49 research outputs found

    a case study of the southern border region of Kenya and the northern border region of Tanzania

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    Thesis(Master) --KDI School:Master of Development Policy,2020Despite the contentions about the effectiveness of decentralization as a form of governance and administration, there has been a rise in the number of countries attempting different forms of decentralization around the world in recent decades. By investigating what impact political decentralization had on service delivery in Kenya this paper seeks to contribute in gaining more understanding of decentralization and circumstances in which it is most effective. The study takes advantage of the border region between Tanzania and Kenya to perfume a natural experiment following the implementation of the county government framework of governance in 2013 through political decentralization in Kenya using difference-in-difference to examine if and what impact political decentralization had on service delivery.Chapter 1: Introduction Chapter 2: Literature Review Chapter 3: Methodology Chapter 4: Results Chapter 5: Discussion and ConclusionmasterpublishedJane Mango ANGAR

    Deswelling of Hydrogels in Aqueous and Polyethylene Glycol Solutions. A New Approach for Drug Delivery Application

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    To enhance the properties of pure poly(acrylamide) hydrogel, diprotic maleic acid co-monomer was included into the reaction mixture during hydrogel synthesis. These hydrogels have been shown important swelling in distilled water and deswelling in acidic solution. In present work, we based on these considerations to study the deswelling behaviour of poly(acrylamide-co-maleic acid) hydrogels in different media (air, polyethylene glycol 200 (PEG200), acidic solution). Hydrogels of poly(acrylamide) and its copolymers with maleic acid were prepared by copolymerization and chemical crosslinking with methylene bisacrylamide. The obtained hydrogels have shown substantial mass swelling in distilled water and shrinking in acidic solution and PEG200. Results showed that the PEG200 was a better solvent for hydrogel deswelling and possibly will be used for gel drying. The swelling and deswelling kinetics were described by second-ordered and first-ordered models, respectively. BSA desorption in PEG200 was also studied

    Meeting the semantic chameleon “peace” with openness and restraint : from Afghanistan to reflections on "peace" in international legal (political) practice

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    Award date: 6 December 2022; Supervisor : Professor Sarah Nouwen, (European University Institute)It is an unspoken assumption that international law and its institutional practice contribute to peace. However, the questions of „what“, regarding the meaning of peace, and the question of „who“, regarding the actors shaping the meaning, have been seldom discussed, despite significant developments in international relations literature. This thesis aims to address these questions by analyzing debates on peace in Afghanistan and examining peace in international relations theory. Presenting eight conceptions of "peace in Afghanistan", the study argues that peace possesses a diverse range of seemingly infinite meanings. Moreover, it contends that the meaning of peace is socially constructed by the respective parties to the conflict, rendering it a relational and thus relative phenomenon. Building upon these findings, the paper reflects on the implications for international legal (political) practice. Firstly, it is argued that an awareness of the plurality of meanings of peace can aid international lawyers in opening limited preconceptions of peace in the service of proper interpretation and identification of (customary) international law. Secondly, it is argued that respecting the meaning-making authority of parties to the conflict should encourage a practice of institutional restraint in shaping the discourse on the meaning of peace. This is because prioritizing an understanding of the conflicting parties' perspectives on their peace fosters better cooperation between institutions and the conflicting parties

    Reciprocal Inhibition of Adiponectin and Innate Lung Immune Responses to Chitin and Aspergillus fumigatus

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    Chitin is a structural biopolymer found in numerous organisms, including pathogenic fungi, and recognized as an immune-stimulating pathogen associated molecular pattern by pattern recognition molecules of the host immune system. However, programming and regulation of lung innate immunity to chitin inhalation in the context of inhalation of fungal pathogens such as Aspergillus fumigatus is complex and our understanding incomplete. Here we report that the systemic metabolism-regulating cytokine adiponectin is decreased in the lungs and serum of mice after chitin inhalation, with a concomitant decrease in surface expression of the adiponectin receptor AdipoR1 on lung leukocytes. Constitutive lung expression of acidic mammalian chitinase resulted in decreased inflammatory cytokine gene expression and neutrophil recruitment, but did not significantly affect lung adiponectin transcription. Exogenous recombinant adiponectin specifically dampened airway chitin-mediated eosinophil recruitment, while adiponectin deficiency resulted in increased airway eosinophils. The presence of adiponectin also resulted in decreased CCL11-mediated migration of bone marrow-derived eosinophils. In contrast to purified chitin, aspiration of viable conidia from the high chitin-expressing A. fumigatus isolate Af5517 resulted in increased neutrophil recruitment and inflammatory cytokine gene expression in adiponectin-deficient mice, while no significant changes were observed in response to the isolate Af293. Our results identify a novel role for the adiponectin pathway in inhibition of lung inflammatory responses to chitin and A. fumigatus inhalation

