71 |
Reprodução induzida da rã-touro Lithobates catesbeianus (Shaw, 1802), utilizando diferentes tipos e dosagens do hormônio liberador da gonadotropina - GnRHCOSTA, Sandro Ricardo da 27 February 2012 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2017-02-21T17:09:23Z
No. of bitstreams: 1
Sandro Ricardo da Costa.pdf: 720379 bytes, checksum: 054515c8a5c3b3fc9ff3150fc0b86e14 (MD5) / Made available in DSpace on 2017-02-21T17:09:23Z (GMT). No. of bitstreams: 1
Sandro Ricardo da Costa.pdf: 720379 bytes, checksum: 054515c8a5c3b3fc9ff3150fc0b86e14 (MD5)
Previous issue date: 2012-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The technique of use of gonadotrophin releasing hormone (GnRH) in the reproduction of amphibians can be used to control spawning throughout the year, avoiding production delays resulting from the seasonality of the reproductive cycle. The objective was to study the induced breeding of bullfrog Lithobates catesbeianus using different types and dosages of GnRH to the optimization of the hormone and the consequent reduction in operating costs in commercial production. Breeders (average weight 650 g) were previously prepared, and conditioned to an average temperature of 26°C, submitted to a photoperiod of 15 hours of light. We tested three different hormone treatments; treatment 1 (T1) with 5 μg Etilamid hydrated acetate, treatment (T2) 2.5 μg Etilamid hydrated acetate and treatment 3 (T3) with 0.8 μg of Buserelin acetate, divided in three experimental groups. For each treatment, three applications were made at intervals of 12 hours hormones application in females and a single one for males. After the hormone treatment was done the extrusion of eggs in females and spermiation in males fertilized eggs hydrated with water at neutral pH. All males responded to the hormones applied resulting in a "pool of sperm" used to fertilize the females. Females of treatments T1 and T2 ovulated in its entirety and there was a failure only in T3. From the first and second trials, it could be detected that the dosages of 2.5 μg Etilamid hydrated acetate and 0.8 μg Buserelin acetate are more technically and economic viable for induced breeding of bullfrog. The average weight of spawning was 92.8 and 93.7 g respectively. The fertilization rate was estimated from the percentage of eclosion, with rates of fertilization rates average with 84.2 % (T2) and 60.3 % (T3). Based on the results, we conclude that the reduction in usual dosages for Etilamid hydrated acetate and the use of Buserelin acetate were efficient on ovulation and spermiation in bullfrogs, but it is necessary to adjust the dosage of Buserelin acetate as well to get a better improvement through environmental control and breeder maturation conditions in further experiments. / A técnica de uso de hormônios liberadores da gonadotrofina (GnRH) na reprodução de anfíbios pode ser usada para controlar as desovas ao longo do ano, evitando atrasos na produção decorrente da sazonalidade do ciclo reprodutivo. Objetivou-se estudar a reprodução induzida da rã touro Lithobates catesbeianus, utilizando diferentes tipos e dosagens do GnRH visando à otimização do hormônio e conseqüente redução nos custos operacionais na produção comercial. Os reprodutores (peso médio de 650 g) foram previamente preparados, sendo climatizados à temperatura média de 26° C, e submetidos a fotoperíodo de 15h luz. Foram testados três diferentes tratamentos hormonais, sendo o tratamento um (T1) com 5 μg/rã de acetato de Etilamida hidratado, o tratamento dois (T2) 2,5 μg/rã de acetato de Etilamida hidratado e o tratamento três (T3) com 0,8 μg/rã de acetato de Busserelina, divididos em três fases experimentais. Em cada tratamento foram feitas três aplicações de hormônios com intervalo de 12 h nas fêmeas, e apenas uma aplicação nos machos. Após o tratamento hormonal foi feita a extrusão dos óvulos nas fêmeas e espermiação nos machos, fecundando e hidratando os ovos com água de pH neutro. Todos os machos responderam aos hormônios aplicados resultando em um ―pool espermático‖, usado na fertilização das fêmeas. As fêmeas dos Tratamentos T1 e T2 ovularam em sua totalidade havendo uma abstenção apenas no T3. Nas primeira e segunda fase experimental, foi detectado que as dosagens de 2,5 μg/rã de acetato de Etilamida hidratado e 0,8 μg/rã de acetato de Busserelina foram mais tecnicamente e economicamente viáveis para indução à reprodução da rã touro. A média no peso das desovas foi de 92,8 e 93,7 g, respectivamente. A taxa de fecundação foi estimada na porcentagem de eclosão das larvas, com índices de fecundação com medias no T2 com 84,2 % e 60,3 % no T3. Com base nos resultados, é possível concluir que houve eficiência com a redução das dosagens usuais para o acetato de Etilamida hidratado e também houve eficiência com o uso do acetato de Busserelina na ovulação e espermiação de rãs, porém se faz necessário ajuste de dosagens para acetato de Busserelina bem como uma melhor adequação entre as condições de controle ambiental e maturação dos reprodutores, afim de melhorar os índices de fecundação em novos experimentos.
