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Establishment and impact of the sap-sucking mirid, Falconia intermedia (Distant) (Hemiptera: Miridae) on Lantana camara (Verbenaceae) varieties in the Eastern Cape Province, South AfricaHeshula, Unathi-Nkosi Lelethu Peter January 2005 (has links)
The biological control of the weedy complex Lantana camara (L.) (Verbenaceae) has been ongoing in South Africa for over 40 years. Despite this, the weed is still not under sufficient control and continues to invade new territories in the country. The biological control programme needs to be bolstered with releases of new and potentially damaging biological control agents. A promising biological control agent endemic to Central America, Falconia intermedia (Distant) (Hemiptera: Miridae), was imported into quarantine from Jamaica in 1994. This agent was released on sites in KwaZulu-Natal and Limpopo provinces of South Africa in 1999. Even though it initially established and damaged L. camara, populations died out at most of the release sites. As varietal difference and adverse climate have been cited as the reason for non-establishment and ineffective control in L. camara biocontrol programmes worldwide, this study attempts to investigate the role that these two factors play in this weed herbivore relationship. Laboratory no-choice trials were conducted to determine the varietal performance of F intermedia, among five Eastern Cape varieties of the weed from East London, Whitney Farm, Heather Glen Farm, Port Alfred and Lyndhurst Farm, and a variety from the Plant Protection Research Institute (PPRI), Pretoria. However, there were differences in performance as the adult mirids performed better on white-pink varieties from Whitney Farm and Heather Glen Farm. To test varietal preference in field conditions, field releases of F intermedia were also made at East London, Whitney Farm, Heather Glen Farm, Port Alfred and Lyndhurst Farm. Post release evaluations were conducted monthly for two years (2002 and 2003). The insect established at East London and Whitney Farm, both of which have white-pink varieties. Insect populations quickly died out at the Lyndhurst Farm and Port Alfred sites, which have dark pink varieties. It is suggested that field conditions may have resulted in poor plant quality and led indirectly to varietal preference, and to non-establishment at these two sites. With the onset of cooler weather, populations disappeared at Heather Glen Farm. This suggested that F. intermedia was suitable for release in more subtropical areas within South Africa where climatic conditions would be suitable throughout the year. The mirid performed well at Whitney Farm, resulting in significant reduction in plant growth parameters such as height and percentage cover, and increasing the cover of other flora growing beneath L. camara plants. Finally, ways to improve the efficacy of this agent are considered in an effort towards better control of L. camara in South Africa.
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Laboratory and field host utilization by established biological control agents of Lantana camara L. in South AfricaHeystek, Fritz January 2006 (has links)
Varieties of Lantana camara (lantana) have been introduced into many countries of the world as ornamental plants and have become invasive weeds in many countries including South Africa. In South Africa, it mostly invades the sub-tropical eastern and northern range. Mechanical and chemical control options are expensive and ineffective. A biocontrol programme was initiated in South Africa in 1961. To date, 22 insect species, and a fungus have been introduced, of these 10, and the fungus have established. Three indigenous lepidopteran species and an exotic generalist pest mealybug are also associated with the weed. The variable success of some of the agents released on L. camara worldwide has been ascribed to a few factors. One important aspect is the large range of varieties encountered in the field. It is therefore essential to be able to predict the possible establishment and impact of agents on many varieties. Laboratory trials on five of the established agents showed clear varietal preferences. In the field, most of the biocontrol agents had limited geographic ranges, linked to altitudinal conditions, as higher populations were recorded at low lying warm summer rainfall areas. A pink and orange flower corolla lobe and throat colour combination and plants with few to medium leaf hairs were most abundant in South Africa. Most of the agent species had individual preferences towards different flower colour combinations, as the agents built up different population levels on varieties in the field, within the suitable geographic region for the insect species. Eight agents preferred smooth leaved varieties, while three preferred hairy leaves, and three had no specific preference