22 resultados para State in Africa
em Helda - Digital Repository of University of Helsinki
Resumo:
This thesis examines the right to self-determination which is a norm used for numerous purposes by multiple actors in the field of international relations, with relatively little clarity or agreement on the actual and potential meaning of the right. In international practice, however, the main focus in applying the right has been in the context of decolonization as set by the United Nations in its early decades. Thus, in Africa the right to self-determination has traditionally implied that the colonial territories, and particularly the populations within these territories, were to constitute the people who were entitled to the right. That is, self-determination by decolonization provided a framework for the construction of independent nation-states in Africa whilst other dimensions of the right remained largely or totally neglected. With the objective of assessing the scope, content, developments and interpretations of the right to self-determination in Africa, particularly with regard to the relevance of the right today, the thesis proceeds on two fundamental hypotheses. The first is that Mervyn Frost s theory of settled norms, among which he lists the right to self-determination, assumes too much. Even if the right to self-determination is a human right belonging to all peoples stipulated, inter alia, in the first Article of the 1966 International Human Rights Covenants, it is a highly politicized and context-bound right instead of being settled and observed in a way that its denial would need special justification. Still, the suggested inconsistency or non-compliance with the norm of self-determination is not intended to prove the uselessness or inappropriateness of the norm, but, on the contrary, to invite and encourage debate on the potential use and coverage of the right to self-determination. The second hypothesis is that within the concept of self-determination there are two normative dimensions. One is to do with the idea and practice of statehood, the nation and collectivity that may decide to conduct itself as an independent state. The other one is to do with self-determination as a human right, as a normative condition, to be enjoyed by people and peoples within states that supersedes state authority. These external and internal dimensions need to be seen as complementary and co-terminous, not as mutually exclusive alternatives. The thesis proceeds on the assumption that the internal dimension of the right, with human rights and democracy at its core, has not been considered as important as the external. In turn, this unbalanced and selective interpretation has managed to put the true normative purpose of the right making the world better and bringing more just polity models into a somewhat peculiar light. The right to self-determination in the African context is assessed through case studies of Western Sahara, Southern Sudan and Eritrea. The study asks what these cases say about the right to self-determination in Africa and what their lessons learnt could contribute to the understanding and relevance of the right in today s Africa. The study demonstrates that even in the context of decolonization, the application of the right to self-determination has been far from the consistent approach supposedly followed by the international community: in many respects similar colonial histories have easily led to rather different destinies. While Eritrea secured internationally recognized right to self-determination in the form of retroactive independence in 1993, international recognition of distinct Western Sahara and Southern Sudan entities is contingent on complex and problematic conditions being satisfied. Overall, it is a considerable challenge for international legality to meet empirical political reality in a meaningful way, so that the universal values attached to the norm of self-determination are not overlooked or compromised but rather reinforced in the process of implementing the right. Consequently, this thesis seeks a more comprehensive understanding of the right to self-determination with particular reference to post-colonial Africa and with an emphasis on the internal, human rights and democracy dimensions of the norm. It is considered that the right to self-determination cannot be perceived only as an inter-state issue as it is also very much an intra-state issue, including the possibility of different sub-state arrangements exercised under the right, for example, in the form of autonomy. At the same time, the option of independent statehood achieved through secession remains a mode of exercising and part of the right to self-determination. But in whatever form or way applied, the right to self-determination, as a normative instrument, should constitute and work as a norm that comprehensively brings more added value in terms of the objectives of human rights and democracy. From a normative perspective, a peoples right should not be allowed to transform and convert itself into a right of states. Finally, in light of the case studies of Western Sahara, Southern Sudan and Eritrea, the thesis suggests that our understanding of the right to self-determination should now reach beyond the post-colonial context in Africa. It appears that both the questions and answers to the most pertinent issues of self-determination in the cases studied must be increasingly sought within the postcolonial African state rather than solely in colonial history. In this vein, the right to self-determination can be seen not only as a tool for creating states but also as a way to transform the state itself from within. Any such genuinely post-colonial approach may imply a judicious reconsideration, adaptation or up-dating of the right and our understanding of it in order to render it meaningful in Africa today.
