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Molecular cloning and characterisation of potential Fusarium resistance genes in banana (Musa acuminata ssp. Malaccensis)Echeverria, Santy Peraza January 2007 (has links)
Banana is the most important fruit crop in the world but ironically one of the crops least studied. This fruit constitutes a major staple food for millions of people in developing countries and also it is considered the highest selling fruit in the world market making this crop a very important export commodity for the producing countries. At the present time, one of the most significant constraints of banana production that causes significant economical losses are fungal diseases. Among these, Panama disease, also known as Fusarium wilt has been the most catastrophic. Panama disease is caused by the soil-borne fungus Fusarium oxysporum formae specialis (f.sp) cubense (FOC), which infects susceptible bananas through the roots causing a lethal vascular wilt. To date, the race 4 of this pathogen represents the most serious threat to banana production worldwide since most of the commercial cultivars are highly susceptible to this pathogen. Introduction of FOC resistance into commercial cultivars by conventional breeding has been difficult because edible bananas are sterile polyploids without seeds. Genetic transformation of banana, which has already been established in various laboratories around the world has the potential to solve this problem by transferring a FOC race 4 resistance gene into susceptible banana cultivars (eg. Cavendish cultivars). However, a FOC resistant (R) gene has not been isolated. Genes that confer resistance to Fusarium oxysporum have been isolated from tomato and melon using a map-based positional cloning approach. The tomato I2 and melon Fom-2 genes belong to the non-Toll/interleukin like receptors (TIR) subclass of nucleotide-binding site and leucine-rich repeat (NBS-LRR) R genes. These genes confer resistance only to certain races of F. oxysporum in their corresponding plant families limiting their use in other plant families. The fact that these two Fusarium resistance genes share the same basic non-TIR-NBS-LRR structure suggests a similar Fusarium resistance mechanism is shared between the families Solanaceae and Cucurbitaceae. This observation opens the possibility to find similar Fusarium resistance genes in other plant families including the Musaceae. A remarkable discovery of a population of the wild banana Musa acuminata subspecies (ssp.) malaccensis segregating for FOC race 4 resistance was made by Dr. Ivan Buddenhagen (University of California, Davis) in Southeast Asia. Research carried out at Queensland Department of Primary Industries (Australia) using this plant material has demonstrated that a single dominant gene is involved in FOC race 4 resistance (Dr. Mike Smith, unpublished results). Tissue-culture plantlets of this FOC race 4 segregating population were kindly provided to the Plant Biotechnology Program (Queensland University of Technology) by Dr. Mike Smith to be used in our research. This population holds the potential to assist in the isolation of a FOC race 4 resistance gene and other potential Fusarium resistance genes. The overall aims of this research were to isolate and characterise resistance gene candidates of the NBS-type from M. acuminata ssp. malaccensis and to identify and characterise potential Fusarium resistance genes using a combination of bioinformatics and gene expression analysis.
Chapter 4 describes the isolation by degenerate PCR of five different classes of NBS sequences from banana (Musa acuminata ssp malaccensis) designated as resistance gene candidates (RGCs). Deduced amino acid sequences of the RGCs revealed the typical motifs present in the majority of known plant NBS-LRR resistance genes. Structural and phylogenetic analyses showed that the banana RGCs are related to non-TIR subclass of NBS sequences. The copy number of each class was estimated by Southern hybridisation and each RGC was found to be in low copy number. The expression of the RGCs was assessed by RT-PCR in leaf and root tissues of plants resistant or susceptible to Fusarium oxysporum f. sp. cubense (FOC) race 4. Four classes showed a constitutive expression profile whereas no expression was detected for one class in either tissue. Interestingly, a transcriptional polymorphism was found for RGC2 whose expression correlated with resistance to FOC race 4 suggesting a possible role of this gene in resistance to this devastating FOC race. Moreover, RGC2 along with RGC5 showed significant sequence similarity to the Fusarium resistance gene I2 from tomato and were chosen for further characterisation. The NBS sequences isolated in this study represent a valuable source of information that could be used to assist the cloning of functional R genes in banana.
