Woo Kwan Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 148-155). / Abstracts in English and Chinese. / Contents --- p.ii / Abstract --- p.iv / Acknowledgements --- p.vii / List of Figures --- p.viii / List of Tables --- p.x / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Literature Reviews --- p.7 / Chapter 2.1 --- Block Clustering --- p.7 / Chapter 2.2 --- Clustering XML by structure --- p.10 / Chapter 2.2.1 --- Definition of XML schematic information --- p.10 / Chapter 2.2.2 --- Identification of XML schematic information --- p.12 / Chapter Chapter 3 --- Bi-Tour Ant Colony Optimization for diagonal clustering --- p.15 / Chapter 3.1 --- Motivation --- p.15 / Chapter 3.2 --- Framework of Bi-Tour Ant Colony Algorithm --- p.21 / Chapter 3.3 --- Re-order of the data matrix in BTACO clustering method --- p.27 / Chapter 3.3.1 --- Review of Ant Colony Optimization --- p.29 / Chapter 3.3.2 --- Bi-Tour Ant Colony Optimization --- p.36 / Chapter 3.4 --- Determination of partitioning scheme --- p.44 / Chapter 3.4.1 --- Weighed Sum of Error (WSE) --- p.48 / Chapter 3.4.2 --- Materialization of partitioning scheme via hypothetic matrix --- p.50 / Chapter 3.4.3 --- Search of best-fit hypothetic matrix --- p.52 / Chapter 3.4.4 --- Dynamic programming approach --- p.53 / Chapter 3.4.5 --- Heuristic partitioning approach --- p.57 / Chapter 3.5 --- Experimental Study --- p.62 / Chapter 3.5.1 --- Data set --- p.63 / Chapter 3.5.2 --- Study on DP Approach and HP Approach --- p.65 / Chapter 3.5.3 --- Study on parameter settings --- p.69 / Chapter 3.5.4 --- Comparison with GA-based & hierarchical clustering methods --- p.81 / Chapter 3.6 --- Chapter conclusion --- p.90 / Chapter Chapter 4 --- Application of BTACO-based clustering in XML database system --- p.93 / Chapter 4.1 --- Introduction --- p.93 / Chapter 4.2 --- Overview of normalization and vertical partitioning in relational DB design --- p.95 / Chapter 4.2.1 --- Normalization of relational models in database design --- p.95 / Chapter 4.2.2 --- Vertical partitioning in database design --- p.98 / Chapter 4.3 --- Clustering XML documents --- p.100 / Chapter 4.4 --- Proposed approach using BTACO-based clustering --- p.103 / Chapter 4.4.1 --- Clustering XML documents by structure --- p.103 / Chapter 4.4.2 --- Clustering XML documents by user transaction patterns --- p.109 / Chapter 4.4.3 --- Implementation of Query Manager for our experimental study --- p.114 / Chapter 4.5 --- Experimental Study --- p.118 / Chapter 4.5.1 --- Experimental Study on the clustering by structure --- p.118 / Chapter 4.5.2 --- Experimental Study on the clustering by user access patterns --- p.133 / Chapter 4.6 --- Chapter conclusion --- p.141 / Chapter Chapter 5 --- Conclusions --- p.143 / Chapter 5.1 --- Contributions --- p.144 / Chapter 5.2 --- Future works --- p.146 / Bibliography --- p.148 / Appendix I --- p.156 / Appendix II --- p.168 / Index tables for Profile A --- p.168 / Index tables for Profile B --- p.171 / Appendix III --- p.174

This research identifies and investigates major issues in inducing accurate and comprehensible fuzzy rules from datasets. A review of the current literature on fuzzy rulebase induction uncovers two significant issues: A. There is a tradeoff between inducing accurate fuzzy rules and inducing comprehensible fuzzy rules; and, B. A common strategy for the induction of fuzzy rulebases, that of iterative rule learning where the rules are generated one by one and independently of each other, may not be an optimal one. FRANTIC, a system that provides a framework for exploring the claims above is developed. At the core lies a mechanism for creating individual fuzzy rules. This is based on a significantly modified social insect-inspired heuristic for combinatorial optimisation -- Ant Colony Optimisation. The rule discovery mechanism is utilised in two very different strategies for the induction of a complete fuzzy rulebase: 1. The first follows the common iterative rule learning approach for the induction of crisp and fuzzy rules; 2. The second has been designed during this research explicitly for the induction of a fuzzy rulebase, and generates all rules in parallel. Both strategies have been tested on a number of classification problems, including medical diagnosis and industrial plant fault detection, and compared against other crisp or fuzzy induction algorithms that use more well-established approaches. The results challenge statement A above, by presenting evidence to show that one criterion need not be met at the expense of the other. This research also uncovers the cost that is paid -- that of computational expenditure -- and makes concrete suggestions on how this may be resolved. With regards to statement B, until now little or no evidence has been put forward to support or disprove the claim. The results of this research indicate that definite advantages are offered by the second simultaneous strategy, that are not offered by the iterative one. These benefits include improved accuracy over a wide range of values for several key system parameters. However, both approaches also fare well when compared to other learning algorithms. This latter fact is due to the rule discovery mechanism itself -- the adapted Ant Colony Optimisation algorithm -- which affords several additional advantages. These include a simple mechanism within the rule construction process that enables it to cope with datasets that have an imbalanced distribution between the classes, and another for controlling the amount of fit to the training data. In addition, several system parameters have been designed to be semi-autonomous so as to avoid unnecessary user intervention, and in future work the social insect metaphor may be exploited and extended further to enable it to deal with industrial-strength data mining issues involving large volumes of data, and distributed and/or heterogeneous databases.