|
72 |
Threat-sensitive learning and generalization of predator recognition by aquatic vertebratesFerrari, Maud C.O. 29 January 2009
Many prey species lack innate recognition of their potential predators. Hence, learning is required for them to recognize and respond to predation threats. When wild-caught, these same species may show amazing sophistication in their responses to predator cues. They are able to adjust the intensity of their antipredator responses to a particular predator according to the degree of threat posed by that predator. This ability is therefore acquired through learning. While many studies have shown that prey can learn to respond to predator cues through different learning modes, little is known about what the prey are actually learning. The results presented in this thesis show that learned predator recognition goes beyond the simple labelling of predators as dangerous. Using fathead minnows (Pimephales promelas), woodfrog (Rana sylvatica) tadpoles and boreal chorus frog (Pseudacris maculata) tadpoles, I demonstrated that a one time learning event, either through pairing with alarm cues or through social learning, was enough for prey to learn the level of threat associated with the novel predator cues. I showed that the level of danger associated with the predator cues was determined by the concentration of alarm cues when learning through pairing of alarm cues, or by the intensity of antipredator response displayed by the tutors and by the tutor-to-observer ratio when learning occurred through cultural transmission. Moreover, when subsequently exposed to predator cues, prey adjusted their antipredator responses according to the change in concentration of predator cues between the learning event and the subsequent exposure. Prey displayed stronger antipredator responses when exposed to higher concentrations of predator cues and vice versa. When minnows were provided with conflicting information about the danger level associated with a predator, they displayed a safety strategy and used the most recent information available to respond to predation threats. On a longer time scale, the data also suggest that woodfrog tadpoles are able to learn to respond to predation threats according to the risk posed by the predator at different times of day. Finally, I showed that prey learn to recognize particular characteristics of predators and can generalize their antipredator responses to novel species sharing those characteristics. However, generalization of predator recognition is dependent on the level of risk associated with the predator. Threat-sensitive learning is an extremely complex process shaped by the millions of years of selection imposed by predators on prey.
|
73 |
Threat-sensitive learning and generalization of predator recognition by aquatic vertebratesFerrari, Maud C.O. 29 January 2009 (has links)
Many prey species lack innate recognition of their potential predators. Hence, learning is required for them to recognize and respond to predation threats. When wild-caught, these same species may show amazing sophistication in their responses to predator cues. They are able to adjust the intensity of their antipredator responses to a particular predator according to the degree of threat posed by that predator. This ability is therefore acquired through learning. While many studies have shown that prey can learn to respond to predator cues through different learning modes, little is known about what the prey are actually learning. The results presented in this thesis show that learned predator recognition goes beyond the simple labelling of predators as dangerous. Using fathead minnows (Pimephales promelas), woodfrog (Rana sylvatica) tadpoles and boreal chorus frog (Pseudacris maculata) tadpoles, I demonstrated that a one time learning event, either through pairing with alarm cues or through social learning, was enough for prey to learn the level of threat associated with the novel predator cues. I showed that the level of danger associated with the predator cues was determined by the concentration of alarm cues when learning through pairing of alarm cues, or by the intensity of antipredator response displayed by the tutors and by the tutor-to-observer ratio when learning occurred through cultural transmission. Moreover, when subsequently exposed to predator cues, prey adjusted their antipredator responses according to the change in concentration of predator cues between the learning event and the subsequent exposure. Prey displayed stronger antipredator responses when exposed to higher concentrations of predator cues and vice versa. When minnows were provided with conflicting information about the danger level associated with a predator, they displayed a safety strategy and used the most recent information available to respond to predation threats. On a longer time scale, the data also suggest that woodfrog tadpoles are able to learn to respond to predation threats according to the risk posed by the predator at different times of day. Finally, I showed that prey learn to recognize particular characteristics of predators and can generalize their antipredator responses to novel species sharing those characteristics. However, generalization of predator recognition is dependent on the level of risk associated with the predator. Threat-sensitive learning is an extremely complex process shaped by the millions of years of selection imposed by predators on prey.
