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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.
141

Comparação de três armadilhas automáticas para coleta de mosquitos (Diptera: Culicidae) em áreas rurais no bioma de Mata Atlântica, sudeste do Estado de São Paulo, Brasil / Comparison of three automatic traps for collecting mosquitos (Diptera: Culicidae) in rural areas in the Atlantic Forest biome, southeastern São Paulo State, Brazil.

Denise Cristina Sant\'Ana 24 May 2013 (has links)
Introdução: Armadilhas automáticas entomológicas são ferramentas importantes para a vigilância e controle de espécies de mosquitos vetoras. Vários estudos mostraram que a armadilha CDC com CO2 + Lurex® e a CDC luminosa são efetivas para a amostragem de culicídeos. A Mosquito Magnet® foi comparada com diferentes métodos de coletas, incluindo a isca humana, para amostragem de mosquitos vetores. Como resultado, a armadilha tem demonstrado boa capacidade de amostragem. No presente estudo, a eficácia da Mosquito Magnet® Independence foi comparada com as armadilhas CDC luminosa e a CDC com atrativos, mas sem luz. As coletas foram realizadas em áreas rurais no sudeste do bioma de Mata Atlântica. Objetivo: Comparar a eficácia da armadilha Mosquito Magnet® Independence + Lurex3® com a da CDC luminosa e da CDC com CO2 + Lurex3®. Métodos: As armadilhas foram instaladas em três locais diferentes durante três dias consecutivos em áreas rurais do município de Iguape, Estado de São Paulo, Brasil, de janeiro a junho de 2012. As armadilhas foram colocadas diariamente às 6h00 pm (ou 7h00 pm, durante os dias de horário de verão) e removidas às 6h00 am (ou 7h00 horas durante os dias de horário de verão). Para avaliar a eficácia das armadilhas para coleta de culicídeos, utilizamos os perfis de diversidade da Rényi, além de outros índices de diversidade, ou seja, riqueza, abundância, dominância, equabilidade e similaridade. Resultados: A armadilha Mosquito Magnet® coletou 53,84 por cento do total (19.016 indivíduos) de mosquitos obtidos com as três armadilhas. Por outro lado, a CDC luminosa obteve os maiores índices de diversidade de Margalef e Shannon. O índice de Pielou mostrou que as espécies se distribuem de maneira mais uniforme quando empregado o uso da armadilha CDC com atrativos. No entanto, a Mosquito Magnet® obteve o maior índice de dominância. O teste de Kruskal-Wallis mostrou diferença significativa apenas para os índices de riqueza observados na série de Rényi. O teste de Bonferroni apontou que apenas a armadilha Mosquito Magnet® apresentou diferença significativa em relação à CDC luminosa (p=6e-05). Os índices de similaridade apontaram maiores semelhanças entre as espécies coletadas pelas armadilhas Mosquito Magnet® e CDC com atrativos. Conclusões: O presente estudo mostrou que é possível coletar número elevado de espécimes de culicídeos com a Mosquito Magnet® Independence em áreas rurais no sudeste de São Paulo. Apesar da armadilha CDC não coletar uma grande abundância de culicídeos é considerado um método de coleta apropriado e indicado para os serviços de saúde, devido a sua funcionalidade e facilidade de transporte. No entanto, os resultados do presente estudo mostraram que a Mosquito Magnet® é mais eficaz do que a CDC luminosa e CDC com CO2 + Lurex3® para as atividades de vigilância entomológica. / Introduction: Automatic entomological traps are important tools for surveillance and control of mosquito vector species. Several studies showed both CDC trap with CO2 plus Lurex3® and CDC light trap to be effective for sampling mosquito species. The Mosquito Magnet® trap was compared with different collecting methods, including human landing, for sampling mosquito vectors. As a result, the former trap was demonstrated to have good sampling capacity. In the present study, efficacy of the Mosquito Magnet® Independence was compared with those of CDC light trap and CDC trap with CO2 plus Lurex3®, but no light. Collections were carried out in rural areas within the southeast Atlantic Forest biome. Objective: to compare the efficacy of a Mosquito Magnet® Independence plus Lurex3® with a CDC light trap and CDC trap with CO2 plus Lurex3®. Methods: Traps were installed in three different locations during three consecutive days in rural areas of the Iguape municipality, São Paulo state, Brazil. The traps were placed daily at 6h00 pm (or 7h00 pm during the summer day light savings) and removed at 6h00 am (or 7h00 am during the summer day light savings). To assess efficacy of the traps for collecting mosquito species, we employed the Rényis diversity profiles, in addition to other diversity indexes, i.e., richness, abundance, dominance, evenness, and similarity. Results: The Mosquito Magnet® trap collected 53.84 per cent of the total number (19,016 individuals) of mosquitoes obtained with all three traps. On the other hand, the CDC trap obtained the highest diversity indexes of Margalef and Shannon. The evenness index showed that species were distributed more evenly when using the CDC trap with CO2 and Lurex3®. However, the Mosquito Magnet® had the highest dominance index. The Kruskal-Wallis test showed a significant difference in the indexes of richness observed in the Rényi profile index. The Bonferroni test demonstrated that only the Mosquito Magnet® trap has a significant difference relative to the CDC light trap (p = 6e-05). The similarity index showed more resemblance between species collected by Mosquito Magnet® Independence and CDC trap with CO2 and Lurex3®. Conclusions: The present study shows that it is possible to collect large numbers of specimen with the Mosquito Magnet® Independence trap in rural areas in southeastern São Paulo State. In spite of the fact that the CDC trap did not abundantly collect mosquitos, it is considered an appropriate collecting method used by health service organizations because of its practicality and ease of transportation. However, results of the present study showed that the Mosquito Magnet® Independence is more effective than both CDC light trap and CDC with CO2 and Lurex3® for entomological surveillance.
142

