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1
Greenfield, Bethany Patricia Jane. "Metarhizium pathogenesis of mosquito larvae". Thesis, Swansea University, 2014. https://cronfa.swan.ac.uk/Record/cronfa42819.
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2
Timmins, William Andrew. "Control of feeding in Manduca sexta larvae". Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380387.
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3
Rethwisch, Michael D., e S. Sherwood Winans. "Control of Liriomyza trifolii Larvae in Head Lettuce". College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/214282.
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4
Theron, Dirk Leopold. "The biological control of malaria mosquito larvae using smaller indigenous freshwater fish species". Thesis, University of Limpopo, 1987. http://hdl.handle.net/10386/2611.
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5
Palumbo, John C. "Management of Lepidopterous Larvae Under Experimental, Biorational and Conventional Control Programs in Lettuce". College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/221643.
Testo completoAbstract (sommario):
A large block experiment was conducted at the Yuma Ag Center to compare the field performance of three lettuce management programs for control of lepidopterous larvae. Conventional, experimental and biorational insecticides were sprayed to control beet armyworm, cabbage looper and Heliothis species throughout the growing season. Differences in populations of total larvae among the four treatments, relative to insecticide treatments and timing of application were observed throughout the season. In general, the standard and experimental treatments provided the most consistent control of lepidopterous larvae following each application. Harvest data showed that the spray regimes had a significant influence of head lettuce yield or quality. Maturity and quality were significantly reduced in the untreated control. An economic analysis shows that net returns varied widely among the management programs at different market prices. In conclusion, this study provides preliminary data to support the need for more development of experimental and biorational insecticide products as alternatives to conventional management programs in desert lettuce production.
6
Autran, Lyris. "Feeding preferences of Chaoborus americanus larvae (Diptera:Chaoboridae) and their potential effect on mosquito populations". Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33376.
Testo completoAbstract (sommario):
Chaoborus americanus larvae were used in laboratory experiments to assess their efficiency at decreasing mosquito larval populations. Third and fourth instar Chaoborus americanus larvae were independently fed assemblages of single prey species to test hunger and several prey species to test preference. Prey species included Daphnia and the four Aedes aegypti larval instars. The results show that Chaoborus americanus larvae will choose early instar mosquito larvae over Daphnia, however, this preference decreases as the mosquito larvae become older. Third instar Chaoborus americanus larvae will choose first instar mosquito larvae over Daphnia 76% of the time, whereas they will select third instar mosquito larvae only 30% of the time. Fourth instar Chaoborus americanus larvae will choose first instar mosquito larvae 94% of the time, and select fourth instar mosquito larvae only 3% of the time. Crowding also has an effect on feeding times; individual Chaoborus larvae take more time to ingest their prey items than do individuals within a group. Chaoborus americanus larvae are good biological control agents within a laboratory setting.
7
Halwani, Adla E. "Role of apolipophorin-III in the immediate antibacterial responses of Galleria mellonella larvae (Lepidoptera:Pyralidae)". Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36602.
Testo completoAbstract (sommario):
Apolipophorin-III is a hemolymph protein known for its role in lipid transport. Apolipophorin-III isolated from the hemolymph of last instar larvae of Galleria mellonella bound to the surface of the insect pathogenic Gram-negative bacterium Xenorhabdus nematophilus and to the lipid A moiety of its lipopolysaccharide. This binding reduced the toxicity of the lipopolysaccharide to hemocytes and decreased the inhibitory effect of the lipopolysaccharide on phenoloxidase. Apolipophorin-III also bound to the Gram-positive bacterium Micrococcus lysodeikticus; this enhanced the activity of hen egg lysozyme on the organism as well as the lytic activity of G. mellonella cell-free hemolymph.The involvement of apolipophorin-III in the immune responses of G. mellonella larvae to lipoteichoic acids, surface components of Gram-positive bacteria, was examined. Lipoteichoic acids from Bacillus subtilis, Enterococcus hirae and Streptococcus pyogenes caused a dose- and time-dependent drop in the total counts of circulating hemocytes and a partial or complete depletion of plasmatocytes depending on the species of lipoteichoic acid. All lipoteichoic acids tested activated phenoloxidase in vitro; however, in vivo, only B. subtilis lipoteichoic acid elevated the phenoloxidase activity while the other two suppressed it. Binding of apolipophorin-III to lipoteichoic acids was demonstrated. Apolipophorin-III prevented the complete depletion of plasmatocytes and depressed the activation of phenoloxidase by lipoteichoic acid from B. subtilis. The concentration of apolipophorin-III in hemolymph two hours post injections of lipopolysaccharides or lipoteichoic acids into larvae of G. mellonella did not change with respect to control insects that received phosphate-buffered saline. The concentration of apolipophorin-III in hemolymph at the end of the feeding larval stage was 8--12 mg/mL of hemolymph. Apolipophorin-III was present in significant amounts in the prepupal, pupal and adult stages. The protein was detected immunologically in hemocyte lysates, plasma and fat body. Non-denaturing polyacrylamide gels and immunoblots of fresh hemolymph suggested that apolipophorin-III is associated with a 77 kDa protein.
8
Zhang, Yun [Verfasser]. "Augmin complex components control branching of sensory neuron dendrites in Drosophila larvae. / Yun Zhang". Bonn : Universitäts- und Landesbibliothek Bonn, 2016. http://d-nb.info/1107184355/34.
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9
Yu, Sanke. "Experimental Trichinellosis : control induced in CD-1 mice by different antigen preparations from L1 larvae". Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66243.
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10
Dongus, Stefan. "Urban agriculture and operational mosquito larvae control : mitigating malaria risk in Dar es Salaam, Tanzania /". [S.l.] : [s.n.], 2009. http://edoc.unibas.ch/diss/DissB_8749.
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11
Santos, Cíntia Pinheiro dos. "Desenvolvimento de metodologia para controle das larvas de Limnoperna fortunei com o uso de radiação ultravioleta e seus impactos sobre Microscystis aeruginosa potencialmente presentes na água superficial". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/37458.
Testo completoAbstract (sommario):
Este trabalho objetivou adaptar um método de controle de larvas do mexilhão dourado (Limnoperna fortunei) com a utilização de radiação ultravioleta e verificar seu efeito sobre cianobactérias e cianotoxinas presentes na água. Limnoperna fortunei (Dunker, 1857), conhecido vulgarmente como mexilhão dourado é proveniente do sudeste asiático. Foi, provavelmente, introduzido nos nossos mananciais, não intencionalmente, através da água de lastro, com os primeiros registros na América do Sul, em 1991, no Rio da Prata, nas proximidades de Buenos Aires, Argentina. No Brasil foi visto pela primeira vez na área do Delta do Jacuí, em frente ao porto de Porto Alegre, RS, no ano de 1998. Além de ameaçar à biodiversidade de ecossistemas, vem provocando a obstrução das tubulações e trocadores de calor junto às estações de tratamento de água e indústrias que utilizam água bruta para resfriamento. As estações de tratamento, além de enfrentarem problemas com o entupimento pelo mexilhão, defrontam-se também com as florações de cianobactérias. As florações, conhecidas também como blooms, são eventos de multiplicação e acumulação de microalgas ou cianobactérias nos corpos hídricos, que podem durar de algumas horas ao longo do dia a meses. As cianobactérias podem liberar cianotoxinas que estão presentes principalmente no interior das células, e são liberadas na lise celular, que ocorre principalmente por senescência natural. Os experimentos foram realizados em uma unidade piloto, onde concentrações conhecidas de larvas do mexilhão dourado foram submetidas a doses de radiação ultravioleta, na faixa de 200 a 800 mWs/cm2. As amostras de água bruta utilizadas nos testes foram avaliadas por meio de métodos analíticos adequados (APHA, 2005). Foram determinados os parâmetros de temperatura (°C), pH, turbidez (NTU), dureza (mgCaCO3/L) e sólidos suspensos (mg/L), os quais poderiam influenciar nas condições dos testes. As mesmas condições testadas para o mexilhão foram utilizadas nos experimentos com cianobactérias. As larvas de mexilhão dourado e a água bruta utilizada no experimento foram obtidos no delta do Jacui, Porto Alegre, Rio Grande do Sul, Brasil. A cianobactéria Microcystis aeruginosa, produtora de microcistina, foi cultivada em laboratório. A mortalidade instantânea das larvas aproximou-se dos 100% nas condições do teste com a dosagem de 781mWs/cm2 , com DL50 de 324 mWs/cm2. Na água residual dos experimentos de exposição à radiação UV, foram realizados ensaios ecotoxicológicos crônicos com Pimephales promelas, Ceriodaphnia dubia e Selenastrum capricornutum, a fim de detectar a presença de subprodutos que poderiam gerar toxicidade aos organismos de diferentes níveis tróficos. Os resultados desta avaliação ecotoxicológica não demonstraram toxicidade residual. Os dados obtidos demonstraram-se satisfatórios no controle daslarvas de mexilhão, entretanto não promoveram a lise das células de M. aeruginosa e a conseqüente liberação de microcistinas nas condições testadas.L. fortunei (Dunker, 1857), commonly known as golden mussel comes from Southeast Asia. It might have been unintentionally introduced in our water sources through ballast water, with the first records in 1991, in Rio de la Plata, near Buenos Aires, Argentina, South America. In Brazil it was first seen in 1998, in Jacuí Delta, opposite Porto Alegre’s harbor. Besides threatening the biodiversity of ecosystems, this mussel has caused the obstruction of pipes and heat exchangers along the water treatment plants and industries that use raw water for cooling. Treatment plants facing problems with the clogging of mussels also have to contend with the cyanobacterial blooms. The blooms are events of multiplication and accumulation of algae or cyanobacteria in water bodies that can last from a few hours to days or months. The cyanobacteria may release cyanotoxins present mainly in cells and are released upon cell lysis, which occurs primarily by natural senescence. Thus, the aim of study is to adapt a control method of golden mussel larvae (L. fortunei) using ultraviolet radiation and verify its effect on cyanobacteria and cyanotoxins in the water. The experiments were performed in a pilot unit, where known concentrations of mussel larvae were subjected to doses of ultraviolet radiation ranging from 200 to 800 mWs/cm2, and the quality of water used, evaluated. The same conditions tested for the mussels were used in experiments with cyanobacteria. Mussel larvae and raw water used in the experiments were obtained from the Jacuí Delta, Porto Alegre, Rio Grande do Sul, Brazil. The cyanobacteria Microcystis aeruginosa, witch produces microcystin, was grown in culture in our laboratory. The instantaneous mortality of larvae was approximately 100% with 781mWs/cm2 in test conditions, with LD50 of 324 mWs/cm2. Ecotoxicological tests were performed with Pimephales promelas, Ceriodaphnia dubia, and Selenastrum capricornutum, to detect the presence of byproducts that could cause toxicity to organisms of different trophic levels in the residual water. The results of ecotoxicological evaluation showed no residual toxicity. The data showed to be satisfactory in larvae control, but did not cause lysis in cells of M. aeruginosa and the consequent release of microcystins in the water.
12
Jacobs, Philippe 1961. "Plagiorchis noblei and blackfly larvae : factors affecting parasite acquisition and the effect of infection on host survival". Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60532.
Testo completoAbstract (sommario):
Cercariae of the digenean Plagiorchis noblei penetrate and kill a variety of aquatic larval dipterans. The present study determined whether these parasites can infect blackfly larvae, and established what biotic and abiotic factors affect parasite acquisition and the survival of infected hosts in the laboratory. Four species of blackfly larvae, Prosimulium mixtum, Simulium vittatum, S. decorum, and Stegopterna mutata, were exposed to cercariae in flowing water. Prevalence and intensity of infection of all species varied directly with exposure intensity and decreased with increasing water velocity, prevalence increased with larval size. Infection levels were higher for P. mixtum. The production of silk strands by the blackfly larvae and their persistence at low water velocities may facilitate parasite acquisition. Mortality among infected larvae of all species was three times that of controls. The data suggest that exposure to P. noblei cercariae adversely affected the survival of blackfly larvae.