Resumo:
In Somalia the central government collapsed in 1991 and since then state failure became a widespread phenomenon and one of the greatest political and humanitarian problems facing the world in this century. Thus, the main objective of this research is to answer the following question: What went wrong? Most of the existing literature on the political economy of conflict starts from the assumption that state in Africa is predatory by nature. Unlike these studies, the present research, although it uses predation theory, starts from the social contract approach of state definition. Therefore, rather than contemplating actions and policies of the rulers alone, this approach allows us to deliberately bring the role of the society – as citizens – and other players into the analyses. In Chapter 1, after introducing the study, a simple principal-agent model will be developed to check the logical consistence of the argument and to make the identification of causal mechanism easier. I also identify three main actors in the process of state failure in Somalia: the Somali state, Somali society and the superpowers. In Chapter 2, so as to understand the incentives, preferences and constraints of each player in the state failure game, I in some depth analyse the evolution and structure of three central informal institutions: identity based patronage system of leadership, political tribalism, and the Cold War. These three institutions are considered as the rules of the game in the Somali state failure. Chapter 3 summarises the successive civilian governments’ achievements and failures (1960-69) concerning the main national goals, national unification and socio-economic development. Chapter 4 shows that the military regime, although it assumed power through extralegal means, served to some extent the developmental interest of the citizens in the first five years of its rule. Chapter 5 shows the process, and the factors involved, of the military regime’s self-transformation from being an agent for the developmental interests of the society to a predatory state that not only undermines the interests of the society but that also destroys the state itself. Chapter 6 addresses the process of disintegration of the post-colonial state of Somalia. The chapter shows how the regime’s merciless reactions to political ventures by power-seeking opposition leaders shattered the entire country and wrecked the state institutions. Chapter 7 concludes the study by summarising the main findings: due to the incentive structures generated by the informal institutions, the formal state institutions fell apart.
Resumo:
The study explores the role of the state in regional integration processes. The question is approached through theoretical discussion and two case-studies - SADC (Southern African Development Community) and the EU. The main research question of the study is, what are the possibilities and problems of the integration process in Southern Africa and how do they differ from the possibilities and problems of the integration process in Europe. The undelrying question of the study is why do states decide to participate in an integration process where they have to limit their sovereignty. Review of the theoretical discussion of the integration studies shows that the integration process is affected by several factors on different levels of the international system. But the state plays a central role in integration processes - integration processes are inititated and carried on by the participatig states. The European integration process shows that the interests of the state can change over time. At the beginning of the integration process, the objective was to strengthen participating states. Later EU member states have decided that it is in their interest to deepen the process even if it has meant limitation of their sovereignty. The determinant factor has been that the member states have considered it to be in their interst to deepen the process. In Southern Africa the integration process is only at the beginning. SADC aims to establish a free trade area by 2008. The biggest challenge is how to implement the integration process so that it benefits all member states in a region that is economically dominated by South Africa. In practice this can be achieved through establishment of corrective mechanisms, which ensure equitable distribution of benefits. This would require deeper integration and South Africa to adapt responsibility towards its regional partners. African integration processes in general have not been as successful as for example the EU. African states have been reluctant to limit their sovereignty in favour of regional organisations.This can be explained by the differences between European and African states. The EU member states have been democracies while African states have been characterised by concentration of power in the executive branch. Furthermore the political systems in Africa have been characterised by vertical clientelist reltionships. As a result it has not been in the interest of the political elite to limit the state sovereignty in favour of regional organisations. In recent years SADC has been relatively succesful in its integration process and reforms, but a lot remains to be done before the implementation of the free trade area can be succesful. The institutional structure and treaties of SADC differ from the structures of the EU. Member states are the main actors of the integration processes. Their differences are reflected in the process and produce different kinds of integration in different parts of the world.
Resumo:
This academic work begins with a compact presentation of the general background to the study, which also includes an autobiography for the interest in this research. The presentation provides readers who know little of the topic of this research and of the structure of the educational system as well as of the value given to education in Nigeria. It further concentrates on the dynamic interplay of the effect of academic and professional qualification and teachers' job effectiveness in secondary schools in Nigeria in particular, and in Africa in general. The aim of this study is to produce a systematic analysis and rich theoretical and empirical description of teachers' teaching competencies. The theoretical part comprises a comprehensive literature review that focuses on research conducted in the areas of academic and professional qualification and teachers' job effectiveness, teaching competencies, and the role of teacher education with particular emphasis on school effectiveness and improvement. This research benefits greatly from the functionalist conception of education, which is built upon two emphases: the application of the scientific method to the objective social world, and the use of an analogy between the individual 'organism' and 'society'. To this end, it offers us an opportunity to define terms systematically and to view problems as always being interrelated with other components of society. The empirical part involves describing and interpreting what educational objectives can be achieved with the help of teachers' teaching competencies in close connection to educational planning, teacher training and development, and achieving them without waste. The data used in this study were collected between 2002 and 2003 from teachers, principals, supervisors of education from the Ministry of Education and Post Primary Schools Board in the Rivers State of Nigeria (N=300). The data were collected from interviews, documents, observation, and questionnaires and were analyzed using both qualitative and quantitative methods to strengthen the validity of the findings. The data collected were analyzed to answer the specific research questions and hypotheses posited in this study. The data analysis involved the use of multiple statistical procedures: Percentages Mean Point Value, T-test of Significance, One-Way Analysis of Variance (ANOVA), and Cross Tabulation. The results obtained from the data analysis show that teachers require professional knowledge and professional teaching skills, as well as a broad base of general knowledge (e.g., morality, service, cultural capital, institutional survey). Above all, in order to carry out instructional processes effectively, teachers should be both academically and professionally trained. This study revealed that teachers are not however expected to have an extraordinary memory, but rather looked upon as persons capable of thinking in the right direction. This study may provide a solution to the problem of teacher education and school effectiveness in Nigeria. For this reason, I offer this treatise to anyone seriously committed in improving schools in developing countries in general and in Nigeria in particular to improve the lives of all its citizens. In particular, I write this to encourage educational planners, education policy makers, curriculum developers, principals, teachers, and students of education interested in empirical information and methods to conceptualize the issue this study has raised and to provide them with useful suggestions to help them improve secondary schooling in Nigeria. Though, multiple audiences exist for any text. For this reason, I trust that the academic community will find this piece of work a useful addition to the existing literature on school effectiveness and school improvement. Through integrating concepts from a number of disciplines, I aim to describe as holistic a representation as space could allow of the components of school effectiveness and quality improvement. A new perspective on teachers' professional competencies, which not only take into consideration the unique characteristics of the variables used in this study, but also recommend their environmental and cultural derivation. In addition, researchers should focus their attention on the ways in which both professional and non-professional teachers construct and apply their methodological competencies, such as their grouping procedures and behaviors to the schooling of students. Keywords: Professional Training, Academic Training, Professionally Qualified, Academically Qualified, Professional Qualification, Academic Qualification, Job Effectiveness, Job Efficiency, Educational Planning, Teacher Training and Development, Nigeria.
Resumo:
Globalisaatio on luonut uuden maailmanjärjestelmän jonka myötä yksittäisten valtioiden vaikutusvalta on vähentynyt entisestään. Tämä pitää paikkansa erityisesti kehittyvien maiden kohdalla, esimerkiksi Afrikassa. Afrikka on pyrkinyt taistelemaan globalisaation tuomia negatiivisia vaikutuksia vastaan alueellistumisen ja maanosan yhtenäisyyttä ajavien hankkeiden kautta jo vuosikymmenien ajan, mutta toistaiseksi tulokset eivät ole olleet vakuttavia. Tällä hetkellä Afrikan Unionissa keskustellaan hankkeesta muodostaa Afrikan Yhdysvallat. Aiemmista hankkeista poiketen tämän uuden aloitteen ajatus perustuu ylikansallisuudelle, jossa yksittäiset valtiot luovuttavat valtaansa ylikansallisille elimille, kuten Afrikan Unionin hallitukselle. Näin ollen on tärkeää tarkastella aloitetta Afrikan Yhdysvaltojen perustamiseksi ja arvioida, voisiko tällainen ylikansallinen organisaatio auttaa Afrikkaa kääntämään globalisaation haittavaikutukset myönteisiksi. Tämä Pro Gradu-tutkielma väittää sen olevan mahdollista, mutta vain siinä tapauksessa että Afrikka on valmis hyväksymään yhtenäisyyden rajoitukset. Aiemman tutkimuksen vähyyden vuoksi on myös tarpeen tutkia Afrikan Yhdysvalloista kansallisilla tasoilla käytävää keskustelua. Tämän vuoksi tässä tutkielmassa painotetaan esimerkkimaa Sambian kautta yhden Afrikan Unionin jäsenmaan keskinäistä keskustelua aiheesta ja verrataan sitä Afrikan Unionin tason keskusteluun. Tutkielma sisältää kirjallisuuskatsauksen sekä tapaustutkimuksen. Tutkimusaineisto koostuu sambialaisista sanomalehtiotteista sekä Sambian valtion ja Afrikan Unionin virallisista asiakirjoista. Pääasiallisena tutkimusmenetelmänä on laadullinen sisällönanalyysi. Teoreettinen viitekehys perustuu afrikkalaisen valtion ja kansalaisyhteiskunnan, alueellistumisen, globalisaation hallinnan, pan-afrikkalaisuuden ja poliittisen integraation teorioihin sekä historialliseen katsaukseen Afrikan yhtenäisyydestä. Perimmäisenä tarkoituksena on lisätä ymmärrystä afrikkalaisesta valtiosta ja politiikasta. Tutkimuksen tulosten mukaan on havaittavissa aukko valtioiden virallisten toimijoiden näkemysten ja kansalaisyhteiskunnan huolenaiheiden välillä. Viralliset toimijat näyttävät olevan kansalaisyhteiskuntaa vahvemmin Afrikan Yhdysvaltojen kannalla. Virallisten toimijoiden korostaessa Afrikan aatteellista yhtenäisyyttä kansalaisyhteiskunta on huolissaan sen toteutumisesta käytännössä. Esiin nousee myös kysymys 'afrikkalaisesta' identiteetistä ja kansalaisuudesta sekä kommunikaatiosta valtion ja kansalaisten välillä.
