54 research outputs found
Use of bioindicators and biomarkers to assess aquatic environmental contamination in selected urban wetlands in Uganda
Pollution of aquatic resources in Uganda is on the increase and the trends are expected to increase with increase in population size and urbanisation. Assessment and mitigation of the environmental impacts on water quality and biodiversity have now become necessary. The aim of the study was to integrate invertebrate and fish as bioindicators and fish histopathology as a biomarker in the assessment of water quality deterioration in urban wetlands in Uganda. The integration harnesses the advantages and counteracts the shortcomings of each method and thus builds a more robust diagnostic tool that gives a better view of the impacts to the entire ecosystem. Four endpoints which included, physicochemical variables, benthic macroinvertebrate bioindicators, fish bioindicators and fish histopathology biomarkers were compared between varied effluent-impacted wetlands (Murchison Bay in Kampala, and Kirinya, Masese and Winday Bay in Jinja) and a non-impacted reference wetland (Lwanika in Mayuge). Results from the effluent-impacted sites differed from the less impacted reference site. The two sampling locations at Murchison Bay (inshore and offshore) and one sampling location at Kirinya (inshore), that were highly impacted with urban effluent, showed elevated nutrient levels, low pH, dissolved oxygen and secchi depth readings. This corresponded with low invertebrate taxa and fish species diversity and richness; and severe histopathological responses in liver, gonads and gills of O. niloticus. Sensitive taxa such as ephemeroptera and trichoptera were completely absent while pollution tolerant taxa Chironomus sp, Corbicula and Oligochaeta were present. Also notable was the absence of many native haplochromines and presence of mainly Brycinus sadleri, Oreochromis niloticus and leucostictus. The organs manifested high prevalence of severe inflammatory and regressive changes and higher organ indices that fell within the pathological category. These sites were consistently classified as highly polluted under the four endpoints. The reference site was classified as least polluted while Masese and Winday Bay were moderately polluted. Results suggested that the approach of using invertebrate and fish as bioindicators and the fish histopathology as a biomarker, in relation to water quality physicochemical variables was a useful tool in highlighting the spatial differences in environmental quality
Bioaccumulation and histopathology of copper in Oreochromis mossambicus
Cu is one of the most toxic elements that affect fish populations when the fish are exposed to concentrations exceeding their tolerance. To investigate the effects of elementary Cu on aspects of bioconcentration, histology and behaviour, O. mossambicus were exposed to 0 and 0.75 ± 0.20 mg/l of Cu for 96 hours (short-term study), and 0, 0.11 ± 0.02, 0.29 ± 0.02, and 0.47 ± 0.04 mg/l of Cu for 64 days (longterm study) under controlled conditions in the laboratory. For the long-term study fish were sampled for gills, liver, and kidney Cu accumulation analysis after 1, 32 and 64 days of exposure and after 1, 2, 4, 16, 32, and 64 days for gills, liver and spleen histology analysis. Cu accumulation was concentration-duration dependent with the highest accumulation capacity in the liver. A multifactor linear model was developed for the relationship between exposure dose, exposure duration and Cu accumulation in the organs with the liver model: Log L = 3.35 + 0.85W + 0.31T (r² = 0.892) giving a better fit than the gills: G = −35.09 + 10.58W + 17.58T (r² = 0.632). Where L = Cu accumulation values in the liver, G = Cu accumulation values in the gills (both in μg/g dry mass); W = exposure dose in water (mg/l); and T = exposure time (days). Using this model Cu accumulation in organs can be estimated when exposure concentration and duration is known. This model should be tested under different conditions to determine the potential of the model in monitoring Cu toxicity in the environment. Lesions were observed in the liver, gills and spleen in all Cu treatments at all exposure concentration and exposure durations. However, the incidence and the degree of alteration was related to the concentration of Cu and duration of exposure. The sequential appearance of lesions in the order of, hepatic vacuolar degeneration, fatty degeneration and necrosis indicated a gradual increase in liver damage with larger duration of exposure time and increasing Cu concentration. The initial lesions in the gills were manifested as hypertrophy and hyperplasia of the gill epithelium causing increase in the thickness of the secondary lamellae, mucous cell hypertrophy and proliferation, mucous hypersecretion, proliferation of eosinophilic granule cells and hyperplasia of interlamellar cells. With increase in exposure time, necrosis of the eosinophilic granule cells, lamellar oedema, epithelial desquamation and increase in severity of lamellar hyperplasia were observed. These lesions indicated an initial defence mechanism of the fish against Cu toxicity followed by advanced