Deposits of the sandy braided South Saskatchewan River: Implications for the use of modern analogs in reconstructing channel dimensions in reservoir characterization

Estimation of the dimensions of fluvial geobodies from core data is a notoriously difficult problem in reservoir modeling. To try and improve such estimates and, hence, reduce uncertainty in geomodels, data on dunes, unit bars, cross-bar channels, and compound bars and their associated deposits are presented herein from the sand-bed braided South Saskatchewan River, Canada. These data are used to test models that relate the scale of the formative bed forms to the dimensions of the preserved deposits and, therefore, provide an insight as to how such deposits may be preserved over geologic time. The preservation of bed-form geometry is quantified by comparing the Alluvial architecture above and below the maximum erosion depth of the modem channel deposits. This comparison shows that there is no significant difference in the mean set thickness of dune cross-strata above and below the basal erosion surface of the contemporary channel, thus suggesting that dimensional relationships between dune deposits and the formative bed-form dimensions are likely to be valid from both recent and older deposits. The data show that estimates of mean bankfull flow depth derived from dune, unit bar, and cross-bar channel deposits are all very similar. Thus, the use of all these metrics together can provide a useful check that all components and scales of the alluvial architecture have been identified correctly when building reservoir models. The data also highlight several practical issues with identifying and applying data relating to cross-strata. For example, the deposits of unit bars were found to be severely truncated in length and width, with only approximately 10% of the mean bar-form length remaining, and thus making identification in section difficult. For similar reasons, the deposits of compound bars were found to be especially difficult to recognize, and hence, estimates of channel depth based on this method may be problematic. Where only core data are available (i.e., no outcrop data exist), formative flow depths are suggested to be best reconstructed using cross-strata formed by dunes. However, theoretical relationships between the distribution of set thicknesses and formative dune height are found to result in slight overestimates of the latter and, hence, mean bankfull flow depths derived from these measurements. This article illustrates that the preservation of fluvial cross-strata and, thus, the paleohydraulic inferences that can be drawn from them, are a function of the ratio of the size and migration rate of bed forms and the time scale of aggradation and channel migration. These factors must thus be considered when deciding on appropriate length:thickness ratios for the purposes of object-based modeling in reservoir characterization.

Activity patterns and foraging behaviour of Audouin's gulls at the Ebro Delta, NW Mediterranean.

Twenty Audouin´s gulls, Larus audouinii, breeding in the Ebro Delta (NW Mediterranean) were radio-tracked in 1998 to study their foraging behaviour and activity patterns. Some detrimental effects of tagging on the breeding success of the birds were detected, especially when both members of the pair were tagged. The results were actually constrained by the low number of locations due to natural breeding failure and failure in tag emission, as well as the adverse effect of tagging. However, through a combination of aircraft surveys at sea and a fixed station for automatic tracking of the presence of the birds at the colony, novel individual-based information of home ranges and activity patterns was obtained. Trawler fishing activity seemed to influence both the foraging range and habitat use: while trawlers operated, gulls overlapped their fishing grounds with vessels, probably to scavenge on discards. Very few locations were obtained during a trawling moratorium period, although they were all recorded in coastal bays and terrestrial habitats. During the trawling activity period, gulls ranged over a minimum convex polygon area of 2900 km2. Gulls were tracked up to 40 km from the colony, but some individuals were observed beyond 150 km while still breeding. Arrivals and departures from the colony were in accordance with the trawling timetable. However, most birds also showed some nocturnal foraging activity, probably linked to active fishing of clupeoids (following diel migrations) or to the exploitation of purse-seine fishing activity. Foraging trips lasted on average 15 hours: males performed significantly shorter trips than females, which spent more time outside the colony. The proportion of nocturnal time involved in the foraging trips was the same for males and females, but whilst all males initiated their trips both during the day and at night, some females only initiated their trips during the day. Hatching success was found to be related to foraging effort by males. Gulls spent on average ca. 38% of their time budget outside the nesting territory, representing the time devoted mainly to flying, foraging and other activities.

Selection on a genetic polymorphism counteracts ecological speciation in a stick insect.

