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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Cross-modal Effects In Tactile And Visual Signaling

Merlo, James 01 January 2008 (has links)
Using a wearable tactile display three experiments were conducted in which tactile messages were created emulating five standard US Army and Marine arm and hand signals for the military commands, namely: "Attention", "Halt", "Rally", "Move Out", and "Nuclear Biological or Chemical event (NBC)". Response times and accuracy rates were collected for novices responding to visual and tactile representations of these messages, which were displayed either alone or together in congruent or incongruent combinations. Results indicated synergistic effects for concurrent, congruent message presentations showing superior response times when compared to individual presentations in either modality alone. This effect was mediated by participant strategy. Accuracy similarly improved when both the tactile and visual presentation were concurrently displayed as opposed to separately. In a low workload condition, participants could largely attend to a particular modality, with little interference from competing signals. If participants were not given instructions as to which modality to attend to, participants chose that modality which was received first. Lastly, initial learning and subsequent training of intuitive tactile signals occurred rapidly with large gains in performance in short training periods. These results confirm the promise for tactile messages to augment visual messaging in challenging and stressful environments particularly when visual messaging is maybe preferred but is not always feasible or possible.
2

Multimodal Communication in the Panamanian Golden Frog (<i>Atelopus zeteki</i>)

Criswell, Joni M. 10 December 2008 (has links)
No description available.
3

Ecologia reprodutiva de Leptodactylus aff. hylaedactylus (Anura: Leptodactylidae) em Ãrea de mata de tabuleiro no Nordeste do Brasil / Reproductive ecology of Leptodactylus aff. hylaedactylus (Anura: Leptodactylidae) in forest area in Northeastern Brazil

Maria Juliana Borges Leite 09 January 2012 (has links)
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / Neste trabalho foram realizados estudos quanto à ecologia reprodutiva de uma espÃcie de anfÃbio anuro ainda em processo de descriÃÃo taxonÃmica, chamada aqui de Leptodactylus aff. hylaedactylus, ocorrente atà o momento somente para o municÃpio de SÃo GonÃalo do Amarante, litoral oeste do CearÃ. O estudo teve duraÃÃo de um ano, porÃm, foi suficiente para confirmar que esta espÃcie apresenta sazonalidade, sendo observada somente em alguns meses chuvosos, de janeiro a maio de 2011, com pico de atividade no mÃs de abril e hÃbitos principalmente noturnos. Das condiÃÃes ambientais analisadas, como umidade, temperatura e pluviosidade, somente esta Ãltima que apresentou correlaÃÃo positiva quando correlacionada com a abundÃncia de indivÃduos em atividade. A espÃcie apresentou o padrÃo reprodutivo descrito para o grupo marmoratus, o qual apresenta cÃmaras subterrÃneas e ninho de espuma como caracterÃsticas principais da reproduÃÃo, em que estas cÃmaras sÃo construÃdas pelo macho da espÃcie antes de atrair a fÃmea. A atividade desta espÃcie ocorre em Ãreas de mata de tabuleiro, onde os machos vocalizam principalmente na serapilheira. Entretanto, foram observados machos vocalizando a cerca de 30 cm do solo, sobre a vegetaÃÃo, onde o macho vocaliza para atrair a fÃmea e esta ao se interessar em acasalar, exibe para o macho chutes no ar (âleg kickingâ). ApÃs isto, seguem para a cÃmara e realizam o amplexo. Foram localizadas quatro cÃmaras subterrÃneas de diÃmetro mÃdio 3,33 cm e profundidade mÃdia de 2,32 cm e trÃs destas foram localizadas com a presenÃa de ninhos de espuma e girinos no interior (n=9, 9, e 10). Esta espÃcie nÃo apresenta fase aquÃtica para desenvolvimento dos girinos, ocorrendo o modo reprodutivo 32. Hà dimorfismo sexual quanto ao tamanho para esta espÃcie e pode-se observar tambÃm diferenÃas morfolÃgicas entre machos e fÃmeas, em que os machos apresentam o focinho espatulado em forma de pÃ. Foram observadas nove sinalizaÃÃes visuais para esta espÃcie, sendo uma inÃdita e descrita neste trabalho, chamada de âcabeÃadasâ, na qual o macho vocaliza intensamente na presenÃa de outro macho invasor e em seguida realiza movimentos para trÃs, retirando as patas dianteiras do solo, chegando a formar um Ãngulo de cerca de 30Â. Dentre estas sinalizaÃÃes visuais exibidas, algumas sÃo de carÃter agressivo, demonstrando a presenÃa de territorialismo nesta espÃcie. / It is presented a detailed study on the reproductive ecology of an undescribed amphibiam anura species, called here Leptodactylus aff. hylaedactylus, occurring at SÃo GonÃalo do Amarante, west coast of CearÃ. The study was during one year, however, this species showed seasonality, observed only in rainy months, from January to May 2011, with peak in April and showing nocturnal habits. We analyzed the environmental conditions like humidity, temperature and rainfall, and only rainfall showed significance when correlated with abundance of individuals. The species has the reproductive pattern described for the marmoratus group which has underground chambers and foam nest as the main features of reproduction, in these chambers are constructed by the male of the species before attracting the female for mating. The activities occurs in forested areas called âmata de tabuleiroâ, vocalizing mainly in litter leaf, however, were observed males calling to about 30cm of soil. Males calls to attract females and if she to be interested in mating, displays leg kicking, after, they head to the chambers to mate. We found four underground chambers of 3.33 cm diameter and 2.32 cm depth mean. Three of these chambers were found with presence of foam nest and tadpoles inside (n= 9, 9 and 10). This species has no aquatic phase for the development of tadpoles, resulting in the reproductive mode 32. There was sexual dimorphism in size and it can be observed morphological differences between males and females, in which males have a rounded snout-shaped shovel. We observed nine visual signaling with one unprecedented being described in this work, called âcabeÃadasâ in which the male vocalized intensely in the presence of another invader male and then performs backwards movements, removing the arms of the soil, reaching an angle of 30Â. Some of these visual displays are aggressive, demonstrating the presence of territorialism in this species.
4

