The research demonstrated that an easily cultivated fungus was screened from filter materials of fresh water recycle aquaculture system. A fungus, characterized as being able to remediate multiple nitrogenous wastes, was identified as Aspergillus niger NBG5. A. niger NBG5 was developed as superior fungus through bioreactor so as to establish a nitrogenous removal system of single tank stirred tank reactor (SSTR). A. niger NBG5¡¦s remediative responses were tested under various temperatures. The experiment showed that specific nitrogen consumption rate was 0.047 g-N g-cell-1 day-1 at 30¢J which were better than nitrite nitrogen and protein nitrogen consumption. When the artificial wastes¡¦ ammonium concentration was set as 50 mg L-1, its ammonium consumption rate was 4.8 mg m-2 day-1. The ammonium consumption rate reached 0.32 mg m-2 day-1 with aquaculture wastes. The result revealed that SSTR removed nitrogen from aquaculture wastes by A. niger NBG5 and achieved a purpose of decreasing ammonium within aquaculture wastes. The research simulated ammonium variable numerals between SSTR and BSTR (the system of bi-tank stirred tank reactor). Through BSTR, regression formula with water flow rate and ammonium removal efficiency rate was y = 5.7219x-0.9616 when the ammonium concentration was set as 50 mg L-1. SSTR simulated a phenomenon¡Xthe more ammonium concentration aquaculture wastes reached, the much waste water volume of aquaculture tank it had. Based on the same requirements, a better water flow rate would be concluded through various water flow rate simulation tests. SSTR numerical simulation system could simulate ammonium production rate of fish tank to get consumption trends of ammonium concentration in fish tank and reactor. The simulation results would be able to decide later system design, water flow rate, feed timing and similar research references.

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Texte remanié de: Th. doct.--Sc. sociales--Paris--EHESS, 1999. Titre de soutenance : Gestion de l'espace et crise pastorale au Sahel. / Bibliogr. p. 289-306. Index. Préf. en anglais.

Diss.--Bayreuth, 2000. / Bibliogr. p. 224-229. Glossaire.

Thesis (Ph.D.) -- University of Texas at Arlington, 2008.

Thesis (doctoral)--Universität, Göttingen, 1999.

University, Hohenheim, Thesis (doctoral), 2001.

In despite of all attention drawn to child marriage across the world, there is a lack of improvement. The object of this research is to look into under what circumstances child marriage does exist and how girls’ living conditions can be improved. Focus shall be put on child marriage in general exemplified in particular by two countries in Africa, namely Niger and Chad, who both are countries with an extremely high rate of child marriage. This is a desk study based on various reports regarding the subject in the different countries and also in general. As the theoretical framework, the sex role theory is applied in order to analyze the phenomenon. Studies indicate a great difference in the number of young married girls in comparison to boys across the globe. Even though boys can be victims of child marriage, the consequences are less severe and therefore, focus shall be put on girls only in this thesis. The number of girls entering early marriage has not been found to stagnate everywhere, but the age of when entering marriage tends to increase. In fact, child marriage has become more common in some areas. From the research it is concluded that one cannot generalize all underlying causes of child marriage, but one must be aware of the specific circumstances in the particular areas. Conclusions regarding underlying factors and correlations are further to be found and presented in the text.

This dissertation clarifies ethnoarchaeology's role in post-positivist epistemology through both a critical re-examination of ethnoarchaeology's position within archaeology and a study of household vessel exchange and consumption in the Inland Niger Delta of Mali. I argue that ethnoarchaeology meets its epistemic raison d'etre by achieving theoretical independence from archaeology's general theories. Independence is "built-in" to ethnoarchaeological study by focusing explicitly on the way material culture is used in daily practice; in particular, by re-embedding material culture in the "modern" contexts where it is used. Ceramic exchange in the Inland Niger Delta can not be understood apart from either the exchange and consumption of other industrial household vessels or the political economies women experience within patrilineal households. Household vessels are distinctly women's tools in the Delta and their consumption is an intimate part of the way women resist exploitation and the appropriation of their wealth within household political economies. The different roles vessels play are manifest in the distances these objects travel during consumption and are also materialized by their location within house compounds. Enamel vessels are used in displays of social and economic capital related to marriage that insulate women from exploitation; aluminum vessels are expensive items bought as part of marriage trousseaus; and plastics are relatively low value items given as small gifts or bought in local markets to insulate small amounts of wealth from appropriation. Pottery is relatively marginal within household economies; yet, potters rely on the income ceramic production creates. Thus, potters use extensive marketing strategies to sell their wares to a relatively disinterested clientele in order to meet their own obligations within patrilineal households and to buy the other types of household vessels that they desire. The findings of thi

Discourse between development agents and nomads implies that development for nomadiccommunities is a contradiction in terms. A "market-oriented" subtext underscores the investors'power of international agencies, the brokers' competition of intermediate organizations, and thenomadic clients' opportunism. Interviews and participant-observation focused on relationsbetween Wo??aa??e communities, bilateral and local organizations, and government extensionservices. I compare the data obtained with historical events to illuminate current phenomena.Approaches of structuration, political ecology, and disequilibrium theory aid an examination ofcommunication and discourses, and gaps in understanding between the parties. I find thatessential pastoral livelihood strategies of mobility and customary institutions are threatened bythe development system. How will social change affect cultural mechanisms that facilitateresource access and allocation? Rather than promoting sustainable development, projects thattarget nomadic communities may only result in increased stratification, wealth disparity andmarginalization for the majority of nomadic households. Will "development" become too costlyfor households, local ecology, and even national economy? I conclude with recommendationsfor participative development through collaborative research.