Resumo:
The purpose of this study was to produce information on and practical recommendations for informed decision-making on and capacity building for sustainable forest management (SFM) and good forest governance. This was done within the overall global framework for sustainable development with special emphasis on the EU and African frameworks and on Southern Sudan and Ethiopia in particular. The case studies on Southern Sudan and Ethiopia focused on local, national and regional issues. Moreover, this study attempted to provide both theoretical and practical new insight. The aim was to build an overall theoretical framework and to study its key contents and main implications for SFM and good forest governance at all administration levels, for providing new tools for capacity building in natural resources management. The theoretical framework and research approach were based on the original research problem and the general and specific aims of the study. The key elements of the framework encompass sustainable development, global and EU governance, sustainable forest management (SFM), good forest governance, as well as international and EU law. The selected research approach comprised matrix-based assessment of international, regional (EU and Africa) and national (Southern Sudan and Ethiopia) policy and legal documents. The specific case study on Southern Sudan also involved interviews and group discussions with local community members and government officials. As a whole, this study attempted to link the global, regional, national and local levels in forest-sector development and especially to analyse how the international policy development in environmental and forestry issues is reflected in field-level progress towards SFM and good forest governance, for the specific cases of Southern Sudan and Ethiopia. The results on Southern Sudan focused on the existing situation and perceived needs in capacity building for SFM and good forest governance at all administration levels. Specifically, the results of the case study on Southern Sudan presented the current situation in selected villages in the northern parts of Renk County in Upper Nile State, and the implications of Multilateral Environmental Agreements (MEAs) and of the new forest policy framework for capacity building actions. The results on Ethiopia focused on training, extension, research, education and new curriculum development within higher education institutions and particularly at the Wondo Genet College of Forestry and Natural Resources (WGCF-NR), which administratively lies under Hawassa University. The results suggest that, for both cases studies, informed decision-making on and capacity building for SFM and good forest governance require comprehensive, long-term, cross-sectoral, coherent and consistent approaches within the dynamic and evolving overall global framework, including its multiple inter-linked levels. The specific priority development and focus areas comprised the establishment of SFM and good forest governance in accordance with the overall sustainable development priorities and with more focus on the international trade in forest products that are derived from sustainable and legal sources with an emphasis on effective forest law enforcement and governance at all levels. In Upper Nile State in Southern Sudan there were positive development signals such as the will of the local people to plant more multipurpose trees on farmlands and range lands as well as the recognition of the importance of forests and trees for sustainable rural development where food security is a key element. In addition, it was evident that the local communities studied in Southern Sudan also wanted to establish good governance systems through partnerships with all actors and through increased local responsibilities. The results also suggest that the implementation of MEAs at the local level in Southern Sudan requires mutually supportive and coherent approaches within the agreements as well as significantly more resources and financial and technical assistance for capacity building, training and extension. Finally, the findings confirm the importance of full utilization of the existing local governance and management systems and their traditional and customary knowledge and practices, and of new development partnerships with full participation of all stakeholders. The planned new forest law for Southern Sudan, based on an already existing new forest policy, is expected to recognize the roles of local-level actors, and it would thus obviously facilitate the achieving of sustainable forest management.
Resumo:
This thesis discusses the contemporary construction of the lived worlds of indigenous Amazonian youths. Today’s native peoples are considerably affected by the processes of globalization and urbanization, which have led to new ways of relating to their cultural traditions. This work presents a case study of Manchineri youngsters aged between 14 and 24 years old living in Acre state in Brazilian Amazonia. The Arawak-speaking Manchineri number some 1,000 people; their legally demarcated reserve is situated next to the River Yaco. The research is based on ethnographic material collected in the Mamoadate reserve and in the state capital, Rio Branco. By comparing the youth in different physical and social environments (the reserve and the city), my attempt has been to search for the most typical elements maintained, altered and created in the current lived worlds of Manchineri youths. Fieldwork methods included interviews, participant observation, photographs, video recordings, and drawings. The material was analyzed within the multidisciplinary framework of the social and cultural construction of knowledge. The study applies the concepts of social field, symbolic capital, and habitus as they have been used by Pierre Bourdieu; perspective as developed recently in Amazonian ethnology; the sacred as a cultural category as understood in the study of religion; and individual and person as concepts central to anthropology and sociology. Additionally, the study can be contextualized within youth studies, Latin American studies, and urban studies. The results of the study show that the everyday lives of young Amazonian native people are formed by a complex mixture of ‘modernity’ and ‘tradition’, fragmentation, and transitions between different conceptual frameworks. Part II discusses the ethnographic material in depth and shows that indigenous adolescents act from a variety of social perspectives: the native youth’s own ethnic group, divided into sub-groups, especially into urban residents and those living in the reserve; ancestors, super-human agents and spirits; other indigenous groups and non-natives. Consequently, besides the traditional initiation ritual, we find various contemporary rites of passage to adulthood: state-education, learning traditional practices, shamanism, matrimony, and transitions between the reserve and urban areas. According to these results, new social roles, political organization, responsibilities, and in general the desire to be respected, require both ‘modern’ and ‘traditional’ abilities. In Part III, the study shows that the current power relations constituted by new social contacts, ethnic recognition, and cooperation with different institutions have resulted in the formation of new social fields: youth cultures, the ethnic group, shamanic practices, the ethnopolitical movement, and indigenous students. The capacity of young Amazonian Indians to act in contemporary social fields produces them as full persons. The study also argues that the elements of the lived worlds can be divided into these social fields. When focusing on these fields, it became evident that these comprise the strategies adopted by young Indians to break through social and cultural barriers.
