'Cand. Actinochlamydia clariae' gen. nov., sp. nov., a Unique Intracellular Bacterium Causing Epitheliocystis in Catfish (Clarias gariepinus) in Uganda

Background and Objectives: Epitheliocystis, caused by bacteria infecting gill epithelial cells in fish, is common among a large range of fish species in both fresh-and seawater. The aquaculture industry considers epitheliocystis an important problem. It affects the welfare of the fish and the resulting gill disease may lead to mortalities. In a culture facility in Kampala, Uganda, juveniles of the African sharptooth catfish (Clarias gariepinus) was observed swimming in the surface, sometimes belly up, showing signs of respiratory problems. Histological examination of gill tissues from this fish revealed large amounts of epitheliocysts, and also presence of a few Ichthyobodo sp. and Trichodina sp. Methods and Results: Sequencing of the epitheliocystis bacterium 16S rRNA gene shows 86.3% similarity with Candidatus Piscichlamydia salmonis causing epitheliocystis in Atlantic salmon (Salmo salar). Transmission electron microscopy showed that the morphology of the developmental stages of the bacterium is similar to that of members of the family Chlamydiaceae. The similarity of the bacterium rRNA gene sequences compared with other chlamydia-like bacteria ranged between 80.5% and 86.3%. Inclusions containing this new bacterium have tubules/channels (termed actinae) that are radiating from the inclusion membrane and opening on the cell surface or in neighbouring cells. Conclusions: Radiation of tubules/channels (actinae) from the inclusion membrane has never been described in any of the other members of Chlamydiales. It seems to be a completely new character and an apomorphy. We propose the name Candidatus Actinochlamydia clariae gen. nov., sp. nov. (Actinochlamydiaceae fam. nov., order Chlamydiales, phylum Chlamydiae) for this new agent causing epitheliocystis in African sharptooth catfish

Two microcrustaceans affect microbial and macroinvertebrate-driven litter breakdown

1. Leaf litter degradation in fresh waters is a fundamental ecosystem process performed by a wide array of decomposers. The meiofauna is an important component of aquatic heterotrophic assemblages, which can provide a trophic link between plant detritus and associated microbial and macroinvertebrate communities, but their contribution to leaf breakdown remains poorly understood. 2. We hypothesised that, through their feeding activity, microcrustaceans influence the structure of fungal assemblages and consequently microbially mediated litter breakdown. Litter-associated microcrustaceans were predicted to change the pathways of energy transfer in the food web according to the positive (e.g. complementarity) or negative (e.g. predation) interactions with macroinvertebrate detritivore taxa. 3. We evaluated experimentally in the laboratory, over 6 and 13 days, the potential contribution of two freshwater microcrustaceans (a cladoceran and a copepod) to litter breakdown in the presence of microfungi (aquatic hyphomycetes), with and without macroinvertebrate detritivores (a trichopteran and a gammarid amphipod). 4. The presence of microcrustaceans enhanced leaf mass loss by 62 and 22% in treatments with fungi or trichopteran alone, respectively, while no significant effect was observed for treatments with the amphipod. Microcrustaceans strongly increased the production of fine particulate organic matter, particularly in treatments with fungi alone (+637%). The leaf consumption rate by the amphipod significantly decreased ( 61%) at 13 days in the presence of microcrustaceans, likely due to predation on cladocerans. 5. Our study supports the potential role of microcrustaceans in the detrital food web of streams and rivers. Interestingly, microcrustaceans may interact with microbial and macroinvertebrate decomposers in either positive or negative ways. Therefore, microcrustaceans add complexity to detrital food webs by increasing vertical diversity and modulating biotic interactions with important consequences for carbon and energy transfers in stream ecosystems

The effects of cyanobacteria on the growth, survival and behaviour of a tropical fish (Nile tilapia) and zooplankton (Daphnia lumholtzi)

