• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 11
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 1
  • Tagged with
  • 28
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
11

An investigation of certain aspects of blackfly control.

Jamnback, Hugo Andrew 01 January 1951 (has links) (PDF)
No description available.
12

The role of bacteria and algae in the diet and distribution of black fly larvae /

Parkes, Alice January 2002 (has links)
Filter-feeding black fly larvae in lake outlet streams convert suspended bacteria and algae into benthic biomass, available to fish. Positive correlations between larval abundance and both bacterioplankton and phytoplankton were significant at the p < 0.10 level among 5 outlet streams of varying trophic status in the Eastern Townships of Quebec, and either food type alone explained &sim;28% of the variance in larval abundance among streams (Chapter 1), suggesting bacterioplankton and phytoplankton to play similar roles in larval distribution. However, when larvae were removed from 3 of 6 oligotrophic outlet streams examined in the Mauricie region of Quebec, calculated ingestion rates revealed larvae to ingest roughly 20 times more phytoplankton carbon than bacterial carbon (Chapter 2). Phytoplankton ingestion rates were high enough to satisfy daily carbon requirements, but bacterivory was low (Chapter 2), indicating that bacterial biomass contributes little to black fly diets in most systems, and will be less useful than phytoplankton biomass when using food to predict larval distribution. The majority of bacteria in streams form a carbon link to fish through sediment food webs, rather than through black fly larvae.
13

The role of bacteria and algae in the diet and distribution of black fly larvae /

Parkes, Alice January 2002 (has links)
No description available.
14

Conservation implications of common loon (Gavia immer) parasites, black flies, haematozoans, and the role of mercury

Weinandt, Meggin Leigh, January 2006 (has links)
Thesis (M.S.)--Northern Michigan University, 2006. / Bibliography: leaves 61-67.
15

Estudo epidemiológico para a avaliação da eliminação da Oncocercose em áreas sentinelas da Região Amazônica, Brasil