to leaf hairiness. Varietal preferences thus did play a significant role in agent populations and accompanied impact achieved in the field. New candidate agents need to be proven specific under quarantine conditions and the results extrapolated to predict specificity in the field, while avoiding potential non-target effects. Many authors have questioned the validity of laboratory host specificity trials. The conventional wisdom is that insects portray a far wider host range in the laboratory than what they would do in the field. In other words, laboratory studies measure the physiological host range of an agent and are conservative and usually don’t reflect the ecological host range of agents in the field. To avoid unnecessary rejections of biocontrol agents, this study has made a retrospective study of the host specificity of agents established in the field. Their laboratory and field host ranges were compared and it was found that virtually all the agents reflect similar or less non-target effects in the field than predicted during multiple choice trials. Of the 14 agents, only one introduced species, Teleonemia scrupulosa, and the indigenous species, Hypena laceratalis and Aristea onychote were able to sustain populations on non-target species in the field in the absence of L. camara. Insect populations on non-target species were much reduced compared to that on L. camara. Furthermore non-target effects were only recorded on plant species closely related to the target weed. The multiple choice trials therefore predict field non-target effects accurately. Predictions of non-target effects of candidate agents can therefore be accurately predicted by laboratory studies, in terms of species likely to be affected and to what extent. One field that need further study though is the impact of non-target effects, especially on Lippia species by L. camara biocontrol agents.
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[en] DO POLITICIANS RESPOND TO POLITICAL PROTESTS?: EFFECTS OF THE 2013 PROTESTS IN BRAZIL / [pt] OS PROTESTOS POLÍTICOS AFETAM OS POLÍTICOS?: EFEITOS DOS PROTESTOS DE 2013 NO BRASIL07 July 2020 (has links)
[pt] Apesar de não ser um fenômeno recente, os protestos políticos tem
ocorrido mais frenquentemente em diversas democracias do mundo. Neste
contexto, é importante analisar se eles de fato são um instrumento efetivo
através do qual os cidadãos podem afetar variáveis políticas e garantir que
suas preferências sejam refletidas no âmbito político. Neste trabalho I estudo
os efeitos dos protestos que ocorreram no Brasil em junho de 2013, olhando
tanto para o comportamento de eleitores e de políticos. Primeiramente,
usando dados das eleições a nível municipal, eu mostro que os protestos
estão associados com uma diminuição nas taxas de comparecimento e um
aumento no percentual de votos de protestos (votos nulos). Além disso, os
protestos afetaram a distribuição de votos: há uma correlação negativa entre
votos em incumbentes e a incidência de protestos. Com respeito ao efeito
nos políticos, eu foco minha análise na Câmara dos Deputados e analiso
se os protestos tiveram algum efeito sobre o comportamento ds deputados
federais. Usando uma abordagem de diferença-em-diferença não tradicional,
eu mostro que os protestos não afetaram todas as dimensões relevantes
da performance dos legisladores, como presença em plenário, alocação de
emedas parlamentares e elaboração de leis. No entanto, há evidência de
efeitos heterogêneos com relação a incentivos à reeleição e posição relativa
na coalizão. / [en] Although political protests are not a new political phenomenon, they
are happening more frequently in democracies all over the world. In this
context, it is important to study whether they are an effective instrument
through which citizens can affect political outcomes and ensure that their
preferences are reflected in politics. In this work, I analyze the effects of
the protests that took place in Brazil in 2013, looking both of voters and
politicians behavior. First, using data on elections at the municipal level,
I show that the protests are associated with a decrease in turnout rate and
an increase in the share of protest votes (the null votes). Moreover, the
protests affected the distribution of votes: there is a negative correlation
between incumbents vote share and the incidence of protests. With respect
to the effects on politicians, I focus my analysis in the Chamber of Deputies
of Brazil to I analyze whether the protests had any effects in the legislators
behavior. Using a difference-in-difference approach, I show that the protests
did not affect all relevant dimensions of the legislators performance, such as
presence in plenary sessions, allocation of federal budget amendments and
proposal of bills. However, I find evidence of heterogeneous effects regarding
reelection incentives and relative position in the coalition.