histological changes that were related to Cu concentration and duration of exposure. Changes in the spleen were haemosiderosis, increase in the white pulp and macrophage centres, reduction in the red pulp, and necrosis suggesting that fish exposed to environmentally relevant levels of Cu may be histopathologically altered leading to anaemia and immunosuppression. Regression analysis was used to quantify the relationship between the total activity of the fish, and duration of exposure. There was a gradual decline in fish activity related to Cu concentration and duration of exposure before introducing food into the tanks. There was a constant activity after introducing food in the tanks at the control and 0.11 ± 0.02 mg/l Cu exposure levels irrespective of exposure time. Analysis of covariance (ANCOVA) was used to test for the difference in slopes between treatments. There was no significant difference (p > 0.05) between slopes of the control and 0.11 ± 0.02 mg/l Cu, and between 0.29 ± 0.02 and 47 ± 0.04 mg/l Cu before and after introducing food in the tanks. The slopes of both the control and 0.11 ± 0.02 mg/l Cu were significantly different from those of 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu (p < 0.05). There were significant differences in the mean opercular movements per minute between treatments (p < 0.05). There was hyperventilation at 0.11 ± 0.02 mg/l Cu i.e. 87 ± 18 opercular movements per minute (mean ± standard deviation) and hypoventilation at 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu i.e. 37 ± 34 and 13 ± 6 opercular movements per minute compared to the control. Hypo- and hyperventilation were related to the lesser and greater gill damage, respectively. In conclusion Cu accumulation and effects on histology of the liver, gills and were related to the concentration of Cu in the water and duration of exposure showing a gradual increase in incidence and intensity with larger duration of exposure time and increasing Cu concentration. The fish were initially able to homeostatically regulate and detoxify Cu. However, as the exposure continued, the homeostatic mechanism appears to have failed to cope with the increasing metal burden causing advanced histological changes
Bioaccumulation and histopathology of copper in Oreochromis mossambicus
Cu is one of the most toxic elements that affect fish populations when the fish are exposed to concentrations exceeding their tolerance. To investigate the effects of elementary Cu on aspects of bioconcentration, histology and behaviour, O. mossambicus were exposed to 0 and 0.75 ± 0.20 mg/l of Cu for 96 hours (short-term study), and 0, 0.11 ± 0.02, 0.29 ± 0.02, and 0.47 ± 0.04 mg/l of Cu for 64 days (longterm study) under controlled conditions in the laboratory. For the long-term study fish were sampled for gills, liver, and kidney Cu accumulation analysis after 1, 32 and 64 days of exposure and after 1, 2, 4, 16, 32, and 64 days for gills, liver and spleen histology analysis. Cu accumulation was concentration-duration dependent with the highest accumulation capacity in the liver. A multifactor linear model was developed for the relationship between exposure dose, exposure duration and Cu accumulation in the organs with the liver model: Log L = 3.35 + 0.85W + 0.31T (r² = 0.892) giving a better fit than the gills: G = −35.09 + 10.58W + 17.58T (r² = 0.632). Where L = Cu accumulation values in the liver, G = Cu accumulation values in the gills (both in μg/g dry mass); W = exposure dose in water (mg/l); and T = exposure time (days). Using this model Cu accumulation in organs can be estimated when exposure concentration and duration is known. This model should be tested under different conditions to determine the potential of the model in monitoring Cu toxicity in the environment. Lesions were observed in the liver, gills and spleen in all Cu treatments at all exposure concentration and exposure durations. However, the incidence and the degree of alteration was related to the concentration of Cu and duration of exposure. The sequential appearance of lesions in the order of, hepatic vacuolar degeneration, fatty degeneration and necrosis indicated a gradual increase in liver damage with larger duration of exposure time and increasing Cu concentration. The initial lesions in the gills were manifested as hypertrophy and hyperplasia of the gill epithelium causing increase in the thickness of the secondary lamellae, mucous cell hypertrophy and proliferation, mucous hypersecretion, proliferation of eosinophilic granule cells and hyperplasia of interlamellar cells. With increase in exposure time, necrosis of the eosinophilic granule cells, lamellar oedema, epithelial desquamation and increase in severity of lamellar hyperplasia were observed. These lesions indicated an initial defence mechanism of the fish against Cu toxicity followed by advanced histological changes that were related to Cu concentration and duration of exposure. Changes in the spleen were haemosiderosis, increase in the white pulp and macrophage centres, reduction in the red pulp, and necrosis suggesting that fish exposed to environmentally relevant levels of Cu may be histopathologically