In this thesis, a novel framework for dynamic congestion control has been proposed. The study is about the congestion control in broadband communication networks. Congestion results when demand temporarily exceeds capacity and leads to severe degradation of Quality of Service (QoS) and possibly loss of traffic. Since traffic is stochastic in nature, high demand may arise anywhere in a network and possibly causing congestion. There are different ways to mitigate the effects of congestion, by rerouting, by aggregation to take advantage of statistical multiplexing, and by discarding too demanding traffic, which is known as admission control. This thesis will try to accommodate as much traffic as possible, and study the effect of routing and aggregation on a rather general mix of traffic types. Software Defined Networking (SDN) and Network Function Virtualization (NFV) are concepts that allow for dynamic configuration of network resources by decoupling control from payload data and allocation of network functions to the most suitable physical node. This allows implementation of a centralised control that takes the state of the entire network into account and configures nodes dynamically to avoid congestion. Assumes that node controls can be expressed in commands supported by OpenFlow v1.3. Due to state dependencies in space and time, the network dynamics are very complex, and resort to a simulation approach. The load in the network depends on many factors, such as traffic characteristics and the traffic matrix, topology and node capacities. To be able to study the impact of control functions, some parts of the environment is fixed, such as the topology and the node capacities, and statistically average the traffic distribution in the network by randomly generated traffic matrices. The traffic consists of approximately equal intensity of smooth, bursty and long memory traffic. By designing an algorithm that route traffic and configure queue resources so that delay is minimised, this thesis chooses the delay to be the optimisation parameter because it is additive and real-time applications are delay sensitive. The optimisation being studied both with respect to total end-to-end delay and maximum end-to-end delay. The delay is used as link weights and paths are determined by Dijkstra's algorithm. Furthermore, nodes are configured to serve the traffic optimally which in turn depends on the routing. The proposed algorithm is a fixed-point system of equations that iteratively evaluates routing - aggregation - delay until an equilibrium point is found. Three strategies are compared: static node configuration where each queue is allocated 1/3 of the node resources and no aggregation, aggregation of real-time (taken as smooth and bursty) traffic onto the same queue, and dynamic aggregation based on the entropy of the traffic streams and their aggregates. The results of the simulation study show good results, with gains of 10-40% in the QoS parameters. By simulation, the positive effects of the proposed routing and aggregation strategy and the usefulness of the algorithm. The proposed algorithm constitutes the central control logic, and the resulting control actions are realisable through the SDN/NFV architecture.

