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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

JOURNALISM AT GROUND ZERO: IMPERIAL WARS AND PRECARIOUS LABOR IN FRONTLINE NEWS PRODUCTION IN PAKISTAN

ASHRAF, SYED IRFAN 01 May 2019 (has links)
This study examines the severe conditions under which local media workers produce reports for global media outlets in conditions of war and the ways in which they cope with and respond to these challenges. I take as my case study, the diminution of the Pashtun journalist into a “fixer” for global media in the U.S.-led, so-called War on Terror (WoT). Based on my experience as a journalist as well as interviews with local Pashtun journalists, I disclose a situation in which the local journalist is compelled to risk his very life to gather news; news, which further exposes him to threats to life from the two warring sides. Precarity, in this scenario, is a fact of life, which carried serious consequences, not just for the journalist and his community, but also for what is passed off as news in global media.
2

Investigating Structure and Function of Rhizosphere Associated Microbial Communities in Natural and Managed Plant Systems

Rodrigues, Richard Rosario 21 April 2016 (has links)
Many plants, especially grasses, have Nitrogen (N) as their growth-limiting nutrient. Large amounts of N fertilizer (>100 kg N ha-1) are used in managed systems to maximize crop productivity. However, the plant captures less than 50% of the (~12 million tons per year, U.S.) applied N-fertilizer. The remaining mobile N lost through leaching and denitrification accumulates in waterways and the atmosphere, respectively. Losses of fertilizers create environmental and economic concerns globally and create conditions that support the invasion of exotic plants in the natural landscapes. There is thus a need to come up with biological solutions to better manage nitrogen for plant growth and ecosystem sustainability. Microbial communities in the rhizosphere are known to potentially have beneficial effects on plant growth. Diazotrophs, for example, are bacteria that can convert the atmospheric nitrogen to ammonia, a process called 'nitrogen fixation.' Utilizing the natural process of associative nitrogen fixation to support most of the plant's N needs would substantially reduce fertilizer use and thus reduce production and environmental costs. The goal of this dissertation was to determine the structure and function of root-zone microbial communities for increasing productivity of native plants. Towards this end, we study the root-zone bacterial and fungal communities of native and exotic invasive plants. This study identifies that shifts in rhizosphere microbial communities are associated with invasion and highlights the importance of rhizosphere associated structure and function of microbes. A study of root-zone associated microbes in switchgrass (Panicum virgatum L.) - a U.S. native, warm-season, perennial, bioenergy crop indicates that high biomass yield and taller growth are associated with increased plant N-demand and supportive of bacteria with greater rates of N2-fixation in the rhizosphere. Another crucial outcome of the thesis is a better description of the core and cultivar-specific taxa that comprise the switchgrass root-zone associated microbiome. The work in this dissertation has brought us closer to designing N supply strategies by utilizing the natural microbial communities to balance the N-cycle in agroecosystems and support a sustainable environment. / Ph. D.
3

