• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 525
  • 118
  • 26
  • 22
  • 17
  • 11
  • 7
  • 7
  • 7
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • Tagged with
  • 878
  • 878
  • 852
  • 158
  • 139
  • 137
  • 115
  • 115
  • 104
  • 91
  • 88
  • 84
  • 79
  • 78
  • 78
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Mapping 20 Years of Urbanization in Sub-Saharan Africa from Space: An approach based on multi-sensor satellite imagery and volunteered geographic information

Forget, Yann 14 May 2020 (has links) (PDF)
Between 2015 and 2050, half of the net increase in the world's urban populationis expected to take place in Sub-Saharan Africa (SSA), driving drastic landcover changes and challenging the spatial organization of human societies.Understanding past and present dynamics of this urbanization process is criticalto achieve a sustainable pattern of urban development, yet is limited by thelack of accurate and multi-temporal spatial data on urban expansion. Since the2000s, the rise of satellite-based Earth Observation (EO) enabled the productionof several global urban maps, thereby mitigating the issue of data scarcity. ButSSA is still characterized by lower accuracies in satellite-based maps becauseof various issues, such as: a lower satellite imagery availability, a lack ofreference datasets, and a high heterogeneity across the urban areas of theregion.In this thesis, I propose to leverage open-access satellite catalogs along withvolunteered geographic information to improve large-scaled and automated mappingof the built environment in SSA. The proposed approach makes use ofOpenStreetMap to support model training and calibration, thereby bypassing theneed for reference datasets or manual digitization campaigns. This method wasassessed in 10 urban areas of SSA, reaching classification performances similarto manual approaches.Moreover, the combined use of multispectral and synthetic-aperture radar (SAR)imagery was explored. In 11 out of 12 case studies in SSA, multi-sensorclassification schemes outperformed single-sensor approaches. More specifically,multi-sensor classification dramatically increased built-up detection rates inarid and semi-arid regions---where bare soil and buildings may share a similarspectral signature.These findings were implemented to map the built environment of 46 urban areasat five different dates from 1995 to 2015, with an average F1-score of 0.93. Thestatistical interpretation of the produced dataset revealed the highheterogeneity that characterizes urban areas in SSA, and confirmed that thespatial patterns of urbanization highly depends on demographic and economicfactors. Overall, the present thesis provides promising insights for large-scaled andautomated mapping of the built environment in data-scarce regions. Severalissues are still affecting the mapping accuracies, such as: multi-temporalinconsistencies caused by the use of imagery from 7 different sensors, lowavailability of historical imagery in SSA, or missing data in OpenStreetMap.Still, with the growing availability of open-access EO catalogs and theincreasingly completeness of OpenStreetMap, the proposed approach is expected tobecome even more relevant in the near future. / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished
202

Systematics of subtribe Anthosperminae and the generic affinities of Anthospermum L. and Nenax Gaertn. (Rubiaceae: Anthospermeae)

Nemando, Rangani January 2021 (has links)
Magister Scientiae (Biodiversity and Conservation Biology) / The last taxonomic treatment of the subtribe Anthosperminae Benth. (Rubiaceae, Rubioideae, Anthospermeae) was in 1986 by Puff., nevertheless, few attempts have been made to resolve the phylogeny and the inter- and infrageneric relationships within the subtribe. The genera Anthospermum L. (39 species) and Nenax Gaertn. (11 species) are considered the most difficult groups to distinguish. Anthospermum species are widely distributed in Sub-Saharan Africa and Madagascar with the highest concentration of taxa in southern Africa, while Nenax species are restricted to southern Africa, in the south-western Cape Floristic Region. The two genera share common morphological and anatomical characters such as the growth form, presence of hairs on the stem, leaf arrangement, presence of petioles, flowers formation, dehiscence and presence of carpophore in fruits. currently combination of characters, woody shrub, needle-like leaves, few-flowered inflorescence and dioecy are considered unique in Nenax. The most recent phylogenetic analysis based on molecular data indicated insights into generic relationships within the two genera and the subtribe Anthosperminae. The present study focussed on expanding the phylogenetic analysis of Anthospermum, Nenax and other genera within the subtribe, as well as assessing the value of selected morphological and anatomical characters for re-assesing generic circumscriptions. Phylogenetic relationships were analysed using Maximum Parsimony, Maximum Likelihood and Bayesian inference, and a Maximum Clade Credibility tree was produced. These analyses were based on both nuclear (ITS, ETS) and plastid (trnL-f, rps16, rpl32) datasets.
203