Chapter 5 describes the isolation and characterisation of the full open reading frame (ORF) of RGC2 and RGC5 cDNAs. The ORFs of these two banana RGCs were predicted to encode proteins that showed the typical structure of non-TIR-NBS-LRR resistance proteins. Homology searches using the entire ORF of RGC2 and RGC5 revealed significant sequence similarity to the Fusarium resistance gene I2 from tomato. Interestingly, the phylogenetic analysis showed that RGC2 and RGC5 were grouped within the same phylogenetic clade, along with the Fusarium resistance genes l2 and Fom-2. These findings suggest that the banana RGC2 and RGC5 are potential resistance gene candidates that could be associated with Fusarium resistance. The case of RGC2 is more remarkable because its expression was correlated to FOC race 4 resistance (Chapter 4). As a first step to test whether RGC2 has a role in FOC race 4 resistance, different expression constructs were made with the ORF of this sequence. One of the constructs contains a RGC2 putative promoter region that was successfully cloned in this work. These constructs will be used to transform susceptible banana plants that can then be challenged with FOC race 4 to assess whether resistance has been acquired by genetic complementation.
The results of this thesis provide interesting insights about the structure, expression and phylogeny of two potential Fusarium resistance genes in banana, and provide a rational starting point for their functional characterisation. The information generated in this thesis may lead to the identification of a Fusarium resistance gene in banana in further studies and may also assist the cloning of Fusarium resistance genes in other plant species.
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Att vara eller icke vara hållbar : En studie om bankernas hållbarhetsarbetePanshiri, Mitra, Lilja, Johanna January 2018 (has links)
All companies, municipalities, governments and private individuals are in need of a functioning banking system. Research shows that for the long-term survival of banks, sustainability is important. However, there are several reasons why the banks are working with sustainability. The purpose of this study is to contribute to a deeper understanding of the sustainability work of banks operating in Sweden and to see how sustainability work differs between banks. The purpose is also to contribute to a deeper understanding of why the banks work with sustainability. The study has examined the banks Nordea, Handelsbanken, Danske Bank, Swedbank, SEB and Ekobanken. The study has a deductive approach and uses mixed methods. Semi-structured interviews have been conducted, sustainability reports have been reviewed, the number of customers and customer satisfaction have been taken into account. The study consists of interviews with Handelsbanken, Danske Bank, Ekobanken, Swedish Financial Supervisory Authority and Fair Finance Guide. A thematic analysis has been made based on the collected data. The study has come to the conclusion that the banks are working with sustainability to meet the expectations of their stakeholders, reduce risks, achieve trust, marketing goals and profitability. The banks work with both long-term social measures and short-term financial targets. The banks, Swedish Financial Supervisory Authority and Fair Finance Guide believe that the climate is a current issue. It is also through the indirect impact they have the greatest opportunity to influence the world towards a more sustainable society. Sustainability is constantly changing as society norms and expectations change. There is also a gap between the banks' policies and what they do in practice regarding their work with sustainability. / Alla företag, kommuner, stater och privatpersoner är i behov av ett fungerande banksystem. Forskning menar att för bankernas långsiktiga överlevnad är hållbarhetsarbetet viktigt, dock finns flera olika anledningar till att bankerna arbetar med hållbarhet. Syftet med denna uppsats är att bidra till en djupare förståelse för hållbarhetsarbetet inom bankerna med verksamhet i Sverige samt att se hur hållbarhetsarbetet skiljer sig mellan olika banker. Syftet är även att bidra till en djupare förståelse för varför bankerna arbetar med hållbarhet. Studien har undersökt bankerna Nordea, Handelsbanken, Danske Bank, Swedbank, SEB och Ekobanken. Studien har en deduktiv ansats och använder sig av metodtriangulering. Semistrukturerade intervjuer har utförts, hållbarhetsrapporter har granskats, antalet kunder och kundnöjdhet har tagits i beaktande. De som har intervjuats är Handelsbanken, Danske Bank, Ekobanken, Finansinspektionen och Fair Finance Guide. En tematisk analys har gjorts med utgångspunkt i den insamlade datan. Studien har kommit fram till att bankerna arbetar med hållbarhet för att leva upp till sina intressenters förväntningar, minska risker, uppnå förtroende, marknadsföringssyfte och för lönsamheten. Bankerna arbetar både långsiktigt med sociala mått och kortsiktigt med finansiella mått. Bankerna, Finansinspektionen och Fair Finance Guide anser att klimatfrågan är väldigt viktig just nu. Det är även genom den indirekta påverkan de har störst möjlighet att påverka världen mot ett mer hållbart samhälle. Hållbarhetsarbetet förändras hela tiden i takt med att samhällets normer och förväntningar förändras. Det finns dessutom ett gap mellan bankernas policy och vad de gör i praktiken när det kommer till deras hållbarhetsarbete.