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La problématique du héros romanesque dans L'aventure ambiguë de Cheikh Hamidou Kane, Un piège sans fin d'Olympe Bhêly-Quénum, Le regard du roi de Camara LayeNnoruka, Matthew Nwaneti. 08 February 2024 (has links)
No description available.
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Induced plant responses of different Lantana camara L. (Verbenaceae) varieties to herbivory by Falconia intermedia (distant) (Hemiptera: Miridae)Heshula, Unathi-Nkosi Lelethu Peter January 2010 (has links)
A highly variable invasive shrub, Lantana camara L. (Verbenaceae), has been notoriously difficult to control thus far despite a well established biological control programme in South Africa. A promising leaf-feeding biological control agent, Falconia intermedia (Distant) (Hemiptera: Miridae), released to control this invasive plant eventually crashed at three out of five sites in the Eastern Cape Province. In the Mpumalanga Province, after initially colonising and building up high numbers on the L. camara stands the agent populations crashed. Several reasons for these population crashes have been suggested, but induced plant defences have not been investigated. Although plants face the challenge of herbivory by various organisms while remaining immobile, some plants may possess the ability to induce physical and/or chemical defensive responses following feeding and thus prevent further plant tissue damage and loss. Laboratory trials were conducted to determine the existence, nature and effect of physical and chemical feeding-induced responses of L. camara on the performance of the leaf-feeding biological control agent, F. intermedia. Lantana camara plants used in the study were obtained from five localities in the Eastern Cape Province, South Africa, while the insect culture was established from field populations. Plants from all varieties on which F. intermedia was released significantly increased the toughness of their leaves compared to control treatment plants. In addition, plants from three localities: Lyndhurst Farm, East London and Port Alfred, significantly increased trichome density after prolonged feeding by F. intermedia. On the three varieties showing increases in these two factors (i.e. leaf toughness and trichome density), oviposition, survival and feeding damage by the mirid agent was significantly lower on previously damaged plants. A significant negative correlation between trichome density and population numbers was found (R²= 0.52, p < 0.0003), suggesting that an increase in trichome density strongly contributes to a reduction in F. intermedia's growth. The growth and reproduction of the resistant plants was not significantly impacted by F. intermedia feeding. The defensive responses were found to be plant systemic and rapidly induced as they were elicited and expressed throughout the plant in both damaged and undamaged leaves within five weeks after insect release. Leaf toughness and trichome density were not significantly increased after feeding on plants from Whitney Farm and Heather Glen Farm. On the contrary, mirid individuals performed significantly better on plants from Whitney Farm and Heather Glen Farm than on plants of other varieties, indicating their susceptibility and suitability to the agent and the lack of induced resistance against the agent. Plants from all localities besides East London showed some level of tolerance and overcompensated for feeding damage by increasing plant growth and reproductive factors on plants fed upon. This was however only significant in two variables of the more susceptible localities, Whitney Farm and Heather Glen Farm. This increase in plant fitness did however indicate an induced defence response by these plants to feeding, a response designed to lessen the effects of agent feeding. Headspace volatile analysis was used to investigate any volatile chemical responses by L. camara due to F. intermedia feeding at two of the five localities chosen: East London and Whitney Farm. There was no significant difference in headspace volatiles emitted by leaves of plants from the East London insect infested and control treatment plants. On the Whitney Farm damaged plants however there was a 2.5 fold increase in the emission intensity of one of the three main compounds, later identified as Beta-caryophyllene. Three major chemical constituents which were found to be common to leaf volatiles of the two varieties were identified through gas chromatography-mass spectrometry (GC-MS) from the damaged and undamaged leaves of these two varieties. The methods used in collecting leaf volatiles were shown to be significant in the strength of chromatogram peaks. Using general authentication methods and purified standards, one of these was identified as the sesquiterpene, Beta-caryophyllene (C₁₅H₂₄). This compound is one of the major constituents found in isolations of L. camara varieties worldwide. This is the first such work done on a variety of L. camara in South Africa, and hopefully the beginning of more in-depth studies of the volatile organic chemicals from the numerous naturalised varieties of L. camara. It is suggested that the sum of these responses may play a role bigger than is currently understood in this plant-insect relationship. It is also argued that feeding induced plant defences may play an important role in attempts to control alien plants using insect agents.
