283 research outputs found
Towards a theory of quantum integrability in finite size systems
No full textWe study general quantum integrable Hamiltonians linear in a coupling constant and represented by finite NxN real symmetric matrices. The restriction on the coupling dependence leads to a natural notion of nontrivial integrals of motion and classification of integrable families into Types according to the number of such integrals. A Type M family in our definition is formed by N-M nontrivial mutually commuting operators linear in the coupling. Working from this definition alone, we parameterize Type M operators, i.e. resolve the commutation relations, and obtain an exact solution for their eigenvalues and eigenvectors. We show that our parameterization covers all Type 1, 2, and 3 integrable models and discuss the extent to which it is complete for other types. We also present robust numerical observation on the number of energy level crossings in Type M integrable systems and analyze the taxonomy of types in the 1d Hubbard model.Ph. D.Includes bibliographical referencesby Haile Owus
Experiencing the armed struggle : the Soweto generation and after
No full textIncludes bibliographical references (p. 354-369).This study explores the experiences of the rank-and-file soldiers of Umkhonto we Sizwe and the Azanian People's Liberation Anny. Extensive interviews by the author and other researchers reveal the voices of the soldiers themselves. The African National Congress and Pan African Congress archives at the University of the Western Cape and the University of Fort Hare supplement and verify these oral testimonies, as do some published sources. Most previously published materials about the armed struggle against apartheid have already focused on diplomacy, strategy and tactics, operations, leadership, and human rights abuses to the neglect of the soldiers' actual experiences. This study complements these with significant new oral history materials from the Soweto generation of soldiers and their successors. When dealing with MK, many authors have documented issues of the camp structure in Angola, and operations inside South Africa, so much of this detail is only addressed briefly, leaving space to explore the soldiers' experiences. In the case of APLA, very little has been written on its history, and more detail is provided on these subjects. This study therefore deals with the soldiers' politicisation and motivation for joining the armed struggle, their experiences in leaving South Africa and training in exile, the crises in exile which limited their effectiveness for a time, their return to fight in South Africa, and their difficulties in the "new" South Africa. These materials reveal that vast problems remain facing these veterans of the struggle against apartheid, and that they have the potential, if properly supported and employed, to contribute substantially to the development of present day South Africa. Conversely, if their neglect continues, they also have the potential to bring vast harm to the country. Further use of the investigative tools of oral history, especially if extended to the former soldiers' vernacular languages, is necessary to augment the history of South Africa, and these soldiers' contributions
Exploring spatial variations and factors associated with childhood stunting in Ethiopia: spatial and multilevel analysis
No full textA critical analysis of Ethiopian Civil Code: in light of the core features of Continental European Codification
No full textThis dissertation examines the core features of codification and applies them to the Ethiopian civil code in order to critically analyze whether that code complies with the core features of continental European codification or not. The author describes the development of the system of law in Ethiopia - explaining how Ethiopia became one of Africa’s states highly influenced by the model of continental European codification, particularly with the introduction during the regime of Emperor Haile Sellasie (between 1957 and 1965) of a group of highly complex codes – Civil code, Civil Procedure code, Penal code, Criminal Procedure code, Commercial code and Maritime code – giving Ethiopia one of the most modern legal systems in the World
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Modeling the Potential Impact of Fortification Programs on Dietary Micronutrient Intakes among Young Children and Women of Reproductive Age in Low- and Middle-income Countries: Case Studies from Cameroon and Zambia
No full textABSTRACTIn low- and middle-income countries (LMICs), the prevalence of inadequate micronutrient intake and micronutrient deficiency is high, particularly among women and young children. Sub-Saharan Africa is disproportionally affected by micronutrient deficiencies (MNDs) and the progress towards sustained reduction in MNDs has been limited. In recent years, large-scale food fortification has gained traction in LMICs, including sub-Saharan African countries, to address micronutrient deficiency. Given the long-term effort and investment that is needed to implement and sustain fortification programs, dietary intake data should be used in overall planning of fortification programs to make informed judgments about the appropriateness of the food vehicle, and the types and amounts of the specific nutrients to be added. Simulation studies provide insights about the potential contributions of food fortification to micronutrient intakes and, alongside information on program costs, can provide an efficient way of comparing hypothetical fortification scenarios that can then be translated into nutrition policies and practices. However, the usefulness of simulation modeling studies depends on the validity of dietary requirements applied and assumptions taken into consideration.
