Research concerning the formation and removal of black crusts on various historical objects is approached from many different angles. The so-called “yellowing effect”, observed after laser treatment for cleaning purposes, has also received a lot of attention. Evidence regarding this phenomenon differs considerably and the actual mechanisms are still speculated on by researchers. In an attempt to elucidate the processes involved in the yellowing effect associated with laser cleaning, a new analytical technique has been used to investigate the black crust, a region of the sample cleaned by laser irradiation at 1064 nm and another region of the same sample subjected to further laser irradiation at 355 nm, on a limestone sample from the cathedral of Seville in Spain. Micro-Raman spectrometry offers the advantage of spatial chemical characterization of the stone, based upon its molecular makeup and was performed on the bulk body of the stone. Raman and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDXS) results indicate that the surfaces cleaned by irradiation at 1064 nm and by double irradiation at 1064 and 355 nm differed in terms of their calcium sulphate, calcium oxalate and iron oxide content, and that this could contribute to the difference in colour observed.

L'objectif de ma thèse était de trouver de nouveaux oncogènes impliqués dans les leucémies de type T, en utilisant la méthode d'étiquetage rétroviral. Pour induire des leucémies de type T chez la souris, nous utilisons le rétrovirus RadLV qui induit la maladie en un temps de latence très court. La première étape de mon travail a consisté en la recherche de sites communs d'intégration (SCIs) de RadLV dans des thymomes de souris induits par ce rétrovirus. Nous avons trouvé un nouveau SCI que l'on a appelé Kis2, situé sur le chromosome X et impliqué dans 11 % des tumeurs analysées. Après avoir répertorié les gènes du locus, nous avons montré que les intégrations de RadLV au niveau du locus Kis2 provoquaient la surexpression de deux gènes. Le premier, situé très proche du SCl, correspond à un ARN non-codant que l'on a baptisé Kis2. Le deuxième, situé 300 kb en amont, correspond au gène Phf6, récemment impliqué dans un syndrome de retard mental. Nous avons donc mis en évidence que les intégrations rétrovirales pouvaient activer plusieurs gènes à la fois, et ce sur de longues distances. La deuxième étape de mon travail a consisté en la caractérisation du gène Kis2. Les intégrations rétrovirales provoquent la surexpression de cinq transcrits de ce gène, mettant en évidence un profil d'épissage complexe. Son caractère non-codant a rendu ce gène énigmatique, jusqu'à ce que l'on découvre en 3' du gène la présence du groupe de microARN (miARN) miR-106-363. Nous avons pu montrer qu'en définitive les ARN Kis2 correspondaient au pri-miARN de miR-106-363, qui se compose de six miARN (miR-106a, miR-18b, miR-20b, miR-19b, miR-92-2 et miR-363). La surexpression de ces pri-miARN dans les tumeurs de souris conduit à l'accumulation de miR-106a, miR-20b, miR-19b et miR92-2. Dans 46% des leucémies de type T humaines, le pri-miARN miR-106-363 est également surexprimé, conduisant à une surproduction de miR-19b et miR-92-2, et parfois de miR-106a. Nous montrons donc l'implication de miR-106-363 dans les leucémies humaines, et également l'existence d'une régulation post-transcriptionelle de ce groupe dont tous les miARN ne sont pas produits en même temps et dans les mêmes quantités. De façon intéressante, miR-106-363 est homologue au groupe miR-17-92, connu pour être impliqué entre autres dans des lymphomes de type B. Pour apprécier le potentiel oncogénique de miR-106-363, nous avons réalisé un test d'indépendance d'ancrage sur des cellules NIH3T3. Les résultats indiquent que miR-106a, miR-20b, miR-19b et miR-92-2 sont capables d'induire la formation de colonies. Nous avons par la suite procédé à l'identification de gènes cibles de ces miARN. Parmi une sélection de prédictions informatiques communes à miR-106a/20b, miR-19b et mir-92, nous avons choisi les gènes à caractère suppresseur de tumeur. Nous montrons que les gènes Mylip. Rbp1-like et possiblement Hipk3 sont ciblés par ces miARN, et que leur expression est inversement corrélée à celle de miR-106-363 dans les tumeurs de souris. Nos résultats constituent de nouveaux indices quant aux mécanismes oncogéniques relatifs à la surexpression de miR-106-363. Le dernier volet de ma thèse concerne l'identification de protéines interagissant avec les ARN Kis2. Ce travail était destiné à nous renseigner sur le rôle de ces ARN, alors que nous n'avions pas connaissance de miR-106-363. J'ai identifié par spectrométrie de masse trois protéines candidates: hnRNP A2/B1, hnRNP A3, KSRP, et possiblement PSF. Le rôle de ces protéines orienté vers la régulation de l'épissage m'a conduit à formuler l'hypothèse de l'implication de ces protéines dans la production des différents transcrits du gène Kis2. Finalement, ce profil d'épissage complexe pourrait être relié à l'expression différentielle des miARN de miR-106-363, et constituer un élément de régulation post-transcriptionelle de l'expression des miARN. Les interactions de ces protéines avec les ARN Kis2 restent toutefois à confirmer in vivo. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Leucémie, Étiquetage rétroviral, Oncogène, MicroARN.

