I sydsvenska Sverige finns en utbredd sägentradition om nedpålade döda som spökar, på svenska kallade ”pålgastar” (pile ghosts). De nedpålade döda sägs spöka på platsen där de pålades, ofta i mossar. Att människor pålats i mossar sedan långt tillbaka i tiden vet vi tack vara arkeologiska fynd av pålade kroppar, framför allt från järnåldern. Den gängse föreställningen är att de döda pålades för att inte spöka. Denna föreställning bygger framför allt på sägner. Ändå spökar de pålade i sägnerna. Syftet med uppsatsen är att med hjälp av närläsning av sägner om pålade döda undersöka om sägnerna kan förklara varför människor pålades i mossar och om pålen kan ha haft något annat syfte än att förhindra den döde från att gå igen. Med hjälp av retroperspektiv metod kommer jag fram till att pålen i sägnerna förknippas med de döda, men inte bara med de som pålats. Pålen tycks användas som ett verktyg för att kommunicera med de döda eller med den andra sidan. Kanske har mossen fungerat som ett gränsland mellan de levandes värld och de dödas, där pålen använts för att tala med den döde i mossen. Sägnerna om de pålade i mossar kan ha uppkommit som förklaringssägner till de pålar och lik man funnit mossarna. Pålarnas funktion som rituella verktyg har i så fall fallit i glömska. Kopplingen mellan kommunikationen med de döda och pålarna har dock levt kvar i sägnerna. / In southern Sweden, there is a widespread legend tradition of piled-up dead people who then return to haunt the living, known in Swedish as "pålgastar" (pile ghosts). The piled-up dead are said to haunt the place where they were piled, often in bogs. We know that people have been piled up in bogs since long ago thanks to archaeological finds of piled bodies, especially from the Iron Age. The common belief is that the dead were piled up so as not to haunt the living. This belief is based mainly on legends. Yet, in the legends, the piled ones are haunting the living. The purpose of this paper is to examine, by means of close reading of legends about the piled-up dead, whether the legends can explain why people were piled up in bogs and whether the pile may have had some other purpose than to prevent the dead from walking again. Using the retrospective method, I conclude that the stake in the legends is associated with the dead, but not only with those who were staked. The stake seems to be used as a tool to communicate with the dead or with the other side. Perhaps the bog has functioned as a borderland between the world of the living and the world of the dead, where the stake has been used to talk to the dead in the bog. The legends of the stakes in bogs may have arisen as explanatory legends for the stakes and corpses found in the bogs. In that case, the function of the stakes as ritual tools has been forgotten. However, the link between communication with the dead and the stakes has survived in the legends.

La deuxième moitié du XXè siècle a vu l'explosion de l'ordre des appareils et de leur milieu, la technologie. L'art n'est pas resté à l'abri de cette invasion, et les œuvres ont, elles aussi, commencé de s'appareiller. Ces œuvres appareillées sont dynamiques, indéterminées, interactives, algorithmiques, instables. Nous chercherons ici à suivre cette irruption technologique dans les différents régimes artistiques : au moment de la création de l'œuvre, dans son existence objectale et au moment de sa réception esthétique. Se dessinera alors, peut-être, une forme spécifique à ce que pourrait être un « art technologique ». L'analyse finie, les lignes de fracture posées – la question décisive pourra alors être posée, à défaut d'être tranchée : l'art survit-il à sa collusion avec la technologie ? / During the second half of the 20th century, the world of devices and their technological ground have tremendously spread. Art, also, has been impacted by this invasion, and some artworks have become equipped-artworks. Those specific artworks are : unstable, dynamic, algorithmic, unseen, interactive. We will try here to follow this technological invasion in the three different places of the artistic regime : how the artist creates his piece of work, how this object appears and exists, and how the spectator receives it. Thus, might appear a new form for a genuine « technological art »… Finally, we will be able to ask the core question and to tackle the main issue : are art and technology compatible ?

