Thesis (Ph. D.)--Cornell University, 1919. / Descriptive letterpress on versos facing the plates. Reprinted from Biological bulletin, v. 38, no. 2, February 1920, the Anatomical record, v. 20, no. 2, January 1921, and Journal of morphology, v. 36, no. 2, March 1922. Bibliography: p. 75-76.

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 177-181).

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Thesis (Ph.D.)--Tufts University, 2000. / Adviser: Sara M. Lewis. Submitted to the Dept. of Biology. Includes bibliographical references (leaves 100-107). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Le but de cette thèse est d'étudier d'une façon expérimentale et théorique le comportement synchrone d'un groupe d'oscillateurs contrôlés par la lumière (LCOs). Ces LCOs sont très simples du point de vue électronique et ont la propriété d'imiter le comportement des lucioles puisqu'ils interagissent par des impulsions de lumière. En même temps, les LCOs sont une bonne approche pour étudier d'autres systèmes qui agissent comme des oscillateurs d'intégration et de tir car un LCO est un oscillateur de relaxation à deux échelles de temps : un long processus de charge alterné avec un très court processus de décharge. Une série d'expériences a été menée pour pouvoir comprendre le processus de synchronisation des LCOs. Nous avons trouvé que l'acquisition de la synchronisation est due aux effets de la perturbation à savoir: le raccourcissement de la charge et l'allongement de la décharge. Les mesures expérimentales ainsi que la physique liée aux LCOs nous ont permis de formuler un modèle qui a été utilisé pour trouver d'une façon analytique la courbe de réponse de phase (PRC) qui caractérise un LCO. Le modèle a ensuite été validé en comparant les résultats expérimentaux et théoriques. Le modèle reproduit même, le phénomène de bifurcation qui apparaît lorsque trois LCOs sont couplés et disposés en ligne : deux états stables différents apparaissent selon les conditions initiales. L'accord trouvé entre théorie et expérience nous permet d'utiliser le modèle pour étudier d'autres situations qui ne sont pas facilement abordables du point de vue expérimental. Nous avons étudié analytiquement deux LCOs identiques couplés. Même pour ce cas idéal, nous étions obligés de faire des simplifications pour pouvoir trouver des solutions exactes. On a trouvé pour ce système deux états possibles qui dépendent des conditions initiales, la synchronisation (stable) et l'anti-synchronisation (instable). Nous avons également montré que le temps de synchronisation augmente avec la distance entre LCOs. La construction des langues d'Arnold (régions de synchronisation) nous a permis de distinguer des régions de synchronisation pure d'ordre n:m et des régions de superposition synchronisation--modulation. Nous avons travaillé numériquement avec des systèmes de LCOs affectés de bruits uniforme et Gaussien. Le comportement synchrone de ce système a été caractérisé en utilisant des paramètres statistiques simples tels que la moyenne de la différence de phase linéaire et la variance de la différence de phase cyclique. Nous avons démontré que le bruit, bien qu'il puisse perturber la synchronisation, peut aussi la favoriser entre deux LCOs qui ne se synchroniseraient pas en conditions normales, surtout quand le bruit est Gaussien et que les variances du bruit ne sont pas égales. Nous avons étudié en termes statistiques la synchronisation de LCOs couplés localement et arrangés en ligne, en anneau et en réseau. Nous avons montré que la synchronisation totale se produit plus facilement pour des LCOs disposés en anneau. Concernant le temps de synchronisation, il est imprédictible. Les résultats analytiques et numériques suggèrent que la synchronisation totale est le phénomène le plus probable quand le nombre d'oscillateurs n'est pas très grand. Finalement, nous avons étudié des LCOs statiques et mobiles couplés globalement. Dans les deux cas, nous avons trouvé que la synchronisation est moins probable quand le nombre d'oscillateurs augmente. Pour la condition statique, en considérant un couplage du type champ moyen, nous avons observé que le temps de synchronisation diminue avec le nombre de LCOs. Cependant, pour la situation plus réaliste dans laquelle l'interaction entre LCOs dépend de la distance les séparant, le temps de synchronisation devient à nouveau imprédictible. Enfin, nous avons étudié l'influence de la mobilité sur la synchronisation, problème qui est important en biologie et en robotique. Notre système, de par ses caractéristiques et sa base expérimentale, est beaucoup plus proche de la réalité que ceux considérés d'habitude dans la littérature. Les résultats obtenus peuvent s'appliquer à des systèmes biologiques (lucioles, cellules cardiaques, neurones, …), mais également à la robotique, où la communication à longue portée par la lumière et l'émergence de patterns de synchronisation pourraient être très utiles dans le but d'effectuer des tâches spécifiques.