Developing a Guide and Template to Aid the Preparation of Mosquito Surveillance Plans in Ohio

Flynn, Rebecca Anne 16 July 2018 (has links)
No description available.
143

Factors influencing U.S. canine heartworm (Dirofilaria immitis) prevalence

Wang, Dongmei, Bowman, Dwight, Brown, Heidi, Harrington, Laura, Kaufman, Phillip, McKay, Tanja, Nelson, Charles, Sharp, Julia, Lund, Robert January 2014 (has links)
BACKGROUND:This paper examines the individual factors that influence prevalence rates of canine heartworm in the contiguous United States. A data set provided by the Companion Animal Parasite Council, which contains county-by-county results of over nine million heartworm tests conducted during 2011 and 2012, is analyzed for predictive structure. The goal is to identify the factors that are important in predicting high canine heartworm prevalence rates.METHODS:The factors considered in this study are those envisioned to impact whether a dog is likely to have heartworm. The factors include climate conditions (annual temperature, precipitation, and relative humidity), socio-economic conditions (population density, household income), local topography (surface water and forestation coverage, elevation), and vector presence (several mosquito species). A baseline heartworm prevalence map is constructed using estimated proportions of positive tests in each county of the United States. A smoothing algorithm is employed to remove localized small-scale variation and highlight large-scale structures of the prevalence rates. Logistic regression is used to identify significant factors for predicting heartworm prevalence.RESULTS:All of the examined factors have power in predicting heartworm prevalence, including median household income, annual temperature, county elevation, and presence of the mosquitoes Aedes trivittatus, Aedes sierrensis and Culex quinquefasciatus. Interactions among factors also exist.CONCLUSIONS:The factors identified are significant in predicting heartworm prevalence. The factor list is likely incomplete due to data deficiencies. For example, coyotes and feral dogs are known reservoirs of heartworm infection. Unfortunately, no complete data of their populations were available. The regression model considered is currently being explored to forecast future values of heartworm prevalence.
144