Cette thèse est consacrée à l'analyse mathématique de quelques modèles hétérogènes intervenants en mécanique des fluides. En particulier, elle est consacré a l'étude théorique des systèmes d'équations aux derivées partielles décrivants les trois modèles principaux que nous voulons présenter dans la suite. Le premier modèle étudié dans cette thèse est consacré à l'étude de l'écoulement d'un fluide visqueux newtonien et incompressible dans un bassin avec bathymétrie qui dégenère proche du bord. Le modèle mathématique étudié provient alors des équations de Navier-Stokes incompressible. On cherche à montrer que le problème de Cauchy correspondant est bien posé, au sens qu'on peut garantir l'existence globale et l'unicité de solutions faibles. Nous discuterons aussi la régularité de la solution faible. Finalement,nous établissons la convergence de la solution du modèle visqueux vers celle du modèle non visqueux quand le coefficient de viscosité tend vers zéro.La deuxième partie est dédiée à l'étude d'un modèle issu du système de Navier-Stokes dispersif ( il contient une correction dispersive) qui est lui meme obtenu à partir de la théorie cinétique des gaz. Notre modèle mathématique est dérivé a partir de ce dernier en supposant que le nombre de Mach est très faible. Le modèle obtenu est nommé effet fantôme (ou ghost effect an anglais), puisqu'il ne peut pas être obtenu à partir du modèle de Navier-Stokes compressible classique. L'objectif dans ce cadre sera d'étendre un résultat concernant l'existence locale d'une solution forte vers l'existence globale d'une solution faible. L'ingrédient principal dans notre analyse est une nouvelle inégalité fonctionnelle de type Log-Sobolev.La troisième partie de ce document est une contribution à une thématique de recherche se proposant d'analyser la compréhension des phénomènes rencontrés en géophysique qui font intervenir des milieux granulaires. Le modèle mathématique choisi est de type Bingham incompressible dont on fait dépendre le seuil de plasticité et le coe fficient de viscosité de la pression. On montre un résultat d'existence globale d'une solution faible du problème de Cauchy associé. / This thesis is devoted to the mathematical analysis of heterogeneous models raised by fluid mechanics. In particular, it is devoted to the theoretical study of partial differential equations used to describe the three main models that we present below.Initially, we are interested to study the motion of a compressible newtonienfluids in a basin with degenerate topography. The mathematical model studied derives from incompressible Navier-Stokes equations. We are interested to prove that the Cauchy problem associated is well posed. Well-posedness means that there exists a solution, that it is unique. In the meantime, we prove that the solution of the viscous model converges to the one of the inviscid limit model when the viscosity coe cient tends to zero.The second part in my thesis is devoted to study a model that arises from dispersive Navier-Stokes equations (that includes dispersive corrections to the classical compressible Navier-Stokes equations). Our model is derived from the last model assuming that the Mach number is very low. The obtained system is a Ghost eect system, which is so named because it can be derived from Kinetic theory. The main goal of this part is to extend a result concerning the local existence of strong solution to a global-in time existence of weak solutions. The main ingredient in this work is a new functional inequality of Log-Sobolev type.The last part of my thesis is a part of a research theme intends to analyze the understanding of phenomena encountered in geophysics which involves granular media. The mathematical model is of Bingham incompressible type with viscosity and placticity depending on the pressure. We provide a global existence of weak solutions of the Cauchy problem associated.