Jämförelse av alternativa fixeringslösningar för humana njurbiopsier

Matshar, Farah January 2015 (has links)
Inom klinisk patologi bedöms vävnadsprover under mikroskop, med syftet att fastställa diagnos. Utgångsmaterial är antingen ett helt organ eller en liten bit från det sjukligt förändrade organet. I det senare fallet kallas preparatet för biopsi och dessa tas med hjälp av biopsiverktyg och oftast under ultraljudledning. Njurbiopsier kan tas vid misstänkt transplantatavstötning, av medicinska skäl, vid inflammatoriska tillstånd (nefriter) samt nefrotiska tillstånd. En del av biopsimaterialet fixeras i 4 % formaldehyd för ljusmikroskopisk (LM) bedömning, medan resten transporteras i transportlösningar som Michels- eller Zeus lösning. Det materialet fryses ned direkt för kryostatsnittning, dessa transportlösningar syftar till att bevara vävnaden färsk för immunofluorescens (IF) analys. Problem kan uppstå när materialet som bedöms med LM inte innehåller ett acceptabelt antal glomeruli, där minst 12- 15 stycken krävs för att biopsin skall vara representativ. Om det är alltför få till antalet brukar man tina och formaldehydfixera IF materialet. Morfologin blir oftast dålig och inte lämplig för bedömning. Den enda som man kan göra är att ombiopsera patienten. Detta är kostsamt, obekvämt för patienten och inte helt riskfritt. Syftet med den här studien var att undersöka ifall man kan ersätta transportlösningarna med ett fixativ som skulle medföra bättre morfologi i de fall som IF materialet måste tinas upp och användas för LM, men samtidigt erbjuda samma kvalitet på IF-signalen. Tre fixeringsmedel jämfördes med rutinmetodens 4 % formaldehyd; dels kommersiellt tillgängliga som Histochoice och HOPE (Hepes-Glutamic acid buffer mediated Organic solvent Protection Effect) och ett fixativ som är baserat på zinkjoner. Resultatet visade att när det gäller LM-undersökning på paraffininbäddat material så gav HOPE och Histochoice acceptabel morfologi av glomeruli. Vid upptinande av materialet följt av formaldehyd/paraffin, sågs fortsatt god kvalitet i den glomerulära morfologin, medan den tubulära morfologin var klart undermålig. Zn-fixering ledde till bubblor i cytoplasman vilket inte är acceptabel morfologi. I IF-analys gav alla fixativ negativ signal utom Zn-fixering, vilken gav en positiv signal. Det innebär att ingen säker diagnos kan ställas vid användning av de undersökta fixeringsmedlen som kan ersätta transportlösningar eller rutinlaboratoriet formaldehyd. Zn-fixativ såg lovande ut om det bortses från bubblorna, men detta behöver undersökas ytterligare i framtida studier / lt is important for clinical pathology to assess tissue samples (preparations) under the microscope to make a diagnosis. Starting materials is either a whole organ, or a small piece of the diseased body. The material can also be in the form of so-called biopsies, which are taken by biopsytools and ultrasound. Kidney biopsy may be taken for suspected transplant rejection, medical reasons and at nephritic (inflammation), and nephrotic states. Half of the material from kidney biopsies are transported in transport solutions of the type Michel / Zeus that serves the purpose of preserving the tissue fresh for immunofluorescence (IF) analysis. The other half is fixed in 4% formaldehyde for light microscope (LM) assessment, a procedure that precludes IF staining due to destruction of the antigenicity of the tissues. Problems might occur when the material is assessed by LM and do not contain an acceptable number of glomeruli, at least 12-15 are regarded as acceptable for diagnosis. If these are fewer in numbers, the material previously used for IF may be thawed and formaldehyde fixed. The morphology is however often adversely affected by this procedure, rendering the tissue unsuitable for morphological assessment. Therefore the only remaining option is to re-biopsy patients. This is costly, inconvenient for the parients, and not completely safe. This study was performed in order to explore if transport solutions can be replaced by a fixative that would result in a better morphology after thawing of the tissues, but with retained IF -quality. Three fixing agents were compared with routine method 4% formaldehyde; the commercially available Histochoice and HOPE fixatives (Hepes-Glutamic acid buffer mediated Organic solvent Protection Effect) and a fixative that was based on zinc ions. The results showed that in terms of LM, the fixatives HOPE and Histochoice gave acceptable morphology of the glomeruli, while the tubules were poor. It also showed that there were a lot of bubbles in the cytoplasm at the Zn-fixing. As for IF-analysis, all were negative except Zn that gave a positive signal. This means that no secure diagnosis can replace the routine transport formaldehyde. Zn fixative looked promising, except the bubbles, but needs to be further investigated in future studies.
4

Degradação de compostos tóxicos e de fatores antinutricionais da torta de pinhão manso por Pleurotus ostreatus / Degradation of toxic and antinutritional compounds present in the Jatropha cake by Pleurotus ostreatus