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O processo legislativo na Camara Municipal de São Paulo e a Constituição Federal de 1988Berardi, Luciana Andrea Accorsi 08 May 2006 (has links)
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Previous issue date: 2006-05-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This labor intents to analyze the Legal Process of Sao Paulo s Municipal District in face to the 1988 Federal Constitution, whose concepts, regiment, principles, organization and performance date from the primordial of Brazilian structures, in parallel with the classical positivist doctrine.
For the had of this premises, this study at first is probing the formation and evolution of the legal classic concepts of power, public opinion, sovereignty, democracy, representation and popular participation.
It s boarding to, at a second, the factors which tempted to the duty and obligation of the State s discussion, the Brazilian Federation internal fragmentation through the distribution of distinct competences as one of the propulsive measures of the local development and incentive to the decision makers concerning to measures and course of peculiar public interest.
It intends to present a brief boarding of the myth s ascension and its decay around the popular representation and participation, until achieving the constitutional position and how both are presented ahead the 1988 Constitution and the District of Sao Paulo s Organic Law.
After a brief incursion on the concept and analysis of the Municipal Legislative Process, under the legal approach, it becomes a reflection on its procedure and formation, recurrent of the legislative office s exercise, always obeying the established Brazilian State principles: democratic, federative and republican, as established specifically in the constitutional law.
Finally, we offer our conclusions and some considerations. / Este estudo tem o objetivo de propor uma análise crítica ao Processo Legislativo do Município de São Paulo em face da Constituição Federal de 1988, cuja noção, regime, princípios, formas e execução remontam aos primórdios da civilização brasileira, sob os auspícios paralelos da doutrina clássica positivista.
A partir dessa colocação, para a devida análise da matéria, o estudo em primeiro lugar, procura examinar a formação e evolução dos conceitos clássicos dos institutos do poder, opinião pública, soberania, democracia, representação e por fim, participação .
Num segundo momento, aborda os fatores que provocaram a rediscussão das funções e os papéis do Estado, a fragmentação interna da Federação brasileira através da distribuição de competências distintas aos entes federativos, como uma das medidas propulsoras ao desenvolvimento local e, o incentivo às tomadas de decisões, não apenas ao Estado, mas também à sociedade civil, relativa a medidas e diretrizes de peculiar interesse público.
Finalmente, faz-se uma breve abordagem da ascensão do mito da representação e da participação popular e a sua decadência, até chegar à postura constitucional de como ambos se apresentam diante da Constituição Federal de 1988 e da Lei Orgânica do Município de São Paulo.
Por derradeiro, após rápida incursão sobre o conceito e análise do processo legislativo municipal, sob o enfoque jurídico, faz-se uma reflexão sobre seu procedimento e formação, decorrente do exercício da função legislativa, obedecendo sempre aos princípios estabelecidos pelo Estado brasileiro: democrático de direito, republicano e federativo, da mesma forma que os especificamente estabelecidos pelo texto constitucional.