13
Saville, Benjamin Grayham. "Differentiation of virulent and biological control Paenibacillus larvae strains associated with American foulbrood in bee hives". Thesis, University of York, 2011. http://etheses.whiterose.ac.uk/3992/.
Testo completoAbstract (sommario):
The detection and control of American Foulbrood (AFB) is made more challenging due to a lack of evidence regarding the virulence mechanisms employed by this honeybee pathogen. Whilst incidence of this pathogen within the UK has recently declined, ~100 colonies were identified as infected with AFB in 2011 (to end of September), so AFB should still be considered a serious threat to honeybee health. It is known that within the species many phenotypes exist, and the infection caused by the phenotypes differs greatly. This PhD thesis presents several advances towards a greater understanding of the intra-specific differences occurring within the species. Chapter 2 evaluates the use of 16S rRNA sequencing as a method of Paenibacillus larvae identification, as well as exploring the use of this ribosomal subunit for differentiation of the species. The sequencing of two housekeeping (purH and PyrE) genes assesses the potential of a Multi Locus Sequence Typing (MLST) method, as a means of subspecies differentiation. Chapter 3 assesses what can be inferred from use of Enterobacterial Repetitive Intergenic Consensus (ERIC) sequence fingerprinting, with regards to prior knowledge genetic differences. Lateral Flow Devices (LFDs), a commonly used diagnostic tool, are tested to ensure P. larvae isolates representing all 4 ERIC types are detected. In Chapter 4 an in-vitro honeybee rearing method is employed to observe the correlation between proteolytic activity of isolates and in-vitro virulence. The method is applied to a wider range of reference isolates, to observe the intra-species differences existing. The ability to produce large numbers of viable spores is explored as a potential difference existing between ERIC types I and IV. Whole genome shotgun sequencing is used in chapter 5 to perform comparative genomic studies on 4 P. larvae isolates also utilising 646 contigs from a previous sequencing project. The possible presence of plasmid DNA is explored, through GC content analysis. The genetic basis of a sporulation phenotypic difference is examined by BLAST analysis of orthologous genes. In Chapter 6 the findings of this thesis are discussed in more detail, and potential areas of further study are identified.
14
Cavalcanti, Luciano Pamplona de GÃes. "Potential of five species of fish as method of biological control of Aedes aegypti larvae, in conditions of laboratory, in CearÃ". Universidade Federal do CearÃ, 2006. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=36.
Testo completoAbstract (sommario):
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgicoDengue fever has been shown to be one of the main public health problems in Cearà the principal vector is the Aedes aegypti mosquito In recent decades chemical control has been under question, both due to the insectâs selective resistance capacity and for environmental reasons Thus the use of biological alternatives has been encouraged worldwide Consequently the objective of this study was to evaluate 5 fish species that have been used as an alternative for the control of Aedes aegypti larvae in domestic water tanks in the State of Cearà Brazil The species evaluated were Betta splendens Trichogaster trichopteros Astyanax fasciatus e Poecilias reticulata and sphenops Larvae-eating capacity prefered predation locations and resistence to chlorine were evaluated All five species had a high larvae-eating capacity; Betta splendens and Poecilias were noteworthy for their larger capacity in relation to weight and body size Astyanax fasciatus and Betta splendens appeared to survive well without the presence of larvae or artificial food in the domestic water tanks whilst Poecilias presented a significant weight loss during the 5-week evaluation Regarding the location of predation it was observed that Poecilias spent most of the time at the surface whereas Trichogaster and Betta had greater mobility in the container As to chorine resistance Poecilias had a significant mortality when exposed to concentrations of 0.5mg/litre while other species of Betta and Trichogaster were able to survive concentrations up to 4.00mg/litre Therefore it was possible to demonstrate that the 5 species can be used as biological control alternatives although each one is indicated for different water tanks due mainly to the food available and the chlorine concentrations
O dengue vem se mostrando como um dos principais problemas de saÃde pÃblica no Cearà e o mosquito Aedes aegypti à seu principal vetor Nas Ãltimas dÃcadas o controle quÃmico vem sendo questionado tanto pela capacidade de seleÃÃo de resistÃncia dos insetos quanto por questÃes ambientais Com isso o uso de alternativas biolÃgicas vem sendo incentivado no mundo Desta forma o objetivo deste trabalho foi avaliar 5 espÃcies de peixe que vem sendo utilizados como alternativa de controle para larvas de Aedes aegypti em depÃsitos domiciliares no Estado do Cearà As espÃcies avaliadas foram o Betta splendens Trichogaster trichopteros Astyanax fasciatus e Poecilias reticulata e sphenops Foram avaliadas capacidade larvÃfaga locais preferenciais de predaÃÃo e resistÃncia ao cloro Todas as cinco espÃcies apresentaram uma elevada capacidade larvÃfaga destacando-se o Betta splendens e os Poecilias por apresentarem as maiores capacidades em relaÃÃo ao peso e tamanho corporal As espÃcies Astyanax fasciatus e Betta splendens parecem sobreviver bem sem a presenÃa de larvas ou alimentos artificiais nos reservatÃrios domiciliares enquanto os Poecilias apresentam uma perda significativa de peso durante as 5 semanas de avaliaÃÃo Em relaÃÃo ao local de predaÃÃo foi possÃvel observar que os Poecilias permaneceram a maior parte do tempo na superfÃcie enquanto o Trichogaster e o Betta apresentaram uma maior mobilidade no reservatÃrio Quanto à resistÃncia ao cloro mostrou-se que as espÃcies de Poecilias jà apresentam uma significativa mortalidade quando expostos à concentraÃÃes de 0,5mg/litro enquanto alguns espÃcimens do Betta e do Trichogaster mostraram capacidade de sobreviver atà concentraÃÃes de 4,00mg/litro Desta forma foi possÃvel demonstrar que as 5 espÃcies podem ser utilizadas como alternativa de controle biolÃgico entretanto cada uma se apresenta mais indicada a depÃsitos diferentes devido principalmente a oferta de alimentaÃÃo e concentraÃÃo de cloro
15
Attramadal, Kari Johanne Kihle. "Water treatment as an approach to increase microbial control in the culture of cold water marine larvae". Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for biologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-15426.
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16
Rüdiger, Nikolas [Verfasser], e Jörg [Akademischer Betreuer] Ganzhorn. "Control and eradication of migrating parasitic nematode larvae by innate effector cells / Nikolas Rüdiger ; Betreuer: Jörg Ganzhorn". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2019. http://d-nb.info/1186892099/34.
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17
Pienaar, Anthony Graham. "A study of coeval sibling cannibalism in larval and juvenile fishes and its control under culture conditions". Thesis, Rhodes University, 1990. http://hdl.handle.net/10962/d1005469.
Testo completoAbstract (sommario):
The primary objective of this study was to examine environmental parameters thought to affect cannibalism in certain fish species. It was found that environmental, behavioural, genetic and physiological factors all affect cannibalism in the species exhibiting the phenomenon. The diversity of factors nfluencing cannibalism served to illustrate the complexity of this behaviour pattern. Feeding to satiation was found to suppress cannibalism in catfish, trout and koi carp. High population densities were found to increase the rate of cannibalism, thereby acting as a population regulation mechanism for catfish, trout and the common and koi carps. Live food, as compared with dry pelletized feed was found to significantly suppress cannibalistic aggression. Catfish grown in total darkness, provided with refuges and living in turbid conditions were found to exhibit lowered cannibalistic and territorial aggression. Various lines of evidence suggested that cannibalism has a genetic basis, as was shown by the differences in cannibalistic behaviour of the two strains of Cyprinus carpio, viz. common and koi carp, with cannibalism being higher in the latter. This finding substantiates the hypothesis that cannibalism is genetically controlled and therefore open to evolutionary change. It is concluded that cannibalism is adaptive in times of food limitation, but that it is merely a by-product of normal feeding behaviour when food is abundant. Since cannibalism is advantageous and thus adaptive, the question arises ai to whether selection is occurring at the individual or the population level (or both). It was concluded that it is acting at the individual level, and that any benefits accruing at the population level iv were simply the effect of the initial cause, viz. individual selection. One of the aims of this study was to determine whether cannibalistic tendencies in fish are influenced by differing life history style trajectories. Based on the results of this study it is hypothesized that cannibalism is an r-selected trait. wi th the understanding gained from the knowl edge of the fundamental principles governing cannibalism, certain recommendations for its control in fish culture could be made. It is, however, imperative that further intensive studies be carried out to understand more fully this complex subject. General "rules" for regulating cannibalism could be helpful for any given cannibalistic species. However, in considering the differing life-history styles of each species, it becomes evident that species-specific guidelines need to be worked out. Until then, any suggestions for cannibalistic control offered to the aquaculturist can only serve as unrefined tools.
18
Salze, Guillaume Pierre. "Nutritional control of gene expression, larval development and physiology in fish". Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/29655.
Testo completoAbstract (sommario):
During preliminary research on cobia (Rachycentron canadum, L.) it became increasingly clear that more in-depth information was required to provide enabling techniques for the cobia aquaculture industry to develop more rapidly. A unifying theme in many of the more important issues facing cobia aquaculture is nutrition. This led to nutritional investigations with larval and juvenile fish highlighting the impacts of dietary ingredients on animal performance. Indeed, nutrition can be viewed as a central lever of action through which many aspects of the physiology and the environmental (water) quality of the animal can be controlled.
The first project focused on studying the larval development of cobia, a fish species highly suitable for aquaculture for which the industry is nascent. I described the time-course of development of external sensory organs, gut morphology and relevant digestive enzymes under controlled conditions using electron microscopy, histology and spectrophotometric assays. The developmental sequence of larval cobia could be separated in two phases, with a transition period between 12 and 14 days post hatch (dph). This transition is characterized by the formation of the intestinal loop, the establishment of basic cranial neuromast configuration, leading to the initiation of the onset of pancreatic enzymes and the increase of growth rate. In addition, the effects of dietary taurine supplementation and incorporation of mannan oligosaccharides (MOS) into live feeds on cobia larvae development was examined. Fish fed supplementary MOS did not grow faster but displayed higher microvilli length and density. In addition, MOS-fed fish were more resistant to salinity stress. The dietary supplementation of taurine resulted in a dramatic increase in survival, growth and development rates, and enzymatic activities.
The second project aimed at refining cobia juvenile nutrition, assessing fish meal and fish oil replacements. Novel sources, including soy protein and oil, were investigated with and without amino acid and MOS supplementations, yielding promising results. Indeed, both fish meal and fish oil were replaced completely and successfully in feeds for juvenile cobia. In addition, novel ingredients (e.g. marine algae meals and soy protein concentrate) were identified to effectively achieve such replacement.
The third and last project dealt with nutrient-gene interactions, specifically centering attention on immunostimulants for which the underlying mechanisms of action remain poorly characterized. Here, dietary MOS, nucleotides and selenomethionine (Se-met) were offered to zebrafish whose transcriptome was analyzed by microarray. The immune system, humoral or cellular, innate or adaptive, exhibited different patterns of response according to the immunostimulating nutrient used. In addition, various genes involved in cell cycle and cytokinesis were concomitantly expressed. An intriguing observation related to the insulinomimetic effect of Se-met. In other words, Se-met impacted pathways normally regulated by insulin, such as the MAPK and PI3K pathways. Some Insulin-like Growth Factors (IGF) and IGF bindgin proteins were up-regulated. Additional research is however necessary prior to advocating for the use of these additives, in order to further investigate their respective pros and cons.Ph. D.
19
Rombe, Bandeira Romana. "The ecology of Papilio demodocus Esper (Lepidoptera: Papilionidae) on citrus tree plantations in southern Mozambique". Thesis, University of Aberdeen, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324147.
Testo completo
20
Schirocki, Anke Gabriele. "The effect of temperature on invasion and pathogencity of entomopathogenic nematodes (nematoda: Rhabditida) to larvae of Galleria mellonella and Otiorhynchus sulcatus". Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308061.