Evolutionary ecology of reproductive strategies in malaria parasites

Carter, Lucy Mary January 2014 (has links)
For vector-borne parasites such as malaria, how within- and between-host processes interact to shape transmission is poorly understood. In the host, malaria parasites replicate asexually but for transmission via mosquitoes to occur, specialized sexual stages (gametocytes) must be produced. Once inside the mosquito vector, gametocytes immediately differentiate into male and female gametes, and motile male gametes must swim through the hostile environment of the bloodmeal to find and fertilise female gametes. Despite the central role that gametocytes play in disease transmission, explanations of why parasites adjust gametocyte production in response to in-host factors remain controversial. Furthermore, surprisingly little is known about the mating behaviour of malaria parasites once inside the mosquito. Developing drugs and/or vaccines that prevent transmission by disrupting sexual stages are major goals of biomedicine, but understanding variation in gametocyte investment and male gamete behaviour is key to the success of any intervention. First, I propose that the evolutionary theory developed to explain variation in reproductive effort in multicellular organisms provides a framework to understand gametocyte investment strategies in malaria parasites. I then demonstrate that parasites appear to change their reproductive strategies in response to environmental cues and in a manner consistent with our predictions. Next, I show how digital holographic microscopy can be used to characterise the morphology and motility of male gametes. I then provide evidence for non-random movement of male gametes and that gamete interactions with red blood cells appear to hinder mating success in a bloodmeal. Finally, I discuss the variation in gametocyte differentiation and fertilisation success when exposed to a number of factors implicated in gametocyte activation. The data presented here provides important information on the basic biology of malaria parasite reproductive stages and demonstrates considerable variation in parasite traits and behaviours in response environmental changes; both in the host and in the mosquito vector.
145

Characterisation of the response of Aedes mosquito cells to Semliki Forest virus infection

Siu, Ricky Wai Chi January 2012 (has links)
Arboviruses are transmitted to vertebrates by arthropod vectors such as mosquitoes or ticks. The replication of Semliki Forest virus (SFV) (Togaviridae; Alphavirus) in vertebrate cells is well established and triggers cell death. SFV infection of Aedes albopictus mosquito cells was characterised. Virus growth curves were compared in three cell lines. Infection of U4.4 cells was persistent and did not affect growth of the culture. In contrast, infection of C6/36 and C7-10 cells resulted in a static culture with no cell division and no cell death. The response of U4.4 cells was characterised in greater detail using viruses containing fluorescent or luciferase markers within the replicase or structural open reading frame of the virus genome. Activation of the STAT/IMD pathway prior to SFV infection significantly reduced virus driven luciferase expression and virus production. Activation of the Toll pathway prior to SFV infection had no effect. However, activation of Toll in addition to STAT/IMD had a cumulative effect on luciferase expression and virus production. viRNAs were characterised by Illumina Solexa sequencing. Two percent of the small RNA species found in virus infected cells were derived from virus RNA. These were predominantly 21 nt long and mapped along the entire SFV genome and genome complementary RNAs. Generation of these viRNAs was not random. Some areas produced high frequencies and others no or very few; hot and cold spots respectively. There were no correlations between viRNA frequency and base pairing or secondary structures predictions. Cold spot-derived viRNAs were more effective than hot-spot viRNAs in inhibiting virus replication. Similar results were observed in Aedes aegypti-derived cells. Attempts were made to investigate the source of these viRNAs using a virus containing an IRES element which had been reported to prevent virus replication in insect cells but which did not efficiently do so in this study. A virus containing the RNAi inhibitor p19 was characterised and shown to increase virus production. Techniques for infecting mosquitoes via a blood meal feed were established. No infection was observed with virus replicon particles carrying a fluorescent marker gene. Infection was established using virus containing p19.
146

Genomic, structural and functional characterization of odorant binding proteins in olfaction of mosquitoes involved in infectious disease transmission / Caractérisation génomique, structurale et fonctionnelle des protéines liant les molécules odorantes dans le système olfactif des moustiques vecteurs de maladies infectieuses