Made available in DSpace on 2014-06-11T19:30:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-10-11Bitstream added on 2014-06-13T19:19:43Z : No. of bitstreams: 1 roma_gc_dr_rcla.pdf: 2022594 bytes, checksum: eece8bf27b13004335d7c54d03d168df (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O corpo gorduroso dos insetos é um tecido de preenchimento que está principalmente no abdômen e ao redor dos órgãos, onde é denominado de corpo gorduroso perivisceral, e logo abaixo do tegumento, ou corpo gorduroso parietal. No presente estudo avaliou-se a morfologia, a morfometria, a histoquímica e a citoquímica ultra-estrutural, além da química dos lipídios, das células do corpo gorduroso das operárias e gynes (fêmeas aladas) de formigas de Cyphomyrmex rimosus e de Mycetarotes parallelus e operárias médias e rainhas de Acromyrmex disciger e de Atta laevigata pertencentes à tribo Attini, com o objetivo de descrever os tipos celulares e analisar morfológica e fisiologicamente suas células, com vistas a detectar a ocorrência de possíveis variações neste tecido tanto entre as espécies quanto entre as castas, além de avaliar se existiriam diferenças entre as espécies basais e derivadas que possivelmente teriam surgido ao longo do processo evolutivo dos indivíduos pertencentes a esta tribo. Os resultados mostraram que em todas as espécies e castas o corpo gorduroso é constituído pelos trofócitos, células que se tornam poligonais devido à compressão de uma contra a outra, com núcleos irregulares e com presença de proteínas, polissacarídeos neutros e lipídios distribuídos por todo o citoplasma. Nas gynes e rainhas, em geral, esses elementos mostraram-se mais evidentes do que nas operárias. Verificou-se ainda que os trofócitos das castas reprodutivas seriam caracterizados pela presença de toda a estrutura relacionada à síntese de proteínas, elementos essenciais nos processos relacionados à vitelogênese. Os lipídios nos trofócitos das operárias e rainhas das espécies derivadas apareceram em maiores quantidades do que nas operárias e gynes basais. Os enócitos, outro tipo celular freqüentemente associado aos trofócitos, mostraram-se... / The insect fat body is a filling tissue which is distributed principally in the abdomen, around the organs (also known as perivisceral fat body) and right above the tegument (called the parietal fat body). The present study evaluated the morphology, morphometry, histochemistry and ultrastructural cytochemistry, as well the lipid chemistry, of the fat body cells of ant workers and gynes (winged females) of Cyphomyrmex rimosus and Mycetarotes parallelus and media workers and queens of Acromyrmex disciger and Atta laevigata belonging to the Attini tribe, with the objective of describing the cell types and the morphological and physiological analysis of their cells. This was done in an attempt to detect the occurrence of possible tissue variations between the species and castes, as well as evaluating if there are differences between the basal and derived species that may have surfaced during the evolution of these individuals belonging to this tribe. The results showed that in all species and castes the fat body is constituted of trophocytes, which are polygonal in shape due to the compression of one cell against another, and with irregular nuclei, proteins, neutral polysaccharides and lipids distributed all over the cytoplasm. In general, these elements were more evident in the gynes and queens than in the workers. It was also verified that the trophocytes of the reproductive castes are characterized by the presence of structures related to protein synthesis, essential elements in activities related to vitellogenesis. The lipids in the worker and queen trophocytes from the derived species are present in larger amounts when compared to the basal workers and gynes. The oenocytes, another cell type frequently associated to the trophocytes, are spherical in all species and castes, in addition to spherical nuclei, proteins, lipids and a few neutral polysaccharides distributed all over the... (Complete abstract click electronic access below)

Resumo: O corpo gorduroso dos insetos é um tecido de preenchimento que está principalmente no abdômen e ao redor dos órgãos, onde é denominado de corpo gorduroso perivisceral, e logo abaixo do tegumento, ou corpo gorduroso parietal. No presente estudo avaliou-se a morfologia, a morfometria, a histoquímica e a citoquímica ultra-estrutural, além da química dos lipídios, das células do corpo gorduroso das operárias e "gynes" (fêmeas aladas) de formigas de Cyphomyrmex rimosus e de Mycetarotes parallelus e operárias médias e rainhas de Acromyrmex disciger e de Atta laevigata pertencentes à tribo Attini, com o objetivo de descrever os tipos celulares e analisar morfológica e fisiologicamente suas células, com vistas a detectar a ocorrência de possíveis variações neste tecido tanto entre as espécies quanto entre as