    Lung eosinophil recruitment in response to Aspergillus fumigatus is correlated with fungal cell wall composition and requires γδ T cells

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    The differential recognition of fungal cell wall polysaccharides that program innate and adaptive immunity to the human opportunistic fungal pathogen Aspergillus fumigatus has been a focus of considerable interest. In a mouse model of fungal conidia aspiration, decreased relative levels of cell wall core carbohydrates β-1,3-glucan to chitin in A. fumigatus isolates and mutant strains were correlated with increased airway eosinophil recruitment. In addition, an increase in fungal surface chitin exposure induced by the β-1,3-glucan synthesis-targeting drug caspofungin was associated with increased murine airway eosinophil recruitment after a single challenge of conidia. The response to increased A. fumigatus chitin was associated with increased transcription of IL-17A after a single aspiration, although this cytokine was not required for eosinophil recruitment. Rather, both RAG1 and γδ T cells were required, suggesting that this subset of innate-like lymphocytes may be an important regulator of potentially detrimental type 2 immune responses to fungal inhalation and infection

    Histological Quantification to Determine Lung Fungal Burden in Experimental Aspergillosis

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    The quantification of lung fungal burden is critical for the determination of the relative levels of immune protection and fungal virulence in mouse models of pulmonary fungal infection. Although multiple methods are used to assess fungal burden, quantitative polymerase chain reaction (qPCR) of fungal DNA has emerged as a technique with several advantages over previous culture-based methods. Currently, a comprehensive assessment of lung pathology, leukocyte recruitment, fungal burden, and gene expression in mice with invasive aspergillosis (IA) necessitates the use of a significant number of experimental and control animals. Here the quantification of lung histological staining to determine fungal burden using a reduced number of animals was examined in detail. Lung sections were stained to identify fungal structures with Gomori's modified methanamine silver (GMS) staining. Images were taken from the GMS-stained sections from 4 discrete fields of each formalin-fixed paraffin-embedded lung. The GMS stained areas within each image were quantified using an image analysis program, and from this quantification, the mean percentage of stained area was determined for each sample. Using this strategy, eosinophil-deficient mice exhibited decreased fungal burden and disease with caspofungin therapy, while wild-type mice with IA did not improve with caspofungin. Similarly, fungal burden in mice lacking γδ T cells were also improved by caspofungin, as measured by qPCR and GMS quantification. GMS quantification is therefore introduced as a method for the determination of relative lung fungal burden that may ultimately reduce the quantity of experimental animals required for comprehensive studies of invasive aspergillosi

    Evaluating biochar and its modifications for the removal of ammonium, nitrate, and phosphate in water

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    Removal of nitrogen (N) and phosphorus (P) from water through the use of various sorbents is often considered an economically viable way for supplementing conventional methods. Biochar has been widely studied for its potential adsorption capabilities for soluble N and P, but the performance of different types of biochars can vary widely. In this review, we summarized the adsorption capacities of biochars in removing N (NH4-N and NO3-N) and P (PO4-P) based on the reported data, and discussed the possible mechanisms and influencing factors. In general, the NH4-N adsorption capacity of unmodified biochars is relatively low, at levels of less than 20 mg/g. This adsorption is mainly via ion exchange and/or interactions with oxygen-containing functional groups on biochar surfaces. The affinity is even lower for NO3-N, because of electrostatic repulsion by negatively charged biochar surfaces. Precipitation of PO4-P by metals/metal oxides in biochar is the primary mechanism for PO4-P removal. Biochars modified by metals have a significantly higher capacity to remove NH4-N, NO3-N, and PO4-P than unmodified biochar, due to the change in surface charge and the increase in metal oxides on the biochar surface. Ambient conditions in the aqueous phase, including temperature, pH, and co-existing ions, can significantly alter the adsorption of N and P by biochars, indicating the importance of optimal processing parameters for N and P removal. However, the release of endogenous N and P from biochar to water can impede its performance, and the presence of competing ions in water poses practical challenges for the use of biochar for nutrient removal. This review demonstrates that progress is needed to improve the performance of biochars and overcome challenges before the widespread field application of biochar for N and P removal is realized