Color and wing size: identifying targets of sexual selection in Drosophila melanogaster / Färg och vingstorlek: att identifiera mål för sexuell selektion hos Drosophila melanogaster

Pääjärvi Våg, Ellen January 2024 (has links)
This study explores the relationship between wing size, coloration, and reproductivesuccess in Drosophila melanogaster, fruit flies. Sexual selection, a key aspect ofevolutionary biology, often involves visual signaling as a means of displaying geneticinformation. The study aims to identify the morphological traits targeted by sexualselection, specifically examining the hypotheses that both wing size and coloration(thin-film interference patterns) influences reproductive success, and that these traitsare correlated. Data was collected from standardized images of 229 fruit flies thatwere used in a competitive mating assay, and the analysis included color analyses inFiji (ImageJ) to obtain red, green, and blue (RGB) values, as well as sizemeasurements in both vertical and horizontal size dimensions for one wing from eachfly. Statistical analyses, including correlation analysis and multiple regression inSPSS, were conducted to examine the relationships between morphological aspects,color, and mating success in the competitive mating assay. Results indicate asignificant relationship between horizontal wing length and male reproductivefitness, suggesting that larger wings may confer advantages in mate choice andreproductive success for males. Phenotypic selection analysis indicated thathorizontal wing length is under significant directional selection independent of wingcoloration, which was not subject to significant selection. The correlation analysisrevealed a weak but significant correlation between wing size and average coloration.Sexual dimorphism in wing dimensions was observed, with females exhibiting largerwings than males. The study suggests that coloration may be influenced by wing size,raising questions about the causal relationship between wing size, coloration, andreproductive success. Importantly, this study suggests that wing size may be a moreimportant target of selection than wing color, suggesting that past findings of sexualselection on color without consideration of wing size or shape may be premature. / Den här studien undersöker förhållandet mellan vingstorlek, färg och reproduktivframgång hos Drosophila melanogaster, bananflugor. Sexuell selektion, en viktigaspekt inom evolutionsbiologi, involverar ofta visuell signalering som ett sätt att visaupp genetisk information. Studien syftar till att identifiera de morfologiskaegenskaper som är mål för sexuell selektion, och framför allt granska hypotesen attbåde vingstolek, färg (“thin-film interference patterns” som uppstår när ljus faller påen tunn film och ger färgglada reflektioner) influerar reproduktiv framgång, och attdessa egenskaper korrelerar med varandra. Data samlades in från standardiseradebilder av 229 bananflugor som använts i ett konkurrensbaserat parningsexperiment,och min analys bestod av färganalys i Fiji (ImageJ) för att få röda, gröna och blå (RGB) värden, såväl som storleksanalys av både vertikal och horisontell längd hosvarje fluga. Statistisk analys, däribland korrelationsanalys och multipelregressionsanalys i SPSS, utfördes för att granska relationen mellan morfologiskaegenskaper, färg och den reproduktiva framgången i parningsexperimentet.Resultaten indikerar att det finns ett signifikant förhållande mellan horisontellvingstorlek och hanarnas reproduktiva framgång, vilket tyder på att större vingar kan medföra fördelar vid partnerval och reproduktiv framgång för dem. Fenotypisktselektionsanalys pekade mot att horisontell vingstorlek är under ett signifikant riktatselektionstryck oberoende av färgen på dem, som i sig inte var föremål för någotsignifikant selektionstryck. Korrelationsanalys visade en svag men signifikantkorrelation mellan vingstorlek och genomsnittlig färgning. Sexuell dimorphismobserverades i vingstorlek, där honorna visade sig ha större vingar än hanarna.Studien föreslår att färgen på vingarna är beroende av vingstorleken, vilket väckerfrågor kring de kausala sambanden mellan vingstorlek, färg och reproduktivframgång. Framför allt föreslår denna studie att vingstorlek att vingstorleken kanvara kan ett vara betydligt större mål för sexuell selektion än vad färgen är, vilket i sintur antyder att de tidigare resultaten som pekat mot att sexuell selektion agerar påvingarnas färg har konstaterats i ett för tidigt skede, då vingstoleken inte varit en aspekt man har haft med sig i beräkningarna.
5