castas, além de avaliar se existiriam diferenças entre as espécies basais e derivadas que possivelmente teriam surgido ao longo do processo evolutivo dos indivíduos pertencentes a esta tribo. Os resultados mostraram que em todas as espécies e castas o corpo gorduroso é constituído pelos trofócitos, células que se tornam poligonais devido à compressão de uma contra a outra, com núcleos irregulares e com presença de proteínas, polissacarídeos neutros e lipídios distribuídos por todo o citoplasma. Nas "gynes" e rainhas, em geral, esses elementos mostraram-se mais evidentes do que nas operárias. Verificou-se ainda que os trofócitos das castas reprodutivas seriam caracterizados pela presença de toda a estrutura relacionada à síntese de proteínas, elementos essenciais nos processos relacionados à vitelogênese. Os lipídios nos trofócitos das operárias e rainhas das espécies derivadas apareceram em maiores quantidades do que nas operárias e "gynes" basais. Os enócitos, outro tipo celular freqüentemente associado aos trofócitos, mostraram-se... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The insect fat body is a filling tissue which is distributed principally in the abdomen, around the organs (also known as perivisceral fat body) and right above the tegument (called the parietal fat body). The present study evaluated the morphology, morphometry, histochemistry and ultrastructural cytochemistry, as well the lipid chemistry, of the fat body cells of ant workers and gynes (winged females) of Cyphomyrmex rimosus and Mycetarotes parallelus and media workers and queens of Acromyrmex disciger and Atta laevigata belonging to the Attini tribe, with the objective of describing the cell types and the morphological and physiological analysis of their cells. This was done in an attempt to detect the occurrence of possible tissue variations between the species and castes, as well as evaluating if there are differences between the basal and derived species that may have surfaced during the evolution of these individuals belonging to this tribe. The results showed that in all species and castes the fat body is constituted of trophocytes, which are polygonal in shape due to the compression of one cell against another, and with irregular nuclei, proteins, neutral polysaccharides and lipids distributed all over the cytoplasm. In general, these elements were more evident in the gynes and queens than in the workers. It was also verified that the trophocytes of the reproductive castes are characterized by the presence of structures related to protein synthesis, essential elements in activities related to vitellogenesis. The lipids in the worker and queen trophocytes from the derived species are present in larger amounts when compared to the basal workers and gynes. The oenocytes, another cell type frequently associated to the trophocytes, are spherical in all species and castes, in addition to spherical nuclei, proteins, lipids and a few neutral polysaccharides distributed all over the... (Complete abstract click electronic access below) / Orientador: Maria Izabel Camargo Mathias / Coorientador: Odair Correa Bueno / Banca: Hélio Conte / Banca: Maria Santina de Castro Morini / Banca: Maria Claudia Colla Ruvolo Takasusuki / Banca: Elaine Cristina Mathias da Silva Zacarin / Doutor

Visando contribuir com o estado-da-arte de sistemas bioinspirados em formigas na robóotica, neste trabalho é abordado o problema do controle de um grupo de robôs para a solução coletiva das tarefas de exploração do ambiente e localização de objetos. Para isso, são utilizados algoritmos inspirados em colônias de formigas. O objetivo deste trabalho, portanto, é o desenvolvimento de um sistema de controle de navegação baseado em colônia de formigas para um time de robôs, de maneira que os robôs resolvam esses problemas utilizando estratégias de controle individuais e simples. Esse sistema tem como base a utilização de marcadores ou feromônios artificiais, que podem ser depositados pelos robôs para marcar determinadas posiçôes do ambiente / Aiming to advance the state-of-the-art of ant bioinspired systems in robotic applications, in this work we study the problem of controling a group of robots for solving colective tasks on environment exploration and object localization. To this end, we used algorithms inspired in ant colonies. Therefore, the objective of this work is to develop a navigation control system based on ant colony can solve the problems using simple control strategies. This system uses marks or artificial pheromones that can be released by the robots to mark specific positions in the environment