Silva, Verônica Marchon da January 2015 (has links)
Submitted by Angelo Silva (asilva@icict.fiocruz.br) on 2016-07-13T18:31:00Z No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 71824.pdf: 2172041 bytes, checksum: 706d176d456c37e0c405bbdd3df5101a (MD5) / Approved for entry into archive by Anderson Silva (avargas@icict.fiocruz.br) on 2016-07-21T19:07:35Z (GMT) No. of bitstreams: 2 71824.pdf: 2172041 bytes, checksum: 706d176d456c37e0c405bbdd3df5101a (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) / Made available in DSpace on 2016-07-21T19:07:35Z (GMT). No. of bitstreams: 2 71824.pdf: 2172041 bytes, checksum: 706d176d456c37e0c405bbdd3df5101a (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2015 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil / No Brasil, a área endêmica para oncocercose está restrita a Amazônia, em Terra Indígena Yanomami. O Programa Brasileiro de Eliminação da Oncocercose (PBEO) adota como principal estratégia de controle o tratamento em massa dessa população com Ivermectina, estando em consonância com o Programa para Eliminação da Oncocercose nas Américas (OEPA) e os outros cinco países endêmicos na América Latina \2013 México, Guatemala, Equador, Colômbia e Venezuela. De acordo com estratégias de monitoramento definidas pela Organização Mundial da Saúde (OMS), foi realizado esse estudo visando à disponibilização de ferramentas para avaliação do estado epidemiológico da oncocercose baseadas em análises de parâmetros entomológicos, fornecendo subsídios para medidas e as ações efetivas de controle. Foram realizadas, de 2009 a 2011, avaliações entomológicas, moleculares e epidemiológicas nos três polos base sentinelas para o PBEO \2013 Xitei (subpolo Ketaa e Watatase), Balawau (subpolo Maxapapi e Wanapiu) e Toototobi (subpolo Xiroxiropiu) para o monitoramento do impacto das estratégias de controle do PBEO/OEPA na transmissão da oncocercose no Brasil. Para análise dos parâmetros entomológicos foram realizadas capturas sistemáticas mensais de simulídeos, de 4-8 dias consecutivos de 7-18h Para análise molecular, grupos de até 50 fêmeas foram organizados de acordo com a espécie e outros parâmetros, separados em cabeças e corpos e cada grupo foi testado para a presença de DNA do parasito por PCR-ELISA. Do total de 74.397 simulídeos capturados (54% S. guianense; 40% S. incrustatum; 6% S. oyapockense), 16.971 foram coletados em Xitei/Watatase, 22.910 em Xitei/Ketaa, 2.301 em Balawaú/Maxapapi, 10.986 em Balawaú/Wanapiu e 21.229 de Toototobi. Do total de 1559 pools examinados (821 de Xitei, 302 de Balawaú e 436 de Toototobi), a prevalência estimada de S. guianense infectado foi de 1,0/2.000 simulídeos (95% LSIC \2013 2,2) no polo base Toototobi e 0,5/2.000 simulídeos (95% LSIC \2013 1,4) no polo base Balawaú. Simulim incrustatum e S. oyapockense não apresentaram nenhum pool considerado positivo. Neste estudo, o uso de diagnóstico molecular combinado com a identificação e aspectos bionômicos das espécies vetores e análises epidemiológicas possibilitou avaliar as informações sobre o estado da transmissão da oncocercose após a intervenção de 15 anos de tratamento com ivermectina. Com base nos parâmetros entomológicos de prevalência da infectividade (TI) e o potencial de transmissão anual (PTA) detectado abaixo do preconizado para as áreas sentinela foi possível verificar para período estudado a supressão da transmissão da oncocercose nas três áreas sentinela \2013 Xitei, Balawaú e Toototobi / Abstract: In Brazil, the onchocerciasis endemic area is restricted to the Amazon region, in the Yanomami area. The Brazilian Program to Eliminate Onchocerciasis (PBEO) adopts as the most important strategy to control the mass treatment of this population with Ivermectina, and so does the Onchocerciasis Elimination Program for the Americas (OEPA), as well as the other five endemic countries in Latin America - Mexico, Guatemala, Equador, Colombia and Venezuela. According to the strategies defined by the World Health Organization (WHO) this study was done aiming the availability of tools for the evaluation of the epidemiological status onchocerciasis based on entomologic parameters, offering subsidies for the study and effective controlling actions. Were conducted, from 2009 to 2011, entomological, molecular and epidemiological evaluations in three sentinels areas under surveillance of PBEO \2013 Xitei (Ketaa and Watatase), Balawau (Maxapapi and Wanapiu) and Toototobi (Xiroxiropiu) to monitor the PBEO/OEPA controlling strategies impact in the onchocerciasis transmission in Brazil. To analyze the entomological parameters, monthly, simulids captures from 4-8 consecutive days, between the hours of 7am\20136pm were done. For the molecular analysis, groups of up to 50 females were organized according to species and other parameters, separated in heads and bodies and each group was tested through PCR-ELISA, for the presence of the DNA parasite From a total of 74,397 captured simulids (54% S. guianense, 40% S. incrustatum; 3% S. oyapockense); 16,971 were captured from Xitei/ Watatase, 22,910 from Xitei/Ketaa, 2,301 from Balawau/Maxapapi, 10,986 from Balawau/Wanapiu and 21,229 from Toototobi. In a total of 1,559 pools examined (821 from Xitei, 302 from Balawau and 436 from Toototobi), the estimated prevalence of infected S. guianense was 1.0/2,000 simulids (95% L SIC\20132.2) in the Toototobi area, and 0.5/2,000, simulids (95% L SIC \2013 1.4) in the Balawau area. Simulium incrustatum and S. oyapockense did not present any pool considered positive. In this study, the use of molecular diagnostic combined with the identification and bionomic aspects of the vector species, and epidemiologic analysis, assisted in the evaluation of the Onchocerciasis transmission after 15 years of Ivermectina treatment, there are presenting an updated epidemiological profile of the disease in the Brazilian Amazon. Based on entomological parameters of prevalence of infectivity (IT) and the potential for transmission (PTA) detected below levels considered the sentinel areas was verified for the period studied the suppression of onchocerciasis transmission in the three sentinel areas\2013 Xitei, Balawaú e Toototobi
16

The Influence of developmental temperature on the adult survival of Simulium chutteri (Diptera: Simuliidae)