Resumo:
In my master’s thesis I analyse mystical Islamic poetry in ritualistic performance context, samā` , focusing on the poetry used by the Chishti Sufis. The work is based on both literary sources and ethnographic material collected in India. The central textual source is Surūd-i Rūhānī, a compilation of mystical poetry. Textual sources, however, can be understood properly only in relation to the living performance context and therefore I also utilise interviews of Sufis and performers of mystical music and recordings of samā` assemblies along with texts. First part of the thesis concentrates on thematic overview of the poems and the process of selecting a suitable text for performance. The poems are written in three languages, viz. in Persian, Urdu and Hindi. Among the authors are both Sufis and non-Sufis. The poems, mystical and non-mystical alike, share the same poetic images and they acquire a mystical meaning when they are set to qawwali music and performed in samā` assemblies. My work includes several translations of verses not previously translated. Latter part of the thesis analyses the musical idiom of qawwali and the ways in which the impact of text on listeners is intensified in performance. Typically the intensification is accomplished in the level of a single poem through three different techniques: using introductory verses, inserting verses between the verses of the main poem and repeating individual units of text. The former two techniques are tied to creating a mystical state in the listeners while the latter aims at sustaining it. It is customary that a listener enraptured by mystical experience offers a monetary contribution to the performers. Thus, intensification of the text’s impact aims at enabling the listeners to experience mystical states.
Resumo:
An important challenge in forest industry is to get the appropriate raw material out from the forests to the wood processing industry. Growth and stem reconstruction simulators are therefore increasingly integrated in industrial conversion simulators, for linking the properties of wooden products to the three-dimensional structure of stems and their growing conditions. Static simulators predict the wood properties from stem dimensions at the end of a growth simulation period, whereas in dynamic approaches, the structural components, e.g. branches, are incremented along with the growth processes. The dynamic approach can be applied to stem reconstruction by predicting the three-dimensional stem structure from external tree variables (i.e. age, height) as a result of growth to the current state. In this study, a dynamic growth simulator, PipeQual, and a stem reconstruction simulator, RetroSTEM, are adapted to Norway spruce (Picea abies [L.] Karst.) to predict the three-dimensional structure of stems (tapers, branchiness, wood basic density) over time such that both simulators can be integrated in a sawing simulator. The parameterisation of the PipeQual and RetroSTEM simulators for Norway spruce relied on the theoretically based description of tree structure developing in the growth process and following certain conservative structural regularities while allowing for plasticity in the crown development. The crown expressed both regularity and plasticity in its development, as the vertical foliage density peaked regularly at about 5 m from the stem apex, varying below that with tree age and dominance position (Study I). Conservative stem structure was characterized in terms of (1) the pipe ratios between foliage mass and branch and stem cross-sectional areas at crown base, (2) the allometric relationship between foliage mass and crown length, (3) mean branch length relative to crown length and (4) form coefficients in branches and stem (Study II). The pipe ratio between branch and stem cross-sectional area at crown base, and mean branch length relative to the crown length may differ in trees before and after canopy closure, but the variation should be further analysed in stands of different ages and densities with varying site fertilities and climates. The predictions of the PipeQual and RetroSTEM simulators were evaluated by comparing the simulated values to measured ones (Study III, IV). Both simulators predicted stem taper and branch diameter at the individual tree level with a small bias. RetroSTEM predictions of wood density were accurate. For focusing on even more accurate predictions of stem diameters and branchiness along the stem, both simulators should be further improved by revising the following aspects in the simulators: the relationship between foliage and stem sapwood area in the upper stem, the error source in branch sizes, the crown base development and the height growth models in RetroSTEM. In Study V, the RetroSTEM simulator was integrated in the InnoSIM sawing simulator, and according to the pilot simulations, this turned out to be an efficient tool for readily producing stand scale information about stem sizes and structure when approximating the available assortments of wood products.