Recent studies on the ecological effects of cyanobacteria in lakes have focused on the harmful effects of blooms to other aquatic organisms including fish and zooplankton. Much of this work has been conducted on temperate and subtropical species whilst few studies have involved tropical species, despite the almost chronic occurrence of cyanobacteria blooms in eutrophic tropical lakes. The main purpose of this study was to fill some of this knowledge gap on the ecological effects of cyanobacteria on fish and zooplankton in tropical lakes and to discover in what ways tropical species may be better adapted to deal with cyanobacteria than temperate species. The study tested fish (Nile tilapia, Oreochromis niloticus L.) and zooplankton growth, survival, and behaviour in relation to different variants (toxic and non toxic) and species of cyanobacteria at varying quantities as well as environmental conditions. Field studies on the diet and presence of cyanobacteria toxins (microcystins) in the guts and tissues (muscle and liver) of Nile tilapia were carried out in two eutrophic tropical aquatic ecosystems (Lake Mburo and Murchison Bay, Lake Victoria) in Uganda, East Africa. The zooplankton behaviour of diel vertical migration (DVM) was investigated in the Murchison Bay in relation to environmental conditions. Laboratory studies investigated the effect of the cyanotoxins, microcystins, on Nile tilapia and zooplankton (Daphnia lumholtzi) growth, survival, and behaviour, using the toxic cyanobacterium Microcystis aeruginosa PCC 7806. Cyanobacteria are the most abundant phytoplankton group in the two study areas contributing to over 60% of the total phytoplankton biovolume. The most dominant cyanobacteria species is Microcystis sp. which makes up approximately 70% of the total cyanobacteria biovolume. Low water transparencies were well associated with high levels of chlorophyll a in the lakes, suggesting that the abundance of cyanobacteria in these lakes may have a significant effect on the light environment. Water transparency is observed to have a close association with the DVM behaviour of at least one zooplankton group in the Murchison Bay. Phytoplankton especially of the cyanobacteria is an important diet item (> 30%) to the Nile tilapia in both lakes. Microcystins (RR, LR &YR) were detected in water samples from both study lakes and in the Murchison bay the concentration of microcystins in water was well associated with the microcystins concentration in the gut of Nile tilapia (p<0.05). Although detected, we found no evidence of microcystin accumulation in the liver or muscle tissue. The ingestion rates and growth rates of juvenile Nile tilapia were not significantly affected by the presence of microcystins in their diets. Likewise growth and survival rates of the tropical cladoceran Daphnia lumholtzi in laboratory experiments were not significantly affected by the presence of microcystins in their diets. The cyanobacteria M. aeruginosa PCC7806 was a poor source of nutrients for juvenile fish and zooplankton, since it did not seem to stimulate growth both in the wild type and mutant type form. Though microcystins were present throughout the study period, our findings do not show that they have a strong effect on the diets of Nile tilapia. Nile tilapia in these lakes probably ingest cyanotoxins mostly through the cell-bound fraction, since cyanobacteria (especially Microcystis sp.) are an important constituent of their diet. Adult fish may have the ability to efficiently get rid of ingested cyanotoxins, but this may not be so for juvenile tilapia and zooplankton. Small amounts of cyanobacteria may actually stimulate growth in juvenile tilapia and even zooplankton, yet when provided in high proportions or as the sole source of nutrients they hinder growth, survival, and reproduction. Juvenile fish and most especially zooplankton, are unlikely to graze on cyanobacteria either due to their frequent formation of large colonies or because juvenile fish and zooplankton may lower their ingestion rates in the presence of cyanotoxins. Findings in this study do not provide any evidence for tolerance of tropical juvenile fish and zooplankton towards cyanobacteria toxins, yet adult fish show both the ability to utilise cyanobacteria and cope with levels of microcystins registered in the lakes

The effects of poverty on child health in relation to thesocioeconomic status of mothers : a case study of Nakawe divison, Kampala district, Uganda