altered leading to anaemia and immunosuppression. Regression analysis was used to quantify the relationship between the total activity of the fish, and duration of exposure. There was a gradual decline in fish activity related to Cu concentration and duration of exposure before introducing food into the tanks. There was a constant activity after introducing food in the tanks at the control and 0.11 ± 0.02 mg/l Cu exposure levels irrespective of exposure time. Analysis of covariance (ANCOVA) was used to test for the difference in slopes between treatments. There was no significant difference (p > 0.05) between slopes of the control and 0.11 ± 0.02 mg/l Cu, and between 0.29 ± 0.02 and 47 ± 0.04 mg/l Cu before and after introducing food in the tanks. The slopes of both the control and 0.11 ± 0.02 mg/l Cu were significantly different from those of 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu (p < 0.05). There were significant differences in the mean opercular movements per minute between treatments (p < 0.05). There was hyperventilation at 0.11 ± 0.02 mg/l Cu i.e. 87 ± 18 opercular movements per minute (mean ± standard deviation) and hypoventilation at 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu i.e. 37 ± 34 and 13 ± 6 opercular movements per minute compared to the control. Hypo- and hyperventilation were related to the lesser and greater gill damage, respectively. In conclusion Cu accumulation and effects on histology of the liver, gills and were related to the concentration of Cu in the water and duration of exposure showing a gradual increase in incidence and intensity with larger duration of exposure time and increasing Cu concentration. The fish were initially able to homeostatically regulate and detoxify Cu. However, as the exposure continued, the homeostatic mechanism appears to have failed to cope with the increasing metal burden causing advanced histological changes
Occurrence and genetic characterisation of Acanthamoeba spp. from environmental and domestic water sources in Queen Elizabeth Protected Area, Uganda
Maternal Literacy, Facility Birth, and Education Are Positively Associated with Better Infant and Young Child Feeding Practices and Nutritional Status among Ugandan Children
Background: Understanding maternal factors that influence child feeding is necessary to inform intervention planning in settings in which mothers experience substantial social vulnerabilities. Objective: The purpose of this study was to assess maternal sociodemographic factors that may constrain women\u27s caring capabilities and subsequent child nutrition in Uganda. Methods: We analyzed data from the 2006 and 2011 Uganda Demographic and Health Surveys to model the associations between maternal sociodemographic factors, child feeding practices, and anthropometry with multivariate logistic regression models. Results: The proportion of children fed according to recommended guidelines declined in Uganda from 2006 to 2011. Mothers who lacked literacy skills were less likely to achieve recommended complementary feeding indicators; however, literacy was not associated with breastfeeding practices. Mothers in the upper 60% wealth percentile were more likely to meet minimum meal frequency, diversity, and adequacy indicators. Mothers who gave birth at health facilities (2006 OR: 0.49; 95% CI: 0.26, 0.91; P \u3c 0.05) and who were in the upper 60% wealth percentile (2011 OR: 0.43; 95% CI: 0.21, 0.69) were less likely to exCIusively breastfeed until 6 mo. There were no significant associations between age at first pregnancy, maternal education, and infant and young child feeding practices. Women with a formal education had children with lower stunting and underweight probabilities in both time periods (OR range: 0.43-0.74). Women who delivered in childbirth facilities were less likely to have a child with low weight-for-age, length-for-age, or weight-for-length z scores (OR range: 0.59-0.82). Marital status, the age at first child birth, not accepting domestic violence, freedom to travel away from home, and involvement in household and reproductive decisions were not associated with child anthropometry in either time period. Conclusions: Mothers with low literacy skills, who deliver their children at home, and who lack formal education are particularly at risk of poor child feeding and represent a group that may benefit from enhanced interventions that address their particular vulnerabilities. Factors that contribute to improved maternal feeding capabilities but may impair breastfeeding practices need to be better understood
Generic health literacy measurement instruments for children and adolescents:a systematic review of the literature