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Valoração econômica do serviço de redução de sedimentos das florestas da bacia hidrográfica do Canal do Panamá / Economic valuation of the impact of the Panama Canal basin forests in sediment reductionEustorgio Jaén Núñez 25 July 2011 (has links)
O processo de sedimentação e assoreamento reduz a profundidade e a capacidade dos lagos de armazenamento de água do Canal do Panamá, obrigando a realizar dragagens periódicas que aumentam os custos de operação. Esses processos são acelerados pela perda de cobertura florestal na bacia. O presente estudo teve por objetivo estimar o valor econômico associado à redução de sedimentos na floresta da bacia do Canal, através do método de custo evitado de dragagem. O efeito físico da cobertura florestal sobre a redução de sedimentos foi estimado a través de regressão linear de dados biofísicos de sete microbacias que dispõem de medições de produção de sedimentos: Chagres, Pequení, Boquerón, Gatún, Trinidad, Cirí Grande e Caño Quebrado. Os resultados mostram que cada hectare de floresta nesta área reduz em 14,76 t.ano-1 de sedimentos em suspensão. Adicionando sedimentos de fundo isso corresponde a 14,32 t.ha-1.ano-1 e a um valor econômico de USD 197,40 por hectare por ano. Concluiu-se que as florestas contribuem significativamente para mitigar o processo de assoreamento dos lagos de armazenamento de água para o funcionamento do Canal do Panamá, e essa contribuição pode ser valorada em USD 39.640.091 por ano, para toda a floresta da bacia. / Sedimentation and siltation reduce the lakes depth and capacity to hold water in the Panama Canal, requiring periodic dredging which increases the operation costs. These processes are accelerated by the loss of forests that cover the basin. This studys objective is to estimate the economic value associated with reduction of sediments in the Canal basin, based on the method of avoided dredging cost. The physical effect of forest on sediment reduction was estimated through linear regression of biophysical data for seven watersheds that have measurements of sediments yield: Chagres, Pequení, Boquerón, Gatún, Trinidad, Cirí Grande and Caño Quebrado. These results shows that each hectare of forest in this area reduces the sediments in suspension. By adding sediments from the bottom of the riverbed, this corresponds to 14.32 m3.ha- 1.year-1 and to an economic value of USD 197.40 per hectare per year. It was concluded that forests contribute significantly to mitigate the process of siltation of lakes water storage for the operation of the Panama Canal, and this contribution may be valued at USD 39,640,091 per year for the entire basin forest.
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¿Necesidad o virtud? Razones y alcances de los tratados continentales hispanoamericanos de 1856 / ¿Necesidad o virtud? Razones y alcances de los tratados continentales hispanoamericanos de 1856Reza, Germán A. De la 12 April 2018 (has links)
This article examines the origins and motivations of the Continental Treaties of 1856, and their differences from the confederative treaties concluded in Panama in 1826 and Lima in 1848. It also seeks to explain the transition from the Bolivarian cooperative approach to a vision based in the balance of powers. As a result of this process, unionism appears as a temporary move, skeptical about its own achievements. / El presente artículo estudia los orígenes y las motivaciones de los tratado scontinentales de 1856 y sus diferencias respecto de los tratados confederativos concluidos en Panamá en 1826 y en Lima en 1848. En particular, se analiza el tránsito del enfoque cooperativo antimonárquico al defensivo excluyente de Estados Unidos; de la visión unionista bolivariana a la concepción del balance de poderes. Como resultado de ese proceso, el unionismo se constituye en una maniobra influida por la coyuntura y el escepticismo sobre sus propios alcances.