The interplay between selection and aspects of the genetic architecture of traits (such as linkage, dominance, and epistasis) can either drive or constrain speciation [1-3]. Despite accumulating evidence that speciation can progress to "intermediate" stages-with populations evolving only partial reproductive isolation-studies describing selective mechanisms that impose constraints on speciation are more rare than those describing drivers. The stick insect Timema cristinae provides an example of a system in which partial reproductive isolation has evolved between populations adapted to different host plant environments, in part due to divergent selection acting on a pattern polymorphism [4, 5]. Here, we demonstrate how selection on a green/melanistic color polymorphism counteracts speciation in this system. Specifically, divergent selection between hosts does not occur on color phenotypes because melanistic T. cristinae are cryptic on the stems of both host species, are resistant to a fungal pathogen, and have a mating advantage. Using genetic crosses and genome-wide association mapping, we quantify the genetic architecture of both the pattern and color polymorphism, illustrating their simple genetic control. We use these empirical results to develop an individual-based model that shows how the melanistic phenotype acts as a "genetic bridge" that increases gene flow between populations living on different hosts. Our results demonstrate how variation in the nature of selection acting on traits, and aspects of trait genetic architecture, can impose constraints on both local adaptation and speciation.

Disentangling the formation of contrasting tree line physiognomies combining model selection and Bayesian parameterization for simulation models.

Alpine tree-line ecotones are characterized by marked changes at small spatial scales that may result in a variety of physiognomies. A set of alternative individual-based models was tested with data from four contrasting Pinus uncinata ecotones in the central Spanish Pyrenees to reveal the minimal subset of processes required for tree-line formation. A Bayesian approach combined with Markov chain Monte Carlo methods was employed to obtain the posterior distribution of model parameters, allowing the use of model selection procedures. The main features of real tree lines emerged only in models considering nonlinear responses in individual rates of growth or mortality with respect to the altitudinal gradient. Variation in tree-line physiognomy reflected mainly changes in the relative importance of these nonlinear responses, while other processes, such as dispersal limitation and facilitation, played a secondary role. Different nonlinear responses also determined the presence or absence of krummholz, in agreement with recent findings highlighting a different response of diffuse and abrupt or krummholz tree lines to climate change. The method presented here can be widely applied in individual-based simulation models and will turn model selection and evaluation in this type of models into a more transparent, effective, and efficient exercise.

Estimating the Ontogenetic Status of an Enantiornithine Bird from the Lower Barremian of El Montsec, Central Pyrenees, Spain.

An Enantiornithes specimen from El Montsec was initially described as an immature individual based upon qualitative traits such as its relatively large orbit and overall proportions of the skull and the postcranium. In this study we re-evaluate the precise determination of the ontogenetic stage of this individual, establishing a cross-talk among taphonomic, anatomic, and morphometric data. The exceptional preservation of the specimen has allowed pondering ontogenetic influence versus preservational bias in features like the external patterns of bone surfaces, instead of being aprioristically considered due to taphonomic alterations only. The rough texture of the periosteal bone associated with pores in the distal, proximal and mid-shaft areas of the humeral shaft, indicates a subadult stage when compared with long bones of modern birds. Forelimb proportions of embryo and juvenile Enanthiornithes are equivalent to those of adult individuals of other taxa within this clade, though this is not a reliable criterion for establishing a precise ontogenetic stage. The El Montsec specimen may be attributed a close adulthood, yet only if growth regimes in Enantiornithes are considered equivalent to those in Neornithes birds.

Partnering in the Dynamic Environment: The Role of Trust in Asymmetric Technology Partnership Formation