Does Education Matter for Income Inequality? Evidence from Sub-Saharan Africa

Panton-Ntshona, Sherine 16 March 2022 (has links)
The issue of income equality has become of great concern on a global scale. Since the 2008 global financial crisis, economists and other socioeconomic analysts have observed the state of the income and wealth gap between the top ten percent rich and the lower forty percent poor of populations, and its far-reaching impact on the lives of ordinary people. Income inequality has become a global challenge and the effects are felt in both developed and developing countries. The socioeconomic disparity between the rich and poor is pronounced in developing countries, and recent trends of growing inequality are being observed in developed countries. This research examines the effect of education on income inequality and GDP per capita, using a panel dataset of 18 selected sub-Saharan countries for the period from 1994 to 2015. The panel models are estimated, using the fixed effects, random effects and generalised methods of moments estimation techniques. The results show that the relationship of education and its impact on income inequality is dependent on the level of education being assessed. High resource input in tertiary education increases income inequality, while high resource input in lower educational levels reduces income inequality. Overall, increases in government expenditure on education lead to increase in inequality and a fall in GDP per capita. These results show possible inefficiencies in the allocation of educational resources in sub-Saharan countries during the period of investigation. Government spending on education does not reduce inequality or boost income unless it is done efficiently. To reduce income inequality and increase average income, educational resources must be efficiently allocated with priority given to the educational levels of the highest proportions of the population.
204

An investigation into combined amorphous form of sufadoxine, pyrimethamine and azithromycin

Okello, Geoffrey January 2021 (has links)
Magister Pharmaceuticae - MPharm / Malaria remains one of the top mortality causes in the sub-Saharan African region, especially among pregnant women and infants. Despite several measures being implemented within the affected areas such as the use of treated mosquito nets, sulfadoxine and pyrimethamine (SULPYR) as an intermittent preventive treatment (IPTp-SP) is still considered the standard prophylactic regimen for pregnant women. Recently, the WHO increased the regimen of IPTp- SP from three to four doses on a monthly interval, this recommendation poses a potential risk of toxicity and resistance to the drugs. An improvement towards this challenge is under clinical trial and consists of the inclusion of azithromycin (AZI), a macrolide antibiotic, to the current IPTp-SP treatment regimen. This will not only aid in the prophylaxis of malaria in pregnant women but will also assist in other pregnancy related infections. All three these drugs exhibit poor aqueous solubility; requiring high concentrations for oral administration to achieve therapeutic plasma concentrations. / 2024
205

The Impact of Groundnut Production and Marketing Decisions upon Household Food Security Among Smallholder Farmers in Sub-Saharan Africa:  Does Gender Matter?

Enterline, Darren James 24 May 2013 (has links)
This thesis investigates the relationship between groundnut cash cropping decisions and household food security in two regions of sub-Saharan Africa.  Particular attention is paid to how the gender of groundnut growers influences this relationship.  Additionally, the thesis examines how gender influences household marketing decisions.  Household groundnut production and marketing data was obtained using surveys administered in eastern Uganda and central Ghana.  A food consumption score developed by the World Food Program is used as a quantitative measure of food security.  Measures of household groundnut cultivation intensity are specified using data on household groundnut production and marketing levels.  An OLS regression estimates the relationship between the food consumption score and measures of cash cropping intensity and other cash crop production decisions.  Apart from the OLS regression, a tobit model is employed to estimate the gender effects on household marketing decisions, examining both the decision to participate in a market and the decision concerning the amount to market.  Cash cropping decisions are found to play no role in the determination of food security.  While the presence of female groundnut growers in a household has a small positive effect on the food consumption score, there is no identifiable gender influence upon the cash cropping and food security relationship.  The tobit model results indicate no gender effect upon household marketing decisions. / Master of Science
206

Structural and Behavioral Correlates of HIV Infection Among Pregnant Women in a Country with a Highly Generalized HIV Epidemic: A Cross-Sectional Study with a Probability Sample of Antenatal Care Facilities in Swaziland. / HIV広汎流行国の妊婦のHIV感染に関連する構造的および行動的要因について:スワジランドの周産期ケア施設の確率サンプルを用いた横断的研究

Bhekumusa, Wellington Lukhele 23 March 2017 (has links)
付記する学位プログラム名: グローバル生存学大学院連携プログラム / 京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20266号 / 医博第4225号 / 新制||医||1021(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 小泉 昭夫, 教授 中山 健夫, 教授 髙折 晃史 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
207