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-09-28T11:47:35Z No. of bitstreams: 1 2011 - Diego da Silva Gomes.pdf: 2619456 bytes, checksum: 54aa7fc27666d0eefe5f74d7131dbd5c (MD5) / Made available in DSpace on 2016-09-28T11:47:35Z (GMT). No. of bitstreams: 1 2011 - Diego da Silva Gomes.pdf: 2619456 bytes, checksum: 54aa7fc27666d0eefe5f74d7131dbd5c (MD5) Previous issue date: 2011-04-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The leaf cutter ant Atta robusta Borgmeier, 1939 (Hymenoptera: Formicidae) is an endemic species existent in restinga environment between States of Rio de Janeiro and Esp?rito Santo. However, with the fragmentation of this environment and consequent loss of the native area, owed due mainly to the urban growth, this species takes serious extinction risk, becoming indispensable studies that seek auxiliary in the understanding of your ecology, as the action of parasitoids phorids (Diptera: Phoridae). This work had as main objective to study possible associations of these flies with A. robusta. During the period between June 2009 and October 2010 two restinga environment were studied in the city of Rio de Janeiro: Parque Marapendi and restinga da Marambaia. In each environment they two areas were chosen (with differentiated vegetable composition), an open and more degraded, and another closed, more preserved. In each area nine colonies of A. robusta were chosen, totaling 36 colonies in the four areas of the two environments. Every day of data collection consisted of six hours of observation, divided in eight times of 45 minutes. These observations were made in trails and entrance of the nests, in a consecutive way, always beginning for the entrance nests. In the first ones 15 of each time were to verify the traffic of ants and the 30 remaining minutes, for capture of the phorids that attacked A. robusta. Environmental variables (temperature and humidity) were logged, as well as the attack place (trails and nests entrances). Seventy three phorid flies of two species were collected: Neodohrniphora sp. (46 individuals) and Myrmosicarius sp. (27 individuals). The first one was confirmed as a new species and it was more frequent in more closed restinga areas, while the second, with open areas. The two species attack in trails and entrance of the nests. The number of individuals of Myrmosicarius sp. was influenced negatively with the temperature and positively with the relative humidity of the air. In the case of Neodohrniphora sp. nov., all the regressions relating the number of individuals captured with the studied variables were not significant. The phorid species appear to be linked to specific areas of restinga, in which temperature and humidity are factors limiting the performance of parasitoids Myrmosicarius sp., but do not regulate the behavior of parasitoid Neodohrniphora sp nov. / A formiga cortadeira Atta robusta Borgmeier, 1939 (Hymenoptera: Formicidae) ? uma esp?cie end?mica de ambientes de restinga existentes entre os Estados do Rio de Janeiro e Esp?rito Santo. Por?m, com a fragmenta??o deste ambiente e conseq?ente perda da ?rea nativa, devido principalmente ao crescimento urbano, esta esp?cie corre s?rio risco de extin??o, tornando-se imprescind?veis estudos que visem auxiliar na compreens?o de sua ecologia, como a a??o de for?deos parasit?ides (Diptera: Phoridae). Este estudo teve como objetivo principal estudar poss?veis associa??es destas moscas com A. robusta. Durante o per?odo entre junho de 2009 e outubro de 2010 foram estudados dois ambientes de restinga na cidade do Rio de Janeiro: Parque Marapendi e restinga da Marambaia. Em cada um destes ambientes foram escolhidas duas ?reas (com composi??o vegetal diferenciada), uma aberta e mais degradada, e outra fechada, mais preservada. Em cada ?rea foram escolhidas nove col?nias de A. robusta, totalizando 36 col?nias nas quatro ?reas dos dois ambientes. Cada dia de coleta de dados constou de seis horas de observa??o, divididas em oito tempos de 45 minutos. Estas observa??es foram feitas em trilhas e em olheiros, de forma consecutiva, sempre se iniciando pelos olheiros. Os 15 primeiros minutos de cada tempo foram para verificar o tr?fego de formigas e os 30 minutos restantes, para captura de for?deos que atacavam A. robusta. Vari?veis ambientais (temperatura e umidade) foram anotadas, bem como o local de ataque (trilha e olheiro). Foram coletados 73 for?deos de duas esp?cies: Neodohrniphora sp. nov. (46 indiv?duos) e Myrmosicarius sp. (27 indiv?duos). A primeira esp?cie foi confirmada como uma nova esp?cie e foi mais frequente em ?reas de restinga mais fechadas, enquanto a segunda, em ?reas abertas. As duas esp?cies atacam em trilhas e olheiros. O n?mero de indiv?duos de Myrmosicarius sp. foi influenciado negativamente pela temperatura e positivamente pela umidade relativa do ar. No caso de Neodohrniphora sp. nov., todas as regress?es relacionando o n?mero de indiv?duos capturados com as vari?veis estudadas foram n?o significativas. As esp?cies de for?deos parecem estar associadas a ?reas espec?ficas de restinga, na qual temperatura e umidade s?o fatores limitantes da atua??o dos parasit?ides Myrmosicarius sp., por?m n?o regulam o comportamento parasit?ide de Neodohrniphora sp nov.