The purpose of this study was to increase the understanding of the role and nature of trust in asymmetric technology partnership formation. In the knowledge-based "learning race" knowledge is considered as a primary source for competitive advantage. In the emerging ICT sector the high pace of technological change, the convergence of technologies and industries as well as the increasing complexity and uncertainty have forced even the largest players to seek cooperation for complementary knowledge and capabilities. Small technology firms need the complementary resources and legitimacy of the large firms to grow and compete in the global market place. Most of the earlier research indicates, however, that partnerships with asymmetric size, managerial resources and cultures have failed. A basic assumption supported by earlier research was that trust is a critical factor in asymmetric technology partnership formation. Asymmetric technology partnership formation is a dynamic and multi-dimensional process, and consequently a holistic research approach was selected. Research issue was approached from different levels: the individual decision-maker, the firm and the relationship between the parties. Also the impact of the dynamic environment and technology content was analyzed. A multitheoretical approach and a qualitative research method with in-depth interviews in five large ICT companies and eight small ICT companies enabled a holistic and rich view of the research issue. Study contributes on the scarce understanding on the nature and evolution of trust in asymmetric technology partnership formation. It sheds also light on the specific nature of asymmetric technology partnerships. The partnerships were found to be tentative and the diverse strategic intent of small and large technology firms appeared as a major challenge. The role of the boundary spanner was highlighted as a possibility to match the incompatible organizational cultures. A shared vision was found to be a pre-condition for individual-based fast trust leading to intuitive decision-making and experimentation. The relationships were tentative and they were continuously re-evaluated through the key actors' sense making of the technology content, asymmetry and the dynamic environment. A multi-dimensional conceptualization for trust was created and propositions on the role and nature of trust for further research are given. The purpose of this study was to increase the understanding of the role and nature of trust in asymmetric technology partnership formation. In the knowledge-based "learning race" knowledge is considered as a primary source for competitive advantage. In the emerging ICT sector the high pace of technological change, the convergence of technologies and industries as well as the increasing complexity and uncertainty have forced even the largest players to seek cooperation for complementary knowledge and capabilities. Small technology firms need the complementary resources and legitimacy of the large firms to grow and compete in the global market place. Most of the earlier research indicates, however, that partnerships with asymmetric size, managerial resources and cultures have failed. A basic assumption supported by earlier research was that trust is a critical factor in asymmetric technology partnership formation. Asymmetric technology partnership formation is a dynamic and multi-dimensional process, and consequently a holistic research approach was selected. Research issue was approached from different levels: the individual decision-maker, the firm and the relationship between the parties. Also the impact of the dynamic environment and technology content was analyzed. A multitheoretical approach and a qualitative research method with in-depth interviews in five large ICT companies and eight small ICT companies enabled a holistic and rich view of the research issue. Study contributes on the scarce understanding on the nature and evolution of trust in asymmetric technology partnership formation. It sheds also light on the specific nature of asymmetric technology partnerships. The partnerships were found to be tentative and the diverse strategic intent of small and large technology firms appeared as a major challenge. The role of the boundary spanner was highlighted as a possibility to match the incompatible organizational cultures. A shared vision was found to be a pre-condition for individual-based fast trust leading to intuitive decision-making and experimentation. The relationships were tentative and they were continuously re-evaluated through the key actors' sense making of the technology content, asymmetry and the dynamic environment. A multi-dimensional conceptualization for trust was created and propositions on the role and nature of trust for further research are given.

Vuokratyöntekijän työsuhdeturva: Sääntelyn haasteita ja tulkintoja

Tutkimus pyrkii selvittämään, vastaako vuokratyöntekijän työsuhdeturva työlainsäädännön tavoitteita ja niiden taustalla vaikuttavaa työntekijän suojelun periaatetta. Lainsäädännössä vuokratyöntekijän työsuhdeturvan kohdalla olevat keskeisimmät aukkokohdat ja tulkinnat esitetään juridisen argumentaation avulla. Tilanteen tekee ongelmalliseksi erityisesti se, että nykylainsäädäntö ei varsinaisesti estä käyttämästä vuokratyössä toistuvia, kunkin toimeksiannon mittaisia määräaikaisuuksia. Tulokset osoittavat, että sekä kollektiivinen että individuaaliperusteinen irtisanomissuoja on käytännössä heikko. Lisäksi työsuhdeturvan ja joustavuuden tasapaino työmarkkinoilla näyttää olevan melko vaikea yhtälö ratkaistavaksi. Eräänä mahdollisena ratkaisuna tutkimuksen lopussa esitetään Ruotsissa käytössä oleva malli, jossa työntekijät ovat toistaiseksi voimassa olevissa työsuhteissa, ja saavat palkkaa myös toimeksiantojen väliseltä ajalta. Järjestelmään liittyy vahvasti myös alan järjestäytyminen ja eettisten pelisääntöjen määritteleminen liittojen välisin sopimuksin. Tällä tavalla vuokratyöntekijän työsuhdeturvaan liittyvät ongelmakohdat ratkaistaan, mutta toisaalta vuokratyön työllisyyttä ja kilpailukykyä tukeva vaikutus menetetään. Vaihtoehtoisina keinoina on esitetty lukuisia kevyempiä keinoja yksittäisten ongelmakohtien ratkaisuksi.