Testo completo
21
Wallage, Helena Rachelle. "The effects of Plagiorchis elegans (Trematoda : Plagiorchiidae) infection on the carbohydrate metabolism of fourth instar Aedes aegypti (Diptera : Culicidae) larvae". Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=30763.
Testo completoAbstract (sommario):
Glucose was present in substantially greater concentrations in whole body extracts of fourth instar Aedes aegypti L. larvae than was trehalose; in contrast, trehalose was more abundant than glucose in haemolymph extracts. Preliminary studies suggested that infection of Ae. aegypti by the entomopathogenic digenean Plagiorchis elegans Rudolphi alters the carbohydrate metabolism of fourth instar larvae. Within 24 hours of cercarial penetration, total body extracts of infected fourth instar larvae exhibited decreased trehalase activity, increased trehalose-6-phosphatase activity, and an accumulation of trehalose in comparison to uninfected larvae. Concentrations of glucose, glycogen and lipids, and the activity of glycogen phosphorylase a were similar in extracts of infected and control larvae. The predominant fatty acids, in both control and infected larvae, were C 18:0, C 18:1 and C 18:3. There were no significant differences in the types and proportions of fatty acids found in control and infected larvae. Parasitic infection is discussed in terms of impaired trehalose metabolism.
22
King, Shirley Anne. "Development of techniques for the isolation of a granulovirus from potato tuber moth, phthorimaea operculella (Zeller)". Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1015202.
Testo completoAbstract (sommario):
Phthorimaea operculella, commonly known as the Potato Tuber Moth, is an economically important agricultural pest worldwide. The baculovirus, Phthorimaea operculella granulovirus (PhoGV) has been considered as a means of control alternative to chemical control because of its host specificity and harmless impact on other organisms and ecosystems. An isolate of PhoGV obtained from a South African PTM population would be beneficial in the production of a biopesticide, which is not yet available. An efficient and cost-effective rearing method would be advantageous for potential commercial production. Commercial table and seed potato plantations and storage facilities located in Patensie, Bathurst, Howick and Ivanhoe were surveyed for PTM infestations. Patensie was the only site where milky discoloured larvae were found, a potential symptom of PhoGV infection. TEM analysis revealed no virus in these samples. Since no virus was found in the field-collected samples, PTM insects were collected to initiate rearing in the laboratory. PTM was raised by three different methods in the laboratory. A cost/benefit analysis, survival rate, fertility and sex ratio were recorded for each rearing method. Rearing method one was deemed unsuccessful for efficient commercial rearing, as survival percentage and fertility were low. Rearing methods two and three had high survival rates and high fertility, and were efficient and less labour intensive than rearing method one. Rearing method three was the most productive technique, but for commercial production rearing method two was considered the most manageable and efficient. The sex ratio was 1:1 for all three cultures. The cost analysis revealed that rearing methods two and three were less expensive than rearing method one because less labour was required to monitor insects. The success of rearing PTM for 19 months will enable these cultures to be up-scaled to a large production facility for mass rearing. Virus was not found in the field surveys or in laboratory cultures, therefore chemical, temperature, humidity and carbon dioxide stressors were used in an attempt to initiate a baculoviral infection. Symptoms were exhibited in larvae subjected to chemical, temperature and humidity treatments, but these were confirmed by TEM analysis not to be a result of PhoGV infection. The success of rearing PTM in the laboratory suggests that the method could be used in the commercial rearing of the insects in a large mass-rearing facility. The data obtained from induction protocols have allowed for better understanding for future induction for PhoGV and other baculoviruses in other insect species. The failure to isolate a South African PhoGV strain for developing a biopesticide against PTM has motivated further studies in obtaining a baculovirus in order for South Africa to develop a commercial product against this pest.
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Crease, Gary John. "Studies of biological efficacy of the pyrethroid insecticide cypermethrin applied to plant surfaces for the control of larvae of Spodoptera littoralis Boisd". Thesis, University of Portsmouth, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329710.
Testo completo
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Maxwell, Philip W. (Philip William). "The interaction of surface components of Xenorhabdus nematophilus (Enterobacteriaceae) with the hemolymph of nonimmune larvae of the greater wax moth, Galleria mellonella (Lepidoptera; Galleridae)". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23285.
Testo completoAbstract (sommario):
The following studies were done to identify factors that influence the virulence of Xenorhabdus nematophilus and the interactions of the bacterium with the nonself defence systems of nonimmune Galleria mellonella. Isolates of X. nematophilus that are qualitatively similar in biochemical properties differed significantly in virulence for G. mellonella larvae. The production of enzymes such as proteases could not account for differences in the virulence of the isolates.Growth conditions, influenced the growth rate and the interactions of the bacterium with nonimmune G. mellonella larvae. In general, X. nematophilus cells grown under aerobic conditions were more susceptible to the nonself defences of G. mellonella larvae than those grown under less than ideal conditions, resulting in increased clearance of the bacteria from the hemolymph (blood) of the insects. Clearance of the bacteria from the hemolymph of the insect was positively correlated with culture condition, culture age, and attachment to insect hemocytes in vitro.
Isolates of X. nematophilus produced flagella and fimbriae when grown under microaerobic and aerobic conditions. The type of fimbriae produced was influenced by culture conditions. The injection of both flagella and fimbriae in picogram quantities into nonimmune G. mellonella caused an increase in total hemocyte counts within these insect larvae. The injection of fimbrial and flagellar antigens into G. mellonella larvae caused changes in the hemocyte types found in circulation in the insect's hemolymph. (Abstract shortened by UMI.)
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Cyr, Hélène. "The impact of restricted access to atmospheric oxygen on the survival and development of Aedes aegypti (Diptera:Culicidae) pre-imagos /". Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=80246.
Testo completoAbstract (sommario):
Reduced access to atmospheric oxygen greatly increased early instar Aedes aegypti mortality. Data suggest that death was by drowning mainly because slow swimming speed and low visual acuity delayed larvae from finding access to air. Late instar larvae experienced developmental delays when food depletion in the immediate vicinity of the breathing site forced them to forage farther away. As the distance between feeding and breathing sites increased, feeding efficiency of fourth instars may have declined enough to reduce their pupation success and to cause increased pupal mortality, reduced adult emergence and sex ratio skewed in favour of males among emerging functional adults. Thus reduced access to atmospheric oxygen at the pre-imago level may reduce the vectorial capacity of emerging adult population.
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Luna, John. "Development, implementation, and economic evaluation of an integrated pest management program for alfalfa in Virginia". Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/49827.
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Schumann, Mario [Verfasser], Stefan [Akademischer Betreuer] Vidal, Stefan [Akademischer Betreuer] Schütz e Stefan [Akademischer Betreuer] Scheu. "Development of an „Attract & Kill“ strategy for the control of western corn rootworm larvae / Mario Schumann. Gutachter: Stefan Vidal ; Stefan Schütz ; Stefan Scheu. Betreuer: Stefan Vidal". Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://d-nb.info/1044426209/34.
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Melathopoulos, Adony P. "Laboratory and field evaluation of neem pesticides for the control of honey bee mite parasites Varroa jacobsoni and Acarapis woodi and brood pathogens Paenibacillus larvae and Ascophaera apis". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ51417.pdf.
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Silva, Najara da [UNESP]. "Caracterização molecular e expressão de aminopeptidase (APNs) de Ostrinia nubilalis HÜBER 1796 (Lepidoptera: Crambidae)". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/108433.
Testo completoAbstract (sommario):
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000738502.pdf: 1467766 bytes, checksum: 7c0de265290f7067173746101d9a2b71 (MD5)Aminopeptidases N (APNs) são uma classe de ectoenzimas presentes no intestino médio das larvas de lepidópteros, que participa no cenário do modo de ação das toxinas Bacillus thuringiensis (Bt). No presente trabalho, duas aminopeptidases (OnAPN5 e OnAPN6) foram clonadas a partir células do intestino de Ostrinia nubilalis, lepidópteros praga do milho dos climas temperados. As duas sequências foram identificadas como APNs pela da presença dos motivos HEXXH18(X)E e GAMEM, bem como o peptídeo sinal. As mesmas se agruparam corretamente quando analisadas com outras sequências de aminopeptidase em uma arvore fenogenética, Pode-se verificar a expressão em tempo real em diferentes tecidos (intestinal, adiposo e tegumento) da APN5 e APN6 e também de uma terceira aminopeptidase APN7 analisada nesta etapa do trabalho, onde APN7 apresentou expressão de 7,5 vezes mais no tegumento quando comparado com o intestino e de 4,9 vezes mais no tecido adiposo quando comparado com o intestino enquanto que a APN5 e APN6 apresentaram expressão relevante apenas no tecido do intestino. Estas identificações de APNs irão facilitar estudos para caracterizar interações de ligação com as toxinas Bt, proporcionando uma forma de compreender e evitar o desenvolvimento da resistência às proteínas Cry de B. thuringiensis. Estas informações são fundamentais para a elaboração de estratégias adequadas para o manejo da resistência de pragas e seu efetivo controle
Aminopeptidases N (APNs) are a class of ectoenzymes present in the midgut of lepidopteran larvae, which participates in setting the mode of action of Bacillus thuringiensis toxin (Bt). In this work, two aminopeptidases (OnAPN5 and OnAPN6) were cloned from cells of the intestine Ostrinia nubilalis, Lepidoptera pests of temperate maize. The two sequences were identified as APNs for the presence of motifs HEXXH18 (X) and E GAMEM as well as the signal peptide. The same when analyzed correctly grouped with other aminopeptidase sequences in a tree fenogenética, can check in real time the expression in different tissues (gut, adipose tissue and carcass) from APN5 and APN6 and also a third aminopeptidase analyzed in this step APN7 work, where APN7 showed expression of 7.5 times the carcass when compared with the intestine and 4.9 times in adipose tissue when compared with the intestine while APN5 and APN6 relevant only showed expression in tissue of the intestine. These IDs APNs will facilitate studies to characterize binding interactions with Bt toxins, providing a way to understand and prevent the development of resistance to Cry proteins of B. thuringiensis. This information is fundamental to the development of appropriate strategies for managing pest resistance and its effective control
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Silva, Najara da. "Caracterização molecular e expressão de aminopeptidase (APNs) de Ostrinia nubilalis HÜBER 1796 (Lepidoptera: Crambidae) /". Jaboticabal, 2013. http://hdl.handle.net/11449/108433.