|
74 |
Evaluating the conservation potential of urban and rural ecosystems for aquatic-breeding amphibians: a case study of two native frogs in southwestern British ColumbiaGreen, Jemma 27 September 2018 (has links)
The conservation of aquatic-breeding amphibian populations and their habitats is increasingly challenged by urban and rural development, which is occurring more intensively and more rapidly than ever before. Some species are now impacted by development throughout their range. This has forced a re-evaluation of the potential of developed landscapes for providing habitat and contributing to regional conservation strategies. For many amphibians, little is known about the criteria necessary for persistence in a developed landscape. Considerable variation in the physiology, habitat requirements, and movement behaviour of amphibians suggests that responses to habitat loss, alteration, and fragmentation are species-specific. In this thesis, I investigate species-habitat relationships for the northern red-legged frog (Rana aurora) and the Pacific chorus frog (Pseudacris regilla) in a mixed urban-rural landscape in southwestern British Columbia to evaluate the potential for species persistence despite urban and rural development throughout their range. I used repeat auditory surveys of the species’ breeding chorus to determine presence or absence at potential breeding wetlands. I then related species occurrence and abundance to characteristics of the aquatic and terrestrial environment measured at multiple spatial scales. Both species were found to use rural and urban wetlands, though R. aurora were rarely detected while P. regilla were common. Occurrence was best explained by characteristics of the terrestrial environment, rather than within-wetland characteristics, though influential terrestrial characteristics and their scale of impact differed between species. Within the context of the developed landscape, I identify species-specific positive and negative habitat associations and suggest the spatial scales at which management of these habitat characteristics will be most effective. These criteria may help to explain the species’ current distribution, prioritize management strategies, predict the effectiveness of habitat conservation and restoration projects, and inform development in municipalities seeking to maintain or enhance amphibian diversity. / Graduate / 2019-09-11
|
75 |
The chilling tail of temperature’s influence on thyroid hormone signalling in the post-embryonic developmental response of Rana catesbeiana cultured tail finKoide, Emily 14 September 2021 (has links)
Thyroid hormone (TH) is a critical signalling molecule for all vertebrate organisms, playing an especially crucial role in postembryonic development. Given its importance, many studies have focused on further elucidating the initial TH signal response and its method of transduction. Although the primary mechanism of TH response is genomic signalling, alternative mechanisms of early TH signal transduction have been relatively poorly studied. The North American bullfrog, Rana catesbeiana, is a useful model to study these early responses as tadpole post-embryonic development, or metamorphosis, can be experimentally induced through exposure to TH. The experimental induction of the TH signalling program leads to similar morphological endpoints as seen in natural metamorphosis in the transition of a tadpole to a juvenile froglet, such as regression of the tail. This TH-induced developmental program can also be manipulated through temperature where, as temperatures lower, developmental rate is delayed and at 5°C metamorphosis is completely stalled. Interestingly, when tadpoles exposed to TH at 5°C are introduced to permissive temperatures (24°C), an accelerated developmental program ensues, even when no more endogenous TH signal remains. Previous research has shown that this phenomenon can also be seen on the molecular level where only a select few transcripts have been shown to be responsive to TH at 5°C. However, the characteristic, if not augmented, TH response program is seen on