Improvement of Water- and Nutrient-Use Efficiency with Optimum Agricultural Management Practices in Upland Cropping Systems in Morogoro, Tanzania / タンザニア・モロゴロ州の畑作地における最適な農業管理による養水分利用効率の改善

Nishigaki, Tomohiro 24 November 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第20769号 / 農博第2252号 / 新制||農||1054(附属図書館) / 学位論文||H29||N5089(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 舟川 晋也, 教授 間藤 徹, 教授 縄田 栄治 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
208

ESSAYS ON ETHNIC FAVORITISM ACROSS AFRICAN COUNTRIES AND OVER TIME

Tiku, Erickosowo Nsan 01 September 2021 (has links) (PDF)
This dissertation examines the differences in ethnic favoritism across African countries. In the first chapter, using survey data from Afrobarometer we consider to what extent ethnic favoritism arises in sub-Saharan African countries by examining whether a person’s perception of government fairness depends on whether he shares the same ethnicity as the country’s leader. I allow associations to differ not only across time but across types of countries such as democracies versus nondemocracies. Such an approach not only can determine whether ethnic favoritism arises but in what cases it might be more pronounced. Findings indicate that the associations with perceived ethnic favoritism have held steady over time. Differences between low- and middle-income countries are also small. Greater differences arise across political regimes as democracies show less ethnic bias than do nondemocracies. More diverse countries also show more ethnic bias. In the second chapter, with the information from two rounds of the Afrobarometer survey, we consider to what extent gender and ethnicity matter for perceived access and quality of education and health facilities. We allow associations to differ not only across time but across types of countries such as democracies versus nondemocracies. Such an approach not only can determine whether ethnic and gender inequalities arise but in what circumstances they might dissipate. Our findings indicate no differences in the perceived access and quality of education and health facilities nor do differences arise in various subgroups of countries such as democracies, resource-rich countries, ethnically diverse countries, or middle-income countries. The third chapter examines how the Nigerian president’s changes in ethnicity and religion affect certain outcomes. Since 2000, Nigerian presidents have come from different ethnic groups and practiced different religions. Using several rounds of the Demographic and Health Surveys, we exploit this variation in leadership to examine if households see greater material wealth or greater access to public services when the president comes from their ethnic group or when he practices the same religion. The analysis indicates that ethnic groups do not benefit (at least, contemporaneously) from having a co-ethnic as president. In fact, co-ethnics are less likely to have access to electricity, protected water, improved sanitation, and more likely to be in the poorest quantile.
209

Excess Fertility and Infant Mortality in Sub-Saharan Africa

Wencak, Jason P. 27 August 2013 (has links)
No description available.
210

Understanding maternal health-care seeking behavior in low-income communities in Accra, Ghana

Anafi, Patricia 01 January 2012 (has links)
This study sought to examine health care decisions and choices that women make during pregnancy and childbirth in selected low-income and poor urban communities in Ghana. Specifically, it examined women's and community members' knowledge and perceptions about pregnancy and childbirth; existing forms of health care available to women during pregnancy and childbirth; and factors that influence preference for the type of health care that women use during pregnancy and childbirth. The study employed a two-phased data collection strategy involving in-depth interviews and focus group discussions to examine maternal health care seeking behavior of the target population. The findings revealed that the poor urban women have a wide range of perceptions and knowledge about pregnancy including knowledge about what constitutes a successful pregnancy and risk factors of pregnancy and childbirth complications. The study found that three major forms of health care exist for pregnant women: biomedical care; herbal-traditional birth attendant care; and spiritual care. While some women use or prefer to use either solely medical care or herbal-traditional birth attendant care for their pregnancy and delivery, others combine two or all the three forms of health care. Pregnant women seek traditional birth attendants (TBAs) and spiritual care for spiritual protection against death, due to affection and cultural attachment to TBAs, fears about medical care and health facilities, and due to cost of seeking medical care. Long waiting time and early reporting time at antenatal clinic were identified as partly limiting the use of medical care during pregnancy. Intimate partners of pregnant women were identified as negative normative influence since most of them do not support their wives during pregnancy. Quality and safety of care were the major reasons why pregnant mothers seek biomedical care other than other forms of care. However, majority of women who seek biomedical care do not seek timely antenatal care. Only 42 percent made their first antenatal visit in the first trimester. These findings have implications for policies and programs that are likely to help increase the use of skilled attendance and improve maternal health outcomes in the study population and other similar low-income urban communities in Ghana.

Page generated in 0.0784 seconds