Ces travaux portent sur la modélisation et la simulation numérique des effets du déplacement d'un corps indéformable dans un écoulement multiphasique compressible. Ils se placent dans le cas où plusieurs objets sont en mouvement ou dans le cas où un objet est en mouvement dans un milieu aux géométries complexes. L'étude ne peut alors pas être placée dans le référentiel lié à l'objet en mouvement. Le modèle est basé sur une méthode multiphasique à interfaces diffuses où les différentes phases sont en équilibre mécanique. Le système régissant l'écoulement fluide est augmenté d'une équation d'advection. Cette dernière s'applique sur une fonction Level Set dont le niveau zéro permet de localiser le mobile dans l'espace. Des termes de couplage sont ajoutés au membre de droite des équations d'évolution de la quantité de mouvement et de l'énergie totale. Ces termes sont composés d'un facteur du type pénalisation et d'un facteur du type relaxation de vitesses. Cette nouvelle méthode permet de simuler des cas complexes où peuvent interagir des mobiles à hautes vitesses, des ondes de choc et des interfaces liquide/gaz. / This work deals with modelling and the numerical simulation of the effects of a moving rigid body on a multiphase flow. Here more than one object is moving, or an object is moving in a complex geometry domain. So the reference frame linked to the moving body can't be used. The model is build on a multiphase diffuse interface method with mechanical equilibrium. An advection equation is added. It applies on a Level Set function used to track the moving body. Coupling terms are added to the momentum equation and to the total energy equation. These terms are made of a penalization factor and a velocity relaxation factor. This new method allows to simulate complex cases where can interact high velocity objects, shock waves and liquid / gas interfaces.

This research is mainly focused on the development of the adaptive Cartesian grid methods for compressibl  e flow. At first, the ghost cell method and its applications for inviscid compressible flow on adaptive tree Cartesian grid are developed. The proposed method is successfully used to evaluate various inviscid compressible flows around complex bodies. The mass conservation of the method is also studied by numerical analysis. The extension to three-dimensional flow is presented. Then, an h-adaptive Runge–Kutta discontinuous Galerkin (RKDG) method is presented in detail for the development of high accuracy numerical method under Cartesian grid. This method combined with the ghost cell immersed boundary method is also validated by well documented test problems involving both steady and unsteady compressible flows over complex bodies in a wide range of Mach numbers. In addition, in order to suppress the failure of preserving positivity of density or pressure, which may cause blow-ups of the high order numerical algorithms, a positivity-preserving limiter technique coupled with h-adaptive RKDG method is developed. Such a method has been successfully implemented to study flows with the large Mach number, strong shock/obstacle interactions and shock diffraction. The extension of the method to viscous flow under the adaptive Cartesian grid with hybrid overlapping bodyfitted grid is developed. The method is validated by benchmark problems and has been successfully implemented to study airfoil with ice accretion. Finally, based on an open source code, the detached eddy simulation (DES) is developed for massive separation flow, and it is used to perform the research on aerodynamic performance analysis over the wing with ice accretion.

Ce travail est une analyse des conséquences de la présence de roches altérées, les altérites, sur les instabilités littorales du Labourd (Pays Basque). Le contexte environnemental des mouvements de terrain qui mobilisent ces matériaux méconnus est étudié afin de mieux appréhender les processus de rupture. Pour cela, d’une part, les altérites sont caractérisées d’un point de vue géologique ; d’autre part, les propriétés géotechniques et les circulations hydrogéologiques sont déterminées. Ces études permettent de mettre en évidence les différents facteurs prédisposant et déclenchant les instabilités, validés par modélisation numérique. La connaissance des processus ainsi améliorée, un outil d’estimation de l’aléa dans les altérites est proposé. / This work is an analysis of the consequences of the presence of weathered rocks, called alterites, on the coastal landslides of the Labourd (Basque country). The environmental context (geological, hydrogeological and morphological) of the landslides is studied to a better understanding of the failure processes. These studies allow to highlight the main triggering factors of the landslides, which are validated by numerical modelling. The knowledge of the processes so improved, a tool to estimate landslide hazards in the alterites is proposed.