Submitted by PPG Hist?ria (historia-pg@pucrs.br) on 2018-09-27T13:32:32Z No. of bitstreams: 1 Vers?o FINAL - Vit?ria.pdf: 2591532 bytes, checksum: 513fc64b10a5a73654afc9135421611c (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-10-01T12:08:10Z (GMT) No. of bitstreams: 1 Vers?o FINAL - Vit?ria.pdf: 2591532 bytes, checksum: 513fc64b10a5a73654afc9135421611c (MD5) / Made available in DSpace on 2018-10-01T12:21:15Z (GMT). No. of bitstreams: 1 Vers?o FINAL - Vit?ria.pdf: 2591532 bytes, checksum: 513fc64b10a5a73654afc9135421611c (MD5) Previous issue date: 2018-08-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The authoritarian regimes, as the Estados Novos from Brazil and Portugal, have speeches and political projects aimed at women in order to establish their roles only to private life. This research has the objective of comparing the representation of women in the feminine magazines Jornal das Mo?as, from Brazil, and Modas e Bordados - Vida Feminina, from Portugal, during the Estados Novos; period of each country from 1937 to 1945. Therefore, this work contextualizes the regimes of Get?lio Vargas and Ant?nio de Oliveira Salazar, as well as the history of these feminine magazines. Based on the press as a central source of analysis, this work has the pretention to investigate the social roles established for women according to these magazines. Lastly, the research proposes a comparison between the regimes and the magazines to understand the effect of this production in society, specialty for women. / Este trabalho de pesquisa tem como objetivo comparar a representa??o das mulheres nas revistas femininas, Jornal das Mo?as no Brasil e Modas e Bordados- Vida Feminina em Portugal durante os Estados Novos dos respectivos pa?ses de 1937-1945. Os regimes autorit?rios, como se caracterizavam os Estados Novos no Brasil e em Portugal, possu?am discursos e projetos pol?ticos voltados ?s mulheres a fim de estabelecer seus espa?os delimitados ao privado. Para tanto, contextualizam-se os regimes de Get?lio Vargas e de Ant?nio de Oliveira Salazar assim como a hist?ria dos peri?dicos em an?lise. Apoiando-se na imprensa peri?dica enquanto fonte central de an?lise tem a pretens?o de investigar os pap?is sociais estabelecidos para as mulheres a partir de an?lise das mat?rias. Por ?ltimo, optou-se por comparar os regimes e os peri?dicos a fim de compreender suas atua??es na sociedade, em especial ?s mulheres.

Ants are ubiquitous in most communities and many form opportunistic mutualisms with honeydew-producing hemipterans (e.g. treehoppers). Hemipterans excrete honeydew, a carbohydrate rich substance, that ants harvest and, in return, ants protect their honeydew-producing partners from parasitoids, predators, and competitors. Given the efficacy of tending ants in removing hemipteran antagonists, and the strong roles that ants play within their communities as predators, competitors, and seed dispersers, surprisingly little is known of the effects of ant-hemipteran mutualisms (AHM) on the invertebrate communities in which they are embedded or on the plants that host AHM. Using observational and manipulative field experiments, I examined the long-term effect of AHM on their host plant’s, honey mesquite (Prosopis glandulosa), reproductive potential and quality. In addition, I measured how the presence of AHM affects the abundance, richness, diversity, and composition of the invertebrate communities living on honey mesquite. Plants hosting AHM may indirectly benefit (through the removal of herbivore arthropods) or suffer (through the loss pollinators) due to the defensive behavior of tending ants. To determine the effects of AHM on their host plant, I established a four-year press experiment in which I removed AHM from 50 randomly trees, while leaving 50 as controls. In addition, I marked and followed 30 trees from which AHM were naturally absent. To assess if mesquite quality differed between trees hosting AHM and trees in which AHM were naturally absent, in 2012 I assayed foliar condensed tannin concentrations, a secondary defense compound, and, in 2015, I measured foliar nitrogen, phosphorous, potassium, magnesium, and iron as they are essential for growth and reproduction. I compared the reproductive potential between AHM present and removed trees by counting flowers and fruits across all 4 years of the study. Mesquite that hosted AHM contained significantly less condensed tannins and significantly higher concentrations of N%, Mg, and Fe. Furthermore, over the duration of the study mesquite hosting AHM contained significantly more flowers than those from which AHM were removed or naturally absent. My results indicate that AHM select trees of high quality and their continued presence is associated with high levels of reproductive potential. Most studies that have evaluated community-level effects of AHM compare total abundance and species richness in communities (or host plants) with and without AHMs. However, both measures are dependent on sampling effort, complicating comparisons across different studies. To examine the effects of AMH on the arthropod community in mesquite, I first compared family richness and alpha diversity using standardized rarefaction and extrapolation curves. I then measured beta diversity and turnover in community composition from one year to the next. The removal of AHM increased invertebrate diversity and significantly altered community composition. Although treatments did not statistically differ in turnover rates, replacements occurred among treatments at the family level which may be biologically meaningful. Furthermore, herbivore and predator populations increased, and pollinator populations decreased following the removal of AHM. These results suggest that the presence of AHM can alter the composition of arthropod communities and food-web dynamics. However, these effects were significant in some years and not others, suggesting the importance of temporal variation in drivers of communities. Overall, my work demonstrates that AHM can be drivers of community composition and illustrate the importance of examining their effects across multiple seasons.

