Feasibility of using Arterial Spin Labeling for Detecting Longitudinal Changes in Cerebral Blood Flow

The ability of the perfusion MRI technique, arterial spin labeling (ASL), to quantify cerebral blood flow (CBF) makes it attractive for longitudinal studies of changes in brain function, such as those related to chronic pain. However, ASL\u27s poor spatial resolution makes image alignment between sessions difficult, leading to increased variance and greater Type-I errors. In addition, variability due to differences in basal blood flow between sessions and confounding effects such as the arterial transit time (ATT) have the potential to reduce reproducibility over time. The focus of this thesis is to investigate the ability of ASL to detect long-term changes in regional CBF within an individual on a voxel-wise level. It is hypothesized that ASL has the sensitivity to detect activation-induced CBF changes over periods as long as a month if the sources of variance that degrade between-session comparisons are minimized. To test this hypothesis rest and activation (motor task) CBF images were acquired from healthy subjects on three separate imaging sessions. Registration errors were minimized by using individual head molds to replicate the head position in successive sessions. Variations in resting CBF were controlled for by performing the imaging during the same time of day, and subjects were asked to refrain from using common substances, such as caffeine, that are known to affect CBF. Finally, ATT maps were generated on each session to investigate its stability. From these data sets, the within- and between-session variability in CBF was determined and motor-related activation maps were generated from rest and activation data acquired on from the same session and from sessions separated by a week and a month. The results demonstrated excellent reliability (intraclass correlation coefficients greater than 0.75) both within- (0.89 ± 0.2) and between-session (0.84 ± 0.15), and high reproducibility (within subject coefficient of variation, wsCV, greater than 20%) within- (wsCV = 4.7 ± 4.5%) and between-session (wsCV = 5.7 ± 4.4%). Between-session reproducibility of the ATT was high (wsCV = 5.0 ± 2.7%), suggesting that the confounding effect of ATT over a month was minimal. The similarity in within- and between-session variability and their activation maps indicated that registration errors between sessions were minimal. Measures of precision of activation demonstrated that less than ~20% of between-session activation were false positives. These results demonstrate the feasibility of conducting voxel-wise analysis of CBF images acquired on different days and highlight the potential of this technique for longitudinal studies

Experiences of research ethics committee members and scientists of the research protocol review process in Uganda: a case study

Background: We investigated how relevant and responsive scientists and research ethics committee (REC) members considered the research protocol review processes for health research practice in Uganda. Methods: Interviews were conducted with five scientists and five REC members. Data were analysed thematically. Results: How much to compensate for time, the amount of study information shared with volunteers and sample storage for future unknown research were areas of concern for REC members. Delays in getting feedback concerned scientists. Conclusions: Researchers and REC members need to hold regular discussions to ensure the review process is relevant and responsive

Production of fish powder by acid hydrolysis.

HapLochromis spp. is an underutilized fish stock abundant in L. Victoria and occurring in many African lakes. Its small size and boniness make it unpopular as human food. A process for producing fish powder for human consumption from whole HapLochromis by partial acid hydrolysis was developed. Whole fish was minced and mixed with hydrochloric acid in the ratio. 30:100 v/wo The mixture was continuously stirred for 30 minutes, neutralised with NaOH to the original pH of the mince, homogenized and drum dried or spray dried. The effect of varying temperature, acid concentration and using cooked or uncooked fish as raw material on hydrolysis were investigated by determining changes in TCA-soluble N of the hydrolysate over the 30 minute period. Seven temperatures between 25 and 84cC and four acid concentrations (2.5M, 5M, 7.5M and 1l.3M) were investigated. The overall extent of hydro lysis for each run was determined by calculating the nett increase in TCA-soluble N expressed as % of total N, and it ranged between 0.8% and 10.4% and 6.7% and 34.1% for cooked and uncooked fish respectively. The extent of hydrolysis was greater in uncooked than cooked fish due to the synergistic effect of the endogenous proteolytic enzymes in uncooked fish and its absence in cooked fish. Cooking had destroyed the enzymes. Eight different products were produced. Data for crude protein, true protein, amino acid profiles, total lipid, ash, NaCl, aw, in vitro digestibility, colour, particle size distribution and sensory evaluation of the products were obtained. The data indicated the products had a high nutritional value and would be micrcbiologically stable for several months but susceptible to oxidative rancidity unless antioxidant were added. Using the data a process in which uncooked fish would be partially hydrolysed with 2.5M HCl at 48oC (approximately) for 30 minutes and the hydrolysate spray dried was propose

The chemical composition of Haplochromis spp.