Manoharan, Malini 28 September 2011 (has links)
Dans le système olfactif des moustiques, les protéines liants les molécules odorantes ou odorant binding proteins (OBPs) interviennent dans les toutes premières étapes permettant d'aboutir à la reconnaissance de leurs hôtes et font l'objet d'un intérêt croissant dans les recherches sur la transmission des maladies infectieuses par ces insectes. Le travail présenté a pour objet d'approfondir les connaissances sur ces OBPs dans trois génomes de moustiques, tous vecteurs de maladies infectieuses : Anopheles gambiae, Aedes aegypti et Culex quinquefasciatus. Une analyse à l'échelle de ces génomes a été réalisée et a permis d'identifier un nombre important de nouveaux gènes d'OBPs notamment chez les espèces de moustiques Aedes aegypti et Culex quinquefasciatus. Complétée par une étude phylogénétique du répertoire complet de ces gènes dans les trois génomes étudiés, cette analyse a permis d'établir une nouvelle classification des sous familles des OBPs. Ce résultat démontre l'extraordinaire multiplicité et diversité des gènes impliqués dans l'olfaction chez ces espèces de moustiques tout en mettant en lumière certaines propriétés des séquences des OBPs qui sont hautement conservés chez les moustiques. Grâce à la disponibilité de certaines structures d'OBPs de moustiques ou d'autres insectes apparentées, des modèles structuraux de tous les OBPs de la sous famille dites Classic dans les trois génomes, soit au total 137 structures, ont été construits. Ces structures ont servi de base pour le criblage à grande échelle par docking moléculaire d'une chimiothèque de 126 molécules odorantes connues pour leurs propriétés attractives ou répulsives vis-à-vis des moustiques. Ces résultats fournissent pour la première fois, les bases structurales et fonctionnelles pour la compréhension au niveau moléculaire de l'efficacité de certains agents répulsifs tout comme de l'attractivité de certains agents provenant des émanations humaines. Par simulation de dynamique moléculaire, les changements qui s'opèrent dans une de ces OBPs lorsque celle ci, liée à une molécule odorante, se retrouve dans des conditions de pH modifiée ont été caractérisée et un mécanisme probable par lequel ces OBPs participeraient à la reconnaissance et la libération des molécules odorantes est proposée. Cette thèse fournit des éléments de réponses importants quant à la caractérisation génomique, structurale et fonctionnelle des OBPs de moustiques et peut servir de base de départ pour des recherches expérimentales plus approfondies sur ces aspects. / The role of odorant binding proteins in the olfaction of mosquitoes, the primary mechanism of human host recognition, has been an important focus of biological research in the field of infectious disease transmission by these insects. This thesis provides an in depth knowledge of these proteins in three mosquito species Anopheles gambiae, Aedes aegypti and Culex quinquefasciatus. A large scale analysis on these genomes has been carried out towards the identification of the odorant binding proteins in the mosquito genomes. Identification of many new OBP members, in particular in the Aedes aegypti and Culex quinquefasciatus species, and an extensive phylogenetic analysis presenting a novel classification of the OBP subfamilies of these mosquito species has been proposed. This results further demonstrates the extraordinary multiplicity and diversity of the OBP gene repertoire in these three mosquito genomes and highlights the striking sequence features that are nevertheless highly conserved across all mosquito OBPs. Owing to the availability of homologous structures from mosquitoes or related species, the 3D structure modelling of all the Classic OBPs from the three genomes (representing in total 137 structures) has been performed. This was completed by large scale docking studies on these structures by screening a large set of compounds that are known to be mosquito attractants or repellents. These provide many exciting new insights into the structural and functional aspects towards understanding the efficacy of some repellents and of some attractants from human emanations. Through molecular dynamics simulation, the structural changes observed in an OBP bounded to an odorant when pH conditions are modified were characterized and the probable mechanism of ligand binding and release is presented. This work provides the first insights to many of the long awaited questions on the genomic, structural and functional characterization of mosquito OBPs and can be viewed as a reliable starting point for further experimental research focussed on these aspects.
147