A subfamília Myrmicinae é um grande desafio à sistemática de formigas por ser a maior e mais diversa subfamília de Formicidae, abrangendo cerca de seis mil espécies distribuídas mundialmente. As relações filogenéticas internas desta subfamília são fonte de discussão e incerteza na literatura. Os estudos moleculares desenvolvidos em Attini e Myrmicini (sensu Bolton) representaram os primeiros passos para a compreensão dos clados existentes em Myrmicinae. Recentemente, as 25 tribos estabelecidas para esta subfamília foram reorganizadas em apenas seis Attini, Crematogastrini, Myrmicini, Pogonomyrmecini, Solenopsidini e Stenammini. Hylomyrma Forel, 1912 o grupo objeto deste estudo atualmente pertence à tribo Pogonomyrmecini junto com outros dois gêneros, Patagonomyrmex Johnson & Moreau, 2016 e Pogonomyrmex Mayr, 1868. Hylomyrma é um gênero exclusivamente Neotropical cujas espécies habitam a serapilheira. Em decorrência do hábito críptico das espécies, a diversidade e a história natural do grupo são pouco conhecidas. Desde a revisão realizada por Kempf (1973), que reconheceu 12 espécies para o gênero, poucas foram as espécies incluídas em estudos filogenéticos e apenas uma espécie foi descrita posteriormente. O presente estudo teve por objetivo realizar um estudo de revisão taxonômica a partir da análise de uma quantidade extensa de material e investigar pela primeira vez as relações filogenéticas internas do gênero com base em caracteres morfológicos externos de operárias. Praticamente todos os espécimes-tipo designados para as espécies de Hylomyrma (com exceção do holótipo de H. reginae Kutter, 1977) foram examinados, além de 2.757 exemplares provenientes de 29 instituições. Quinze espécies novas foram reconhecidas, sendo 10 descritas com base tanto em operárias quanto em gines. Novos dados de distribuição foram registrados para as 13 espécies já conhecidas, bem como a descrição de cinco gines e seis machos. Além disso, o estudo taxonômico indica que a presença de espécimes cuja morfologia externa representa um mosaico entre gine e operária (intercastas) não é incomum no grupo, sendo observada para 11 espécies. O estudo filogenético foi realizado a partir de uma matriz composta por 88 caracteres e 31 terminais, sendo três espécies do grupo-externo. As análises de máxima parcimônia (MP) foram realizadas no programa TNT através de buscas tradicionais empregando o algorítmo de rearranjo de ramos TBR com 3.000 réplicas, 10 árvores salvas por réplica, random seed=0 e colapse trees=ON, sob esquemas de pesagem igual e implícitos. Os valores de concavidade (k) utilizados variaram entre 1-25. O suporte dos ramos foi calculado através do índice de Bremer. A análise com pesagem igual resultou em uma árvore com 269.274 passos (IC=0,379 e RI=0,59). Quatro diferentes árvores foram obtidas a partir das análises com pesagem implícita, k1, k3-9, k15 e k20-25. O resultado da análise filogenética corrobora a monofilia de Hylomyrma, com pelo menos nove sinapomorfias sustentando esta hipótese de agrupamento. Três grandes linhagens podem ser reconhecidas em Hylomyrma: A, espécies com tamanho corporal relativamente grande (car. 52, variando de 0,534 a 0,785); B, espécies com face posterior do pró-fêmur lisa (car. 45 1), estriação do primeiro tergito gastral restrita à base do segmento (car. 79 0) e presença de pelos ramificados no primeiro tergito do gáster (car. 85 1), condição posteriormente perdida por Hylomyrma sp. T; e C, caracterizado por espécies cujos pelos apresentam ramificações de tamanho igual (car. 15 0) e superfície dorsal do mesonoto com estriação irregular (car. 19 4). O conhecimento sobre a biologia das espécies de Hylomyrma é ainda bastante incipiente e grande parte das informações é proveniente de dados de rótulo e de raras observações em campo. As espécies deste grupo são comumente coletadas em amostras de serapilheira em florestas úmidas e secas, e plantações em locais ao nível do mar até elevações de 3.600 m. Aparentemente, as colônias de Hylomyrma são bastante pequenas, os ninhos são feitos em pequenos galhos caídos na serapilheira, os indivíduos são capazes de se fingir de mortos (tanatose) (observações pessoais) e as espécies apresentam dieta generalista. Como etapas futuras para a melhor compreensão deste grupo, sugere-se uma análise das relações internas dos gêneros através de ferramentas