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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.
71

Sélection des rhizobactéries phytostimulatrices par la plante : impact sur la distribution des propriétés phytobénéfiques chez les Pseudomonas fluorescents / Plant-beneficial rhizobacteria selection by plant : impact on plant-beneficial property distribution in fluorescent Pseudomonas

Vacheron, Jordan 10 December 2015 (has links)
Les plantes interagissent en permanence avec une grande diversité de microorganismes qu'elles sélectionnent entre autre au niveau de leurs racines. Certaines bactéries, qualifiées de PGPR (Plant Growth-Promoting Rhizobacteria), sont capables de stimuler la croissance et la santé de la plante, grâce à l'expression d'une large panoplie de propriétés phytobénéfiques. L'hypothèse actuelle serait que les PGPR possédant un nombre maximal de ces fonctions auraient un plus fort impact bénéfique sur le végétal. Toutefois, l'occurrence de ces PGPR multifonctions dans la rhizosphère n'est pas connue. De plus, les possibles interactions entre propriétés co-occurrentes au sein d'une même PGPR et la résultante de ces interactions sur la plante sont relativement peu documentées. Dans ce contexte, ce projet de thèse a eu comme objectif général de mieux comprendre la distribution des propriétés phytobénéfiques chez un groupe bactérien possédant un large éventail de ses propriétés, celui des Pseudomonas fluorescents et d'évaluer chez une PGPR modèle multifonction, Pseudomonas fluorescens F113, si des interactions fonctionnelles existent entre ces propriétés et déterminer leurs contributions respectives à l'effet phytostimulateur. L'étude d'environ 700 isolats de Pseudomonas provenant de la rhizosphère de deux cultivars de maïs et de sol nonrhizosphérique, a mis en évidence que ces cultivars sélectionnent majoritairement des Pseudomonas fluorescents (i) arborant un nombre réduit de propriétés phytobénéfiques (1 à 5 propriétés) et (ii) appartenant à des sous-groupes taxonomiques particuliers. Par ailleurs, l'étude de génomique comparative que nous avons menée au sein du groupe des Pseudomonas fluorescents souligne le lien entre phylogénie et les profils de propriétés phytobénéfiques possédées par les Pseudomonas. Enfin, chez P. fluorescens F113, les propriétés co-occurrentes ne contribuent pas de façon égale à l'effet observé sur la plante. L existence d'interactions entre ces propriétés co-occurrentes a également été mise en évidence. De ce réseau d'interactions, résultera un effet bénéfique observé sur la plante particulier. Ces résultats sont importants pour mieux comprendre la place et le rôle de ces PGPR multifonctions dans la rhizosphère. Ils permettent d'approfondir nos connaissances à propos du fonctionnement écologique des Pseudomonas fluorescents au sein du rhizomicrobiote / Plants are constantly interacting with a huge diversity of microorganisms, especially in the rhizosphere, where plant roots (through rhizodeposition) will select particular bacterial populations. Some bacteria, called PGPR (Plant Growth-Promoting Rhizobacteria), are able, in turn, to improve plant growth and health, through the expression of a wide range of plantbeneficial properties. The current hypothesis is that PGPR harboring a maximum number of these plant-beneficial properties would provide a better effect on plant. However, the occurrence of these multi-trait PGPR in the rhizosphere is unknown. In addition, the interaction between co-occurring plant-beneficial properties within the same PGPR and their resulting effects on plant are poorly documented. In this context, the aims of this thesis were to (i) determine the distribution of plant-beneficial properties in the fluorescent Pseudomonas bacterial group, known to harbor a wide range of these properties, and (ii) to evaluate in the PGPR model strain Pseudomonas fluorescens F113, if a crosstalk between plant-beneficial properties occurs and to determine the relative contribution of each co-occurring plantbeneficial properties. The study of 700 Pseudomonas isolates from the rhizosphere of two maize cultivars and from non-rhizosphere soils shows that cultivars mostly select fluorescent Pseudomonas (i) displaying few plant-beneficial properties (up to 5 properties) and (ii) belonging to particular taxonomic subgroups. Furthermore, the comparative genomic study we conducted within the fluorescent Pseudomonas group emphasizes the link between phylogeny and plant-beneficial profiles owned by Pseudomonas. Finally, in P. fluorescens F113, co-occurring plant-beneficial properties do not contribute equally to the observed effects on plant. The existence of crosstalks between these co-occurring plant-beneficial properties was also highlighted. This network of functional interactions may lead to specific effects on plant. These results are important for understanding the place and role of multi-trait PGPR in the rhizosphere. They help to deepen our understanding of the ecological functioning of fluorescent Pseudomonas among the rhizomicrobiote
72