This study has its basis on the Millennium Development Goal 4 that has to do with reduction of the under five mortality rate by two thirds between 1990 and 2015 (United Nations 2009; 24). Children from developing countries are more likely to die within the first five years of life than children in industrialized countries. About half of the deaths of children in the developing world are in Sub-Saharan Africa; many of these deaths are caused by preventable diseases like diarrhea, pneumonia measles and HIV. Poverty has a negative effect on child health, it is no surprise that the highest numbers of infant deaths are in the “developing countries” (United Nations 2008; 21). Poverty goes hand in hand with low socio-economic status of mothers like unemployment, high illiteracy levels, inappropriate accommodation, high fertility rates, poor child spacing among others which all contribute to the vicious cycle of poverty and disease. Improving the socioeconomic status of women would go a long way in reducing child mortality. There are some immediate changes that can be made by governments in the third world to reduce the number of children’s lives lost. Governments of countries in the developing world have a more urgent need to address the problems like the socioeconomic status of women, related to child health, however the amount of resources allocated to these sectors does not seem to reflect its importance. This research was carried out in Nakawa division Kampala district Uganda and it examines to what extent poverty has an effect on child health in relation to the socio–economic status of the mothers in Nakawa division. In this study I investigate if there is a relationship between high rates of morbidity and socio economic status of the mothers. To achieve this objective both quantitative and qualitative methods were used to collect data. The data was presented in graphs and tables in the methodology chapter. The results from the study showed that under five morbidity was high in Nakawa division. The mothers I interviewed had a low socio-economic status. Many of them had a minimum level of education and had their first children during their teenage years, many of them did not have secondary education, had no access to proper accommodation (which has a lot to do with health generally), just a hand full had employment and were able to save money to support their families. The mothers need to be provided with more information on how to improve the health of their children, in terms of nutrition, hygiene, sanitation and the way they live from day to day. IV Breastfeeding and immunization as ways of improving their children’s health seemed to be on track since all the respondents had breastfed and immunized their children at some point. But these have to be used hand in hand with other practices that contribute to improving the health of children. It is better to prevent diseases in the first place using cost-effective means than waiting for the children to get sick and then look for finances to treat them. The government, Non-governmental organizations and other institutions still have a lot to do if the MDG 4 on child health is to be achieved by 2015. The study recommends that clinics need to be equipped better with staff, medicine and medical equipment because congestion was a very big problem in the health centers where the research was carried out. This is due to the fact that they are just a hand full of public health centers serving such a large population in the division. In addition mothers need to be helped at the community level and provided with basic information that enables them improve the livelihoods of their families and improve their health most especially that of their children

Non-Destructive Detection of Abnormal Chicken Eggs by Using an Optimized Spectral Analysis System

Environmental pressures, such as temperature and light intensity, food, and genetic factors, can cause chicken eggs to develop abnormalities. The common types of internal egg abnormalities include bloody and damaged egg yolk. Spectrometers have been recently used in real-time abnormal egg detection research. However, there are very few studies on the optimization of measurement systems. This study aimed to establish optimum parameters for detecting of internal egg abnormalities (bloody and damaged-yolk eggs) using visible and near-infrared (Vis/NIR) spectrometry (192&ndash;1110 nm range) and multivariate data analysis. The detection performance using various system parameters, such as the types of light sources, the configuration of the light, and sensor positions, was investigated. With the help of collected data, a partial least-squares discriminant analysis (PLS-DA) model was developed to classify normal and abnormal eggs. The highest classification accuracy for the various system parameters was 98.7%. Three band selection methods, such as weighted regression coefficient (WRC), sequential feature selection (SFS), and successive projection algorithm (SPA) were used for further model optimization, to reduce the spectral bands from 1028 to less than 7. In conclusion the results indicate that the types of light sources and the configuration design of the sensor and illumination affect the detection accuracy for abnormal eggs

Hyperspectral total upward sea surface leaving radiance observed at 45° nadir angle observed during cruise aboard RV IBIS on Lake Victoria, Uganda, from 13 to 15 October 2021