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Caracterização funcional e estrutural de fosfolipases A2 isoladas da peçonha da serpente Bothrops asper do Panamá / Functional and structural characterization of phospholipases A2 isolated of Bothrops asper snake venom from Panamá.Aristides Quintero Rueda 04 November 2009 (has links)
Os envenenamentos causados pelas serpentes do gênero Bothrops são os mais importantes do ponto de vista médico e econômico na América Central. Dentre estas, a serpente Bothrops asper é responsável por 90% dos envenenamentos ofídicos registrados no Panamá anualmente. Apesar da relevância médica e econômica, só a peçonha de populações de B. asper da Costa Rica e Guatemala tem sido estudadas em detalhes. Neste trabalho apresentamos a caracterização da peçonha da B. asper do Panamá e o isolamento, a caracterização funcional e estrutural de quatro fosfolipases A2 básicas denominadas MTX-I, MXT-II, MTX-III e MXT-IV e de uma fosfolipase A2acídica denominada Basp-I-PLA2. As fosfolipases A2 foram isoladas da peçonha em duas etapas usando cromatografia de troca iônica em CM-Sepharose (0,05 M NH4HCO3 pH 8,1), e cromatografia hidrofóbica em Fenil-Sepharose (0,05 M Tris-HCl pH 7,4) seguida de gradiente de concentração de 4 a 0 M NaCl no mesmo tampão a temperatura ambiente (25°C). A isoforma acídica demonstrou maior atividade catalítica que as isoformas básicas, quando atuou sobre fosfatidilcolina e fosfatidilglicerol. A focalização isoelétrica evidencia pIs de 8,1 a 8,3 para as MTXs e 4,6 para isoforma Basp-I-PLA2. A determinação da massa molecular por espectrometria de massa mostrou que MTX-1 14,156.5; MTX-2 14,249.5 e MTX-3 14,253.0 e Basp-I-PLA2 14,246.0 Da. As PLA2s (MTX-I, II, III e IV) induziram atividade miotóxica, reação inflamatória com migração de leucócitos ao músculo e ativação de macrófagos para exercer fagocitose e produção de superóxido. MTX-II exerceu um forte efeito citotóxico contra células tumorais JURKAT, C. albicans e E. coli. A fosfolipase A2 acídica, testada no plasma enriquecido com plaquetas, mostrou potente efeito inibitório na agregação plaquetária induzida pela ADP e colágeno. A análise de seqüência N- terminal demonstrou que as proteínas MTX-I, MTX-III e Basp-I-PLA2 pertencem à subclasse de fosfolipases A2 Asp49 cataliticamente ativas, enquanto que, MTX-II e MTX-IV pertencem à subclasse de fosfolipases A2 Lys49-homólogas cataliticamente inativas. Além disso, a sequência N-terminal das fosfolipases A2 básicas isoladas, demonstrou claramente que as miotoxinas isoladas neste trabalho são similares às miotoxinas previamente isoladas da peçonha da B. asper da Costa Rica. A Basp-I-PLA2 é uma nova fosfolipase A2 acídica isolada da peçonha de B. asper do Panamá e sua seqüência N-terminal revelou uma alta homologia com outras PLA2s acídicas Asp49 isoladas de peçonhas de serpentes. / Envenoming by Bothrops snakes is the most serious kind of envenoming from the medical and economical point of view in Central America. Bothrops asper snake is responsible for 90% of the snakebites registered in Panama every year. Despite its medical and economical relevance, only the venom of Costa Rica and Guatemala populations of this species has been studied to some detail, and there is very little information on intraspecies variability in venom composition and toxicity. In this