Involvement of Beneficial Microbe-derived Cyclodipeptides (CDPs) in Promoting Plant Tolerance to Abiotic Stresses

abdulhakim, fatimah 07 1900 (has links)
Cyclodipeptides (CDPs) are the smallest, most stable cyclic peptides that are synthesized as secondary metabolites by bacteria. The aim of this study was to investigate the effect of the Pseudomonas argentinensis (SA190) and four (CDPs), named as cis-cyclo-(Pro-Phe) (Cyclo2), cis-cyclo-(Pro-Leu) (Cyclo3), cis-cyclo-(Pro-Tyr) (Cyclo4) and cis-cyclo-(Pro-Val) (Cyclo5), with three concentrations (1µM, 100nM, and 10nM), on the growth of Arabidopsis thaliana under normal plant growth conditions [1/2MS media], salt conditions [125 mM NaCl] and drought conditions [25% PEG]. Moreover, we determined the most effective CDPs with optimal concentration. It was found that cis-cyclo-(Pro-Tyr) (Cyclo4) at a concentration of 100nM had an effect on the plant growth and can mimic the effect of SA190 under normal [1/2MS media] conditions. Also, cis-cyclo-(Pro-Tyr) (Cyclo4) at a concentration of 1µM can mimic the effect of SA190 under salt conditions [125mM NaCl]. Finally, cis-cyclo-(Pro-Val) (Cyclo5) at a concentration of 1µM can mimic the effect of SA190 under drought conditions [25% PEG].
73

Konsten att hantera samhällsnyttiga- och affärsmässiga principer : En studie om hur det kommunala bostadsaktiebolaget hanterar konkurrerande krav.

Blomster, Emma, Karlsson, Elvira January 2021 (has links)
The municipal housing company is a form of hybrid organization whose operations meet demands and expectations. These requirements can be perceived as competitive as the company is expected to act commercially but also fulfill a socially beneficial purpose. A municipal housing company operates in institutional environments where it influences and is influenced by its surroundings. Previous research has identified the concept of hybrid organization and the emergence of institutional logic. With this study, we have investigated how competing requirements from business and socially beneficial principles are handled internally within a municipal housing company. The purpose of this study is to describe and explain how competing requirements from socially beneficial and business principles are handled in municipal housing companies. Our study is conducted based on the theory of institutional logic. We have studied which strategies the municipal housing company uses in its operational management when they meet competing requirements. To fulfill our purpose and answer the question, we interviewed six employees with different positions within Halmstad Fastighet AB. The empirical material has been compared with our theoretical framework and then we have a discussion about how the company handles the competing requirements. The results of our study show that the organization defies institutional logic and acts more rationally than expected when dealing with the requirements of business and socially beneficial principles in its operations. Our conclusion is that we can see elements of all three strategies in the business: the decoupling, compromise and combination strategy. We note that a balance between business and socially beneficial principles is not possible as there is a dominant requirement. In order for a municipal housing company to succeed in handling competing requirements, the company needs to change shape. We also see a purpose in maintaining the ambiguity surrounding the prioritization of business and socially beneficial principles. / Det kommunala bostadsaktiebolaget är en form av hybridorganisation vars verksamhet ställs inför krav och förväntningar. Dessa krav kan upplevas som konkurrerande då bolaget förväntas agera affärsmässigt men även uppfylla ett samhällsnyttigt syfte. Ett kommunalt bostadsaktiebolag verkar i institutionella miljöer där den påverkar samt påverkas av sin omgivning. Tidigare forskning har identifierat begreppet hybridorganisation och uppkomsten av institutionell logik. Vi har med denna studie undersökt hur konkurrerande krav från affärsmässiga- och samhällsnyttiga principer hanteras intern inom ett kommunalt bostadsaktiebolag. Syftet med denna studie är att beskriva och förklara hur konkurrerande krav från samhällsnyttiga- och affärsmässiga principer hanteras i kommunala bostadsaktiebolag. Vår studie genomförs med grund i teorin om institutionell logik. Vi har studerat vilka strategier det kommunala bostadsaktiebolaget använder sig av i sin verksamhetsstyrning då de möter konkurrerande krav. För att uppfylla vårt syfte och besvara vår frågeställning har vi intervjuat sex medarbetare med olika positioner inom Halmstad fastighets AB. Det empiriska materiale thar jämförts med vårt teoretiska ramverk och därefter för vi en diskussion om hur verksamheten hanterar de konkurrerande krav. Resultatet av vår studie visar att organisationen inte går i linje med institutionell logik och handlar mer rationellt än förväntat vid hantering av kraven från affärsmässiga- och samhällsnyttiga principer i verksamheten. Vår slutsats är att vi i verksamheten kan se inslag av samtliga tre strategier; frikoppling-, kompromiss- och kombinationsstrategin. Vi konstaterar att en balans mellan affärsmässiga- och samhällsnyttiga principer inte är möjlig då det finns ett dominerande krav. För att ett kommunalt bostadsaktiebolag ska lyckas hantera konkurrerande krav behöver bolaget skifta i skepnad. Vi ser även ett syfte med att ha en otydlighet kring prioriteringen av affärsmässiga- och samhällsnyttiga principer.
74