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Caractérisation par CPG/IK, CPG/SM et RMN du carbone-13 d'huiles essentielles de MadagascarCAVALLI, Jean-François 17 October 2002 (has links) (PDF)
Cette étude a pour objectif d'une part, de développer une méthode d'analyse des huiles essentielles basée sur la combinaison du couplage CPG/SM et de la RMN du carbone-13, avec ou sans fractionnement, en utilisant les données de la littérature, en reconstruisant les spectres de molécules absentes de nos bibliothèques et d'autre part, de contribuer à une meilleure connaissance de l'huile essentielle de diverses plantes de Madagascar, endémiques ou introduites, en les caractérisant et en décrivant une éventuelle variabilité chimique. Ces analyses nous ont permis d'identifier efficacement des composés délicats à analyser par les techniques conventionnelles (stéréoisomères, molécules thermosensibles). Nous avons également étudié six échantillons de Cedrelopsis grevei et réalisé un fractionnement poussé de l'un d'entre eux, ce qui nous a permis d'identifier de très nombreux sesquiterpènes. Enfin, nous avons montré la variabilité interspécifique des huiles essentielles du genre Helichrysum.
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Har befrielseteologin någon förankring i den latinamerikanska kulturen? : Brasilien som exempelSöberg, Annika January 2002 (has links)
<p>Den latinamerikanska befrielseteologin har nått ut över världen. I alla fall till en del grupper. De radikala katolska befrielseteologerna och deras medkämpar har med hjälp av Bibeln kombinerad med samhällsvetenskaplig analys ökat medvetenheten om de sociala och ekonomiska orättvisorna men de har inte lyckats lösa problemen. Konservativa krafter har motarbetat befrielseteologerna i alla år. Samtidigt som befrielseteologerna hyllas över världen för sitt arbete till förmån för de fattiga och förtryckta har de blivit hårt kritiserade. Bland annat har de kritiserats för sitt samarbete med marxister och för att de blandar politik och religion. Befrielseteologerna har också kritiserats för att de inte har tänkt tillräckligt på kvinnofrågor och ursprungsbefolkningar.</p><p>I denna uppsats söker författaren via litteraturstudier svaret på om befrielseteologin har någon förankring i den latinamerikanska kulturen. Latinamerika är stort. Därför har arbetet avgränsats till att handla om den brasilianska kulturen. Brasilien är ett motsägelsefullt land. Kontrasterna är stora mellan kulturerna, mellan fattiga och rika samt mellan utveckling och underutveckling. Miljöproblemen och de sociala problemen är komplicerade. Befrielseteologerna är många. Författaren har valt att titta närmare på peruanen Gustavo Gutiérrez som brukar anses som befrielseteologins grundare, brasilianaren Leonardo Boff som nyligen fick alternativa nobelpriset för fredsbevarande arbete och brasilianaren Helder Camara som levde ett långt liv i befrielseteologins tjänst.</p>
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Har befrielseteologin någon förankring i den latinamerikanska kulturen? : Brasilien som exempelSöberg, Annika January 2002 (has links)
Den latinamerikanska befrielseteologin har nått ut över världen. I alla fall till en del grupper. De radikala katolska befrielseteologerna och deras medkämpar har med hjälp av Bibeln kombinerad med samhällsvetenskaplig analys ökat medvetenheten om de sociala och ekonomiska orättvisorna men de har inte lyckats lösa problemen. Konservativa krafter har motarbetat befrielseteologerna i alla år. Samtidigt som befrielseteologerna hyllas över världen för sitt arbete till förmån för de fattiga och förtryckta har de blivit hårt kritiserade. Bland annat har de kritiserats för sitt samarbete med marxister och för att de blandar politik och religion. Befrielseteologerna har också kritiserats för att de inte har tänkt tillräckligt på kvinnofrågor och ursprungsbefolkningar. I denna uppsats söker författaren via litteraturstudier svaret på om befrielseteologin har någon förankring i den latinamerikanska kulturen. Latinamerika är stort. Därför har arbetet avgränsats till att handla om den brasilianska kulturen. Brasilien är ett motsägelsefullt land. Kontrasterna är stora mellan kulturerna, mellan fattiga och rika samt mellan utveckling och underutveckling. Miljöproblemen och de sociala problemen är komplicerade. Befrielseteologerna är många. Författaren har valt att titta närmare på peruanen Gustavo Gutiérrez som brukar anses som befrielseteologins grundare, brasilianaren Leonardo Boff som nyligen fick alternativa nobelpriset för fredsbevarande arbete och brasilianaren Helder Camara som levde ett långt liv i befrielseteologins tjänst.