Ce travail aborde les dynamiques géomorphologiques des bas-plateaux calcaires du Bassin parisien. Ces dynamiques géomorphologiques sont généralement étudiées à partir d'observations de surface avec l'étude des formes et des formations et la cartographie géomorphologique. Cependant, avec la disparition des sites d'extractions et des carrières, les affleurements se font rares, ce qui ne facilite pas l'interprétation des morphologies et des processus associés. Les chercheurs sont alors obligés de recourir à des procédés de reconnaissances lourds et coûteux comme l'instrumentation de géophysiques ou de profiter des sondages archéologiques. L'intérêt de cette contribution est de montrer l'apport de l'étude des carrières souterraines dans la compréhension des dynamiques géomorphologiques, hydrogéologiques et hydrologiques des bas plateaux tertiaires du Bassin parisien. La bibliographie fait souvent référence à des processus occultes, sous couverture, comme la crypto-corrosion, le soutirage ou l'hydrocompaction, difficilement observables en surface qui laissent souvent trop de place à l'interprétation. Le secteur de Reims, Laon, Soissons et Villers-Cotterêts est particulièrement intéressant car il regroupe plus de 400 carrières souterraines dans les calcaires lutétiens. Les héritages historiques y sont importants avec un patrimoine monumental très dense construit grâce aux géomatériaux calcaires locaux fournis par les carrières souterraines. / This work tackles the geomorphological dynamics of calcareous low-plateaus, in the Paris basin. These dynamics are usually studied from observations of surface, the study of shapes and superficial formations and geomorphological mapping. However, with the disappearance of sites and quarries, outcrops are scarce, which does not facilitate the interpretation of morphologies and associated processes. Researchers are forced to resort to methods of reconnaissance heavy and expensive, as instrumental geophysical or benefit of archaeological surveys. The value of this work is to show the contribution of the study of underground quarries in the understanding of geomorphological, hydrogeological and hydrological tertiary lowlands of the basin of Paris. The literature often refers to the process of hidden under cover as the crypto-corrosion, racking or hydrocompaction, easily observable on the surface or often leaving too much room for interpretation of fault outcrops. The area of Reims, Laon, Soissons and Villers-Cotterets is particularly interesting because it includes more than 400 underground quarries in the lutetian limestone. Historical legacies are important monuments with very dense built through geomaterials local limestone quarries provided by underground quarries.

Herança portuguesa, as festividades em homenagem ao Espírito Santo encontraram terreno fértil no Brasil, onde ganharam contornos populares. Em Mogi das Cruzes, município pertencente à Região Metropolitana de São Paulo, a Festa do Divino Espírito Santo é realizada, segundo os documentos consultados, há quase duzentos anos. Em vários momentos, a tradição quase sucumbiu na luta pela sua manutenção diante do processo urbano-industrial, que fragmenta a vida e enfraquece as relações próximas. No início da década de 1990, alguns moradores de Mogi, interessados na manutenção da Festa do Divino do Espírito Santo se reuniram com o objetivo de fundar uma associação que auxiliasse na sua realização, a fim de não deixar a tradição desaparecer. Para isso, a Associação Pró-Festa do Divino, como foi denominada, passou a buscar recursos financeiros junto a empresas (de grande e de pequeno porte) em troca de divulgação de seus logotipos na Festa, colocados em cartazes, panfletos, livros de cânticos, uniformes, etc. Divulgada pelos meios de comunicação, a Festa do Divino de Mogi das Cruzes ganhou impulso, agregando cada vez mais, novos participantes. Nesta \"euforia\" de crescimento e de arrecadação de recursos, a Festa do Divino foi se configurando também como mercadoria, embora a Associação se identifique e aja como órgão responsável pelo não \"desvirtuamento\" da tradição. Apesar da crescente espetacularização, acompanhada, inevitavelmente, de uma crescente racionalização na preparação e na realização da Festa, acredita-se haver momentos e elementos que escapam à espetacularização e à racionalização, revelando-a como manifestação da cultura popular. Esta é a questão maior que a pesquisa se propôs a elucidar. Para tanto, buscou no passado da Festa (na Europa, no Brasil, sobretudo em Mogi das Cruzes), elementos que a definiram como manifestação da religiosidade popular e que estariam presentes ainda hoje, como