the transcriptomic level when tadpoles are shifted to 24°C. This indicates that there is a molecular memory where the TH signal is induced in cold temperatures but not executed until more permissive temperatures arise. The extent and regulation of the transcriptomic program involved in this TH-induced molecular memory has yet to be understood. Herein we use the broader probing technique of RNA-seq analysis to identify potential components of the molecular memory. Eighty-one gene transcripts were TH-responsive at 5°C in cultured R. catesbeiana tail fin indicating that the molecular memory is more complex than previously thought. A number of these transcripts encoded regulators of transcription. Closer examination of select transcripts including a novel krüppel-like factor family member, klfX, at 5oC indicated that not all of the candidate molecular memory transcripts are regulated through active transcription and active translation is not required. When moved into 24°C an accelerated transcriptomic response occurred even when no additional TH is added, suggesting that a priming event occurs by TH exposure at 5°C allowing an accelerated metamorphosis at permissive temperatures. The molecular memory may be used as a means to isolate the initiating TH signalling response and the regulation of this program to allow further elucidation of early TH signalling in post-embryonic development. / Graduate
|
76 |
Detekce, lokalizace a určení plochy chronických ran / Detection, Localization and Determination of Chronic WoundsGulán, Filip January 2018 (has links)
The aim of this diploma thesis is to design and implement a multiplatform application for detection, localization and determination of the extent of chronic wounds. The application is intended to assist nurses, doctors and healthcare assistants to monitor and evaluate chronic wounds in the course of treatment. The application is based on the Typescript programming language, on the Ionic hybrid application framework and on the Electron desktop application framework. Chronic wound assessment runs on the server-side where the Python programming language is used. The Flask application framework is used for the RESTful application interface and the OpenCV library is used for image processing.
|
77 |
Diversitet av amfibier och förhållandet mellan gruppens reproduktiva framgång och evertebrater knutna till dammarAndersson, Susanna January 2020 (has links)
Inledning: Småvatten som dammar har försummats i bevarande-och övervakningsstrategier där fokus har lagts på större sötvattensmiljöer. Kunskap om småvattens roll i bevarandet av biologisk mångfald är bristfällig men studier har visat att dammar kan försörja fler arter, fler unika arter och mer ovanliga arter än sjöar, floder och vattendrag. I Sverige är 100 av 240 rödlistade sötvattensorganismer knutna till småvatten, där de flesta är arter av evertebrater men inkluderar även 38 % arter av den svenska amfibiefaunan. För att säkra den svenska amfibiefaunan måste faktorerna som missgynnar faunan, framförallt de hotade arterna, bli kända. Att bedöma vattenmiljöer lämpade för framgångsrik reproduktion hos amfibier kan vara komplicerad med hjälp av instrumentmätningar och vattenprover då kemiska parametrar i vattnet är ostabila. Alternativt kan man studera sötvattenslevande makroevertebrater där sammansättning, förekomst eller frånvaro kan indikera om miljön är utsatt för stressfaktorer. Utdikningar, övergödning och introduktion av invasiva arter har missgynnat amfibiefaunan genom minska reproduktionslokaler och skapa spridningsbarriärer. I Skånes region, som har högst diversitet av groddjur, har hundratals vatten återskapats för amfibier men behovet att fortsätta med naturvårdsinsatser kvarstår. Syfte: Med denna studie önskar jag lyfta vikten av att bevara och återskapa dammar för amfibier. Studien fokuserar på artrikedom hos amfibier, hotade arter samt reproduktiv framgång hos dessa. Studien omfattar 15 dammar fördelade över tre områden i Skåne. I två områden har flera dammar återskapats för att gynna amfibiefaunan och genom att följa upp kolonisering av dessa och utvärdera reproduktiv framgång, önskar jag bidra med lärdom om naturvårdsinsatsers effektivitet. De två områdena kommer även att jämföras med ett referensområde där inga omfattande naturvårdsinsatser har genomförts. Kemi- och fysikaliska parametrar kommer mätas i dammarna men även makroevertebrater i vattnet kommer att studeras för att se om det finns ett samband mellan dammar med framgångsrik reproduktion hos amfibier och förekomsten av makroevertebrater. Frågorna som ska besvaras är 1) vilket område är mest artrikt? 