"Dirty Money Exploits Weakness to Enter" : A Narrative Literature Review on the Challenges of Combatting Money Laundering

Svensson, Matilda January 2021 (has links)
Money laundering is believed to have been around since the introduction of money. It is a vast, international problem which challenges law enforcement agencies and legislating authorities, as well as financial institutions and organizations of interest, all over the world. The past few years, something new has snuck up on law enforcement agencies and legislating authorities, namely Blockchain technology and cryptocurrency. This has caused a number of reactions, such as nations and international organizations quickly updating their anti-money laundering regulations. This goes to show how money laundering is constantly evolving, which makes targeting this crime a constant challenge. There is currently a lot of research being conducted on Money Laundering and specifically research on how to tackle the issue. What this study wishes to contribute with is an overview of the recently published (year 2020), available literature on the matter, to facilitate the continuous work on how to best prevent and detect this crime. The aim with this study is to look at already existing literature and to establish what the current focus is when combatting Money Laundering. It is based on three research questions; What are the three main focus’ areas? What are the challenges? How is anti-money laundering regulations tackling cryptocurrency? The method used is a narrative literature review and the search was conducted through Malmö University Electronic Library. Following explicit inclusion and exclusion criteria, the analysis was based on a total of 22 articles. The results show that the focus’ areas’ and challenges are; cryptocurrency and specifically the EU’s fifth anti-money laundering directive, challenges with international cooperation, and lastly, the role of financial institutions and identifying the beneficial owner.
75

The Roles of Natural and Semi-Natural Habitat in the Provisioning of Biodiversity and Ecosystem Services of Beneficial Insects in Agricultural Landscapes

Nelson, Jason M. 13 August 2012 (has links)
No description available.
76

Silicon and tanzania guinea grass tolerance to stress by copper toxicity / Silício e a tolerância do capim-tanzânia ao estresse pela toxidez por cobre