Background Health literacy is an important health promotion concern and recently children and adolescents have been the focus of increased academic attention. To assess the health literacy of this population, researchers have been focussing on developing instruments to measure their health literacy. Compared to the wider availability of instruments for adults, only a few tools are known for younger age groups. The objective of this study is to systematically review the field of generic child and adolescent health literacy measurement instruments that are currently available. Method A systematic literature search was undertaken in five databases (PubMed, CINAHL, PsycNET, ERIC, and FIS) on articles published between January 1990 and July 2015, addressing children and adolescents ?18 years old. Eligible articles were analysed, data was extracted, and synthesised according to review objectives. Results Fifteen generic health literacy measurement instruments for children and adolescents were identified. All, except two, are self-administered instruments. Seven are objective measures (performance-based tests), seven are subjective measures (self-reporting), and one uses a mixed-method measurement. Most instruments applied a broad and multidimensional understanding of health literacy. The instruments were developed in eight different countries, with most tools originating in the United States (n =?6). Among the instruments, 31 different components related to health literacy were identified. Accordingly, the studies exhibit a variety of implicit or explicit conceptual and operational definitions, and most instruments have been used in schools and other educational contexts. While the youngest age group studied was 7-year-old children within a parent-child study, there is only one instrument specifically designed for primary school children and none for early years. Conclusions Despite the reported paucity of health literacy research involving children and adolescents, an unexpected number of health literacy measurement studies in children?s populations was found. Most instruments tend to measure their own specific understanding of health literacy and not all provide sufficient conceptual information. To advance health literacy instruments, a much more standardised approach is necessary including improved reporting on the development and validation processes. Further research is required to improve health literacy instruments for children and adolescents and to provide knowledge to inform effective interventionspublishersversionPeer reviewe
Advancing the measurement of Critical Nutrition Literacy in adolescents
Aim: To evaluate the psychometric properties of scales measuring adolescents’ proficiency to critically appraise nutrition information, their engagement in dietary behaviour and self-efficacy in the science topic ‘Body and Health’, and test a theoretical model linking these latent traits. Methods: A sample of 1622 tenth graders at 58 randomly sampled schools in Norway voluntary responded to a questionnaire containing the three scales. The scale measuring adolescents’ proficiency to critically appraise nutrition information was validated by applying the partial credit parameterization of the polytomous unidimensional Rasch model. The scale measuring self-efficacy in the science topic ‘Body and Health’ was validated by using the partial credit parameterization of the polytomous unidimensional Rasch model and confirmatory factor analysis. The theoretical model linking the latent traits was tested by using structural equation modelling. Structural equation modelling was preferred to regression models as this method properly handles latent traits measured with standard errors. The data was tested up against the appropriate Rasch model by using the statistical software package RUMM2030. The confirmatory factor model and the “structural equation modelling” model were estimated by using the statistical software package Lisrel 9. Owing to data at the ordinal measurement level, “diagonally weighted least square” estimation was applied. “Goodness of fit” indexes were also estimated by using robust maximum likelihood estimation, as published target values typically rely on this type of estimation. Main results: The data collected sufficiently fit the polytomous unidimensional Rasch model. Confirmatory factor analysis displayed strong standardized factor loadings, which strengthened the idea of one underlying latent factor (unidimensional scale). The scales were slightly less than optimally targeted for the sample, as the distribution of person location estimates were somewhat shifted toward higher values than the distribution of item threshold locations. Overall, the scales were reliable and able to separate between students with different standing on the latent trait. The theoretical model was empirically strengthened, which means that the model implied variance-covariance matrix fairly well reproduced the observed variance-covariance matrix. Conclusions: Valid and reliable scales for measuring adolescents’ critical nutrition literacy were established, and self-efficacy in the health-related science topic explained variation in students’ critical nutrition literacy. Hence, there is a relation between adolescents’ self-perceived nutrition literacy and self-perceived health-related scientific literacy
Advancing the measurement of Critical Nutrition Literacy in adolescents
OsloMet Avhandling 2021 nr 43 av Desire Alice Naigaga. Dissertation for the degree of philosophiae doctor (PhD). Department of Nursing and Health Promotion. Faculty of Health Sciences. OsloMet – Oslo Metropolitan University. Autumn 2021.
