterns have been reported across the tropics and good performance on independent data was retrieved for the most recent pantropical model predicting tree aboveground biomass (AGB) from stem diameter, wood density and total height. General models are undoubtedly useful for the estimation and monitoring of biomass and carbon stocks in tropical forests, however specific allometry, allocation, and traits, are at the core of many models of vegetation dynamics, and there is lack of such information for some regions and species. In this study, we specifically evaluated how size-dependent changes in above-ground biomass and biomass allocation to crown relate to other allometric and life-history traits for tropical tree species. We gathered destructive data available in eight terra firme forest sites across central Africa and the combined dataset consisted of 1,023 trees belonging to 54 tropical tree species phylogenetically dispersed, with only two congeneric species. A huge body of field and laboratory measurements was used for computing AGB and crown mass ratio (CMR) at the tree level, and to derive key allometric traits at the species level. For the latter, species-specific relationships between tree diameter and total height, crown exposure to light, wood density, and bark thickness were fitted for 50 species. Our results show interspecific variation in the relationships relating tree diameter to both AGB and CMR, and including species traits in a multi-specific AGB model confirmed that interspecific variation in biomass allometry is primarily determined by species wood density. We also showed that the allocation of biomass to crown increases linearly with tree diameter for most species, and that interspecific variation in the CMR model is associated with the species dispersal mode and maximum height. Trait covariations among our set of tropical tree species widespread and/or locally abundant in central Africa, revealed a continuum between large-statured species, which tended to be light-demanding, deciduous and wind-dispersed, and species with opposite attributes. Information on allometry, allocation, and traits provided here could further be used in comparative ecology and for parameterizing dynamic and succession models. Also importantly, the species-specific AGB models fitted for major tree species, including most timber species of central Africa, will help improve biomass estimates