Zinc Nutrient Reference Values (NRVs) set by several expert groups differ widely. The effects of these differences on the predicted impacts and on the cost-effectiveness of zinc fortification programs have not been fully explored. In the first study, we estimated the prevalence of inadequate zinc intake and the predicted impact and cost-effectiveness of zinc fortification programs using NRVs published by different authorities based on data from a nationally representative nutrition survey among children and women in Cameroon. The distribution of usual zinc intakes was estimated using the National Cancer Institute (NCI) method. Prevalence of total zinc intake below the estimated average requirement (i.e. dietary requirement) and prevalence of “absorbable zinc intake” below the physiological requirement were estimated using NRVs from 4 expert groups: World Health Organizations (WHO), Institute of Medicine (IOM), International Zinc Nutrition Consultative Group (IZiNCG) and European Food Safety Authority (EFSA). The estimated prevalence of inadequate zinc intake varied substantially ranging from 10% (IZiNCG-physiological requirement) to 81% (EFSA-physiological requirement) among children, and from 9.4% (WHO-physiological requirement) to 94% (IOM-physiological requirement) among women. These differences observed in the prevalence of inadequate intake translated to differences in the estimated benefits and cost-effectiveness of zinc fortification programs. Therefore, depending on the NRVs applied, assessments will differ regarding the need for, and the benefits and cost-effectiveness of, zinc fortification programs. Efforts are needed to harmonize NRVs for zinc.
Snack products that are voluntarily fortified with micronutrients are increasingly available but are not necessarily formulated to meet known dietary nutrient gaps, so the potential impacts on population micronutrient intake adequacy are uncertain. In the second study, we predicted the impacts of hypothetical micronutrient-fortified biscuits on inadequate micronutrient intake among children and women of reproductive age (WRA) based on nationally representative data in Cameroon. We estimated usual nutrient intake distributions using the NCI method and simulated the impacts of biscuit fortification on prevalence of micronutrient intake (vitamin A (VA), folate, vitamin B-12, iron, and zinc) below the estimated average requirement, given observed biscuit consumption, in the presence and absence of large-scale food fortification (LSFF) programs. In the absence of LSFF programs, biscuits fortified with retinol (600μg/100g), folic acid (300μg/100g), and zinc (8mg/100g) were predicted to reduce the prevalence of inadequacy among children by 10.3 ± 4.4, 13.2 ± 4.2 and 12.0 ± 6.1 percentage points, respectively, in Yaoundé/Douala. However, when the impact of existing national VA-fortified oil, and folic acid and zinc-fortified wheat flour programs were considered, the additional impacts of fortified biscuits were reduced substantially. Micronutrient-fortified biscuits were predicted to have minimal impacts on dietary inadequacy among WRA, with or without LSFF programs. Given observed patterns of biscuit consumption in Cameroon, biscuit fortification is unlikely to reduce dietary inadequacy of studied micronutrients, except possibly for selected nutrients among children in urban areas, but only in the absence of LSFF programs.
Zambia has been implementing mandatory sugar fortification with VA, however the contribution of VA-fortified sugar to VA intakes and status has not been directly assessed. In the third study, we predicted the potential impacts of sugar fortification with VA on prevalence of VA inadequacy, and examine its association with plasma and breast milk retinol among lactating women based on baseline data from a randomized trial from Mkushi District in rural Zambia. We simulated VA intake under various sugar fortification scenarios: 3.1 and 8.8 mg/kg (measured median fortification levels of VA in sugar from previous studies), 10 mg/kg (minimum legal requirement) and 15 mg/kg (minimum legal requirement at factory level). We applied the NCI’s bivariate model to examine associations of usual intake of sugar and dietary VA with plasma and breast milk retinol concentrations measured by high performance liquid chromatography.
Our model predicted that sugar fortification with VA at 3.1 mg/kg, 8.8 mg/kg, 10 mg/kg and 15 mg/kg would reduce the prevalence of VA inadequacy by 7 (SE:6), 24 (SE:14), 30 (SE:15) and 47 (SE:18) percentage points, respectively, without increasing the risk of retinol intake above the UL. Usual sugar intake and usual VA intake were not associated with plasma retinol (β = 0.003; 95% CI: -0.015, 0.020) or with breastmilk retinol concentrations (β = 0.012; 95% CI: -0.002, 0.026). Usual VA intake from other foods sources was significantly associated with the log of breast milk retinol in µmol/ L (β = 0.001; 95% CI: 0.0002, 0.002), but not with plasma retinol (β = -0.0001; 95% CI: -0.001, 0.001). In Zambia, sugar fortification has the potential to reduce dietary VA inadequacy. However, the impacts on VA intakes and any improvements in VA status are likely to be limited if the program is not implemented as planned. Even if target fortification levels are achieved (10 mg/kg), sugar fortification alone is unlikely to eliminate dietary VA inadequacy among lactating women in Zambia.
Together, the three studies from the dissertation provide evidence on the effect of using different zinc reference values on the predicted benefits and cost-effectiveness of zinc fortification programs, and the impacts of voluntary snack food fortification and mandatory sugar fortification on prevalence of inadequate intake. These findings have important implications with regard to planning and evaluation of fortification programs in LMIC contexts.