moleculares e a utilização de caracteres morfológicos de gines, bem como o estudo dos padrões biogeográficos e o estudo mais detalhado das intercastas para o entendimento da evolução de novidades morfológicas. / The subfamily Myrmicinae is a major challenge to ant systematics due to its outstanding diversity, which encompasses nearly six thousand species distributed worldwide. Phylogenetic relationships within this speciose subfamily are still subject to controversy in the literature. Molecular-based studies in Attini and Myrmicini (sensu Bolton) were the first to provide phylogenetic hypotheses for relationships within Myrmicinae. More recently, the twenty-five tribes of Myrmicinae were reorganized into only six Attini, Crematogastrini, Myrmicini, Pogonomyrmecini, Solenopsidini, and Stenammini. Hylomyrma Forel, 1912 the focal group of this study is currently classified in the tribe Pogonomyrmecini, along with two other genera, Patagonomyrmex Johnson & Moreau, 2016 and Pogonomyrmex Mayr, 1868. Members of Hylomyrma are exclusively found in the Neotropics, and live in leaf-litter. Due to their cryptic habits, the diversity and natural history of Hylomyrma species are still poorly known. Since the revision of Kempf (1973), who recognized 12 species in the genus, few representatives of Hylomyrma have been included in phylogenetic studies, and one species was described. Presented here is the first phylogenetic analysis of Hylomyrma based on a comprehensive taxon sampling, which is used as basis for a taxonomic revision of the genus. This study includes data retrieved from first-hand examination of nearly all types (except for the holotype of H. reginae Kutter, 1977), in addition to 2.757 exemplars from 29 institutions. Fifteen new species of Hylomyrma are recognized, ten of which were characterized based on worker and gyne morphology. New distribution records are provided for the thirteen previously known species, as well as morphological descriptions for gynes and males (in five and six species, respectively). Specimens showing features from both gynes and workers were observed in 11 species, suggesting that intercastes are not uncommon in this group. Phylogenetic analyses were performed on a matrix comprising 88 characters and 31 terminal taxa, including three species as outgroups. Maximum parsimony (MP) reconstructions were computed on the software TNT. The traditional search analysis were implemented with 3,000 replicates using the TBR algorithm, 10 trees saved per replication, random seed=0 and colapse trees=ON, under equal and implied weighing schemes. The concavity values (k) used were set between 1-25. The branch support was calculated by Bremer score. Unweighted MP analyses resulted in one cladogram with 269.274 steps (IC=0.379 and RI=0.59). Four different topologies were obtained for the following k intervals k1, k3-9, k15 and k20-25. Results strongly corroborate Hylomyrma as a monophyletic clade defined by nine synapomorphies. Internal phylogenetic relationships indicate three main lineages: A, species with large body lenght (char. 52, ranging from 0.534 to 0.785); B, species with posterior face of the anterior leg shiny (char. 45 1), first gastral tergite with very short striae (char. 79 0) and multibranched hairs (char. 85 1), condition subsequently lost by Hylomyrma sp. T; and C, characterized by species with multibranched hairs, being the branch with the same size (car. 15 0) and irregular striae on mesonotum dorsal side (car. 19 4). Natural history data, still unavailable for most Hylomyrma species, is mostly obtained from labels and scattered field observations. Exemplars are usually collected in leaf-litter samples in wet and dry forests, and cultivated areas from sea level up to elevations at 3,600 m. Hylomyrma colonies are apparently small, nests are made from small branches found in the leaf-litter, and these generalist ants which take on the appearance of being dead when they are threatened (thanatosis) (personal observations). Future developments in the systematics of Hylomyrma should include morphological characters based on gynes and molecular characters to increase the resolution of internal relationships, which will also allow the investigation of biogeographic patterns. A more detailed study of intercastes will shed light on the evolution of morphological novelties in ants.