Testo completoAbstract (sommario):
Orientador: Manoel Victor Franco LemosBanca: Lucia Maria Carareto Alves
Banca: Vitor Fernandes Oliveira da Miranda
Banca: Cristina Lacerda Soares Petrarolha Silva
Banca: Renato Pariz Maluta
Resumo: Aminopeptidases N (APNs) são uma classe de ectoenzimas presentes no intestino médio das larvas de lepidópteros, que participa no cenário do modo de ação das toxinas Bacillus thuringiensis (Bt). No presente trabalho, duas aminopeptidases (OnAPN5 e OnAPN6) foram clonadas a partir células do intestino de Ostrinia nubilalis, lepidópteros praga do milho dos climas temperados. As duas sequências foram identificadas como APNs pela da presença dos motivos HEXXH18(X)E e GAMEM, bem como o peptídeo sinal. As mesmas se agruparam corretamente quando analisadas com outras sequências de aminopeptidase em uma arvore fenogenética, Pode-se verificar a expressão em tempo real em diferentes tecidos (intestinal, adiposo e tegumento) da APN5 e APN6 e também de uma terceira aminopeptidase APN7 analisada nesta etapa do trabalho, onde APN7 apresentou expressão de 7,5 vezes mais no tegumento quando comparado com o intestino e de 4,9 vezes mais no tecido adiposo quando comparado com o intestino enquanto que a APN5 e APN6 apresentaram expressão relevante apenas no tecido do intestino. Estas identificações de APNs irão facilitar estudos para caracterizar interações de ligação com as toxinas Bt, proporcionando uma forma de compreender e evitar o desenvolvimento da resistência às proteínas Cry de B. thuringiensis. Estas informações são fundamentais para a elaboração de estratégias adequadas para o manejo da resistência de pragas e seu efetivo controle
Abstract: Aminopeptidases N (APNs) are a class of ectoenzymes present in the midgut of lepidopteran larvae, which participates in setting the mode of action of Bacillus thuringiensis toxin (Bt). In this work, two aminopeptidases (OnAPN5 and OnAPN6) were cloned from cells of the intestine Ostrinia nubilalis, Lepidoptera pests of temperate maize. The two sequences were identified as APNs for the presence of motifs HEXXH18 (X) and E GAMEM as well as the signal peptide. The same when analyzed correctly grouped with other aminopeptidase sequences in a tree fenogenética, can check in real time the expression in different tissues (gut, adipose tissue and carcass) from APN5 and APN6 and also a third aminopeptidase analyzed in this step APN7 work, where APN7 showed expression of 7.5 times the carcass when compared with the intestine and 4.9 times in adipose tissue when compared with the intestine while APN5 and APN6 relevant only showed expression in tissue of the intestine. These IDs APNs will facilitate studies to characterize binding interactions with Bt toxins, providing a way to understand and prevent the development of resistance to Cry proteins of B. thuringiensis. This information is fundamental to the development of appropriate strategies for managing pest resistance and its effective control
Doutor
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Love, Claire Natalie. "The biology, behaviour and survival of pupating false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), a citrus pest in South Africa". Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1018907.
Testo completoAbstract (sommario):
Control of the citrus pest, false codling moth (FCM), Thaumatotibia leucotreta Meyrick (Lepidoptera: Tortricidae) is crucial for the South African citrus industry. The economic losses and phytosanitary status of this pest, coupled with increased consumer awareness and demands, has created a need for effective, IPM-compatible control measures for use against the soil-dwelling life stages of FCM. Promising developments in the field of microbial control through the use of entomopathogenic fungi (EPF) and entomopathogenic nematodes (EPNs) have highlighted the need for research regarding pupation biology, behaviour and survival of FCM, as a good understanding of biology of the target organism is an important component of any biological control programme. The aim of this study was to improve the current understanding of FCM pupation habits through the manipulation of soil texture class, ground cover, shading, soil compaction, air temperature, and soil moisture in the laboratory. These findings would then be used to aid the biological control programmes using EPF and EPNs against FCM in the soil. Three soil texture classes (sandy loam, silt loam and silty clay loam) were obtained from orchards for use in the study. FCM larvae were allowed to drop into the soil of their own accord and the pupation behaviour that followed was then captured on film with pupae formed in the soil being kept in order to measure adult eclosion. In general, very few abiotic factors had a clear influence on FCM pupation. Larval wandering time and distance was short, but also variable between individuals. Distance did increase when soils were moist. Pupation depth was shallow, with pupal cocoons generally being formed on the soil surface. Depth of pupation was less than one centimetre for all abiotic conditions, with little burrowing into soil. Eclosion success was higher for sandier soils when these were dry and uncompacted, but the addition of both moisture and soil compaction increased FCM eclosion success. FCM was sensitive to desiccation when the soils were dry and temperature limits of 15 °C and 32 °C had a strongly negative impact on eclosion success. Preferences for particular abiotic conditions were limited to only certain moisture conditions when interacting with soil texture class and a preference for pupating in soil when it is available. Limited preference was found for particular soil textures despite this having a strong influence on eclosion success, but individuals did appear to pupate in close proximity to one another. Viable direct habitat manipulation for FCM control could not be identified. These results and all of the abiotic variables measured have important implications for EPF and EPN application, survival and persistence in the soil in order to improve the ability of these biological control agents to control FCM. These are discussed in each chapter.
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Suster, Maximiliano Leon. "Neural control of larval locomotion in Drosophila melanogaster". Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621137.
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Destefano, Ricardo Henri Rodrigues. "Detecção e identificação de Metarhizium anisopliae em larvas de Diatraea saccharalis por Primers específicos". Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/11/11138/tde-15072003-141752/.
Testo completoAbstract (sommario):
A região espaçadora ITS rDNA tem sido utilizada como uma importante ferramenta molecular para a identificação de fungos. Neste estudo a região ITS1 - 5.8S - ITS2 foi analisada em diferentes espécies do fungo entomopatogênico Metarhizium incluindo M. anisopliae, M. album e M. flavoviride com o objetivo de se construir primers específicos para a detecção e identificação do fungo no interior de larvas infectadas de Diatraea saccharalis. A amplificação desta região produziu um fragmento único de aproximadamente 540 pb para as linhagens E9, B/Vi e C, e de 600 pb para a linhagem 14 de M. anisopliae var. anisopliae; de 650 bp para M. album e 600 pb para M. flavoviride. Os produtos de PCR obtidos foram digeridos com diferentes enzimas de restrição Afa I, Alu I, Dde I, Hae III, Hpa II e Sau 3A I; e os perfis de PCR-RFLP mostraram nítidas diferenças entre as espécies analisadas. O sequenciamento da região ITS1 5.8S ITS2 permitiu o desenho de primers específicos para as linhagens de M.a. var. anisopliae do Brasil e da Austrália. A amplificação não ocorreu em linhagens de M. álbum, M. flavoviride e Beauveria bassiana. Os DNAs extraídos de larvas infectadas pelas linhagens E9, B/Vi e C do Brasil e linhagem 14, da Austrália, foram testados utilizando-se os primers desenvolvidos. Em todos os experimentos o fungo M.a. var. anisopliae foi detectado 48 horas após a inoculação. A técnica molecular empregada neste estudo permite a rápida e segura detecção e identificação de M.a. var. anisopliae em bioensaios de laboratório e de campo, programas de manejo de pragas e estudos de epizootiologia.The ITS rDNA have been used as an important molecular tool for fungi identification. In this study the ITS1 - 5.8S ITS2 rDNA regions were analyzed in different species of the entomopathogenic fungus Metarhizium including M. anisopliae, M. album and M. flavoviride, in order to construct specific primers for their detection and identification within infected Diatraea saccharalis larvae. The amplification of this region yielded a unique fragment of approximately 540 bp for E9, B/Vi and C, and 600 bp for strain 14 of M. anisopliae var. anisopliae; of 650 bp for M. album and 600 bp for M. flavoviride. The PCR products were digested with the different restriction endonucleases Afa I, Alu I, Dde I, Hae III, Hpa II and Sau 3A I; and the PCR-RFLP profiles showed clear differences amongst the species. The sequencing of the ITS-5.8S rDNA regions allowed for the design of specific primers for M. anisopliae var. anisopliae. The amplification was not observed with M. album, M flavoviride and Beauveria bassiana strains. DNAs extracted from infected larvae by E9 and C strains from Brazil and the strain 14 from Australia in individual bioassays were tested using previously designed specific primers. In all experiments, the fungus was detected after 48 hours of post-inoculation. This molecular technique allows a fast and secure detection and identification of the entomopathogen in bioassays, in pest management programs and epizootiology.
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Fernandes, Fernanda Mara. "Avaliação da ação do fungo predador de nematóide Duddingtonia flagrans sobre larvas infectantes de Ancylostoma ceylanicum". Universidade Federal de Viçosa, 2011. http://locus.ufv.br/handle/123456789/5069.
Testo completoAbstract (sommario):
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Previous issue date: 2011-08-09Ancylostoma ceylanicum is a gastrointestinal nematode of dogs and cats, can parasitize humans. Is important to use alternative ways that can be used to fighting the spread of these parasites and their environmental infective forms, such as the use of natural antagonists of nematodes The biological control with nematophagous fungi has been suggested as an alternative to reduce this and other gastrointestinal infections caused by nematodes. The genus Duddingtonia stands out by control of nematodes in the environment. Duddingtonia flagrans is considered as the most promising species, due to the abundance of chlamydospores, which are structures of resistance. This study evaluated a fungus isolated from D. flagrans (AC001) in vitro for their ability to prey infective L3 larvae of A. ceylanicum, and its effectiveness in capturing larvae. Then, evaluated the ability to withstand the passage through the gastrointestinal tract of hamsters and ability to prey on the larvae. Was assessed on the dose of the mycelium would be more effective in relapse of the infection, were used 50 hamsters that received orally 100 L3 of A. ceylanicum. After, were formed five groups of 10 animals each, receiving fungal mycelia (25grams by weight) for a period of 14 days, every two days, and four groups treated with the fungus D. flagrans in different concentrations: group 1 (0.04 grams), group 2 (0.08 grams), group 3 (0.16 grams), group 4 (0.32 grams) and a control group that don t received this treatment. The animals were placed in separate cages and after the period of patency by A.ceylanicum (20 days) every two days, 2 grams of faeces from each group were collected from beds of hamsters for further proceed with the count of eggs per gram of feces (OPG).The results showed that there was difference (p<0.05) in reduction of the OPG of treated groups when compared to the control group.There was no difference (p>0.05) in reducing the OPG in the treated groups at different concentrations. The results of this study suggest that the fungus D. flagrans could be used as a tool in biological control of A. ceylanicum in natural conditions.
Ancylostoma ceylanicum é um nematoide gastrointestinal de cães e gatos, podendo parasitar o ser humano. Medidas alternativas que possam ser empregadas no combate à disseminação ambiental destes parasitos e suas formas infectantes são importantes, como o uso de antagonistas naturais de helmintos. O controle biológico com fungos nematófagos tem sido sugerido como uma alternativa para a redução desta e de outras infecções causadas por helmintos gastrintestinais. O gênero Duddingtonia se destaca pelo controle de nematoides no ambiente. Duddingtonia flagrans é considerada como a espécie mais promissora, devido à abundância de clamidósporos, que são estruturas de resistência. O presente estudo avaliou um isolado do fungo D. flagrans (AC001) in vitro quanto à capacidade de predar larvas infectantes L3 de A. ceylanicum, e sua eficácia na captura das larvas. Em seguida, foi avaliada a capacidade de suportar a passagem pelo trato gastrointestinal de hamsters, e habilidade de predar as larvas. Foi avaliada qual a dose do micélio seria mais eficaz na recidiva da infecção. Foram utilizados 50 hamsters que receberam por via oral 100 L3 de A. ceylanicum e formados 5 grupos com 10 animais cada um, que receberam micélio fúngico por um período de 14 dias, a cada dois dias, sendo 4 grupos tratados com o fungo D. flagrans em diferentes concentrações: grupo 1 (0,04g); grupo 2 (0,08g); grupo 3 (0,16g); grupo 4 (0,32g) e o grupo controle que não recebeu esse tratamento. Os animais foram colocados em gaiolas separadas e, após o período de patência do A. ceylanicum (20 dias), a cada dois dias, 2g de fezes de cada grupo foram coletados das camas dos hamsters para posterior realização da contagem de ovos por grama de fezes (OPG). Os resultados demonstraram que houve diferença (p<0,05) na redução do OPG dos grupos tratados em relação ao grupo controle. Não foi observada diferença (p>0,05) na redução do OPG nos grupos tratados nas diferentes concentrações. Os resultados do presente trabalho sugerem que o fungo D. flagrans poderia ser utilizado como uma ferramenta no controle biológico de A. ceylanicum em condições naturais.
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Misciattelli, Natalia. "Control of pathogenic bacteria in marine larval culture systems". Thesis, Bangor University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311387.
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Wee, Caroline Lei. "Neuromodulatory Control of Motivated Behavior in the Larval Zebrafish". Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:33493507.
Testo completoAbstract (sommario):
An animal’s behavior is strongly influenced by homeostatic drives that are crucial for survival and reproduction, such as the drive to eat, or to escape from harmful threats. In vertebrates, an evolutionarily ancient brain structure, the hypothalamus, is particularly important for coordinating these essential survival functions. Here, I leverage the simple and transparent brain of the vertebrate larval zebrafish to dissect the conserved hypothalamic networks that regulate appetite and defensive behaviors, focusing on how these overlapping circuits interact with and influence each other.