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"Give poor communities the opportunity, and then get out of the way" Philosophy of FINCA Research has shown that in the provision of financial services to the poor there are two highly distinct approaches. The one considered the 'formal institutional approach', which attempts to provide these services but are motivated by the need to maintain financial sustainability and therefore generally operate on a wide scale, with large clientele that would not be served by the formal banking sector. The second encompasses those providers who are purely motivated by the need for the social upliftment of poor communities. Their aim is to effect change in the living standards of the poor via financial assistance and the encouragement of economic empowerment and independence. The Foundation for International Community Assistance (FINCA), whose aims and objectives, whilst falling into the latter category of providers still needs to address the question of sustainability, as it is solely dependent on donor funding. Most donors usually demand clear and sustainable results. This places an onerous task on the managers and providers of credit for social development to design sustainable and practical models for disbursement and payback. The financial services industry is still grossly underdeveloped in its ability to cater to the socio-economic needs of people and communities around the world. While there have been enormous innovations in the for-profit financial services industry, there have been few breakthroughs in the ways social sector activities iv are funded . As a result social entrepreneurs are attempting to create alternate financial services and models of funding for social ventures. Dr. Younus, of The Grameen Bank, has given birth to dozens of new enterprises using what he calls 'social venture capital'. Many initiatives are under way to explore a better way of financing social ventures. However, the question still remains, Can and do these Programmes extend the Philosophy of Pro-Poor Upliftment yet Maintain Financial Sustainability? Against this backdrop, the Individual Loans Programme was designed and piloted by FINCA - Durban. The Individual Loans Programme claims to economically empower poor communities yet be financially sustainable for FINCA. Its pilot phase analysis reveals many merits in its approach and financial sustainability if evaluated solely against the criteria mandated by FINCA. Utilising the Consultative Group to Assist the Poorest (CGAP) guidelines in setting interest rates and assuming costing values, an appropriate interest rate falls between 41 % and 44% for the Individual Loans Programme. The fact that it charges an interest rate of 84% per annum more than meets the requirements of financial sustainability. However, if it aims to reach the truly poor, then not only are its charges exorbitant but its strategy contains many requirements contrary to pro poor practices and therefore revisions in its dispensation are needed as it fails in terms of a pro poor model of micro finance practice. / Thesis (MBA)-University of Natal, 2003.

A delay line phase shifter for the 30-70 GHz range is presented that uses an aluminum micro-ribbon array fabricated in the ground plane of a microstrip transmission line. Phase shift is achieved by changing the propagation velocity of an RF signal in the transmission line by controlling the effective permittivity of the substrate. This is done by actuating the micro-ribbons away from the substrate. This phase shifter has the benefits of analog phase shifts and high Figure of Merit. Simulations were done to model the micro-ribbon deflections, transmission line performance and phase shift. Arrays of 5, 10, and 20 μm wide micro-ribbons were fabricated and tested. At 40.80 GHz, the 20 μm wide micro-ribbons had a measured phase shift of 33º with an actuation voltage of 120 V. The corresponding Figure of Merit was a negative value indicating that there was no line loss due to ribbon deflection.

This study investigates women's economic empowerment in relation to micro'credit schemes in southern Nigeria. The study also evaluates the benefits and limitations of micro'credit as a resourceful means of enhancing women's economic activities in the labour market and eliminating poverty among market and rural women. Micro'credit schemes and institutions which provide soft loans to women have become a critical tool in development programmes aiming to empower them. The Nigerian government (both at Federal and State levels) has pursued this development trend since 1985 and today, it is estimated that an increasing number of Nigerian women participate in these schemes. Besides, it is widely accepted among development practitioners that micro'credit schemes not only contribute to poverty reduction but also empower the have'nots. My research design has drawn on gender analytical frameworks such as the 1980 Harvard Analytical Framework, Kabeer's 1998 Women's Empowerment Assessment, and Mayoux' 2001 micro'credit empowerment paradigm. This study employed as its methodology, ethnographic field research. This includes semi'structured interviews and participant observation. In addition, data was obtained from state databases, archives and development websites. Throughout, both qualitative and quantitative methods and analysis were used. This study found that women in southern Nigeria are extensively engaged in economic activities. It also established that micro'credit provides finance to enhance market and rural women's participation in production and trade. The study further ascertains that women have some control over their loans. However, increased economic activities may have also increased participants' financial responsibilities and household decision'making is still a prerogative of male head of the family. In addition, this study found that older married women in this region enjoy a comparatively high degree of personal mobility, but restrictions on travel in terms of distance and time are very common for younger married women. These restrictions are sanctioned by customs, household obligations, and social infrastructures. While problems with the transportation network have enhanced the middlemen's domination of economic activities in this region they increased women's dependence on their services. All this renders empowerment for women more difficult to achieve although it makes a practical contribution to their everyday lives.