The effect of learning on the evolution of new courtship behavior: a simulation model

The fact that individuals learn can change the relationship between genotype and phenotype in the population, and thus affect the evolutionary response to selection. Here we ask how male ability to learn from female response affects the evolution of a novel male behavioral courtship trait under pre-existing female preference (sensory drive). We assume a courtship trait which has both a genetic and a learned component, and a two-level female response to males. With individual-based simulations we show that, under this scenario, learning generally increases the strength of selection on the genetic component of the courtship trait, at least when the population genetic mean is still low. As a consequence, learning not only accelerates the evolution of the courtship trait, but also enables it when the trait is costly, which in the absence of learning results in an adaptive valley. Furthermore, learning can enable the evolution of the novel trait in the face of gene flow mediated by immigration of males that show superior attractiveness to females based on another, non-heritable trait. However, rather than increasing monotonically with the speed of learning, the effect of learning on evolution is maximized at intermediate learning rates. This model shows that, at least under some scenarios, the ability to learn can drive the evolution of mating behaviors through a process equivalent to Waddington's genetic assimilation.

The Association of H1N1 Pandemic Influenza with Congenital Anomaly Prevalence in Europe: An Ecological Time Series Study.

BACKGROUND: In the context of the European Surveillance of Congenital Anomalies (EUROCAT) surveillance response to the 2009 influenza pandemic, we sought to establish whether there was a detectable increase of congenital anomaly prevalence among pregnancies exposed to influenza seasons in general, and whether any increase was greater during the 2009 pandemic than during other seasons. METHODS: We performed an ecologic time series analysis based on 26,967 pregnancies with nonchromosomal congenital anomaly conceived from January 2007 to March 2011, reported by 15 EUROCAT registries. Analysis was performed for EUROCAT-defined anomaly subgroups, divided by whether there was a prior hypothesis of association with influenza. Influenza season exposure was based on World Health Organization data. Prevalence rate ratios were calculated comparing pregnancies exposed to influenza season during the congenital anomaly-specific critical period for embryo-fetal development to nonexposed pregnancies. RESULTS: There was no evidence for an increased overall prevalence of congenital anomalies among pregnancies exposed to influenza season. We detected an increased prevalence of ventricular septal defect and tricuspid atresia and stenosis during pandemic influenza season 2009, but not during 2007-2011 influenza seasons. For congenital anomalies, where there was no prior hypothesis, the prevalence of tetralogy of Fallot was strongly reduced during influenza seasons. CONCLUSIONS: Our data do not suggest an overall association of pandemic or seasonal influenza with congenital anomaly prevalence. One interpretation is that apparent influenza effects found in previous individual-based studies were confounded by or interacting with other risk factors. The associations of heart anomalies with pandemic influenza could be strain specific.

Tipping the scales: Evolution of the allometric slope independent of average trait size.

The scaling of body parts is central to the expression of morphology across body sizes and to the generation of morphological diversity within and among species. Although patterns of scaling-relationship evolution have been well documented for over one hundred years, little is known regarding how selection acts to generate these patterns. In part, this is because it is unclear the extent to which the elements of log-linear scaling relationships-the intercept or mean trait size and the slope-can evolve independently. Here, using the wing-body size scaling relationship in Drosophila melanogaster as an empirical model, we use artificial selection to demonstrate that the slope of a morphological scaling relationship between an organ (the wing) and body size can evolve independently of mean organ or body size. We discuss our findings in the context of how selection likely operates on morphological scaling relationships in nature, the developmental basis for evolved changes in scaling, and the general approach of using individual-based selection experiments to study the expression and evolution of morphological scaling.

Application of differential scanning calorimetry in hair samples as a possible tool in Forensic Science

The Differential Scanning Calorimetry (DSC) was used to study the thermal behavior of hair samples and to verify the possibility of identifying an individual based on DSC curves from a data bank. Hair samples of students and officials from Instituto de Química de Araraquara, UNESP were obtained to build up a data bank. Thus to sought an individual, under incognito participant of this data bank, was identified using DSC curves.