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An approach to coded structured light to obtain three dimensional informationSalvi, Joaquim 16 February 1998 (has links)
The human visual ability to perceive depth looks like a puzzle. We perceive three-dimensional spatial information quickly and efficiently by using the binocular stereopsis of our eyes and, what is mote important the learning of the most common objects which we achieved through living. Nowadays, modelling the behaviour of our brain is a fiction, that is why the huge problem of 3D perception and further, interpretation is split into a sequence of easier problems. A lot of research is involved in robot vision in order to obtain 3D information of the surrounded scene. Most of this research is based on modelling the stereopsis of humans by using two cameras as if they were two eyes. This method is known as stereo vision and has been widely studied in the past and is being studied at present, and a lot of work will be surely done in the future. This fact allows us to affirm that this topic is one of the most interesting ones in computer vision.The stereo vision principle is based on obtaining the three dimensional position of an object point from the position of its projective points in both camera image planes. However, before inferring 3D information, the mathematical models of both cameras have to be known. This step is known as camera calibration and is broadly describes in the thesis. Perhaps the most important problem in stereo vision is the determination of the pair of homologue points in the two images, known as the correspondence problem, and it is also one of the most difficult problems to be solved which is currently investigated by a lot of researchers. The epipolar geometry allows us to reduce the correspondence problem. An approach to the epipolar geometry is describes in the thesis. Nevertheless, it does not solve it at all as a lot of considerations have to be taken into account. As an example we have to consider points without correspondence due to a surface occlusion or simply due to a projection out of the camera scope.The interest of the thesis is focused on structured light which has been considered as one of the most frequently used techniques in order to reduce the problems related lo stereo vision. Structured light is based on the relationship between a projected light pattern its projection and an image sensor. The deformations between the pattern projected into the scene and the one captured by the camera, permits to obtain three dimensional information of the illuminated scene. This technique has been widely used in such applications as: 3D object reconstruction, robot navigation, quality control, and so on. Although the projection of regular patterns solve the problem of points without match, it does not solve the problem of multiple matching, which leads us to use hard computing algorithms in order to search the correct matches.In recent years, another structured light technique has increased in importance. This technique is based on the codification of the light projected on the scene in order to be used as a tool to obtain an unique match. Each token of light is imaged by the camera, we have to read the label (decode the pattern) in order to solve the correspondence problem. The advantages and disadvantages of stereo vision against structured light and a survey on coded structured light are related and discussed. The work carried out in the frame of this thesis has permitted to present a new coded structured light pattern which solves the correspondence problem uniquely and robust. Unique, as each token of light is coded by a different word which removes the problem of multiple matching. Robust, since the pattern has been coded using the position of each token of light with respect to both co-ordinate axis. Algorithms and experimental results are included in the thesis. The reader can see examples 3D measurement of static objects, and the more complicated measurement of moving objects. The technique can be used in both cases as the pattern is coded by a single projection shot. Then it can be used in several applications of robot vision.Our interest is focused on the mathematical study of the camera and pattern projector models. We are also interested in how these models can be obtained by calibration, and how they can be used to obtained three dimensional information from two correspondence points. Furthermore, we have studied structured light and coded structured light, and we have presented a new coded structured light pattern. However, in this thesis we started from the assumption that the correspondence points could be well-segmented from the captured image. Computer vision constitutes a huge problem and a lot of work is being done at all levels of human vision modelling, starting from a)image acquisition; b) further image enhancement, filtering and processing, c) image segmentation which involves thresholding, thinning, contour detection, texture and colour analysis, and so on. The interest of this thesis starts in the next step, usually known as depth perception or 3D measurement.
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