Khat Chewing Practice and Associated Factors among Adults in Ethiopia: Further Analysis Using the 2011 Demographic and Health Survey.
No full textBackgroundKhat chewing has become a highly prevalent practice and a growing public health concern in Ethiopia. Although there have been many small scale studies, very limited national information has been available in the general population. This study aimed to identify factors associated with khat chewing practice among Ethiopian adults.MethodsThe study used the 2011 Ethiopian demographic and health survey data. The survey was cross-sectional by design and used a multistage cluster sampling procedure. Bivariate and multivariable logistic regression models with adjusted odds ratio (AOR) and their 95% confidence intervals (CI) were used to quantify the predictors.ResultsThe overall khat chewing prevalence was 15.3% (95% CI: 14.90-15.71). Regional variation was observed with the highest in Harari [(53.2% (95% CI: 43.04-63.28)] and lowest in Tigray regional state [(1.1% (95% CI: 0.72-1.66)]. Multivariable analysis showed that Islam followers were 23.8 times more likely to chew khat as compared to Orthodox followers. Being a resident in Oromiya, South Nation, Nationalities and People (SNNP), Gambella, Harari and Dire Dawa regions had 1.9, 1.6, 3.1, 5.2 and 3.5 times higher odds of chewing khat as compared to Addis Ababa residents, respectively. Adults in the age group 45-49 years were 3.6 times more likely to chew khat as compared to 15-19 years. The middle and richest wealth quintiles were 1.3 and 1.5 times more likely to chew khat, respectively, as compared to the poorest category. Rural residents had 1.3 odds of chewing khat than urban residents. Those individuals who had occupation in sales, agriculture, service sector, skilled and unskilled manual workers were 1.6, 1.3, 2.4, 1.7 and 2.3 times more likely to chew khat, respectively, as compared to those who have no occupation. Females were 77% less likely to chew khat as compared to males. Formerly married and those experienced in child death had 1.4 and 1.2 times higher odds to chew khat as compared with those never married and never had child death, respectively. Those who attended mass media were 1.4 times more likely to chew khat compared with not attended.ConclusionKhat chewing is a public health concern in Ethiopia. The highest wealth quintiles, older age group, rural residence, child death, formerly married, males, regions of Oromiya, SNNP, Gambella, Harari and Dire Dawa and Islamic followers had statistically significant association with khat chewing. Due attention needs to be given for these factors in any intervention procedures
Tobacco use and associated factors among adults in Ethiopia: further analysis of the 2011 Ethiopian Demographic and Health Survey
No full textPrevalence of antenatal depression and associated factors among pregnant women in Addis Ababa, Ethiopia: a cross-sectional study
No full textBook Review: Stories from the fireplace: theological meditations on Haile Gerima’s cinema
No full text[This multi-disciplinary study examines the works of Ethiopian scholar and filmmaker Haile Gerima from a theological perspective. The author was inspired to write this book because of “the persisting, provoking and lingering representation of Africa as ‘the radical other’ through intellectual and artistic media” (xxi). Historians, anthropologists, and missionaries create and recreate Africa’s otherness in film and other texts. The “Afro-pessimistic” history of (mis)representations can be traced in travelogues, cartography (mapmaking), anthropozoology (human zoos), and the Hollywood types of conventional cinema (zoo-keepers) (57). By engaging with African cinematic discourses, Belachew tries to demonstrate the kind of positive role African Christian theology can play in the pursuit of human dignity and flourishing. He creates a counter narrative against Afro-pessimist films, which frequently perpetuate inferior images of the African other.
Development of relations between Ethiopia and China during Emperor Haile Selassie: a product of timing or the leadership?
No full textThis article delves into the development of the diplomatic relationship between Ethiopia and China during Emperor Haile Selassie. The author utilizes a combination of primary and secondary sources. The primary sources were collected from various institutions and offices such as the Institute of Ethiopian Studies (IES), the Ministry of Foreign Affairs of Ethiopia, and periodicals that included memoirs, speeches, and correspondence exchanges. Secondary sources were gathered from both published and unpublished materials. The study focuses on defining the evolution of diplomatic relations between the two countries throughout the 1970s. This particular period witnessed China’s diplomatic triumph on the global stage, prompting Ethiopia to seek an alternative ally to the West. This development occurred when the United States attempted to exploit this advantage by re-establishing its ties with the People’s Republic of China (PRC). The findings of this study assert that after Ethiopia set aside all obstacles and endeavored to establish diplomatic ties with China on December 1, 1970, it became evident that the country was adopting a hedging strategy to distance itself from its long ally, the US. Following Haile Selassie’s visit to Beijing, Ethiopia and China signed a joint communiqué on economic and technical cooperation. Consequently, the study concludes that the development of diplomatic relations between the two countries coincided with the gradual decline of the US’s influence in Ethiopia
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