Enterococcus species are found in faeces of mammals, birds, insects, reptiles, but also soil, plants and water. These bacteria can also be isolated from animal products such as milk, cheese and meat. This study was aimed at isolating Enterococcus species from communal and commercial cattle faecal and water samples. A further objective was to determine the antibiotic resistance profiles of the isolates as well as some of the potential factors and mechanisms that could be responsible for their resistance to antibiotics. A total of 79 cattle faecal and water samples were collected from the communal and commercial farms. Sixty-five faecal samples were collected from commercial (33 healthy and 16 diarrhoeal cattle) and communal (16 healthy cattle) farms. Twelve water samples were collected from the commercial farms and 2 from the communal farm. From all the samples collected, 129 Enterococcus isolates were identified. Isolates, which included Enterococcus faecium (E. faecium), Enterococcus avium (E. avium), Enterococcus durans (E. durans) and Streptococcus bovis I (Sc. bovis !), were isolated from bovine faeces and water samples, while E. avium was only isolated from water at the communal farm. Furthermore, isolates from the healthy and diarrhoeal commercial cattle included E. faecium, E. avium, E. durans and Sc. bovis I. E. faecium and E. avium species were also isolated from the commercial farm cattle water sources. However, E. faecium was the predominant species in communal cattle faecal and water samples. On the other hand, E. avium was dominant in. commercial cattle faecal and water samples. Multiple antibiotic resistance (MAR) was observed in enterococci from all samples at both farm types. The predominant MAR phenotype that was prevalent in all enterococci species was GENSMX- NAL-NIT-KAN-STR All isolates showed an MAR index above 0.2 (water; 0.58 to 0.68 and faeces; 0.6 to l. 7). Cluster analysis based on antibiotic inhibition zone diameter data, resulted in dendrograms that showed a similar relationship of Enterococcus isolates from the two farms. Between 13% and 50% of Enterococcus isolates from cattle faeces and water samples from communal and commercial farms were resistant to vancomycin and oxytetracycline. In general, 11% of all the Enterococcus isolates from the cattle faeces was resistant to vancomycin. Thirty one per cent of the isolates from cattle water sources were resistant to both drugs. Vancomycin Resistant Enterococcus (VRE) genes conveying the vanC phenotype were obtained from E. durans and E. avium. This was an unexpected result. The tet A, tet Band tet C genes were not obtained from any of the Enterococcus species. Further studies on antibiotic resistance should be undertaken especially in rural areas, where farmers could be using over-the-counter medicines such as tetracycline even when it is not necessary. It was speculated in this study that there could be a development of potential reservoirs of antibiotic resistance in farmlands. In order to prevent the distribution of MAR organisms or their transferable resistance genes, a sensible use of antibiotics is necessary in veterinary medicine, animal husbandry and human medicine. / MSc. (Agriculture) North-West University, Mafikeng Campus, 2006

A delay line phase shifter for the 30-70 GHz range is presented that uses an aluminum micro-ribbon array fabricated in the ground plane of a microstrip transmission line. Phase shift is achieved by changing the propagation velocity of an RF signal in the transmission line by controlling the effective permittivity of the substrate. This is done by actuating the micro-ribbons away from the substrate. This phase shifter has the benefits of analog phase shifts and high Figure of Merit. Simulations were done to model the micro-ribbon deflections, transmission line performance and phase shift. Arrays of 5, 10, and 20 μm wide micro-ribbons were fabricated and tested. At 40.80 GHz, the 20 μm wide micro-ribbons had a measured phase shift of 33º with an actuation voltage of 120 V. The corresponding Figure of Merit was a negative value indicating that there was no line loss due to ribbon deflection.