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Made available in DSpace on 2016-06-02T19:26:23Z (GMT). No. of bitstreams: 1 SANTOS_Raphael_Machado_2013.pdf: 6874760 bytes, checksum: f35ab24f9948043239dd26f9df3fc5b5 (MD5) Previous issue date: 2013-12-12 / Universidade Federal de Minas Gerais / Bioluminescent beetles are common for their wide distribution in the world, but the composition of the fauna of these organisms is still unknown to most of the areas where they occur. Brazil is the country with the largest number of cataloged species of bioluminescent insects, but studies of faunal surveys, which allow observing the composition of the assemblies of these insects, with the aim of monitoring impacts in natural areas has only recently been realized. The present study focuses on the artificial night lighting as a possible impact on assemblies of bioluminescent beetles. To the knowledge of the fauna of luminous beetles in the State of São Paulo, surveys were conducted by sampling at three sites of the Atlantic Forest in the SA of Paranapiacaba. The species found were: Aspisoma lineatum, Aspisoma physionotum, Aspisoma sp., Cratomorphus beskei, Cratomorphus giganteus, Photinoides penai, Photinus sp1, Photinus sp9, Ethra aff. malledicta ou axilaris, Ethra aff. adicta, Cladodes demoulini, Cladodes flabelicornis, Amydetes sp., Bicellonycha sp., Bicellonycha sp8, Pyrogaster lunifer, Pyrogaster moestus, Pyrogaster sp3 ref. (PORTO, 2011), Photuris elliptica, Photuris sp1, Photuris sp7 Stenophrixotrix sp1, Brasilocerus sp1, Phrixotrix hirtus, Pseudophengodes sp1, Hapsodrilus pyrotis, Pyroptesis cincticollis, Ptesiomopsia luculenta, Pyrearinus candelarius, Pyrearinus micatus e Pyrophorus divergens. The investigated area in SA Paranapiacaba has the second highest species richness of bioluminescent insects of the state of São Paulo until now. From the cluster analysis was done with the data obtained in the field and published data to categorize areas as more and less urbanized was possible to deduce a dependence relationship between species and area in which they can occur. Like other studies, lower richness of bioluminescent beetles in more urbanized areas was observed, we chose a species to investigate the possible effects of artificial lighting. For the study we used the method of counting grid in two similar areas, where only one had artificial lighting. Was possible to compare the data obtained from the two sites with randomization of the same data through a robust non-parametric test, thereby we verified that the sample populations showed no number of different occurrences, the p value is not significant (t=1,780787, R=5000, P=0,059988). We conclude that Bicellonycha lividipennis is not sensitive to ligth of sodium vapor lamps. So this species is not a good indicator species to light pollution for this type of light source. The bioluminescence spectra and the sodium light were superimposed; a possible explanation for that B. lividipennis is not sensitive to light sodium is the activity of the species which is relatively early when there is still strong lighting of twilight. / Coleópteros bioluminescentes são conhecidos pela sua ampla distribuição no mundo, porém a composição da fauna desses organismos ainda é desconhecida para a maior parte das áreas onde eles ocorrem. O Brasil é o país com o maior número de espécies de insetos bioluminescentes catalogadas, porém estudos de levantamentos faunísticos, que possibilitam observar a composição das assembleias d esses organismos, com o objetivo de monitoramento de impactos em áreas naturais só tem sido realizados recentemente. O presente trabalho foca a iluminação artificial noturna como um possível impacto nas assembleias de coleópteros bioluminescentes. Para o conhecimento da fauna de coleópteros no Estado de São Paulo, foram realizadas séries de levantamentos por meio da coleta em três locais de Mata Atlântica na Serra de Paranapiacaba. As espécies encontradas foram: Aspisoma lineatum, Aspisoma physionotum, Aspisoma sp. (não foi identificada), Cratomorphus beskei, Cratomorphus giganteus, Photinoides penai, Photinus sp1, Photinus sp9, Ethra aff. malledicta ou axilaris, Ethra aff. adicta, Cladodes demoulini, Cladodes flabelicornis, Amydetes SP (ainda não foi identificad), Bicellonycha sp. (ainda não