Metody odhadů složitosti důkazů ve výrokové logice / Methods of proving lower bounds in propositional logic

Peterová, Alena January 2013 (has links)
In the present work, we study the propositional proof complexity. First, we prove an exponential lower bound on the complexity of resolution applying directly Razborov's approximation method, which was previously used only for bounds on the size of monotone circuits. Next, we use the approximation method for a new proof of an exponential lower bound on the complexity of random resolution refutations. That should have further applications in separating some theories in bounded arithmetic. In both cases, we use a problem from the graph theory called Broken Mosquito Screens. Finally, we state a conjecture that the approximation method is applicable even for stronger propositional proof systems, for example Cutting Plane Proofs. Powered by TCPDF (www.tcpdf.org)
148

Struktura a využití Guerilla marketingu v praxi / Structure and application of guerilla marketing in practise

Ertelt, Marek January 2009 (has links)
Dissertation "Structure and application of guerilla marketing in practise" is concerned with detailed analysis of different types of guerilla marketing. It finds recommendation for an application of each type in dependence on the type of company. It uses a lot of real examples for this purpose. This dissertation also offers modern rules for creating efficient and succesfull guerilla campain. It is also concerned with the guerilla marketing legislation.
149

Insights into vector control through the modulation of An. gambiae G protein-coupled receptors

Regna, Kimberly January 2015 (has links)
Thesis advisor: Marc A.T. Muskavitch / Malaria is a life-threatening infectious disease caused by inoculation of the apicomplexan Plasmodium parasite into vertebrate hosts. Transmission of the parasite is mediated by the Anopheles mosquito, which has the capacity to efficiently transmit the parasite from host to host, as the disease vector. There are many factors that make anopheline mosquitoes competent vectors for disease transmission. The hematophagous (blood-feeding) behavior of the female mosquito is one of most fundamental factors in physical transmission of parasites, because the ingestion of blood from an infected host allows parasite entry into the mosquito and the completion of parasite sexual reproduction. In addition to this blood-feeding behavior, there are a host of biological (i.e., parasite replication) and behavioral factors (i.e., mosquito chemosensation, host preference) that contribute to the high vectorial capacity of these vector species. There are over four hundred Anopheles species worldwide, approximately forty of which are considered epidemiologically critical human malaria vectors. Anopheles gambiae, the primary vector in malaria-endemic sub-Saharan Africa, is responsible for the largest number of malaria cases in the world and is therefore one of the most important vectors to study and target with control measures. Currently, vector-targeted control strategies remain our most effective tools for reduction of malaria transmission and incidence. Although control efforts based on the deployment of insecticides have proven successful in the past and are still widely used, the threat and continuing increases of insecticide resistance motivate the discovery of novel insecticides. In this thesis, I provide evidence that G protein-coupled receptors (GPCRs) may serve as “druggable” targets for the development of new insecticides, through the modulation of developmental and sensory processes. In Chapter II, “A critical role for the Drosophila dopamine 1-like receptor Dop1R2 at the onset of metamorphosis,” I provide evidence supporting an essential role for this receptor in Drosophila melanogaster metamorphosis via transgenic RNA interference and pharmacological methods. In An. gambiae, we find that the receptor encoded by the mosquito ortholog GPRDOP2 can be inhibited in vitro using pharmacological antagonists, and that in vivo inhibition with such antagonists produces pre-adult lethality. These findings support the inference that this An. gambiae dopamine receptor may serve as a novel target for the development of vector-targeted larvicides. In Chapter III, “RNAi trigger delivery into Anopheles gambiae pupae,” I describe the development of a method for injection directly into the hemolymph of double strand RNA (dsRNA) during the pupal stage, and I demonstrate that knockdown of the translational product of the SRPN2 gene occurs efficiently, based on reductions in the levels of SRPN2 protein and formation of melanized pseudo-tumors, in SRPN2 knockdown mosquitoes. This method was developed for rapid knockdown of target genes, using a dye-labeled injection technique that allows for easy visualization of injection quality. This technique is further utilized in Chapter IV, “Uncovering the Role of an Anopheles gambiae G Protein-Coupled Receptor, GPRGR2, in the Detection of Noxious Compounds,” where the role for GPRGR2 in the detection of multiple noxious compounds is elucidated. We find that pupal stage knockdown of this receptor decreases the ability of adult Anopheles gambiae to identify multiple noxious compounds. While these findings provide a strong link between GPRGR2 and a very interesting mosquito behavior, they may also provide opportunities to develop better field-based strategies (i.e., insecticides baited traps) for vector control. The goal of this thesis is to understand the functional roles of selected mosquito GPCRs that may serve as targets for the development of new vector-targeted control strategies. Exploiting these GPCRs genetically and pharmacologically may provide insights into novel vector control targets that can be manipulated so as to decrease the vectorial capacity of An. gambiae and other malaria vectors in the field, and thereby decrease the burden of human malaria. / Thesis (PhD) — Boston College, 2015. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.
150