Vieira Filho, Leandro Otávio 02 August 2018 (has links)
Whist copper (Cu) is an essential element for plants, when this element is present in excess quantities it can cause irreversible damage. This metal induces excessive production of reactive oxygen species (ROS), which damages organelles causing dysfunction. A possible means for the promotion of metal tolerance in plants is the adition of the element silicon (Si). The current study was conducted with the aim of evaluating the role of Si (0, 1 and 3 mmol L-1) on the morphologic, nutritional, metabolic and physiological responses of Panicum maximum cv. Tanzania under different Cu rates (0.3, 250, 500 and 750 μmol L-1). The grass was grown in a greenhouse under hydroponic conditions for two growth periods (33 and 30 days). Thirteen days after sowing, the seedlings were transplanted to a nutrient solution and supplied just with the Cu rate of 0.3 μmol L-1 and the set Si rates for 25 days. The remaining Cu rates were only added for a seven day period during the first growth stage. The second harvest took place 31 days after the first harvest. The experiment had six randomized blocks: three for yield, morphology and nutritional analyses and three for metabolic and physiological analyses. Plant yield, morphology and metabolic parameters were quantified in shoots and roots. Chlorophyll content index (SPAD values) and gas exchange parameters were determined in diagnostic leaves (DL), and Cu and Si concentrations were analysed from the DL and roots. The calculation of Cu and Si contents took into account the whole plant biomass. Plants exposed to Cu rates above 0.3 μmol L-1 showed low values of plant yield, morphologic parameters and SPAD, in both growth periods. Silicon supplied plants showed lower Cu concentration and content, and higher values of plant yield, morphlogic parameters and SPAD than the ones with no Si application. Silicon concentration and content were higher in plants exposed to excess Cu compared to those exposed to the control rate (0.3 μmol L-1). Gas exchange parameters in plants of the first growth were positively affected by Si supply and negatively affected by Cu rates. In the second growth, an eustress event was observed, in which plants exposed to stressing rates of residual Cu showed the highest values of gas exchange parameters and the lowest values of stress indicators. The activities of antioxidant enzymes were reduced with the increment in Cu rates. Silicon supply resulted in an increment in superoxide dismutase (SOD) activity. Tanzania guinea grass supplied with Si was able to better deal with Cu toxicity, showing increases in plant yield, morphologic and gas exchange parameters. Silicon supplied plants reduced their absorption of Cu and consequently, plants exposed to high Cu rates were still able to produce considerable biomass in the regrowth. / O cobre (Cu) é um elemento essencial para as plantas, porém, quando em excesso, pode causar danos irreversíveis às plantas. Este metal induz a produção excessiva de espécies reativas de oxigênio (ERO), que danificam organelas causando a disfunção delas. Uma possível maneira de aumentar a tolerância de plantas aos metais é o fornecimento de silício (Si). Um experimento foi conduzido com o objetivo de avaliar o papel do Si (0, 1 e 3 mmol L-1) nas respostas morfológicas, nutricionais, metabólicas e fisiológicas do Panicum maximum cv. Tanzânia sob doses de Cu (0,3, 250, 500 e 750 μmol L-1). Esse capim foi cultivado hidroponicamente em casa de vegetação por dois períodos de crescimento (33 e 30 dias). Treze dias após a semeadura, plântulas foram transplantadas para solução nutritiva, fornecendo-se apenas as doses de Si por 25 dias. A exposição ao cobre foi realizada apenas no primeiro crescimento das plantas e durou sete dias. O segundo corte ocorreu 31 dias após o primeiro corte. O experimento consistia de seis blocos completos ao acaso: três para avaliações de produção, morfologia e análises nutricionais e três para análises metabólicas e fisiológicas. A produção, a morfologia e o metabolismo das plantas foram quantificados na parte aérea e nas raízes. O índice de conteúdo de clorofila (valores SPAD) e as análises fisiológicas foram determinados nas lâminas diagnósticas (LD), e as concentrações de Cu e Si nas LD e nas raízes. Para o cálculo dos acúmulos de Cu e Si levou-se em consideração toda a biomassa da planta. Plantas expostas a doses de Cu acima de 0,3 μmol L-1 apresentaram menores valores de produtividade, parâmetros morfológicos e de SPAD. Plantas supridas com Si apresentaram menor concentração e acúmulo de Cu, e maiores valores de produtividade, parâmetros morfológicos e SPAD do que aquelas que não receberam o fornecimento de Si. A concentração e o acúmulo de silício foram maiores nas plantas expostas ao excesso de Cu do que nas expostas à dose controle de Cu (0,3 μmol L-1). Os parâmetros de trocas gasosas das plantas no primeiro crescimento foram afetados positivamente pelo Si e negativamente pelo incremento nas doses de Cu. No segundo crescimento, observou-se evento de eustresse em que plantas expostas à dose de Cu residual apresentaram os valores mais altos de parâmetros de troca gasosa e os valores mais baixos de indicadores de estresse. As atividades de enzimas antioxidantes foram reduzidas com o incremento nas doses de Cu. O suprimento de silício resultou em incremento na atividade da superóxido dismutase (SOD). O capim tanzânia suplementado com Si foi capaz de suportar melhor a toxicidade do Cu, mostrando um aumento na produção de biomassa da planta, e em parâmetros morfológicos e de trocas gasosas. As plantas suplementadas com Si reduziram a absorção de Cu e, consequentemente, plantas expostas a altas taxas de Cu e suplementadas com Si ainda foram capazes de produzir uma biomassa apreciável na rebrota.
77

Agricultural practices and water quality in Saskatchewan : the social ecology of resource management