foi identificada), Bicellonycha sp8, Pyrogaster lunifer, Pyrogaster moestus, Pyrogaster sp3 ref. (PORTO, 2011), Photuris elliptica, Photuris sp1, Photuris sp7 Stenophrixotrix sp1, Brasilocerus sp1, Phrixotrix hirtus, Pseudophengodes sp1, Hapsodrilus pyrotis, Pyroptesis cincticollis, Ptesiomopsia luculenta, Pyrearinus candelarius, Pyrearinus micatus e Pyrophorus divergens. A área de investigada na SA de Paranapiacaba apresenta a segunda maior diversidade de insetos bioluminescentes do Estado de São Paulo até o momento. A partir da análise de agrupamento que foi realizada com os dados obtidos em campo e dados da literatura, é possível deduzir uma relação de dependência entre espécies e área em que elas podem ocorrer, quando categorizamos as áreas como mais e menos urbanizadas. Como tem sido observada uma menor riqueza de besouros bioluminescentes em áreas mais urbanizadas neste e em outros trabalhos, elegemos uma espécie para investigar os possíveis efeitos da iluminação artificial. Para o estudo utilizamos o método de contagem em grid em duas áreas semelhantes, onde apenas uma era iluminada; com a análise dos dados obtidos, por meio de um teste não-paramétrico robusto realizado com aleatorizações dos dados, foi possível comparar os dados obtidos com aqueles gerados ao acaso, e com isso verificamos que as populações amostrais não apresentaram número de ocorrências diferentes, sendo o valor de p encontrado, não significativo (t=1,780787, R=5000, P=0,059988). Dessa maneira, concluímos Bicellonycha lividipennis não é sensível à luz de sódio. Portanto, não é uma espécie boa para ser indicadora de poluição luminosa para esse tipo de fonte. Os espectros de bioluminescência e da luz de sódio foram confrontados e, uma possível explicação para que B. lividipennis não seja sensível à luz de sódio é que o início da atividade da espécie ocorre quando ainda há forte iluminação do crepúsculo.

Fireflies are beetles that generate yellow-green light when their luciferase enzyme activates and oxidizes its substrate, D-luciferin. This bioluminescent reaction is widely used as a sensitive reporter both in vitro and in vivo. However, the light-emitting chemistry is limited by the properties of the small molecule D-luciferin. Our lab has developed a panel of synthetic luciferin analogs that improve on the inherent characteristics of D-luciferin. My thesis work focuses on harnessing these novel substrates to further expand the utility and molecular understanding of firefly bioluminescence. The first part of my thesis focuses on using synthetic luciferins to improve bioluminescence imaging beyond what is possible with D-luciferin. Our substrates emit red-shifted light compared to D-luciferin, bringing the wavelength to a range that is more able to penetrate through tissue, but at a cost of lower signal intensity. I developed mutant luciferases that increase the maximal photon flux with the synthetic luciferins over what is achievable with the wild-type luciferase, and furthermore discriminate between substrates based on their chemical structures. Additionally, I have expanded the bioluminescence toolkit by harnessing the intrinsic properties of the luciferins to non-invasively and specifically assay the activity of a single enzyme (fatty acid amide hydrolase) in live mice. Therefore, my work presents an effective way to generally improve upon bioluminescent reporters, but also to measure the activity of a specific enzyme of interest in the context of a living organism. The second part of my thesis employs synthetic luciferins to more deeply probe the light-emitting chemistry of bioluminescence. Our synthetic substrates reveal latent luciferase activity from multiple luciferase homologs that are inactive with D-luciferin. These enzymes, the fatty acyl-CoA synthetases, are predicted to be luciferase’s evolutionary predecessors, but it was not clear how the light emitting chemistry originated. My work shows that the luciferase must activate the luciferin and provide oxygen access, but the light emitting chemistry is a fundamental property of that activated intermediate. In summary, the work described herein not only expands our understanding of firefly bioluminescence, but also broadens its practical applications to shine bioluminescent light on the dark corners of biology.