Luz, José Maria Rodrigues da 24 July 2009 (has links)
Made available in DSpace on 2015-03-26T13:51:59Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1426624 bytes, checksum: 8ec26861eeae9b5c7bd7e331f352548c (MD5) Previous issue date: 2009-07-24 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The oil extraction from Jatropha curcas seeds as raw material to biodiesel production releases a large quantity of solid residue, called cake.This Jatropha cake is formed by lignocellulolytic residues, water, minerals salts, but also contains toxic compounds and antinutritional factors. The correct destination of this residue is of great interesting to biofuel industries. The use of these residues as a substrate to grow the white rot fungi, Pleurotus ostreatus, may be a low cost alternative to produce the economic and industrial interesting products such as enzymes, proteins and edible mushrooms. Moreover, this fungus produces enzyme capable of degrade different toxic compounds and antinutritional factors. ln this study Jatropha cake, pure or in mixture with agro-industrial residues, was used as substrate to grow P. ostreatus objecting to produce mushrooms, eliminate phorbol ester, antinutritional factors and also, to evaluate the reduce lignin, cellulose and hemicellulose. After 45 days of P. ostreatus mycelia inoculation in the substrate, it was observed high production of fungus biomass, and degradation of 50 % of lignin and 20 % of cellulose and hemicellulose. The substrates which present higher fungus biomass production and lignocellulolitic degradation were used to assess the ability of P. ostreatus to produce mushroom and to degrade phorbol ester, phytic acid and tannins. After 60 d of incubation, it was observed good production of mushroom, reduction of lignocellulolytic compounds and loss of dry mass, reduction of phytic acid in 95 % and 85 % of tannins (equivalent a tannin acid) and 99 % of phorbol ester. These mushrooms and the substrates after 60 d of colonization by P. ostreatus had concentrations of phorbol esters smaller than that found in provenances of non toxic J. curcas from México. Therefore, P. ostreatus has the ability of degrade toxic compounds, antinutritional factors and lignooellulosio compounds present in Jatropha cake. The alternative of using Jatropha cake as substrate to mushroom and enzymes production, add value to this residues, as well as detoxifying it show high potential to use Jatropha cake as animal food, beyond deoreasing the environmental damage. / A produção de biodiesel utilizando o óleo da semente de pinhão manso (Jatropha curcas) como matéria-prima libera grande quantidade de resíduos sólidos, denominado de torta.Essa torta apresenta composição diversificada, contendo não só compostos ligninocelulósicos, água e sais minerais, mas também compostos tóxicos e fatores antinutricionais. A destoxificação e o reaproveitamento dessa torta de pinhão manso são de grande interesse da indústria do biocombustível. A utilização desses resíduos como substrato para cultivo de fungos de podridão branca, Pleurotus ostreatus, pode ser uma alternativa de baixo custo e que permite a produção de produtos de interesse econômico e industrial como enzimas, proteínas e cogumelos comestíveis. Além disso, esse fungo produz enzimas capazes de degradar diferentes substâncias tóxicas, fatores antinutricionais e compostos ligninocelulósicos. Neste trabalho, a torta de pinhão manso pura, ou em mistura com outros resíduos agroindustriais, foi utilizada como substrato para crescimento micelial de P. ostreatus visando à eliminação de compostos tóxicos, fatores antinutricionais e a redução do teor de lignina, celulose e hemicelulose. Inicialmente, para verificar a viabilidade micelilal e a degradação compostos ligninocelulósicos presente na torta de pinhão manso. P. ostreatus PLO 6 foi inoculado em substratos à base da torta de pinhão manso, adicionado ou não de resíduos agroindustriais. Após 45 dias de incubação, verificou-se elevada produção de biomassa fúngica, 50 % de degradação de lignina e 20 % de consumo de celulose e hemicelulose. Os substratos que apresentaram maior produção de biomassa fúngica e também a maior degradação de compostos ligninocelulósicos foram utilizados para avaliar a capacidade de P. ostreatus formar cogumelos, além de degradar éster de forboI, ácido fítico e taninos. Após 60 dias de incubação, observou-se boa produção de cogumelos e degradação de compostos Iigninocelulósicos, com significativa perda da massa seca, redução de 95 % de ácido fítico, 85 % de taninos (equivalente a ácido tânico), 99 % de éster de forboI e aIta produtividade de cogumelos. Após o período de incubação, tantos os cogumelos de P. ostreatus como os substratos utilizados apresentaram concentrações de éster de forboI menor que o encontrado em variedade de J. curcas não tóxicas do México. Conclui-se que P. ostreatus tem capacidade de degradar composto tóxico, fatores antinutricionais e compostos Iigninocelulósicos presentes na torta de pinhão manso. O uso alternativo de torta de pinhão manso como substrato para cultivo de cogumelos e enzimas, destoxificando-o, agrega vaIor a esse resíduo, e apresenta um aIto potencial do uso dessa torta como alimento, além de diminuir os danos ambientais causados peIo descarte direto.

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