The Haplochromis genus constitutes about 80% by weight of the fish in Lake Victoria yet only small amounts are utilised directly for food. There are over 150 species of Haplochromis, in the lake forming a species flock and any typical catch is made up of a mixture of many species. Morphological resemblance of the species makes identification of individual species very difficult. Little information has been published about the chemical composition of Haplochromis. The present study provides chemical composition data for lipid, protein and other nutritionally important constituents of Haplochromis as an aid to the processing of the resource and its nutritional evaluation. Four batches of Haplochromis from Lake Victoria were received. The first batch was analysed only for total lipid. Fish from the other three batches, caught over a five month period, were each split into four weight groups. Data were obtained for the weight distribution in the batches., the relationship between weight and length of the fish, weight and maximum depth of the fish and for the proportions of head, gut and headless gutless portions in the different weight groups. Total lipid determinations were carried out on the head, gut and headless, gutless portions for all four groups for each batch. On average 54% of the total lipid in the whole fish was present in the head, 19% in the gut and 27% in the headless, gutless portion. Small variations were found in the total lipid .content and distribution between size groups and batches, although on average the whole fish contained about 6% total lipid. Analyses for the lipid fatty acids profile, crude protein, true protein, amino acid profile, ash, calcium, vitamin A and moisture were carried out on the head, gut, fillet and residue for the major group and on the whole fish for other groups. Processing and nutritional implications of the results are discussed . The results generally indicate that for practical processing purposes the species flock may be treated as a single species

Contribution of fisheries to food production, and prospects for processors and consumers

Fish production is an important source of food in Uganda, but the amount made available for human consumption is also being reduced by post-harvest losses. African fisheries scientist recently at the Conference of the Committee for Inland fisheries of Africa observed that increases in fish production and yields towards the year 2000 are possible through: (a) establishing better fisheries information base for fisheries planning development and management (b) creation Of new reservoirs (dams, valley tanks and fish ponds) for fish production (c) opening up new capture fisheries on the major lakes (d) intensifying culture - based fisheries; and (e) better management of the large lake systems through appropriate fisheries legislation

Awareness and Need for Knowledge of Health and Safety among Dairy Farmers Interviewed in Uganda

Introduction: Safe working conditions are essential for healthy living and for ensuring food security among farmers and farm communities in developing countries. There is limited research on this topic, and documentation is essential to understand and change patterns of human health and safety. Methods: In May 2014, six male and female farmers on four dairy farms in Uganda and a female veterinarian were interviewed about their awareness and attitudes to agricultural risk factors, health, and safety. In addition, transect walks were conducted on the four dairy farms. Results: The dairy farmers reported health and safety concerns, e.g., diarrhea, coughs, fever, cuts while using machetes in plantations, bruises when handling animals, and dizziness and poisoning symptoms from using different agrochemicals, and considered these an occupational hazard. The most important topic mentioned was the use of agrochemicals and drugs on livestock. The farmers spray their animals with insecticides to prevent ticks, lice, tsetse flies, and other biting nuisance flies, using a backpack or hand sprayer. Spraying is conducted without personal protection equipment, which is considered too expensive and difficult to obtain. The farmers reported that they usually feel dizzy, vomit, and have pain and a burning feeling in their face and eyes after spraying. The symptoms are sometimes so severe that they require treatment. In such cases, the farmers buy medication without a prescription at the local drugstore, where the storekeeper often has limited or no knowledge of agrochemicals or drugs except for dosage. Agricultural health and safety training in the region is non-existent, and the farmers expressed a need and desire for improvements in this area. Conclusion: The level of knowledge and awareness of agricultural health and safety risks, disease, and injury prevention among the Ugandan dairy farmers interviewed was low. The farmers mentioned few agriculture-related complaints, injuries, or diseases except poisoning from using agrochemicals. Training on health and safety in Ugandan agriculture is urgently needed

Volunteer experiences and perceptions of the informed consent process: Lessons from two HIV clinical trials in Uganda.

BACKGROUND: Informed consent as stipulated in regulatory human research guidelines requires that a volunteer is well-informed about what will happen to them in a trial. However researchers are faced with a challenge of how to ensure that a volunteer agreeing to take part in a clinical trial is truly informed. We conducted a qualitative study among volunteers taking part in two HIV clinical trials in Uganda to find out how they defined informed consent and their perceptions of the trial procedures, study information and interactions with the research team. METHODS: Between January and December 2012, 23 volunteers who had been in the two trials for over 6 months, consented to be interviewed about their experience in the trial three times over a period of nine months. They also took part in focus group discussions. Themes informed by study research questions and emerging findings were used for content analysis. RESULTS: Volunteers defined the informed consent process in terms of their individual welfare. Only two of the volunteers reported having referred during the trial to the participant information sheets given at the start of the trial. Volunteers remembered the information they had been given at the start of the trial on procedures that involved drawing blood and urine samples but not information about study design and randomisation. Volunteers said that they had understood the purpose of the trial. They said that signing a consent form showed that they had consented to take part in the trial but they also described it as being done to protect the researcher in case a volunteer later experienced side effects. CONCLUSION: Volunteers pay more attention during the consent process to procedures requiring biological tests than to study design issues. Trust built between volunteers and the research team could enhance the successful conduct of clinical trials by allowing for informal discussions to identify and review volunteers' perceptions. These results point to the need for researchers to view informed consent as a process rather than an event