Resumo:
Here I aimed at quantifying the main components of deadwood dynamics, i.e. tree mortality, deadwood pools, and their decomposition, in late-successional boreal forests. I focused on standing dead trees in three stand types dominated by Picea mariana and Abies balsamea in eastern Canada, and on standing and down dead trees in Picea abies-dominated stands in three areas in Northern Europe. Dead and living trees were measured on five sample plots of 1.6-ha size in each study area and stand type. Stem disks from dead trees were sampled to determine wood density and year of death, using dendrochronological methods. The results were applied to reconstruct past tree mortality and to model deadwood decay class dynamics. Site productivity, stand developmental stage, and the occurrence of episodic tree mortality influenced deadwood volume and quality. In all study areas tree mortality was continuous, leading to continuity in deadwood decay stage distribution. Episodic tree mortality due to either autogenic or allogenic causes influenced deadwood volume and quality in all but one study area. However, regardless of productivity and disturbance history deadwood was abundant, accounting for 20 53% of total wood volume in European study areas, and 15 27% of total standing volume in eastern Canada. Deadwood was a persistent structural component, since its expected residence time in early- and midstages of decay was 18 yr even in the area with the most rapid decomposition. The results indicated that in the absence of episodic tree mortality, stands may eventually develop to a steady state, in which deadwood volume fluctuates around an equilibrium state. However, in many forests deadwood is naturally variable, due to recurrent moderate-severity disturbances. This variability, the continuous tree mortality, and variation in rates of wood decomposition determine the dynamics and availability of deadwood as a habitat and carbon storage medium in boreal coniferous forest ecosystems.
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The studies presented in this thesis contribute to the understanding of evolutionary ecology of three major viruses threatening cultivated sweetpotato (Ipomoea batatas Lam) in East Africa: Sweet potato feathery mottle virus (SPFMV; genus Potyvirus; Potyviridae), Sweet potato chlorotic stunt virus (SPCSV; genus Crinivirus; Closteroviridae) and Sweet potato mild mottle virus (SPMMV; genus Ipomovirus; Potyviridae). The viruses were serologically detected and the positive results confirmed by RT-PCR and sequencing. SPFMV was detected in 24 wild plant species of family Convolvulacea (genera Ipomoea, Lepistemon and Hewittia), of which 19 species were new natural hosts for SPFMV. SPMMV and SPCSV were detected in wild plants belonging to 21 and 12 species (genera Ipomoea, Lepistemon and Hewittia), respectively, all of which were previously unknown to be natural hosts of these viruses. SPFMV was the most abundant virus being detected in 17% of the plants, while SPMMV and SPCSV were detected in 9.8% and 5.4% of the assessed plants, respectively. Wild plants in Uganda were infected with the East African (EA), common (C), and the ordinary (O) strains, or co-infected with the EA and the C strain of SPFMV. The viruses and virus-like diseases were more frequent in the eastern agro-ecological zone than the western and central zones, which contrasted with known incidences of these viruses in sweetpotato crops, except for northern zone where incidences were lowest in wild plants as in sweetpotato. The NIb/CP junction in SPMMV was determined experimentally which facilitated CP-based phylogenetic and evolutionary analyses of SPMMV. Isolates of all the three viruses from wild plants were genetically similar to those found in cultivated sweetpotatoes in East Africa. There was no evidence of host-driven population genetic structures suggesting frequent transmission of these viruses between their wild and cultivated hosts. The p22 RNA silencing suppressor-encoding sequence was absent in a few SPCSV isolates, but regardless of this, SPCSV isolates incited sweet potato virus disease (SPVD) in sweetpotato plants co-infected with SPFMV, indicating that p22 is redundant for synergism between SCSV and SPFMV. Molecular evolutionary analysis revealed that isolates of strain EA of SPFMV that is largely restricted geographically in East Africa experience frequent recombination in comparison to isolates of strain C that is globally distributed. Moreover, non-homologous recombination events between strains EA and C were rare, despite frequent co-infections of these strains in wild plants, suggesting purifying selection against non-homologous recombinants between these strains or that such recombinants are mostly not infectious. Recombination was detected also in the 5 - and 3 -proximal regions of the SPMMV genome providing the first evidence of recombination in genus Ipomovirus, but no recombination events were detected in the characterized genomic regions of SPCSV. Strong purifying selection was implicated on evolution of majority of amino acids of the proteins encoded by the analyzed genomic regions of SPFMV, SPMMV and SPCSV. However, positive selection was predicted on 17 amino acids distributed over the whole the coat protein (CP) in the globally distributed strain C, as compared to only 4 amino acids in the