2) Har naturvårdsinsatserna i relation till referensområdet gynnat hotade arter? 3) Skiljer sig sammansättningen av vattenkemiska parametrar åt mellan dammar med framgångsrik reproduktion hos Anura med dammar utan framgångsrik reproduktion? 4) Skiljer förekomst, diversitet, sammansättning av evertebrater samt andelen rovinsekter åt mellan dammar med framgångsrik reproduktion hos Anura med dammar utan framgångsrik reproduktion? Metod: Projektområdet begränsades till sydöstra Skåne. Två områden, Ravlunda och Högestad valdes ut efter vetskapen om att omfattande naturvårdsinsatser utförts i områdena med syftet att gynna amfibier. Markanvändningen i områdena skiljer sig åt där Ravlunda är ett aktivt skjutfält och i Högestad drivs bland annat jord- och skogsbruk. Det tredje området, Referensområdet, bestod av spridda dammar runt Ravlunda skjutfält. Här hade inga naturvårdsinsatser utförts i syftet att gynna amfibier. Amfibier och deras utvecklingsstadium inventeras under säsongen när gruppen är som mest aktiv i vattenmiljön. Utvalda kemi-och fysikaliska mätningar tas med hjälp av mätinstrument och vattenprover analyseras i laboratorium. Evertebrater samlas in genom håvning för att beräkna Shannons diversitet index och Average score per taxon (ASPT) index. Andelen rovinsekter beräknas från antalet larver av Odonata och individer från familjerna Dytiscidae och Notonectidae. Variansanalyser kommer utföras för att identifiera skillnader mellan områdena och korrelationsanalyser utförs för att identifiera samband mellan evertebrater och framgångsrik reproduktion hos amfibier. Non-metric multidimensional scaling analyser kommer utföras för att identifiera hur lokalerna förhåller sig till varandra i sammansättning av vattenkemi samt sammansättning av familjer och fördelning hos evertebrater. Resultat: Högestad var det mest artrika området. Där var signifikant skillnad i antalet individer av hotad art mellan Ravlunda och de andra områdena. Naturvårdsinsatserna bedömdes gynnat hotad art i Ravlunda men inte i Högestad. Korrelationsanalysen visade inget samband mellan framgångsrik reproduktion och index-beräkningarna. Slutsats: Naturvårdsinsatser i syftet att bevara den svenska amfibiefaunan och dess hotade arter kan vara framgångsrik om man lägger alla bitar i pusslet rätt, för det är många faktorer som spelar in för att insatser ska bli både effektiva och framgångsrika. Att fortsätta med uppföljningar av naturvårdsinsatser efter att projekttiden är slut är viktigt för att kunna ta lärdom om vilka metoder som skapar bäst förutsättningar för stabila populationer hos amfibier.
|
78 |
Ecological Effects of Climate Change on AmphibiansRollins, Hilary Byrne 28 August 2019 (has links)
No description available.
|
79 |
Effects of an Insecticide on Competition in Anurans: Could Pesticide-Induced Competitive Exclusion be a Mechanism for Amphibian Declines?Distel, Christopher A. 02 August 2010 (has links)
No description available.
|
80 |
The Histological Effects of Injections of Fish Pituitary Extracts on the Testes of Male Frogs, (Rana Pipiens), and the Reproductive System of Immature MiceRobertson, William George 08 1900 (has links)
The purpose of this investigation was first, to make a histological and cytological study of the testis of male frogs, Rana pipiens, and to determine if there were tissue or cellular changes as well as physiological effects caused by fish pituitary-extract injections. Second, to determine if injections of fish pituitary extract into immature female white mice caused histological changes in the ovaries and uteri.
|
Page generated in 0.0162 seconds