ISSN 2535-471X (trykket)/ISSN 2535-5454 (online)ISBN 978-82-8364-347-3 (trykket)/ ISBN 978-82-8364-361-9 (online
The influence of tone at the top management level and internal audit quality on the effectiveness of risk management practices in the financial services sector
The purpose of this study is to examine the contribution made by the tone at the top management level and internal audit quality on the effectiveness of risk management practices (RMPs) in the financial services sector. This study is cross-sectional and correlational, and it uses firm-level data that were collected by means of a questionnaire survey from a sample of 62 financial services firms in Uganda. Results suggest that the tone at the top management level and internal audit quality are both significant predictors of effective RMPs. However, the predictive potential of tone at the top management level towards effective RMPs reduces when internal audit quality is present. These results support the idea that in terms of agency theory, top management should oversee and review the organization’s risks as a way of spearheading effective RMPs. Similarly, internal auditors should sufficiently and appropriately review and coordinate risk management efforts in the organization, since high-quality internal audits lead to effective RMPs. Top managers of financial services firms should encourage periodic reviews of the appropriateness and effectiveness of risk management systems and controls. At the same time, regulators should ensure that top managers of financial services firms have adequate risk management expertise, with no conflict of interest and apply mechanisms that detect significant risks in time. The study contributes to the strategic risk management position by showing that the tone at the top management level and internal audit quality sets pace for an organization culture towards effective RMPs
Assessing adolescents’ perceived proficiency in critically evaluating nutrition information
Background
Over the recent past, there has been an increase in nutrition information available to adolescents from various sources, which resulted into confusion and misinterpretation of the dietary advice. Results from international assessment frameworks such as PISA and TIMMS reflect the need for adolescents to critically appraise health information. While a number of scales measuring the critical health literacy of individuals exist; very few of these are devoted to critical nutrition literacy. More so, these scales target individuals with an advanced level of nutrition education, often gaging their proficiency in information appraisal in relation to principles of evidence-based medical research. The purpose of the present study was to examine the psychometric properties of a newly developed critical nutrition literacy scale (CNL-E) measuring adolescents’ perceived proficiency in ‘critically evaluating nutrition information from various sources’.
Methods
During spring 2015, more than 1600 tenth graders aged 15–16 years from approximately 60 schools in Norway responded to the five-item questionnaire using an electronic survey system. Applying Rasch analysis approach, we examined the psychometric properties of the CNL-E scale employing the RUMM2030 statistical package. To further investigate the dimensionality of the scale and test the underlying structure, we applied multidimensional Rasch modelling using the ConQuest 4 software and confirmatory factor analysis (CFA) using the Lisrel 9.30 software.
Results
In our sample, the CNL-E stood out as a valid, reliable and well-targeted scale with good overall fit to the partial credit parameterization of the polytomous unidimensional Rasch model (PCM). All the items were sufficiently statistically independent, had ordered response categories and showed acceptable individual fit to the PCM. No item displayed within-item bias or differential item functioning (DIF).
Conclusions
From the observed CNL-E sum score, it is possible to draw plausible conclusions about how individuals critically evaluate nutrition information. Efforts to improve communication of nutrition information could benefit from applying validated measures such as the CNL-E scale. The CNL-E scale provides insight into how individuals without an advanced level of nutrition education, such as adolescents, determine the validity and reliability of nutrition information from various sources
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