study the crude venom of B. asper from Panama was characterized and its pharmacological and biochemistry activities were investigated with standard laboratory assays. Furthermore, we describe the isolation, functional and structural characterization of four basic phospholipases A2, named MTX-I, MTX-II, MTX-III, MTX-IV and a new acid phospholipase A2 named Basp-I-PLA2. The proteins were isolated from the crude venom by a combination of two chromatographic steps, using ion-exchange chromatography on CM-Sepharose (0.05 M NH4HCO3 pH 8.1 buffer), and hydrophobic chromatography on Phenyl-Sepharose (0.05 M Tris-HCl pH 7.4), followed by concentration gradient from 4 to 0 M NaCl at 25°C in the same buffer. Analyses of phospholipids hydrolyzed by these enzymes have shown that all phospholipases belong to type A2. The acidic isoform demostraded more catalytic activity than the basic PLA2s. This enzyme was more active on substrates as phosphotidylcholine and phosphatidylglycerol. The isoelectric focusing evidenced pIs beetwen 8.1 to 8.3 for the MTXs and 4.6 for the isoform Basp-I-PLA2. Its mol. Wt was estimated by Mass spectrometry to be MTX-1 14,156.5; MTX-2 14,249.5 and MTX-3 14,253.0 and Basp-I-PLA2 14,246.0 Da. The PLA2s (MTX-I, II, III and IV) induced myotoxic activity, inflammatory reaction mainly leukocyte migration to the muscle and activation of macrophages to exert phagocytic activity and production of superoxide. MTX-II, the most abundant one showed to be cytotoxic against JURKAT tumor cell line, C. albicans and E. coli. The acidic phospholipases A2 when tested in platelet rich plasma, showed a potent inhibitory effect on aggregation induced by ADP and collagen. The analysis of the sequence N-terminal demonstrated that the MTX-I, MTX-III and BASP-I-PLA2 belong to the subclass of Asp49 phospholipases A2 catalytically active, whereas, MTX-II and MTX-IV belong to proteins of the subclass of the enzymatically inactive Lys49 PLA2 s-like. In addition, a sequence of the region N-terminal of the PLA2s basic isolated, demonstrated clearly, that the isolated myotoxins in this work are similar of the previously isolated myotoxins of the snake venom Bothrops asper from Costa Rica. The Basp-I-PLA2 is a new acidic PLA2 and his sequence N-terminal revealed a high homology with other Asp49 acidic PLA2 s from snake venoms.
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Rättfärdigade argument? USA:s militära intervention i Panama 1989Löving, Anna January 2008 (has links)
In 1989 the United States choose, after years of conflict, to carry out a military intervention in Panama, to remove Manuel Noriega, convicted for drug dealing and for threatening the lives of the Americans living in Panama. The aim of this study is to examine whether George H. W Bush’s arguments for the military intervention comply with the principles of the just war. The method chosen for this study is a qualitative literature study, based primarily on secondary data. It is a case study with two complementing theories, the theory of the just war and the world system theory. The result showed that the American intervention both can be justified and unjustified following the principles of the Just War Theory. The World system Theory shows typical signs for a relationship between USA and Panama, built on economic, political and military control.