resíduos de tempos e relações pretéritas. / Portuguese heritage, the parties in honor to the Holy Ghost met fertile land in Brazil, where they acquired a popular profile. In Mogi das Cruzes, city of Metropolitan Region of São Paulo, the Holy Ghost Party has been performed, according to researched documents, for almost two hundred years. For several times, the tradition was almost finished due to the industrial-urban process, which fragments the life and weaken the nearby relations. In the beginning of 90\'s, some Mogi residents, interested in the conservation of Holy Ghost gathered themselves in order to found an association to help its achievement and avoid the extinction of the tradition. For that, the Pro-Holy Ghost Party Association, as it has been called, started looking for a sponsorship company (the big or the small ones), by exchanging the company\'s name divulgation during the Party through logotypes in posters, folders, book\'s music, uniforms etc. Divulgated by the communication means, the Holy Ghost Party of Mogi das Cruzes received impulse, adding increasingly, new attendees. In the \"enthusiasm\" of the growth and the finance resource collection, the Holy Ghost Party became a merchandise, however the Association identifies itself and acts as an institution responsible for the \"no disparage\" of the tradition. In spit of the growing of the spectacle process, necessarily accompanied of growing rationalization in the Party preparing and achievement, we believe there are moments and elements that escape from the spectacling and from the rationalization, showing it as expression of the popular culture. This is the most important question that the research proposed to clarify. For that, pursued in the past of the Party (in Europe, in Brazil, especially in Mogi das Cruzes), elements that defined it as manifest of the popular religiosity and that would be present up to nowadays as residues of time and preterit relations.

Made available in DSpace on 2016-04-25T19:20:27Z (GMT). No. of bitstreams: 1 Gyorgy Henyei Neto.pdf: 2465564 bytes, checksum: 2e55534db00b1f28c9f38e1870f15931 (MD5) Previous issue date: 2013-06-07 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The following dissertation presents symbolic ressignifcation of a cultural/religious manifestation within the immigration movement from the Azores to São Paulo. The hypotheses reflect on the observation of the several possibilities for re-adaptation of a religious ceremony, such as the Holy Ghost Festival, in a new place, which, even though it has some resemblances on their origins, are both original constructions of the human creativity. The House of the Azores in São Paulo was the object of ethnographical research, been part also of the thematic on the diversity among the other House of the Azores in Brazil and around the world. During the three-chapter work, there would be shown the methods and questions to be answered, in the hope of enlarge the knowledge about the Azorean immigration to Brazil and also offer a renewed look inside the glossary of interpretation of significance trauma-suffered significance, as a transposition from one side to the other of the Atlantic. The point reached is that the materiality and the immateriality are not stationary inferences in the universe, but always substance and product of human invention / A dissertação a seguir tem como tema a ressignificação simbólica de uma manifestação cultural/religiosa dentro do movimento imigratório dos Açores para São Paulo. As hipóteses recaem na tentativa de observar as possibilidades de readaptação de uma festa religiosa, como a Festa do Espírito Santo, num novo local, que mesmo tendo características e origens semelhantes, são construções originais da criatividade humana. A Casa dos Açores de São Paulo foi o alvo da pesquisa etnográfica, sendo também temática da diversidade entre as Casas dos Açores pelo Brasil e pelo mundo. Durante três capítulos, serão explicitados os métodos e as perguntas a serem respondidas, na tentativa de aprofundar o conhecimento sobre a imigração açoriana para o Brasil, oferecendo uma nova visão dentro do glossário de interpretações das significâncias que passam por traumas, como uma transposição de um lado a outro do oceano Atlântico. A conclusão a que se chega é que a materialidade e a imaterialidade não são inferências móveis no universo, sendo sempre matéria e produto da invenção humana