    Oxydation de l'azote ammoniacal par voie chimique, électrochimique et biologique : application au traitement des eaux usées

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    148 p. : ill. ; 30 cmLes activités agricoles entraînent une émission excessive de l'azote ammoniacal dans l'environnement et peuvent profondément perturber l'équilibre des écosystèmes naturels conduisant à leur contamination à cause de l'extrême toxicité pour les espèces aquatiques, l'environnement et la santé humaine. Le traitement de cette pollution a été étudié par application de diverses techniques d'épuration. Dans ce contexte nous avons étudié trois méthodes performantes, rapides et ayant un cout économique faible. Dans la première partie, nous avons étudié l'adsorption de l'ammonium sur la bentonite modifiée par la soude encapsulée dans des billes d'alginate de calcium réticulées à l'aide d'un incubateur rotatif maintenu à une vitesse d'agitation et une température constantes. L'étude de l'effet des paramètres expérimentaux sur le processus d'adsorption a révélé que l'adsorbant a pu adsorber environ 97,91% de la concentration initiale de l'ammonium de 100 mg-NH4+/L à pH 7 et une température de 30 ° C. En outre, la modélisation des données expérimentales nous a permis de conclure que l'adsorption obéit à l'isotherme de Langmuir et Freundlich, la cinétique de la réaction est de 2nd ordre. La détermination des différents paramètres thermodynamiques indique que la réaction est spontanée et exothermique. Dans la deuxième partie de notre travail, nous avons étudié l'oxydation électrochimique directe de l'azote ammoniacal en solution aqueuse, en appliquant diverses techniques électrochimiques; voltamétrie cyclique (CV), voltamétrie de balayage linéaire (LSV) et chrono ampérométrie (CA). Les résultats suggèrent que l'électro-oxydation est importante en utilisant une anode de Pt par rapport à celle réalisée sur les autres électrodes testées. Les ions chlorures et le pH du milieu ont affecté le processus. L'électro-oxydation de l'ammonium dans un milieu acide et alcalin a montré une certaine efficacité et donne des rendements d'élimination appréciables respectivement de 73,77% et 86,45%, qui sont plus importants par rapport au rendement de l'électro-oxydation en milieu neutre qui a été de 55,59%. Cependant, des réactions indésirables liées à la valeur de pH peuvent avoir lieu conduisant à la contamination de la solution par formation et accumulation des nitrites qui sont des substances plus toxique que l'ammonium. En outre, la concentration initiale de l'ammonium et la valeur de potentiel appliqué ont affecté l'intensité du pic caractéristique de l'oxydation. Dans la dernière partie, nous avons étudié l'épuration biologique de l'ammonium. Pour cela, deux nouvelles souches du genre d 'Alcaligenes sp. S84S3 et de Proteus sp. S19 ont été isolées à partir de boues activées et appliquées dans le traitement de l'ammonium et du nitrite en solution aqueuse. Sous les conditions optimales de température (30°C), pH (7), substrat de carbone (2 g / l de glucose) et de la durée d'incubation (69 heures), la souche Alcaligenes sp. S84S3 a pu oxyder 65% de l'ammonium. En outre, après 48 heures d'incubation de la souche Proteus sp S19, le taux de réduction des nitrates était d'environ 99% sans production de l'intermédiaire du nitrite (en concentration négligeable). Sous les mêmes conditions opératoires, en fournissant l'aération dans la première phase de traitement, la co-culture des deux souches d'Alcaligenes sp S84S3 et de Proteus sp. S19 a pu éliminer 65,83% des ions d'ammonium pendant une courte période d'incubation (118 h), sans production d'aucune forme toxique d'azote. La coculture de nos isolats est supposé avoir un bon potentiel pour les réactions de nitrification et de dénitrification appliquées dans le traitement des eaux usées contenant de grandes concentrations des ions ammoniums, nitrites et nitrate

    الاقتضاء والحساب المنطقي للدلالة عند فريجه

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    Comment pourrons dire d’une proposition vraie ou fausse ? Lorsqu’elle est cohérentedans sa structure et ses parties, ou bien, quand elle exprime une chose que ça soit réelletangible ou représentation? Est-ce que la certitude d’une proposition est liée à uneréférence réelle? Ou bien la certitude d’une proposition nécessite d’autres conditionscomme le cas chez Frege
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