By using an unbiased brain-wide activity mapping approach, I pinpoint hypothalamic oxytocin (OXT) neurons as a key hub for the control of defensive behaviors against pain. I show that OXT neurons integrate multiple noxious stimuli, in particular input from TRPA1 damage-sensing receptors, to drive pain avoidance behavior via co-release of OXT and glutamate in the hindbrain and spinal cord. Furthermore, OXT neurons can also integrate information about the animal’s social context to control appetite, a separate homeostatic drive. These findings provide insight into how a single neuromodulatory circuit can exert flexible, context-dependent control over diverse social and non-social behaviors.
To further probe the hypothalamic networks controlling appetite, I have utilized whole-brain activity mapping to identify hypothalamic neural populations encoding hunger and satiety. My results indicate that, similar to mammals, medial and lateral regions of the hypothalamus show anti-correlated activity patterns, which likely regulate distinct phases of appetite. In hungry fish, medial hypothalamic nuclei report an energy deficit, whereas more lateral regions may be involved in voracious eating. I demonstrate that one medial hypothalamic population, the serotonergic caudal periventricular hypothalamus, is an important regulator of lateral hypothalamic (LH) activity and food intake, and a separate serotonergic population, the superior raphe nucleus, is important for regulating food intake during satiety, also via the LH, but is dispensable during hunger. Thus, by dissecting serotonin circuit function in the context of other hypothalamic feeding networks, I show how a single neuromodulator can control food intake in a satiation state-dependent manner. Overall, these studies provide insights into the underlying evolutionary principles and logic governing hypothalamic function, and demonstrate how diverse neuromodulatory circuits in the hypothalamus and beyond can exert state-dependent control over an animal’s most primitive, yet essential, survival drives.Biology, Molecular and Cellular
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Brentano, Adriana Maria. "Controle de larvas de Limnoperna fortunei coletadas em ambiente natural com o uso de agente oxidante clorado". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/129521.
Testo completoAbstract (sommario):
Limnoperna fortunei (Dunker, 1875), conhecido como mexilhão-dourado é um molusco bivalve invasor de origem asiática. Foi introduzido em 1991, no Rio da Prata em Buenos Aires, chegando assim nas águas da América do Sul, provavelmente através da água de lastro. Foi observado pela primeira vez no Brasil, em dois locais distintos, na área do Delta do Jacuí, em Porto Alegre, Rio Grande do Sul e em Corumbá, Mato Grosso do Sul, no ano de 1998. Essa espécie invasora vem causando significativos impactos ambientais e prejuízos econômicos para as indústrias que utilizam água bruta para resfriamento, pois entopem as tubulações pela formação de aglomerados (macrofouling), que vão obstruindo o fluxo contínuo da água. Para minimizar os danos causados pelas espécies invasoras, são recomendados diversas formas de controle, estes podem ser físicos, químicos e biológicos. Neste trabalho, para os testes de controle utilizamos a forma química, e o agente químico controlador, o hipoclorito de sódio. Conforme descrito em bibliografia, alguns estudos comprovam que os indivíduos adultos são mais resistentes a agentes químicos, nesse sentido, demonstrou ser mais vantajoso utilizar as larvas como alvo de controle, para que elas não se fixem nas tubulações, evitando a formação e aumento dos macrofouling. Esse trabalho objetivou adaptar um método de controle de larvas do mexilhão-dourado (Limonperna fortunei) com a utilização de hipoclorito de sódio, testando uma concentração baixa e eficaz na mortalidade das larvas. Os experimentos foram realizados em laboratório, onde larvas de mexilhão-dourado foram expostas por cinco minutos em solução de hipoclorito de sódio e avaliadas em tempos pós-exposição de 1 hora, 6 horas, 12 horas e 24 horas. Para avaliar o percentual de mortalidade foi utilizado o método de Análise de Variância (ANOVA) e para verificar quais concentrações são estatisticamente diferentes ao nível de significância de 5% foi feito o teste de Tukey. Os resultados obtidos no sistema estudado com aplicação do agente clorado, demonstraram que mesmo quando em baixos teores de cloro livre e com tempo de exposição de cinco minutos, se mostrou eficiente no controle das larvas do mexilhão-dourado. A exposição de uma solução de 0,001mg.L-1 de cloro livre, a mortalidade das larvas avaliadas atingiu 100% em 24 horas. As concentrações de Cloro Livre testadas atendem a Resolução CONAMA 357 de 2005 para uma condição de qualidade Classe I de águas doces e a Portaria 2914 do Ministério da Saúde que estabelece a qualidade da água para consumo humano.Limnoperna fortunei (Dunker, 1875), known as the golden mussel is from Asia and was probably introduced in 1991, in the La Plate river in Buenos Aires, thus reaching the waters of South America via ballast water. Was first observed in Brazil in area of the Delta Jacuí, in Porto Alegre, Rio Grande do Sul and in Corumbá, Mato Grosso do Sul, in 1998. This invasive species has caused significant environmental impacts and huge losses for industries that use raw water for cooling because they form clumps that clog pipes (macrofouling), blocking the stream of water. To minimize the damage caused by invasive species, various forms of control, which can be physical, chemical and biological agents are used. In this work, to do the control tests, we used as chemical form the agent sodium hypochlorite. As described in some studies, adults mussels are more resistant to chemical agents, this sense proved to be more advantageous to use the larvae as target, preventing them from attaching the pipes and form the macrofoulings. This study aimed to adapt a method of controlling larvae of the golden mussel (Limonperna fortunei) with the use of sodium hypochlorite, and verifying a low and effective concentration on larval mortality. The experiments were performed in the laboratory, where golden mussel larvae were exposed for five minutes in a solution of sodium hypochlorite and evaluated in post-exposure times of 1 hour, 6 hours, 12 hours and 24 hours. To evaluate the percentage of mortality was used the method of analysis of variance (ANOVA) and to see which concentrations are statistically different at a significance level of 5% was done the Tukey test. The system studied with application of chlorinated agent, even at low levels of free chlorine and exposure time of five minutes, proved effective in controlling larvae of the golden mussel, because even with the exposure of a solution of 0.001 mg. L-1 of free chlorine, the mortality of larvae reached 100% in 24 hours. The concentrations of free chlorine tested attend CONAMA Resolution 357 of 2005, to a condition of quality Class I of freshwater and 2914 Ordinance of the Ministry of Health, establishing water quality for human consumption.
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Leles, Renan Nunes. "Efeito de fungos entomopatogênicos na mortalidade de adultos, oviposição e eclosão de larvas de Aedes aegypti". Universidade Federal de Goiás, 2009. http://repositorio.bc.ufg.br/tede/handle/tede/3071.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Aedes aegypti is the main vector of dengue fever in tropical and subtropical countries in the world. Due to the absence of a vaccine for dengue fever, the vector´s combat is fundamental fot the disease control. The spread of mosquito populations resistant to chemical insecticides shows the necessity to establish integrate vector control programs. Entomopathogenic fungi have potential for biological control of A. aegypti; however, only tow fungal species. Metarhizium anisopliae and Beauveria bassiana, have been stutied more intensely for this purpose. The present study evaluated the pathogenicity of nineteen fungal species of the Hypocreales order against A. aegypti adults, and investigated new methods for fungal application to control these mosquitoes and for detection and isolation of fungi and oomycetes from A. aegypti larvae and adults. The results clearly showed the potential of fungi, especially form the Metarhizium genus, for the combat of eggs and adult mosquitoes. The present study proposes a new pratical method for the detection and isolation of entomopathogenic fungi from infected mosquitoes collected in the field.
O interesse em fungos entomopatogênicos para controle integrado de mosquitos é grande. Entretanto pouco se sabe sobre o efeito de fungos em adultos e transmissão de micoses em Aedes aegypti. No presente trabalho, estudaram-se, em condições de laboratório, a atividade adulticida e a propagação da infecção para ovos postos por fêmeas tratadas com três isolados de Paecilomyces spp, dois Isaria spp, um Penicillium sp e um Metarhizium anisopliae. Foram realizados dois experimentos: Com conídios secos de M. anisopliae IP 46 a 5x104 conídios/cm3 (Teste 1) e com conídios dos outros fungos formulados em óleo-água, a 10% do óleo, a 106 conídios/cm2 (Teste 2). As fêmeas foram alimentadas com sangue de camundongo em dias alternados e, para ambos os sexos, solução açucarada (5%) foi ofertada ad libitum. Os adultos foram mantidos a 25ºC, umidade relativa (UR) de 70% e fotofase de 12 h até 10 d póstratamento (p.t.). Indivíduos mortos e ovos postos foram retirados, contados e incubados em UR > 98% e 25ºC por 15 d. Os ovos foram em seguida submersos em água e a eclosão de larvas avaliada diariamente até 5 d para todos os testes. Primeiros ovos postos foram encontrados em até 48 horas após a primeira hematofagia das fêmeas. O número médio de ovos/fêmea/dia (o/f/d) no teste 1 foi de 2,5 e no teste 2 variou entre 0,15 (Paecilomyces carneus CG 525) e 1,3 o/f/d (Isaria fumoserosea CG 325). Apenas IP 46 formou hifas e novos conídios sobre ovos e reduziu significativamente a eclosão quantitativa de larvas (39,2%), comparado com o grupo controle (68,6%; t = 2,3; P = 0,04). Nos demais testes a eclosão foi acima de 40%. Primeiros adultos geralmente morreram a partir de 48 h p.t. e o maior número de mortos foi encontrado 2 a 4 d depois, independentemente do teste realizado. A maior mortalidade, 10 d p.t. foi 39% (IP 46), seguido por 28% (Isaria farinosa CG 195), 16,4% (Paecilomyces marquandii CG 190), 8% (Penicillium sp IP 182), 6,8% (P. carneus CG 525), 4,7% (Paecilomyces lilacinus CG 362) e 4,6% (I. fumoserosea CG 325). A mortalidade encontrada para os controles foi ≤ 12% no mesmo momento. Mosquitos tratados com CG 195, CG 525, IP 46, CG 325 e CG 190 tiveram desenvolvimento de fungo em cadáveres. Mosquitos mortos pertencentes aos grupos tratados com os isolados IP 182, CG362 e controle não tiveram desenvolvimento de micélio. Os resultados mostraram que, de acordo com o tipo de aplicação utilizada, fêmeas de A. aegypti contaminaram ovos e assim propagaram a micose. Tratamento com conídios secos levou a uma maior contaminação das fêmeas e assim também dos ovos postos, comparada com a aplicação indireta utilizada para os demais fungos, no qual provavelmente a contaminação ficou restrita às partes do corpo em contato com a superfície tratada. A mortalidade reduzida encontrada para todos os fungos e para ambas técnicas pode estar relacionada à umidade subotima na qual foram mantidos os mosquitos e também ao tempo curto de observação dos adultos póstratamento. Os fungos testados têm atividade reduzida em adultos de A. aegypti e fêmeas desse mosquito podem transmitir a micose durante a oviposição. Mais estudos precisam ser feitos para selecionar linhagens mais virulentas e entender melhor mecanismos de infecção e transmissão horizontal de fungos em A. aegypti.
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Cordeiro, Juliana Xavier [UNESP]. "Obtenção de mutantes de Bacillus thuringiensis por inserção do transposon Tn-5 e avaliação da toxicidade frente a larvas de Spodoptera frugiperda". Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/94948.