O camarão corrupto Callichirus seilacheri foi erigido por Bott (1955) através de uma breve e incompleta descrição carente da maioria das ilustrações sobre as principais estruturas corporais desta espécie. Callichirus seilacheri é considerada, atualmente, como o único representante do gênero Callichirus na costa do Pacífico Leste. Sua distribuição geográfica abrange um amplo gradiente latitudinal de aproximadamente 50º graus (~13º N - 37º S) desde a praia Los Blancos (localidade-tipo), El Salvador até Lenga na costa de Chile. O estado taxonômico da grande população de C. seilacheri tem sido questionado no passado em reiteradas oportunidades. Este questionamento tem relação com a falta de estudos taxonômicos associados com estas populações e com o fato que alguns antecedentes moleculares têm demonstrado que as populações de Callichirus da costa do Pacífico de Nicarágua e México são diferentes. Considerando estes antecedentes, o primero objetivo do presente estudo foi avaliar o estado taxonômico de C. seilacheri na costa do Pacífico Leste da América Central. Para isto, foi coletado material de C. seilacheri em diferentes localidades da costa do Pacifico de América Central, incluindo a localidade-tipo desta espécie na costa de El Salvador. Conforme as observações morfológicas do material coletado, os caracteres diagnósticos de C. seilacheri incluem entre outros aspectos: (i) pedúnculos oculares com uma alongada projeção pré-córneal, cujas pontas divergem lateralmente; (ii) segmentos terminais do pedúnculo antênular e antenal com as bases paralelas; e (iii) pereiópodo maior do primeiro par de pereiópodos dos machos adultos com o mero armado de um lóbulo retangular na região ventral anterior e ísquio curvado para baixo com um gancho na margem ventral. Uma das descobertas mais relevantes foi que todas as fêmeas de C. seilacheri têm ambos gonóporos masculino e feminino, o qual representa o primeiro registro de intersexualidade no gênero Callichirus. O segundo objetivo desta tese foi avaliar se a espécie da costa chilena Callichirus garthi (Retamal, 1975), considerada como uma sinonímia-junior de C. seilacheri da costa do Pacífico da América Central, é uma espécie válida. Para isto, comparou-se o material-tipo de C. garthi e outros lotes desta espécie coletados ao longo da costa de Chile (~18º e 37º S) com os espécimes de C. seilacheri coletados na localidade-tipo (Playa Los Blancos, El Salvador) e em outras localidades da América Central. A comparação morfológica revelou importantes diferenças morfológicas entre os tipos morfológicos identificados em ambas espécies. Entre as principais diferenças e possível mencionar que C. garthi possui as pontas dos pedúnculos oculares paralelas, enquanto que em C. seilacheri são divergentes formando um angulo de 60-70°. Os machos adultos de ambas espécies compartilham quelípodos desiguais na fase adulta, mas somente, C. seilacheri tem um gancho sobre a margem ventral do ísquio e um lóbulo meral retangular. A analise morfológica do material biológico coletado em ambas regiões permite concluir que os espécimes coletados ao longo da costa do Chile pertencem à C. garthi, enquanto que os exemplares coletados na costa do Pacífico da Costa Rica pertencem à espécie C. seilacheri. Conforme a essas informações, C. garthi é uma espécie válida. Portanto, sugere-se a separação da grande população de C. seilacheri em duas diferentes populações: (i) uma pertencente ao C. seilacheri a qual ocorre desde a costa do El Salvador ate Costa Rica (~19º N 08º N), (ii) outra pertencente ao C. garthi a qual ocorre entre os 18º S e 37º S da costa chilena. A hipótese do centro abundância (HCA) é baseada na suposição de que as retricções fisiológicas limitam o desenvolvimento das populações nas bordas do seu intervalo de distribuição. Com o intuito de testar a validez desta hipótese, espécimes da espécie modelo Callichirus garthi foram coletados em sete populações distribuídas ao longo da costa chilena. Em cada população foram avaliados a densidade junto com uma serie de atributos populacionais de C. garthi (e.g. tamanho máximo do corpo, razão sexual, etc). Os principais resultados revelaram que C. garthi foi significativamente menos abundante nas populações locais, perto do centro e aumentou para as bordas norte e sul da sua distribuição na costa do Chile. No extremo sul e norte da distribuição, a estrutura da população foi composta por indivíduos de todos os tamanhos, em contraste com às localidades do centro, onde os indivíduos estavam concentrados em uma faixa de tamanho mais estreita. Surpreendentemente, nas bordas (norte e sul), à razão entre os sexos foi estremamente equilibrada. A abundância local foi levemente correlacionada com a distância entre cada localidade e o rio mais próximo e foi fortemente correlacionada com a estrutura da população. Aparentemente, a proximidade de um rio oferece as condições ideais para