multifunctional CP N-terminus (CP-NT) of strain EA largely restricted geographically to East Africa. A few amino acid sites in the N-terminus of SPMMV P1, the p7 protein and RNA silencing suppressor proteins p22 and RNase3 of SPCSV were also submitted to positive selection. Positively selected amino acids may constitute ligand-binding domains that determine interactions with plant host and/or insect vector factors. The P1 proteinase of SPMMV (genus Ipomovirus) seems to respond to needs of adaptation, which was not observed with the helper component proteinase (HC-Pro) of SPMMV, although the HC-Pro is responsible for many important molecular interactions in genus Potyvirus. Because the centre of origin of cultivated sweetpotato is in the Americas from where the crop was dispersed to other continents in recent history (except for the Australasia and South Pacific region), it would be expected that identical viruses and their strains occur worldwide, presuming virus dispersal with the host. Apparently, this seems not to be the case with SPMMV, the strain EA of SPFMV and the strain EA of SPCSV that are largely geographically confined in East Africa where they are predominant and occur both in natural and agro-ecosystems. The geographical distribution of plant viruses is constrained more by virus-vector relations than by virus-host interactions, which in accordance of the wide range of natural host species and the geographical confinement to East Africa suggest that these viruses existed in East African wild plants before the introduction of sweetpotato. Subsequently, these studies provide compelling evidence that East Africa constitutes a cradle of SPFMV strain EA, SPCSV strain EA, and SPMMV. Therefore, sweet potato virus disease (SPVD) in East Africa may be one of the examples of damaging virus diseases resulting from exchange of viruses between introduced crops and indigenous wild plant species. Keywords: Convolvulaceae, East Africa, epidemiology, evolution, genetic variability, Ipomoea, recombination, SPCSV, SPFMV, SPMMV, selection pressure, sweetpotato, wild plant species Author s Address: Arthur K. Tugume, Department of Agricultural Sciences, Faculty of Agriculture and Forestry, University of Helsinki, Latokartanonkaari 7, P.O Box 27, FIN-00014, Helsinki, Finland. Email: tugume.arthur@helsinki.fi Author s Present Address: Arthur K. Tugume, Department of Botany, Faculty of Science, Makerere University, P.O. Box 7062, Kampala, Uganda. Email: aktugume@botany.mak.ac.ug, tugumeka@yahoo.com
Resumo:
Eutrophication of the Baltic Sea is a serious problem. This thesis estimates the benefit to Finns from reduced eutrophication in the Gulf of Finland, the most eutrophied part of the Baltic Sea, by applying the choice experiment method, which belongs to the family of stated preference methods. Because stated preference methods have been subject to criticism, e.g., due to their hypothetical survey context, this thesis contributes to the discussion by studying two anomalies that may lead to biased welfare estimates: respondent uncertainty and preference discontinuity. The former refers to the difficulty of stating one s preferences for an environmental good in a hypothetical context. The latter implies a departure from the continuity assumption of conventional consumer theory, which forms the basis for the method and the analysis. In the three essays of the thesis, discrete choice data are analyzed with the multinomial logit and mixed logit models. On average, Finns are willing to contribute to the water quality improvement. The probability for willingness increases with residential or recreational contact with the gulf, higher than average income, younger than average age, and the absence of dependent children in the household. On average, for Finns the relatively most important characteristic of water quality is water clarity followed by the desire for fewer occurrences of blue-green algae. For future nutrient reduction scenarios, the annual mean household willingness to pay estimates range from 271 to 448 and the aggregate welfare estimates for Finns range from 28 billion to 54 billion euros, depending on the model and the intensity of the reduction. Out of the respondents (N=726), 72.1% state in a follow-up question that they are either Certain or Quite certain about their answer when choosing the preferred alternative in the experiment. Based on the analysis of other follow-up questions and another sample (N=307), 10.4% of the respondents are identified as potentially having discontinuous preferences. In relation to both anomalies, the respondent- and questionnaire-specific variables are found among the underlying causes and a departure from standard analysis may improve the model fit and the efficiency of estimates, depending on the chosen modeling approach. The introduction of uncertainty about the future state of the Gulf increases the acceptance of the valuation scenario which may indicate an increased credibility of a proposed scenario. In conclusion, modeling preference heterogeneity is an essential part of the analysis of discrete choice data. The results regarding uncertainty in stating one s preferences and non-standard choice behavior are promising: accounting for these anomalies in the analysis may improve the precision of the estimates of benefit from reduced eutrophication in the Gulf of Finland.