Métodos de coletas de mosquitos (Diptera: Culicidae) alternativos ao de atração humana direta

VIEIRA, Paoola Cristina Bezerra January 2007 (has links)
Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-02-01T20:25:56Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_MetodosColetasMosquitos.pdf: 3989932 bytes, checksum: e2eb87c0013bd429a0c794c17179b3c6 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-02-04T14:07:40Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_MetodosColetasMosquitos.pdf: 3989932 bytes, checksum: e2eb87c0013bd429a0c794c17179b3c6 (MD5) / Made available in DSpace on 2013-02-04T14:07:40Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_MetodosColetasMosquitos.pdf: 3989932 bytes, checksum: e2eb87c0013bd429a0c794c17179b3c6 (MD5) Previous issue date: 2007 / Vários métodos de captura de mosquitos foram desenvolvidos, demonstrando que houve uma evolução dos tipos de armadilhas ao longo do tempo, porém nenhum se comparou à coleta direta por Atração Humana (AH). Este trabalho teve por objetivo, testar métodos alternativos, desenvolvidos para coletar mosquitos, incluindo o desenvolvimento de novas técnicas, que podem substituir o método tradicional de captura direta em humanos. O estudo foi desenvolvido próximo ao Parque Ambiental de Belém, Pará, Brasil. Os métodos utilizados foram: armadilhas CDC, CDC UV, Shannon, armadilha desenvolvida por J. A. Rocha, armadilha desenvolvida por I. S. Gorayeb e coleta por AH. As armadilhas foram instaladas em seis pontos, por seis noites consecutivas. Foram capturados 13.099 espécimes de Culicidae distribuídas em sete gêneros e 27 espécies, sendo Anopheles trianulatus a mais abundante. Os dados foram tratados estatisticamente pelos métodos ANOVA, Análise multivariada – distâncias euclidianas. A coleta por AH direta foi o método que coletou maior diversidade e abundância de mosquitos, seguidos da armadilha de Shannon para abundância e armadilha de Gorayeb para diversidade. / Some methods capture of mosquitoes already had been developed, demonstrating that it had an evolution of the types of the trap to the long one of the time, however none has shown to be comparable to the direct human attraction (AH). This work had for objective, to test the methods alternative, developed to collect mosquitoes, including the development of new techniques, that can substitute the traditional method of direct human attraction. The study it was developed next to “Parque Ambiental de Belém”, Pará state, Brazil. The used methods were: traps CDC, CDC UV, Shannon, trap developed by Rocha, trap developed by Gorayeb and collect for AH direct. The traps were installed in six points, for six consecutive nights. Were captured 13,099 specimens of Culicidae of seven genera and 27 species, being Anopheles trianulatus the most abundant. The direct human attraction, what it collected greater diversity and abundance of mosquitoes, followed of the Shannon’s trap for abundance and Gorayeb’s trap for diversity.

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