que C. garthi forme populações densas e equilibradas, o qual seria um reflexo do sucesso a nível individual que esta espécie atinge em direção às bordas. O modelo de distribuição de abundância de C. garthi pode ser considerado como uma exceção nas populações naturais devido que na maioria dos estudos prévios nesta matéria o modelo usualmente reportado é o modelo normal de abundância para um dos extremos. As generalizações acerca do padrão reprodutivo dos invertebrados bentônicos costeiros propõem que as espécies tropicais tenham reprodução do tipo continua, como reflexo das baixas oscilações térmicas ao longo de todo o ano (hipótese de Orton). Com o propósito de testar esta suposição em um ambiente tropical da América, foram realizados durante um ano amostragens mensais em uma população de C. seilacheri da costa do Pacífico de Costa Rica (América Central). Os resultados revelaram que C. seilacheri tem uma marcada sazonalidade reprodutiva, a qual contradiz os padrões esperados em regiões tropicais. As fêmeas ovígeras estiveram presentes desde maio até novembro, o que está estatisticamente relacionado com a diminuição da salinidade durante a estação chuvosa. A temperatura não teve influência sobre a periodicidade reprodutiva. Aparentemente, à reprodução em C. seilacheri está fortemente relacionada com a variabilidade climática da costa do Pacífico na Costa Rica, sendo desencadeada por oscilações na salinidade. Uma comparação entre C. garthi da costa chilena e C. seilacheri da costa do Pacífico da América Central revelou importantes diferenças na produção de ovos. Callichirus seilacheri produz uma media de quatro menos ovos e menores que C. garthi da costa do Chile. A variabilidade nas características reprodutivas (produção e tamanho dos ovos) e de tamanho corporal dos indivíduos observada nestas duas espécies de camarões corruptos sugerem a imposição de importantes restrições fisiológicas dadas principalmente por a temperatura em ambas às regiões da América. Os aspectos examinados no presente estudo constituem novos antecedentes sobre a taxonômia, morfologia e ecología em um dos gêneros da família Callianassidae mais representativos nas praias de areia da América. Cada um destas informações pode ser considerado de especial relevância para a conservação das populações de C. garthi e C. seilacheri no Pacífico Leste. Especialmente, porque ambas espécies são frequentemente recolhidas como isca para a pesca comercial e esportiva em algumas pequenas vilas costeiras. / The ghost shrimp Callichirus seilacheri was erected by Bott (1955) through a brief and poorly illustrated description. This species is considered as the only one current representative of genus Callichirus along the eastern Pacific. Their distribution encompasses approximately 50 degree of latitude, from Los Blancos, El Salvador (13º N) to Lenga, Chile (37º S). The identity of the large population of C. seilacheri along the Pacific coast of Americas has been questioned by different researchers whom have indicated the existence of more than one species of Callichirus for the Pacific coast of Mexico and the Pacific coast of Costa Rica and Nicaragua. Considering this information, the first focus of this thesis was realize a redescription of C. seilacheri based on specimens collected in different localities from Central America, including the type-locality of this species. According to the observations, the diagnostic features of C. seilacheri include (i) the eyestalks with elongated precorneal projection with tips diverging laterally; (ii) terminal segments of antennular peduncle and antennal with the parallel base and (iii) adult male with larger cheliped with rough rectangular lobe over anterior ventral margin of merus, ischium curved downward with a hook on ventral margin. All females analyzed herein have both male and female gonopores, thus firstly recorded the presence of intersex within the genus Callichirus. The second objective of this thesis was test whether Callichirus garthi (Retamal, 1975) which is considered as a junior synonymy of C. seilacheri constitute a valid species for the eastern Pacific. For this, a full comparison between specimens of the genus Callichirus collected along the Pacific coast of Central America and Chilean coast, including the type-locality of C. seilacheri and C. garthi was realized. The comparison revealed important morphological differences between both species. For example, in C. garthi the tips of the eyestalk are parallel while diverge distally forming an about 60-70° angle in C. seilacheri. Adult males of both species share unequal chelipeds; however, only C. seilacheri has a hook on ventral