Resumo:
In Tanzania, indigenous forests can still be found whose existence is based on the management systems of precolonial society. This study covers material from over 900 forests. There are similar types of forests elsewhere in Africa, and similar forests can also be found in indigenous cultures on every continent. In this study they are called traditionally protected forests (TPFs). They have a high level of endemism and a rich biodiversity. The field study was carried out during the years 1997-2003 using participatory methods. An active debate is going on concerning the capacity of local communities to manage their environment. The role of indigenous people and their institutions in the development of the physical environment is a central issue in the debate. This study discusses the opportunities that the local people have had to decide on how to conserve, maintain, utilise, and manage their environment during different political periods. The study explains what kinds of changes have taken place in these forests and institutions in northeastern Tanzania among the matrilinear Zigua and patrilinear Gweno ethnic groups. About 2% of the land area of the communities was still protected by the precolonial structures. The communities have established their protection systems for different reasons, not only because of their beliefs but also because of different secular and clearly environmentally motivated reasons. There are different TPF types. Less than half of them are directly related to spirituality, and more than half are not. In earlier research elsewhere, it has been commonly understood that spiritual reasons played the main role in the protection of these environments. This study is also part of the postcolonial geographical discussion on the precolonial landscape and environmental management which was started by Carl Sauer. In the Zigua case study villages, only two out of five first comer clans have performed rain rituals in the past 30 years. Many of the most respected sacred sites do not have a ritual maker or even a person who knows how to perform rituals any longer. The same is happening with male initiation rites. In all case study villages there have been illegal cuts in the TPFs, but variations can be seen between the communities. The number of those who neither respect indigenous regulations nor accept indigenous penalties is growing. Positive developments have also taken place. Nowadays, the Forest Act of 2002 is in effect, which works as a cornerstone of community-based land ownership and also allows elders to protect TPFs, and by-laws are created with the support of different projects. Moreover, during the field study it was found that many young people are ignorant about their village's TPF sites, but interested in learning about their history and values.
Resumo:
Atherosclerosis is an inflammatory disease characterized by accumulation of lipids in the inner layer of the arterial wall. During atherogenesis, various structures that are recognized as non-self by the immune system, such as modified lipoproteins, are deposited in the arterial wall. Accordingly, atherosclerotic lesions and blood of humans and animals with atherosclerotic lesions show signs of activation of both innate and adaptive immune responses. Although immune attack is initially a self-protective reaction, which is meant to destroy or remove harmful agents, a chronic inflammatory state in the arterial wall accelerates atherosclerosis. Indeed, various modulations of the immune system of atherosclerosis-prone animals have provided us with convincing evidence that immunological mechanisms play an important role in the pathogenesis of atherosclerosis. This thesis focuses on the role of complement system, a player of the innate immunity, in atherosclerosis. Complement activation via any of the three different pathways (classical, alternative, lectin) proceeds as a self-amplifying cascade, which leads to the generation of opsonins, anaphylatoxins C3a and C5a, and terminal membrane-attack complex (MAC, C5b-9), all of which regulate the inflammatory response and act in concert to destroy their target structures. To prevent uncontrolled complement activation or its attack against normal host cells, complement needs to be under strict control by regulatory proteins. The complement system has been shown to be activated in atherosclerotic lesions, modified lipoproteins and immune complexes containing oxLDL, for instance, being its activators. First, we investigated the presence and role of complement regulators in human atherosclerotic lesions. We found that inhibitors of the classical and alternative pathways, C4b-binding protein and factor H, respectively, were present in atherosclerotic lesions, where they localized in the superficial proteoglycan-rich layer. In addition, both inhibitors were found to bind to arterial proteoglycans in vitro. Immunohistochemical stainings revealed that, in the superficial layer of the intima, complement activation had been limited to the C3 level, whereas in the deeper intimal layers, complement activation had proceeded to the terminal C5b-9 level. We were also able to show that arterial proteoglycans inhibit complement activation in vitro. These findings suggested to us that the proteoglycan-rich layer of the arterial intima contains matrix-bound complement inhibitors and forms a protective zone, in which complement activation is restricted to the C3 level. Thus, complement activation is regulated in atherosclerotic lesions, and the extracellular matrix is involved in this process. Next, we studied whether the receptors for the two complement derived effectors, anaphylatoxins C3a and C5a, are expressed in human coronary atherosclerotic lesions. Our results of immunohistochemistry and RT-PCR analysis showed that, in contrast to normal intima, C3aR and C5aR were highly expressed in atherosclerotic lesions. In atherosclerotic plaques, the principal cells expressing both C3aR and C5aR were macrophages. Moreover, T cells expressed C5aR, and a small fraction of them also expressed C3aR, mast cells expressed C5aR, whereas endothelial cells and subendothelial smooth muscle cells expressed both C3aR and C5aR. These results suggested that intimal cells can respond to and become activated by complement-derived anaphylatoxins. Finally, we wanted to learn, whether oxLDL-IgG immune complexes, activators of the classical complement pathway, could have direct cellular effects in atherogenesis. Thus, we tested whether oxLDL-IgG immune complexes affect the survival of human monocytes, the precursors of macrophages, which are the most abundant inflammatory cell type in atherosclerotic lesions. We found that OxLDL-IgG immune complexes, in addition to transforming monocytes into foam cells, promoted their survival by decreasing their spontaneous apoptosis. This effect was mediated by cross-linking Fc receptors with ensuing activation of Akt-dependent survival signaling. Our finding revealed a novel mechanism by which oxLDL-IgG immune complexes can directly affect the accumulation of monocyte-macrophages in human atherosclerotic lesions and thus play a role in atherogenesis.