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The Soil Moisture Niche in a Moist Tropical Forest – A Demographic ApproachKupers, Stefan Jonathan 16 January 2020 (has links)
Water availability affects tree species performance and distributions in tropical forests. However, there are no studies that have measured detailed spatial variation in soil water availability within a tropical forest. This limits our understanding of how water availability shapes the demography and distributions of tree species within tropical forests. In this dissertation, I measured detailed spatial variation in soil water potential (SWP), the relevant measure of water availability for plant performance, in the seasonal tropical moist forest of the 50-ha Forest Dynamics Plot on Barro Colorado Island, Panama. In Paper 1, I mapped spatial variation in SWP across the 50-ha plot in various stages of the dry season using information on topography, soil type, dry season intensity and more. In Paper 2, I quantified the soil moisture niches of species in terms of demographic responses (growth and mortality) and species distributions. I related seedling growth and mortality responses to SWP of 62 species to their distributional centre along the SWP gradient, using data from 20 years of annual seedling censuses across 200 seedling census sites. I found that species that grew faster (slow) with increasing SWP were more common on wetter (drier) parts of the SWP gradient. Moreover, wet-distributed species grew faster on the wet side of the SWP gradient than dry-distributed species. Mortality was unrelated to species distributions but decreased strongly with seedling height. These findings indicate that species with a growth advantage with respect to SWP grow faster out of the vulnerable small size ranges, reducing their mortality in later seedling stages and thus shaping species distributions indirectly. This mechanism is a form of niche differentiation that contributes to species coexistence. In Paper 3, I related seedling growth and mortality responses to spatiotemporal variation in water availability with responses to light availability, another highly limiting resource in tropical forests. I found an interspecific trade-off in responses to shade versus inter-annual drought (dry season intensity): species that performed relatively well in the shade performed worse during more severe dry seasons and vice versa. This trade-off enables coexistence, because species are adapted to perform well under either shade or drought. In sum, water availability contributes to the maintenance of the high diversity of tropical forests through hydrological niche differentiation and a trade-off between performance in shade versus drought. Future work can use my SWP maps and species responses to SWP to identify the functional traits that underlie the species responses and improve Dynamic Global Vegetation Models. Finally, my work facilitates the prediction of future species composition, diversity and ecosystem functioning of tropical forests with shifts in rainfall patterns caused by climate
change.
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Hållbarhetsredovisning inom finansbranschen : en studie om legitimitetsstrategier i svenska bankers hållbarhetsrapporter / Sustainability reporting in the finance sector : a study of sustainability reports in Swedish banksAbdi, Najib, Lemmetty, Fredrik January 2020 (has links)
This study examines annual and sustainability reports from Swedish banks in the pursuit of legitimacy strategies. The study applies content analysis on the annual and sustainability reports from four banks from the period 2013-2018. Keywords for the study were extracted from an anti-corruption report. After which an interpretive analysis is done to classify the banks different legitimacy strategies for the period. The study found that there was an increase in anti-corruption related CSR in line with earlier studies in the banks SEB, Swedbank, Handelsbanken and Nordea. Several different legitimacy strategies were detected and the shift between them could be identified. / Denna studie granskar års och hållbarhetsrapporter i sökandet efter legitimeringsstrategier hos svenska banker. Studien använder sig av innehållsanalyser på fyra bankers års- och hållbarhetsrapporter för perioden 2013–2018. Studiens nyckelord är sammanställda utifrån en rapport om anti-korruptionsarbete. Varvid tolkande analys utförts för att identifiera bankernas olika legitimeringsstrategier under perioden. Studien fann en ökning av anti-korruptionsrelaterad CSR i linje med tidigare forskninghos bankerna SEB, Swedbank, Handelsbanken och Nordea. Dessutom kunde olika legitimeringsstrategier skönjas och övergångar dem emellan identifieras.
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The Strait Defense: A Case Study Comparison of Global StraitsEndicott, Travis Wayne January 2016 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The global climate is creating more ice-free waters in the Arctic. These new navigation possibilities around the Arctic lead to increased global trade, tourism, and oil and gas exploration. With the foreseeable increased nautical transportation through the Northwest Passage, the United States needs to revisit its security posture in and around the Bering Strait. At least five different grand strategies are potentially relevant in addressing this question. By comparing the suggestions of these leading grand strategy approaches to what has actually been implemented by the United States in the Strait of Hormuz, the Strait of Malacca, and the Panama Canal, similarities emerge that can help the United States shape their strategy for the defending of its national interests in the Bering Strait. By testing the different grand strategies against three reasonably similar cases, I find that a forward military presence and supporting a liberal institutionalist approach are the two key aspects that the United States should employ in the Bering Strait. Increasing and improving the military presence that the United States has in the region should be a top priority. In addition, supporting the Arctic Council would provide an increased level of security to the United States and other nations in the region. This strategy is not without its challenges and it will require artful statecraft in order to be successful.
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A Multi-Scale Analysis of Jaguar (Panthera onca) and Puma (Puma concolor) Habitat Selection and Conservation in the Narrowest Section of Panama.Craighead, Kimberly A. 02 May 2019 (has links)
No description available.
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