margin of ischium and its merus is armed with a rectangular lobe over anterior ventral margin. Additional material collected along the Chilean coast and from different localities from the Pacific coast of Costa Rica allowed confirms the taxonomic status of both species in the Eastern Pacific. All specimens collected along the Chilean coast belong to C. garthi while those of Costa Rica fit to form of C. seilacheri from El Salvador. According to the results, C. garthi is a valid species. Therefore, it is postulated the separation of large population of C. seilacheri into two different populations: (i) one belonging to C. seilacheri which distributes from Mexico to Costa Rica (~19º 08º N), (ii) other assigned to C. garthi which encompasses, at least, between 18º S 37º S of the Chilean coast. The abundant-centre hypothesis (ACH) is based on the assumption that physiological constraints limit populations at the edges of their distributional range. In the third chapter is examined the applicability of the ACH in a marine system by testing whether physiological predictions are reflected in large-scale variations of life-history traits. In order to achieve this information, specimens of Callichirus garthi were collected in the intertidal zone at seven sampling sites. In each site we evaluated (i) local abundance, (ii) maximum body size, (iii) sex-ratio, (iv) length-size frequency distribution, and (v) size at maturity. The main outcomes revealed that C. garthi is a species of low occurrence which was present in seven of all visited beaches (N = 61). Callichirus garthi was clearly less abundant within local populations near the centre and increased towards the northern and southern edges of its distribution. This pattern of abundance was significantly fitted by the abundant edge model. At the southern end and northern of the distribution, population structure was composed by individuals of all sizes in contrast with localities from the centre where individuals were concentrated in a narrow size range. Surprisingly at the edges (north and south), the sex ratio was extremely balanced. Physical variables (SST, grain size) had not influences on variation of life-history traits; however, the local abundance was slightly correlated with the distance between each locality and the closest river and was strongly correlated with population structure. Overall, the observed pattern was intimately linked with input of nutrients from the closest rivers. The findings allow separate the great population of C. garthi along the Chilean coast in two kinds: (A) stable populations (at the border of distribution), and (B) unstable populations (at the centre of distribution). In both cases, the population demography is controlled by dense-dependent factors. The results underline the importance of incorporating ecological, physiological and life-history studies in future tests of the ACH. Generalizations about breeding patterns of near-shore benthic marine invertebrates have proposed that tropical species have continuous reproduction as a reflection of constant temperature throughout the year (Ortons hypothesis). Based on this assumption, it was analysed the reproductive periodicity and egg production in the intertidal ghost shrimp Callichirus seilacheri from the Central Pacific coast of Costa Rica. In order to obtain such information, a total of 449 individuals were collected monthly from December 2011 to November 2012. The results showed that females with ovaries filled with mature oocytes were present throughout the whole year. However, the presence of ovigerous females was restricted to the period between May and November which fits to a seasonal breeding cycle. Apparition of egg-bearing females was statistically correlated with the decrease of salinity detected during rainy season, but not with temperature. Compared to C. garthi from temperate waters, C. seilacheri produced on the average four times less eggs and smaller. Variability in reproductive features and body size of these species seem to reflect physiological constraints imposed by temperature in cold and warm regions. The aspects examined in each chapter of this thesis constitute new antecedents about morphology, taxonomy, and ecology of one of the most representative genus of the family Callianassidae from American coast. Each one of these informations may be considered of especial importance for the management and conservation of the Callichiruss populations from the eastern Pacific. Especially, because both species herein analyzed are frequently collected as bait for commercial and recreational fishing in some small villages along Pacific coast of America.