Hyperspectral radiometric quantities were observed at a 5-minute sampling interval in the Ugandan portion of Lake Victoria during a scientific field campaign aboard research vessel (RV) IBIS from 13 to 15 October 2021. The three day fieldwork was cooridnated starting from the Napoleon Bay, Jinja, Uganda. A radiometer setup one TriOS RAMSES-ARC hyperspectral radiance meters to measure total upward sea surface leaving radiance (Lsfc) at 45° nadi was installed using a custom-made frame at the bow of RV IBIS. Data logging of raw and calibrated radiometric quantities was automated using TriOS MSDA XE version 8.9.2 software. Further processing was done using Mathworks Matlab 2016a and R software. Processed data was interpolated to 1 nm spectral resolution using PCHIP function in Matlab between 320 and 950 nm. Only the data with valid GPS coordinates and with spectra contributing less than 3% is included in this file, the rest of the data is available on request

Hyperspectral downward irradiance observed during cruise aboard RV IBIS on Lake Victoria, Uganda, from 13 to 15 October 2021

Hyperspectral radiometric quantities were observed at a 5-minute sampling interval in the Ugandan portion of Lake Victoria during a scientific field campaign aboard research vessel (RV) IBIS from 13 to 15 October 2021. The three day fieldwork was cooridnated starting from the Napoleon Bay, Jinja, Uganda. A radiometer setup with one TriOS RAMSES-ACC hyperspectral cosine irradiance meter to measure incoming solar irradiance was installed using a custom-made frame at the bow of RV IBIS. Data logging of raw and calibrated radiometric quantities was automated using TriOS MSDA XE version 8.9.2 software. Further processing was done using Mathworks Matlab 2016a and R software. Processed data was interpolated to 1 nm spectral resolution using PCHIP function in Matlab between 320 and 950 nm. Only the data with valid GPS coordinates and with spectra contributing less than 3% is included in this file, the rest of the data is available on request

Hyperspectral above-water radiometric quantities observed during cruise aboard RV IBIS on Lake Victoria, Uganda, from 13 to 15 October 2021

Hyperspectral radiometric quantities were observed at a 5-minute sampling interval in the Ugandan portion of Lake Victoria during a scientific field campaign aboard research vessel (RV) IBIS from 13 to 15 October 2021. The three-day fieldwork was coordinated starting from the Napoleon Bay, Jinja, Uganda. A radiometer setup with one TriOS RAMSES-ACC hyperspectral cosine irradiance meter to measure incoming solar irradiance and two TriOS RAMSES-ARC hyperspectral radiance meters to measure total upward sea surface leaving radiance (Lsfc) at 45° nadir and sky-leaving radiance (Lsky) at 45° zenith angle, was installed using a custom-made frame at the bow of RV IBIS. Data logging of raw and calibrated radiometric quantities was automated using TriOS MSDA XE version 8.9.2 software. Further processing was done using Mathworks Matlab 2016a and R software. Processed data was interpolated to 1 nm spectral resolution using PCHIP function in Matlab between 320 and 950 nm. Only the data with valid GPS coordinates and with spectra contributing less than 3% is included in this file, the rest of the data is available on request

Hyperspectral downward sky leaving radiance observed at 45° zenith angle during cruise aboard RV IBIS on Lake Victoria, Uganda, from 13 to 15 October 2021

Hyperspectral radiometric quantities were observed at a 5-minute sampling interval in the Ugandan portion of Lake Victoria during a scientific field campaign aboard research vessel (RV) IBIS from 13 to 15 October 2021. The three day fieldwork was cooridnated starting from the Napoleon Bay, Jinja, Uganda. A radiometer setup one TriOS RAMSES-ARC hyperspectral radiance meters to measure total upward sky-leaving radiance (Lsky) at 45° zenith angle was installed using a custom-made frame at the bow of RV IBIS. Data logging of raw and calibrated radiometric quantities was automated using TriOS MSDA XE version 8.9.2 software. Further processing was done using Mathworks Matlab 2016a and R software. Processed data was interpolated to 1 nm spectral resolution using PCHIP function in Matlab between 320 and 950 nm. Only the data with valid GPS coordinates and with spectra contributing less than 3% is included in this file, the rest of the data is available on request