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cordeiro_jx_me_jabo.pdf: 844386 bytes, checksum: ae05c2706130041d387b83b68d235663 (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Bacillus thuringiensis é uma bactéria gram-positiva e possui habilidade de produzir proteínas denominadas Cry ou delta-endotoxinas, durante a fase de esporulação. Estas proteínas são utilizadas no controle biológico de várias ordens de insetos. No entanto, pouco se conhece a respeito das vias metabólicas envolvidas na produção dessas proteínas, por exemplo, na natureza, é possível encontrar isolados que produzem grande quantidade de proteínas Cry, como também é possível encontrar outros isolados que produzem poucas quantidades. Considerando que essa diferença é devida a uma regulação gênica diferenciada entre isolados, a identificação dessa regulação pode levar a um incremento na produção de proteínas. Neste trabalho, foram analisados 10 clones mutantes comparados com o isolado selvagem (Bt1) quanto à mortalidade de lagartas neonatas de Spodoptera frugiperda considerando também a quantidade de proteínas Cry produzidas por estes mutantes. Os resultados demonstram que dois clones identificados como B9 e E2, demonstraram um bom controle dessas lagartas, mesmo aquelas que permaneceram vivas, ocorreu um atraso em seu desenvolvimento. Quanto à produção de proteínas, os clones apresentaram perfil protéico entre ~45 kDa e ~120 kDa, perfil característico encontrado entre estirpes ativas contra Lepidópteros. No entanto, os clones que apresentaram bons níveis de mortalidade (B9 e E2) mostraram somente a banda de ~65 kDa similar ao isolado selvagem, que pode ser a responsável pela sua ação inseticida. Os resultados obtidos demonstram a possibilidade de efetuar melhoramento genético em B. thuringiensis por meio de mutagênese mediada por transposon e abre caminho para o estudo das vias metabólicas envolvidas na produção de proteínas Cry.
Bacillus is a gram-positive bacterium and produces internal crystal inclusions named crystal (Cry) proteins or d - endotoxins during the sporulation phase. These proteins as used to control several agriculture insect pests. However little is known concerning the metabolic pathways involved in the production of these proteins. For example, in nature, it is possible to find isolates that produce large quantities of the Cry proteins as well as it is possible to find ones that produce limited quantities. Since such difference might be related to gene regulation the identification of regulation factors found in these isolated should lead to an increment on the crystal protein production found in isolated naturally exhibiting lower production. In this work, ten mutant clones were analyzed compared to the wild type (Bt1) with respect to Spodoptera frugiperda neonatal larvae mortality considering also the amount of crystal protein produced by these mutants. The results have demonstrated that two mutant clones named B9 and E2 have produced strong control of these larvae; while at the same time eliciting a delay on the development of the ones that eventually did not dye at first. As for the Cry protein content, the cloned presented a protein profile ranging from ~45 kDa to ~120 kDa which is typical of Cry proteins acting on lepidopterans. The clones that have shown good mortality levels (B9 and E2) have exhibited only a protein band with ~65 kDa, similar to the one produced by the wild type strain, which might be related to its control activity. Finally, the results obtained seem to lead to the possibility of improving genetically B. thuringiensis using mutagenesis induced by transposon and at the same time might pave the way to the shed light on the study of metabolic pathways involved in the Cry proteins production.
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Giglioti, Rodrigo [UNESP]. "Efeito de extratos de sementes de Nim (Azadirachta indica) sobre fêmeas ingurgitadas e larvas de Rhipicephalus (boophilus) microplus (CANESTRINI, 1887) (ACARI: IXODIDAE)". Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/96563.
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giglioti_r_me_jabo.pdf: 1368226 bytes, checksum: e45d49f6dc56df0b171216857782ba51 (MD5)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Rhipicephalus (Boophilus) microplus é considerado o mais importante parasito de bovinos no Brasil. Atualmente seu controle é dificultado pela exigüidade de moléculas acaricidas geradas, e pelo rápido desenvolvimento de resistência dos carrapatos. O presente trabalho teve por objetivo estudar o efeito de quatro extratos oleosos de sementes de Nim (Azadirachta indica) contento 2.000, 5.000, 9.000 e 10.000 ppm de azadiractina (AZA) quantificados por cromatografia líquida de alta eficiência (CLAE) em fêmeas ingurgitadas e larvas de R. (B.) microplus, in vitro. Para os ensaios com fêmeas ingurgitadas foi usado o Teste de Imersão de Adultas e para os ensaios com as larvas o Teste do Pacote com Larvas. Os resultados obtidos nos ensaios com fêmeas ingurgitadas mostraram que o principal efeito tóxico produzido pelos extratos, está relacionado à inibição da reprodução deste parasito. Foram verificadas reduções nas taxas de ovipostura e eclodibilidade das larvas oriundas das fêmeas tratadas com várias diluições dos extratos, em relação aos controles. Nos cálculos de Eficácia do produto (EP) para todas as soluções testadas, observou-se que a solução de 10.000ppm de AZA (N10) apresentou a maior eficácia. Os resultados das análises dos ensaios mostraram significância (p<0,01) dos dois efeitos incluídos no modelo, indicando variações significativas tanto devidas à concentração de AZA, quanto do ensaio realizado. Nas concentrações letais para as fêmeas ingurgitadas verificou-se que as CL50 não apresentaram variações, enquanto que as CL90 apresentaram grandes variações entre os extratos estudados. Nos ensaios com as larvas, não foram observadas mortalidade das larvas, indicando eficácia zero de todos os extratos testados. Os resultados dos ensaios com fêmeas ingurgitadas de R. (B.) microplus mostraram que os extratos oleosos de Nim apresentaram atividade...
Rhipicephalus (Boophilus) microplus is considered the most important cattle parasite in Brazil. Nowadays, his control is complicated by the slowness that acaricides molecules are generated, synthesized through and by the fast development of the resistance of these ticks to the market available products. This work aims to study the effect of four extracts of Neem seed oil (Azadirachta indica) containing 2.000, 5.000, 9.000 and 10.000 ppm of azadirachtin (AZA) quantified by high performance liquid chromatography (HPLC) on engorged females and larvae of R. (B.) microplus, in vitro. For the tests with engorged females, the Adult Immersion Test was used and for the larvae was used the Larvae Package Test. The test results with the engorged females showed that the main toxic effect produced by the extracts is related to the inhibition of the parasite reproduction. Were observed reductions in oviposition and hatchability rates of the larvae derived from the female treated with several dilutions of extracts, compared to controls. In the Product Effectiveness (PE) for all the test solutions, the 10.000ppm (N10) solution showed the highest efficiency. The analysis results from the tests showed significance (p<0,01) of the two effects included in the model, indicating variations both due to AZA and to the test performed. In the lethal concentration to the engorged females was verified that the CL50 did not show great variation, while the CL90 showed great variation between the studied extracts. In the tests with larvae was not observed mortality of them, indicating zero effectiveness of all tested extracts. The results of the tests with R. (B.) microplus engorged females demonstrated that the extract of Neem seeds oils showed acaricide activity. Thus, it is suggested that further studies can be conducted, such as development of the methods and of excrection, and characterization of other secondary ... (Complete abstract click electronic access below)
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Blackford, Michaela Jane Periander. "The significance of phytoecdysteroids in the diet of larval lepidoptera". Thesis, University of Exeter, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294485.
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Santos, Samara dos. "Efeito de produtos fitossanitários sobre larvas de Rhynchophorus palmarum L., 1764 (Coleoptera: Curculionidae) em laboratório". Universidade Federal de Alagoas, 2016. http://www.repositorio.ufal.br/handle/riufal/1530.
Testo completoAbstract (sommario):
Rhynchophorus palmarum is the most harmful weevil pest of coconut palm due to its ability to find hosts from long distances and also to the direct and indirect losses it causes to the crop. Besides this, spores of the fungus that causes the stem bleeding disease have been found over R. palmarum body. Thus, the objective of this work was to evaluate the effect of the insecticide thiamethoxam and its association to the fungicide cyproconazole against R. palmarum larvae under laboratory conditions, aiming at the possible use of these products for managing R. palmarum and the fungal diseases associated to it. Newly-hatched and intermediate-instar larvae were fed with artificial diet containing insecticide or fungicide in the concentrations of 0.1%; 0.5%; 1.0% and 2.0%, and also the mixture of both. Larvae mortality on the treatments was assessed daily, during 48 hours. Means were subjected to analysis of variance and compared by Tukey’s test (P < 0.05). Regression analysis between the different product doses and larval mortality was also performed. Thiamethoxam caused mortality of 100 and 95% to newly-hatched and intermediate-instar larvae, respectively, statistically differing from cyproconazole (50 and 0%, respectively) and from the control (23.2 and 0%, respectively), but not differing from the two products mixture (100 and 92.5%, respectively). Such results point out that newly-hatched larvae are more sensitive than the intermediate-instar ones; that thiamethoxam in the doses here used is toxic to both newly-hatched and intermediate-instar larvae; that cyproconazole in the doses here used is toxic only to newly-hatched larvae; and that cyproconazole, when mixed to thiamethoxam does not improve its toxicity. Linear regression showed that thiamethoxam and its mixture with cyproconazole caused 100% mortality to newly-hatched larvae, and between 80 and 100% and between 90 and 100% to intermediate-instar larvae, respectively, in all tested concentrations. All concentrations were considered high. The thiamethoxam + cyproconazole mixture showed to be promising for the management of R. palmarum and the fungal diseases associated to it in coconut palms.Conselho Nacional de Desenvolvimento Científico e Tecnológico
Rhynchophorus palmarum é, dentre os curculionídeos que atacam o coqueiro, o mais severo, pois além da capacidade de localizar sua planta hospedeira a longas distâncias, causa perdas diretas e indiretas à cultura. Além disso, esporos do fungo causador da doença resinose do coqueiro já foram encontrados no corpo de R. palmarum. Assim, o objetivo deste trabalho foi verificar em laboratório o efeito do inseticida tiametoxam, associado ao fungicida ciproconazol, sobre larvas de R. palmarum, visando a possibilidade de uso conjunto contra a praga e doenças fúngicas associadas a ela. Larvas de instares iniciais e de instares intermediários foram confinadas em dieta artificial contendo o inseticida e o fungicida isoladamente, nas concentrações de 0,1%; 0,5%; 1,0%; 2,0%, e também a mistura de ambos. A mortalidade das larvas nos tratamentos foi avaliada diariamente, durante 48 horas. As médias foram submetidas à análise de variância e comparadas entre si pelo teste de Tukey (P < 0,05). Também foi realizada a análise de regressão entre as diferentes doses dos produtos testados e a mortalidade das larvas. O tiametoxam causou mortalidade de 100 e 95% para larvas recém-eclodidas e intermediárias, respectivamente, diferindo estatisticamente do ciproconazol (50 e 0%, respectivamente) e da testemunha (23,2 e 0%, respectivamente), mas não diferindo da mistura dos dois produtos (100 e 92,5%, respectivamente). Tais resultados evidenciam que as larvas recém-eclodidas são mais sensíveis que as intermediárias; que o tiametoxam nas doses utilizadas é tóxico às larvas de ambas as idades; que o ciproconazol, nas doses utilizadas, é tóxico apenas para as larvas recém-eclodidas; e que o ciproconazol, quando adicionado ao tiametoxam, não potencializa o efeito deste. A regressão linear mostrou que tiametoxam e a mistura dos produtos causaram 100% de mortalidade às larvas recém-eclodidas, e entre 80 e 100% e entre 90 e 100% às larvas de tamanho intermediário, respectivamente, em todas as concentrações testadas, sendo estas consideradas altas para uso. A mistura de tiametoxam + ciproconazol se mostrou promissora para o manejo de R. palmarum e das doenças fúngicas associadas a ele em coqueiro.
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Ribeiro, Raul Rio. "Atividade predatória sobre larvas de trichostrongilídeos de isolados fúngicos do gênero Monacrosporium após a passagem pelo trato gastrintestinal de bovinos". Universidade Federal de Viçosa, 2003. http://locus.ufv.br/handle/123456789/5176.