Myburgh, Ernest 21 November 2005 (has links)
Simulium chutteri is considered a major pest in South Africa and it has been estimated that it can potentially cause stock losses amounting to more than R88 million per annum. Although a larval control programme has been launched to control the pest, major outbreaks still occur, since major fitness traits such as longevity are ignored in the planning of control actions. To improve the control programme, the aim of this study was to study the longevity of S. chutteri females under various conditions, and also to relate longevity to factors such as size, mass and metabolic reserves as these traits show variation that can be linked to changes in developmental temperature. It was conclusively demonstrated in this study that the body size and mass of S. chutteri increases with a decrease in temperature and therefore both seasonal and geographical variations occur. A consequence of larger body size is that these individuals carry proportionally more lipid reserves than smaller ones, although these relationships were not found for glycogen. It was shown that major seasonal variation occurred in the survival of S. chutteri, although these could not be attributed solely to variations in size, mass and metabolic reserves. For example, despite the large body size and mass and metabolic reserves of the winter population, it showed comparatively lower survival than all the other populations. It is argued that this is due to the interaction between fecundity and other fitness traits such as desiccation and starvation resistance. Adaptive explanations are, however, also proposed. These results are used to explain the seasonal variation found in the annoyance levels of S. chutteri along the lower Orange River. Moreover, recommendations are given for the improvement of the current blackfly control programme. These include the need to control the summer population (when certain criteria are met) and showing the importance of effectively controlling the winter population. / Dissertation (MSc (Entomology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted
17

Utility of the Cytochrome Oxidase I gene (COI) for Species Identification and Phylogeographic Analysis in Black Flies (Diptera: Simuliidae)

Rivera Castillo, Julio Martin 26 February 2009 (has links)
A short sequence of ca. 658-bp of the mitochondrial gene COI was used to investigate its utility as a DNA barcode in the medically important Simuliidae or black flies. Sixty-five species and species complexes were tested. Results indicate that the barcoding gene discriminated among morphologically distinct species with nearly 100% of efficacy and proved useful for revealing cryptic diversity. The DNA barcoding gene was also tested for revealing phylogeographic patterns in the western cordilleran Prosimulium travisi and the Prosimulium neomacropyga species-group. Phylogeographic analyses on these species revealed areas that acted as glacial refugia, postglacial history, cryptic speciation episodes and timing of the events that lead to their present-day distribution. The results obtained concur with other phylogeographic studies on similarly-distributed cordilleran organisms. In conclusion, the barcoding gene not only resulted useful for species discrimination in black flies but also for studies at the population level, providing value-added to this molecular marker.
18

Utility of the Cytochrome Oxidase I gene (COI) for Species Identification and Phylogeographic Analysis in Black Flies (Diptera: Simuliidae)

Rivera Castillo, Julio Martin 26 February 2009 (has links)
A short sequence of ca. 658-bp of the mitochondrial gene COI was used to investigate its utility as a DNA barcode in the medically important Simuliidae or black flies. Sixty-five species and species complexes were tested. Results indicate that the barcoding gene discriminated among morphologically distinct species with nearly 100% of efficacy and proved useful for revealing cryptic diversity. The DNA barcoding gene was also tested for revealing phylogeographic patterns in the western cordilleran Prosimulium travisi and the Prosimulium neomacropyga species-group. Phylogeographic analyses on these species revealed areas that acted as glacial refugia, postglacial history, cryptic speciation episodes and timing of the events that lead to their present-day distribution. The results obtained concur with other phylogeographic studies on similarly-distributed cordilleran organisms. In conclusion, the barcoding gene not only resulted useful for species discrimination in black flies but also for studies at the population level, providing value-added to this molecular marker.
19

Études sur Isomermis lairdi (Nematoda, Mermithidae), parasite de Simulium damnosum S.L. (Diptera, Simuliidae) en Afrique de l'Ouest.

Mondet, Bernard, January 1981 (has links)
Th. 3e cycle--Entomol., méd. vét.--Paris 11--Orsay, 1980. N°: 2868.
20

Associations among selected physico-chemical parameters and Simuliidae (Diptera) from 23 lake-outlet sites in Newfoundland /

Perez, J. M. January 1999 (has links)
Thesis (M.Sc.)--Memorial University of Newfoundland, 1999. / Restricted until June 2000. Bibliography: leaves 136-149.

Page generated in 0.0242 seconds