Kehrig, Randall Francis 10 April 2003
This thesis presents the results of exploratory sociological research designed to better understand how farmers select agricultural practices with the potential to effect water quality. The primary research methodology is a Rapid Rural Appraisal of thirty farms in five rural municipalities in Saskatchewan, Canada during the year 2000 growing season. The data establishes that a variety of economic, institutional, organizational, and social factors interact in dynamic ways to influence farmer resource management decisions and that the resulting agricultural practices have the potential for subtle and dramatic effects on water quality in Saskatchewan. Risk-mitigating farming methods known as Best Management Practices (BMPs) are interpreted by farmers in the field research as being both appropriate and problematic. Alternative initiatives and communication strategies are identified in the field data that offer support to production and productivity in the agriculture sector while also promoting water quality. The research suggests that measures such as providing accessible public water quality data, promoting water treatment for individual households, and educating rural women and youth about water quality issues may merit further investigation.
78

Agricultural practices and water quality in Saskatchewan : the social ecology of resource management

Kehrig, Randall Francis 10 April 2003 (has links)
This thesis presents the results of exploratory sociological research designed to better understand how farmers select agricultural practices with the potential to effect water quality. The primary research methodology is a Rapid Rural Appraisal of thirty farms in five rural municipalities in Saskatchewan, Canada during the year 2000 growing season. The data establishes that a variety of economic, institutional, organizational, and social factors interact in dynamic ways to influence farmer resource management decisions and that the resulting agricultural practices have the potential for subtle and dramatic effects on water quality in Saskatchewan. Risk-mitigating farming methods known as Best Management Practices (BMPs) are interpreted by farmers in the field research as being both appropriate and problematic. Alternative initiatives and communication strategies are identified in the field data that offer support to production and productivity in the agriculture sector while also promoting water quality. The research suggests that measures such as providing accessible public water quality data, promoting water treatment for individual households, and educating rural women and youth about water quality issues may merit further investigation.
79

Konsumenters kunskap och uppfattning om nyckelhålsmärkta produkter

Laitila, Katarina January 2010 (has links)
Syftet med studien är att klargöra om nyckelhålsmärkningen har betydelse för konsumentens uppfattning och val av produkt, samt belysa förekomsten av källkritiskt tänkande kring nyckelhålsmärkningen. Som metod tillämpades intervjuer på 50 respondenter. Studien indikerar att nyckelhålsmärkningen har en inverkan på både val av produkt samt den generella uppfattningen om hur hälsosam en produkt är. Studien visar även på en slående avsaknad av källkritik då konsumenter utvärderar nyckelhålsprodukter. / The purpose with this study is to illustrate if the keyhole-symbol of food products has an impact on consumers view on, and choice of food product. This study will also illuminate if the consumers reasoning is critical of the sources. Fifty interviews were applied. The study shows that the keywhole-symbole has a positive influence on respondent's perception of healthiness and on likelihood to buy the product. The study also shows striking results int the absence of critical thinking about the sources.
80

Topology-aware vulnerability mitigation worms

Al-Salloum, Ziyad January 2011 (has links)
In very dynamic Information and Communication Technology (ICT) infrastructures, with rapidly growing applications, malicious intrusions have become very sophisticated, effective, and fast. Industries have suffered billions of US dollars losses due only to malicious worm outbreaks. Several calls have been issued by governments and industries to the research community to propose innovative solutions that would help prevent malicious breaches, especially with enterprise networks becoming more complex, large, and volatile. In this thesis we approach self-replicating, self-propagating, and self-contained network programs (i.e. worms) as vulnerability mitigation mechanisms to eliminate threats to networks. These programs provide distinctive features, including: Short distance communication with network nodes, intermittent network node vulnerability probing, and network topology discovery. Such features become necessary, especially for networks with frequent node association and disassociation, dynamically connected links, and where hosts concurrently run multiple operating systems. We propose -- to the best of our knowledge -- the first computer worm that utilize the second layer of the OSI model (Data Link Layer) as its main propagation medium. We name our defensive worm Seawave, a controlled interactive, self-replicating, self-propagating, and self-contained vulnerability mitigation mechanism. We develop, experiment, and evaluate Seawave under different simulation environments that mimic to a large extent enterprise networks. We also propose a threat analysis model to help identify weaknesses, strengths, and threats within and towards our vulnerability mitigation mechanism, followed by a mathematical propagation model to observe Seawave's performance under large scale enterprise networks. We also preliminary propose another vulnerability mitigation worm that utilizes the Link Layer Discovery Protocol (LLDP) for its propagation, along with an evaluation of its performance. In addition, we describe a preliminary taxonomy that rediscovers the relationship between different types of self-replicating programs (i.e. viruses, worms, and botnets) and redefines these programs based on their properties. The taxonomy provides a classification that can be easily applied within the industry and the research community and paves the way for a promising research direction that would consider the defensive side of self-replicating programs.

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