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Previous issue date: 2003-02-27Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Three isolates of predators fungi of the genus Monacrosporium (M. sinense SF-53, M. appendiculatum CGI and M. sinense SF-139) were evaluated in vivo regarding the capacity of supporting passage through the gastrointestinal tract of calves without losing the ability to entrap infective Cooperia sp. and Haemonchus sp. larvae. The isolates SF-53 and CGI were managed orally, separately to the calves, fresh mycelium form at dose only of 100 g. Collected fecal Samples 12, 18, 24, 48, 72 and 96 hours after the treatments were allocated in Petri dishes with 5-cm diameter, added of 750 infective Cooperia sp. and Haemonchus sp. larvae. At the end of the experiment, reproductive structures (conidia) from both isolates were visualized in every the studied times. There was significant reduction of the average number of nematodes larvae recovered of the Petri dishes when compared with the control group. Such evidences confirm the transit of these fungi by the digestive tract of the calves without loss of the predatory viability. There are no evidences that the isolated SF-139 has passed by the gastrointestinal tract of calf after oral administration, fresh mycelium form at dose only of 87 g.
Três isolados de fungos predadores do gênero Monacrosporium (M. sinense SF-53, M. appendiculatum CGI e M. sinense SF-139) foram avaliados in vivo quanto à capacidade de suportar a passagem pelo trato gastrintestinal de bezerros sem perda da habilidade para predar larvas infectantes de Cooperia sp. e Haemonchus sp. Os isolados SF-53 e CGI foram administrados por via oral, separadamente aos bezerros, na forma de micélio fresco em dose única de 100 g. Amostras fecais coletadas 12, 18, 24, 48, 72 e 96 horas após os tratamentos foram alocadas em placas de Petri com 5 cm de diâmetro, adicionadas de 750 larvas infectantes de Cooperia sp. e Haemonchus sp. Ao final do experimento, estruturas reprodutivas (conídios) de ambos isolados foram visualizadas em todos os tempos estudados. Houve redução significativa do número médio de larvas de nematóides recuperadas das placas de Petri quando comparado com o grupo controle. Tais evidências confirmam o trânsito destes fungos pelo trato digestivo dos bezerros sem perda da viabilidade predatória. Não existem evidências de que o isolado SF-139 tenha passado pelo trato gastrintestinal do bezerro após administração oral, na forma de micélio fresco, em dose única de 87 g.
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Deogade, Ajinkya 1989. "Fine-grained model of the sensorimotor control underlying Drosophila larval chemotaxis". Doctoral thesis, Universitat Pompeu Fabra, 2017. http://hdl.handle.net/10803/665160.
Testo completoAbstract (sommario):
Chemotaxis is a powerful paradigm to study how sensory stimulations
drive orientation behaviors in an organism. Drosophila larvae navigate
odor gradients by controlling the duration of runs and the direction of
turns. A turn is preceded by lateral head sweeps (“casts”) that sample the
stimulus from the surroundings. In addition, larvae correct their course
towards the odor source during runs, a phenomenon called “weathervaning”.
Peristaltic waves that propagate along the body axis drive forward
run events. We showed that the peristaltic wave cycle acts as a natural unit
of movement and sets a physical constraint on the amount of reorientation
achieved during runs. Moreover, head-casts are strictly observed within
the bounds of the peristaltic cycle that can be categorized into either runcasts
or stop-casts based on the presence or absence of the peristaltic wave
respectively. Integrating behavioral experiments and extracellular electrophysiological
recordings from the olfactory sensory neurons (OSNs), we
observed a remarkable ability of larva to sense, to process and to act at
short timescales of head-casts. In particular, we found that the larval sensorimotor
system is able to modulate the amplitude of stop-casts based on
the changes in the OSN firing rate during casts. Finally, integrating models
for OSN activity, peristaltic locomotion, and behavioral quantification,
we built an agent-based model that recapitulates essential aspects of larval
chemotactic behavior. Overall, our findings provide a new formalism
to study larval sensorimotor control. Additionally, we developed a high
spatiotemporal resolution larval tracker with an ability to detect and precisely
stimulate individual sensory organs. The tracker is highly effective
tool to discern neural basis of behaviors occurring at short timescales in
Drosophila larvae and other model systems.La quimiotaxis es un poderoso paradigma para estudiar en un organismo comportamientos de orientación derivados de estímulos sensoriales. La larva de la Drosophila navega por gradientes de olor gracias al control de la duración y la dirección de sus giros. El giro va precedido por barridos laterales de la cabeza (“head-casts”) que muestrean estímulos de los alrededores de la larva. Además, las larvas corrigen su trayectoria en dirección a la fuente de olor, un fenómeno llamado “weathervaning”. Movimientos peristálticos que se propagan por el eje del cuerpo conducen a carreras (runs) hacia adelante. Demostramos que los ciclos de ondas peristálticas actúan como unidades naturales del movimiento y establecen un límite físico en cuanto a la cantidad de reorientaciones conseguidas en una carrera. Además, los “head-casts” sólo se observan en los límites de los ciclos peristálticos que pueden ser categorizados en “run-cast” o “stopcast” basándonos en la presencia o ausencia de ondas peristálticas respectivamente. Asimismo, hemos descubierto que la magnitud del “stop-cast” es mayor al encontrarse con un estímulo positivo y menor al detectar un cambio negativo. Combinando experimentos de comportamiento y registros de electrofisiología extracelulares en neuronas sensoriales del olfato (OSNs), hemos observado una remarcable habilidad en la larva para sentir, procesar y actuar en escalas a corto tiempo durante los “head-casts”. Combinando un modelo para la actividad de OSN, un modelo para la locomoción peristáltica, y la cuantificación del comportamiento, hemos construido un modelo “agent-based” que recapitula aspectos esenciales del comportamiento quimiotáctico de la larva. En general, nuestro estudio aporta un nuevo formalismo para estudiar el control sensomotor de la larva. De la misma manera, hemos desarrollado un rastreador de larvas espacio-temporal de alta resolución con habilidad para detectar y estimular con precisión órganos sensoriales. El rastreador nos permite investigar el papel del muestreo activo y el olfato estéreo en transformaciones sensomotoras durante la quimiotaxis de la larva.
45
Krzemien, Joanna. "Control of larval hematopoiesis in Drosophila ; microenvironment, precursors and cell lineage". Toulouse 3, 2008. http://www.theses.fr/2008TOU30206.
Testo completoAbstract (sommario):
L'hématopoiése larvaire de la drosophile a lieu au sein d'un organe spécialisé, la glande de la lymphe (LG) qui produit des plasmatocytes spécialisés dans la phagocytose et des cellules à cristaux nécessaires à la mélanisation des corps étrangers (4). La LG est aussi à l'origine des lamellocytes nécessaires à l'encapsulation de gros corps étrangers et qui se différencient en réponse à des challenges immuns particuliers tels que le parasitisme par des hyménoptères. En 2004, notre laboratoire a montré que Collier (Col), l'orthologue du facteur de transcription mammifère Early B-Cell Factor est exprimé et requis dans un petit groupe de cellules spécialisées de la LG, le PSC, pour la différenciation des lamellocytes en réponse au parasitisme. Outre le PSC, la LG est organisée en deux zones distinctes : une zone médullaire (MZ) contenant les cellules précurseurs et une zone corticale (CZ) formée des cellules différenciées ayant quitté la MZ. Au cours de la première partie de ma thèse, j'ai étudié le contrôle de l'hématopoièse larvaire et montré que le PSC régulait de manière cellulaire non autonome, l'activité de la signalisation JAK/STAT dans les cellules précurseurs, empêchant ainsi leur différenciation prématurée et préservant leur capacité à se différencier en lamellocytes. Le rôle clef du PSC dans le maintien d'un pool de progéniteurs l'apparente à la niche hématopoiétique des vertébrés, un micro-environnement cellulaire requis pour le maintien de cellules souches tout au long de la vie adulte. Ceci posait la question de l'existence de cellules souches hématopoiètiques chez la drosophile, une question que j'ai abordée dans la deuxième partie de ma thèse. L'utilisation de marqueurs de cellules souches, de marqueurs de division asymétrique, ou la recherche de cellules quiescentes ne m'ont pas permis d'identifier des cellule souches dans la LG. J'ai alors mis en oeuvre des expériences de lignage cellulaire et montré que les pro-hémocytes acquièrent un destin plasmatocyte ou cellule à cristaux dés le premier stade larvaire, avant une phase de prolifération intense. .The Drosophila larval hematopoietic organ, the lymph gland (LG), disperses at metamorphosis, releasing two types of hemocytes: plasmatocytes involved in phagocytosis and crystal cells necessary for encapsulation which differentiate in response to specific immune challenges, such as parasitization by wasps. Collier (Col), the Drosophila ortholog of mammalian Early B - Cell Factor, is expressed and required in a small group of cells of the LG, the PSC and in the differentiation of lamellocytes. In addition to the PSC, the LG is organised in two zones: a medullary zone (MZ) containing prohemocytes and a cortical zone (CZ) containing differentiating cells. I showed that the PSC controls the balance between the pool of prohemocytes and differentiating hemocytes. PSC cells act, in a non-cell autonomous manner, to maintain JAK/STAT signaling in prohemocytes, preventing their premature differentiation and preserving the multipotent character necessary for lamellocyte differentiation. The PSC acts a micro-environment for Drosophila hematopoietic precursors which is reminiscent of the HSC (Hematopoietic Stem Cell) niche of vertebrates. To see if there exist HSC in the LG, I looked for stem cell markers and I could't get evidence for the presence of bona fide stem cells in the LG. Using clonal analyses, I determined that hemocyte precursors become committed to either plasmatocytes or crystal cells durind the L1 larval stage, followed by a phase of intense proliferation. Finally, I obtained evidence that lamellocytes and crystal cells share a common progenitor
46
Profit, Michael Alastair. "Bionomic variation, oviposition strategy and larval competition in West African Bruchid populations". Thesis, Royal Holloway, University of London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266395.
Testo completo
47
Giglioti, Rodrigo. "Efeito de extratos de sementes de Nim (Azadirachta indica) sobre fêmeas ingurgitadas e larvas de Rhipicephalus (boophilus) microplus (CANESTRINI, 1887) (ACARI: IXODIDAE) /". Jaboticabal : [s.n.], 2010. http://hdl.handle.net/11449/96563.