Fatores associados ao sucesso reprodutivo de duas espécies coocorrentes de Jacaranda Juss. (Bignoniaceae)

Souza, Camila Vaz de. January 2019 (has links)
Orientador: Elza Guimarães / Resumo: Nessa tese estudamos duas espécies melitófilas de Bignoniaceae, Jacaranda caroba e J. decurrens, que coocorrem em formações savânicas de cerrado e que se mostraram modelos interessantes para explorarmos aspectos ecológicos e evolutivos relacionados à sua reprodução sexual, tendo em vista que apresentam uma complexa rede de interações com mutualistas e antagonistas. A sobreposição geográfica dessas duas espécies nos permitiu avaliar padrões de coexistência relacionados à dinâmica de florescimento, bem como seu anúncio floral relacionado à atração de visitantes florais mutualistas e antagonistas. Além disso, essa interação com mutualistas e antagonistas possibilitou averiguar o impacto da atuação de antagonistas que roubam néctar sobre a polinização de ambas as espécies e como os danos realizados por abelhas roubadoras de néctar interferem na sinalização visual e química aos polinizadores. Também avaliamos a exploração de néctar por diferentes grupos funcionais de visitantes florais de J. caroba e J. decurrens. Por fim, considerando que o sucesso reprodutivo está diretamente relacionado com a eficiência da polinização investigamos o sistema reprodutivo dessas duas espécies e o efeito da qualidade do pólen transferido entre flores associado ao comportamento dos polinizadores durante o forrageamento, buscando compreender os fatores intrínsecos relacionados à seleção mecanismos de autoincompatibilidade nas populações naturais amostradas. / Abstract: In this dissertation we studied two mellithiphilous Bignoniaceae species, Jacaranda caroba and J. decurrens, that co-occur in savanic cerrado formations. This is an interesting model to explore ecological and evolutionary aspects related to their sexual reproduction taking into account that they present a complex network of interactions with mutualists and antagonists. These species‟ geographical overlap allowed us to evaluate patterns of coexistence related to the flowering dynamics, as well as its floral display related to the attraction of mutualists and antagonists‟ floral visitors. Besides, their interactions with mutualists and antagonists allowed us to evaluate the impact of nectar-robbing antagonists on both species and how damage by nectar-robber bees interferes with visual and chemical signaling to pollinators. We also evaluated the nectar exploitation by different functional groups of J. caroba and J. decurrens floral visitors. Finally, considering that these species‟ reproductive success and the effect of pollinator behavior during foraging on the quality of the pollen that is transferred among flowers. Considering that species‟ reproductive success is directly related to the pollination efficiency, we investigated the reproductive system of these two species and the effect of the quality of the pollen transferred between flowers associated to the pollinators‟ behavior during the foraging, trying to understand the intrinsic factors related to mechanisms of self-in... (Complete abstract click electronic access below) / Doutor

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