Magnetic micro-robots are small robots under 1mm in size, made of magnetic materials, with relatively simple structures and functionalities. Such micro-robots can be actuated and controlled remotely by externally applied magnetic fields, and hence have the potential to access small and enclosed spaces. Most of the existing magnetic micro-robots can operate in wet environments. When the robots are actuated by the applied magnetic field to move inside a viscous liquid, they invoke flow motions around them inside the liquid. The induced flows are relatively local as the velocity of these flows decays rapidly with the distance from a moving robot, and the flow patterns are highly correlated with the motions of the micro-robots which are controllable by the applied magnetic field. Therefore, it is possible to generate local flow patterns that cannot be easily done using other microfluidic techniques. In this work we propose to use rotational motion of the magnetic micro-robots for local manipulation of flows. We employ electromagnetic techniques to successfully deliver actuation and motion control onto the micro-robots. Rotational magnetic field is applied to induce rotational motion of micro-robots both when they stay near a surface and are suspended in the liquid. Rotational flows are locally generated in the vicinity of micro-robots inside the viscous liquid. Implementation of three major applications using the flows generated by the rotating micro-robots are demonstrated in this work: 1) Two-dimensional (2D) non-contact manipulation of micro-objects. 2) Three-dimensional (3D) propulsion for the micro-robot to swim in a liquid. 3) Size-based sorting of micro-particles in microfluidic channels under continuous flow. The first two applications occur in otherwise quiescent liquid, while the third requires the presence of non-zero background flow. For the first application, we propose two methods to achieve precise positioning of the microrobots on a surface: 1) Using visual-feedback-control to adjust the rotation for one single microrobot. Micro-robot can be precisely positioned at any location on a surface using this method. 2) Using a specially prepared surface with magnetic micro-docks embedded in it, which act as local magnetic traps for multiple micro-robots to hold their positions and operate in parallel. Physical models are established for both the micro-robot and the micro-objects present in the induced rotational flow. The rotational flows induced by rotating micro-robots are studied with numerical simulations. Experimental demonstrations are first given at sub-millimeter scale to verify the proposed method. Micro-manipulation of polymer beads is performed with both positioncontrol methods. Automated micro-manipulation is also achieved using visual-feedback. Micromanipulation at micron-scale is then performed to demonstrate the scalability and versatility of the proposed method. Non-contact manipulation is achieved for various micro-objects, including biological samples, using a single spherical micro-robot. Inspired by flagellated microorganisms in nature, we explore the hydrodynamics of an elastic rod-like structure - the artificial flagellum, and verify by both simulation and experiments that rotation and deformation of such structure can result in a propulsive force on a micro-robot it is attached to. Optimization of flagellum geometry is achieved for a single flagellum. A swimming micro-robot design with multiple flexible flagella is proposed and fabricated via an inexpensive micro-fabrication process involving photolithography, micro-molding and manual assembly. Experiments are perform to characterize the propulsive force generation and the resulting swimming performance of the fabricated micro-robots. It is demonstrated that the swimming speed can be improved by increasing the number of attached flagella. For the size-based sorting application, we integrate the micro-robots into microfluidic channels by using the substrate embedded with magnetic micro-docks, which are capable of holding the robots under continuous flow inside the channels while the robots spin. Numerical analysis is carried out of the flows inside the microfluidic channel in the presence of rotating micro-robots, and a physical model is established and discussed for size-based lateral migration of spherical micro-objects inside the induced rotational flows. Experimental demonstrations are performed for using the induced rotational flows to divert the trajectories of micro-particles based on their sizes under continuous flow. In addition, we propose the method of using the two photon polymerization (TPP) technique to fabricate magnetic micro-robots with complex shapes. The method could also achieve fabrication of arrays of micro-robots for more sophisticated applications. However, experimental results prove that the TPP is insufficient to achieve magnetic micro-robots that meet our needs for size-based sorting application due to physical limitations of the materials. Despite that, it is potentially powerful and suitable for fabrication of micro-robots with complex structures at small scales.

The study makes use of theories of emotions to describe and analyze interviewsconducted with eight students who had recently taken part in, or were at the moment,taking part in a doctoral education at the Faculties of Humanities or Social Science atStockholm University. This study is thus a qualitative study focusing on the followingresearch questions: Firstly, how does the Ph.D education influence the studentemotionally. Secondly: do the participants in the doctoral education experienceemotionally intense situations related to contexts interpretable in terms of rites ofpassage. Thirdly: can the student, looking back, rate how the education met theexpectations the student had beforehand.Results regarding the first research question point to that the education as such – astime goes – becomes a part of the student.Results regarding the second research question indicate that doctoral educationmostly, with exceptions, is looked upon as a steady trot towards the dissertation, duringwhich you are made as a researcher.Results regarding the third research question indicate that many of the students hadvery vague ideas of what the the education would be like and thus; they had no clearpicture to measure their education against.