Testo completoAbstract (sommario):
Resumo: Rhipicephalus (Boophilus) microplus é considerado o mais importante parasito de bovinos no Brasil. Atualmente seu controle é dificultado pela exigüidade de moléculas acaricidas geradas, e pelo rápido desenvolvimento de resistência dos carrapatos. O presente trabalho teve por objetivo estudar o efeito de quatro extratos oleosos de sementes de Nim (Azadirachta indica) contento 2.000, 5.000, 9.000 e 10.000 ppm de azadiractina (AZA) quantificados por cromatografia líquida de alta eficiência (CLAE) em fêmeas ingurgitadas e larvas de R. (B.) microplus, in vitro. Para os ensaios com fêmeas ingurgitadas foi usado o Teste de Imersão de Adultas e para os ensaios com as larvas o Teste do Pacote com Larvas. Os resultados obtidos nos ensaios com fêmeas ingurgitadas mostraram que o principal efeito tóxico produzido pelos extratos, está relacionado à inibição da reprodução deste parasito. Foram verificadas reduções nas taxas de ovipostura e eclodibilidade das larvas oriundas das fêmeas tratadas com várias diluições dos extratos, em relação aos controles. Nos cálculos de Eficácia do produto (EP) para todas as soluções testadas, observou-se que a solução de 10.000ppm de AZA (N10) apresentou a maior eficácia. Os resultados das análises dos ensaios mostraram significância (p<0,01) dos dois efeitos incluídos no modelo, indicando variações significativas tanto devidas à concentração de AZA, quanto do ensaio realizado. Nas concentrações letais para as fêmeas ingurgitadas verificou-se que as CL50 não apresentaram variações, enquanto que as CL90 apresentaram grandes variações entre os extratos estudados. Nos ensaios com as larvas, não foram observadas mortalidade das larvas, indicando eficácia zero de todos os extratos testados. Os resultados dos ensaios com fêmeas ingurgitadas de R. (B.) microplus mostraram que os extratos oleosos de Nim apresentaram atividade ... (Resumo completo, clicar acesso eletrônico abaixo)Abstract: Rhipicephalus (Boophilus) microplus is considered the most important cattle parasite in Brazil. Nowadays, his control is complicated by the slowness that acaricides molecules are generated, synthesized through and by the fast development of the resistance of these ticks to the market available products. This work aims to study the effect of four extracts of Neem seed oil (Azadirachta indica) containing 2.000, 5.000, 9.000 and 10.000 ppm of azadirachtin (AZA) quantified by high performance liquid chromatography (HPLC) on engorged females and larvae of R. (B.) microplus, in vitro. For the tests with engorged females, the Adult Immersion Test was used and for the larvae was used the Larvae Package Test. The test results with the engorged females showed that the main toxic effect produced by the extracts is related to the inhibition of the parasite reproduction. Were observed reductions in oviposition and hatchability rates of the larvae derived from the female treated with several dilutions of extracts, compared to controls. In the Product Effectiveness (PE) for all the test solutions, the 10.000ppm (N10) solution showed the highest efficiency. The analysis results from the tests showed significance (p<0,01) of the two effects included in the model, indicating variations both due to AZA and to the test performed. In the lethal concentration to the engorged females was verified that the CL50 did not show great variation, while the CL90 showed great variation between the studied extracts. In the tests with larvae was not observed mortality of them, indicating zero effectiveness of all tested extracts. The results of the tests with R. (B.) microplus engorged females demonstrated that the extract of Neem seeds oils showed acaricide activity. Thus, it is suggested that further studies can be conducted, such as development of the methods and of excrection, and characterization of other secondary ... (Complete abstract click electronic access below)
Orientador: Lucia Galvão de Albuquerque
Coorientador: Márcia Cristina de Sena Oliveira
Banca: Gilson Pereira de Oliveira
Banca: Moacir Rossi Forim
Mestre
48
Souza, Larissa Marila de. "Fotossensibilizadores no controle de larvas do Aedes aegypti (Diptera : Culicidae)". Universidade Federal de São Carlos, 2015. https://repositorio.ufscar.br/handle/ufscar/7203.
Testo completoAbstract (sommario):
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
The Aedes aegypti mosquito is the main responsible for the transmission of dengue. Among numerous alternatives to combat vector, we can cite the use of photosensitizers (PSs) as inactivating of Aedes aegypti larvae. These compounds are able to interact with the light in a specific wavelength, so the cause highly reactive cytotoxic oxygen, resulting in the oxidation of biological targets. The present study had as main objective to analyze the phototoxic effects of PSs: Photogem® and turmeric, in three molecular variations (curcumin, curcuminoids pigment mixture (curcumin, desmethoxycurcumin and bisdemethoxycurcumin) and curcumin in sucrose), against Aedes aegypti larvae under different conditions of delivery of the PSs and lighting. The experiments of this study were divided into two stages: i) Photogem® and the three compositions of turmeric were applied in trials of photodynamic inactivation (PDI) in solution. The groups that received the Photogem®, were also fed with two different types of food, in order to verify the influence of these foods on larval mortality. ii) in a second step the three compositions of turmeric were incorporated in pet food, where it obtained a lyophilized powder, which was subsequently offered to the larvae for scanning. After the receipt of the PSs in solution as in the form of freeze-dried powder, the larvae were irradiated with two sources of light: artificial and natural. In addition to the trials of mortality, other studies were performed, such as checking the time of degradation of PSs when exposed to light, the anatomical location of accumulation of FSs in the larvae, and characterization studies of the product obtained in the form of lyophilized powder. On PDI with the Photogem® comparing the foods, exposed to artificial lighting, one of the foods introduced a higher mortality, indicating the importance of this on effectiveness of PDI. Already on PDI with variations of turmeric, mortality rates varied according to the molecular forms of this compound, showing high mortality for curcumin and curcumin in sucrose. In conditions involving sunlight, high mortality rates were obtained for all FSs delivered solution, featuring in various conditions 100% mortality in 8 hours from exposure to light. For IFD using the freeze-dried powder of three variations of turmeric and sunlight, mortalities in the order of 80% were achieved in lighting 16 hours. The analysis of the fluorescence image obtained by confocal microscope showed that both the three variations of turmeric, such as Photogem®, after an incubation period of 12 hours, accumulated throughout the alimentary canal of the larvae. The Photogem®, as well as turmeric showed potent photodynamic activity being more effective in conditions with higher light intensities. Regarding the delivery conditions of the PS, we observe that the highest values of mortality were obtained through the application of PSs in solution, when compared with the mortality studies using the freeze-dried powder. These results indicate that PDI can be a promising technique in the control of vectors as the Aedes aegypti.
O mosquito Aedes aegypti é o principal vetor responsável pela transmissão da dengue. Dentre as inúmeras alternativas de combate ao vetor, podemos citar o uso de fotossensibilizadores (FSs) como inativadores de larvas do Ae. aegypti. Esses compostos são capazes de interagir com a luz, num comprimento de onda específico, de modo a originar espécies altamente reativas de oxigênio citotóxico, resultando na oxidação de alvos biológicos. O presente estudo teve como principal objetivo analisar os efeitos fototóxicos dos FSs: Photogem® e cúrcuma, em três variações moleculares (curcumina, mistura de pigmentos curcuminóides (curcumina, demetoxicurcumina e bis-demetoxicurcumina) e curcumina em sacarose), contra larvas do Ae. aegypti sob diferentes condições de entrega dos FSs e de iluminação. Os experimentos deste estudo foram divididos em duas etapas: i) tanto o Photogem® quanto as três composições de cúrcuma foram aplicados nos ensaios de inativação fotodinâmica (IFD) em solução. Os grupos que receberam o Photogem® foram também alimentados com dois diferentes tipos de ração, com a finalidade de verificar a influência desses alimentos na mortalidade larval. ii) em uma segunda etapa as três composições de cúrcuma foram incorporadas nas rações, onde obteve-se um pó liofilizado, que foi posteriormente ofertado às larvas para a verificação da mortalidade. Após o recebimento dos FSs, tanto em solução como na forma de pó liofilizado, as larvas foram irradiadas com duas fontes de luz: artificial e natural. Além dos ensaios de mortalidade, outros estudos foram realizados, como a verificação do tempo de degradação dos FSs quando expostos à luz, o local anatômico de acumulação dos FSs nas larvas, e estudos de caracterização do produto obtido na forma de pó liofilizado. Na IFD com o Photogem® comparando as rações, expostas à iluminação artificial, uma delas apresentou uma mortalidade superior, indicando a importância desta na efetividade da IFD. Já na IFD com as variações de cúrcuma, as porcentagens de mortalidade variaram de acordo com as formas moleculares deste composto. Nas condições envolvendo luz solar, foram obtidas altos valores de mortalidade para todos os FSs entregues em solução, apresentando em diversas condições 100% de mortalidade em 8 horas de exposição à luz. Nos ensaios de IFD utilizando o pó liofilizado das três variações de cúrcuma e luz solar, mortalidades da ordem de 80% foram atingidas em 16 horas de iluminação. As análises das imagens de fluorescência obtidas por microscópio confocal mostraram que tanto as três variações de cúrcuma, como o Photogem®, após um período de incubação de 12 horas, acumularam-se em todo o canal alimentar das larvas. O Photogem®, assim como a cúrcuma apresentaram atividade fotodinâmica potente, sendo mais efetivos em condições com maiores intensidades de luz. Com relação às condições de entrega do FS, observamos que as maiores mortalidades foram obtidas através da aplicação dos FSs em solução, quando comparadas com os estudos de mortalidade utilizando o pó liofilizado. Esses resultados indicam que IFD pode ser uma técnica promissora no controle de vetores como o Ae. aegypti.
49
Hoover, Trent. "Hydrodynamic controls on the movement of invertebrate larvae and organic matter in small streams". Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1394.
Testo completoAbstract (sommario):
The movement of organisms and resources within ecosystems are essential elements in the productivity, stability, and distribution of communities. This thesis examines how water velocity, a defining factor of lotic systems, influences the dispersion of benthic organisms and particulate organic matter in small stream ecosystems. Variation in movement-related behaviours in two rheophilous (‘flow-loving’) mayflies (Epeorus and Baetis) and two rheophobic (‘flow-avoiding’) mayflies (Ameletus and Paraleptophlebia) were compared to determine how benthic organisms disperse between and within habitat patches in hydrodynamically complex landscapes. The degree to which water velocity and particle shape influence the retention of organic matter (including deciduous leaves, conifer needles, red-cedar fronds, and branch fragments) was examined to determine how physical factors determine detrital resource availability in streams.
Although water velocity did not influence the crawling rates of Baetis and Ameletus in daylight conditions, both mayflies dispersed rapidly upstream in low-velocity flows in dark conditions. Drift rates of both mayflies were lower in daylight than dark conditions, and were generally inversely related to their habitat preferences. Escape responses in grazing Epeorus, Baetis, and Ameletus larvae in a range of flow conditions showed that retreat distance was more sensitive than flight initiation distance to variation in water velocity, suggesting that hydrodynamics mediate the risks of predation and the costs of flight in stream systems. Comparisons of the transport distances of live larvae, dead larvae, and passive tracer particles in low and high water velocities showed that drift distance varied substantially among taxa, and that behavioural control over drift distance generally declined as water velocity increased.
While organic matter particles generally travelled further in high-velocity reaches, leaves were retained in riffles when they impacted on protruding clasts, while ‘stiff’ particles were retained when they settled into streambed interstices. Leaves placed in high-velocity microhabitats were broken down more slowly than leaves in low-flow areas, likely due to the exclusion of large-bodied detritivores.
In conclusion, this thesis supports the view that hydrodynamic forces control trophic interactions and local population dynamics in stream ecosystems by directly altering the physical – and sometimes behavioural – processes of particle entrainment, transport, and deposition.
50
Huang, Kuo-Hua. "Control of Turning Behaviors by Spinal Projection Neurons in the Larval Zebrafish". Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10232.
Testo completoAbstract (sommario):
This thesis aims to examine how hindbrain spinal projection neurons (SPNs), namely RoV3, MiV1 and MiV2 control tail undulations during turning behaviors. I find that phototaxic turns differ from forward swims by an increased tail bend and a prolonged cycle period during the first undulation, while the later undulations are largely identical. Interestingly, laser ablation of RoV3, MiV1 and MiV2 neurons specifically affects the first undulation cycle by reducing the tail bend and the cycle period. Thus fish without the SPNs mainly perform forward swims in
response to the turn-inducing phototaxic cues. These results suggest that the descending motor command that generates turns in larval zebrafish are composed of two pathways: one generates symmetric tail undulations, and the other, mediated by RoV3, MiV1 and MiV2 neurons, provides a brief and biased effect that modulates the first cycle of tail movement. Furthermore, fish whose unilateral SPNs are ablated are unable to perform turns toward the ablated side during the phototaxis, the optomotor response, the dark-flash response, and spontaneous swims, indicating the universal role of the SPNs in controlling visually-induced and spontaneous turns. Simultaneous two-photon calcium imaging and motor nerve recording in paralyzed fish show that RoV3, MiV2 and most MiV1 neurons on the turning side are active during turns, and that these activities are linearly correlated to the vigor of the intended turns. However, some MiV1 neurons are broadly tuned for all swimming directions. Computer simulations suggest that unilateral descending innervations to a specific type of spinal interneurons, namely commissural inhibitory interneurons, can generate a two-fold increase in the spinal network’s cycle period. This suggests that the SPNs could potentially innervate two types of spinal interneurons, namely \(CoBL_{gly}\) and CoLo, in order to control the rhythm during turns. An additional chapter of this thesis examines the ontogeny of operant and classical learning behaviors in zebrafish. Using strategically positioned visual cues paired with electroshocks, I find that both learning behaviors are expressed reliably around week 3, and reach adult performance levels at week 6. These memories are behaviorally expressed in adults for 6 hours and retrievable for 12 hours.