On advancing business intelligence in the electricity retail market

In recent decades, business intelligence (BI) has gained momentum in real-world practice. At the same time, business intelligence has evolved as an important research subject of Information Systems (IS) within the decision support domain. Today’s growing competitive pressure in business has led to increased needs for real-time analytics, i.e., so called real-time BI or operational BI. This is especially true with respect to the electricity production, transmission, distribution, and retail business since the law of physics determines that electricity as a commodity is nearly impossible to be stored economically, and therefore demand-supply needs to be constantly in balance. The current power sector is subject to complex changes, innovation opportunities, and technical and regulatory constraints. These range from low carbon transition, renewable energy sources (RES) development, market design to new technologies (e.g., smart metering, smart grids, electric vehicles, etc.), and new independent power producers (e.g., commercial buildings or households with rooftop solar panel installments, a.k.a. Distributed Generation). Among them, the ongoing deployment of Advanced Metering Infrastructure (AMI) has profound impacts on the electricity retail market. From the view point of BI research, the AMI is enabling real-time or near real-time analytics in the electricity retail business. Following Design Science Research (DSR) paradigm in the IS field, this research presents four aspects of BI for efficient pricing in a competitive electricity retail market: (i) visual data-mining based descriptive analytics, namely electricity consumption profiling, for pricing decision-making support; (ii) real-time BI enterprise architecture for enhancing management’s capacity on real-time decision-making; (iii) prescriptive analytics through agent-based modeling for price-responsive demand simulation; (iv) visual data-mining application for electricity distribution benchmarking. Even though this study is from the perspective of the European electricity industry, particularly focused on Finland and Estonia, the BI approaches investigated can: (i) provide managerial implications to support the utility’s pricing decision-making; (ii) add empirical knowledge to the landscape of BI research; (iii) be transferred to a wide body of practice in the power sector and BI research community.

Food webs in the era of molecular revolution – Like resolving the Gordian knot with a tricorder

Living nature consists of countless organisms, which are classified into millions of species. These species interact in many ways; for example predators when foraging on their prey, insect larvae consuming plants, and pathogenic bacteria drifting into humans. In addition, abiotic nature has a great initiative impact on life through many factors (including sunlight, ambient temperature, and water. In my thesis, I have studied interactions among different life forms in multifaceted ways. The webs of these interactions are commonly referred to as food webs, describing feeding relationships between species or energy transfer from one trophic level to another. These ecological interactions – whether they occur between species, between individuals, or between microorganisms within an individual – are among the greatest forces affecting natural communities. Relationships are tightly related to biological diversity, that is, species richness and abundances. A species is called a node in food web vocabulary, and its interactions to other species are called links. Generally, Artic food webs are considered to be loosely linked, simple structures. This conception roots into early modern food webs, where insects and other arthropods, for example, were clumped under one node. However, it has been shown that arthropods form the greatest part of diversity and biomass both in the tropics and in Arctic areas. Earlier challenges of revealing the role of insects and microorganisms in interactions webs have become possible with the help of recent advances in molecular techniques. In the first chapter, I studied the prey diversity of a common bat, Myotis daubentonii, in southwestern Finland. My results proved M. daubentonii being a versatile predator whose diet mainly consists of aquatic insects, such as chironomid midges. In the second chapter, I expanded the view to changes in seasonal and individual-based variation in the diet of M. daubentonii including the relationship between available and observed prey. I found out that chironomids remain the major prey group even though their abundance decreases in proportion to other insect groups. Diet varied a lot between individuals, although the differences were not statistically significant. The third chapter took the study to a large network in Greenland. I showed that Artic food webs are very complex when arthropods are taken into account. In the fourth chapter, I examined the bacterial flora of M. daubentonii and surveyed the zoonotic potential of these bacteria. I found Bartonella bacteria, of which one was described as a new species named after the locality of discovery. I have shown in my thesis that Myotis daubentonii as a predator links many insect species as well as terrestrial and aquatic environments. Moreover, I have exposed that Arctic food webs are complex structures comprising of many densely linked species. Finally, I demonstrated that the bacterial flora of bats includes several previously unknown species, some of which could possibly turn in to zoonosis. To summarize, molecular methods have untied several knots in biological research. I hope that this kind of increasing knowledge of the surrounding nature makes us further value all the life forms on earth.

Structure et dynamique des communautés multi-espèces : le rôle de l’espace

Cette thèse porte sur le rôle de l’espace dans l’organisation et dans la dynamique des communautés écologiques multi-espèces. Deux carences peuvent être identifiées dans les études théoriques actuelles portant sur la dimension spatiale des communautés écologiques : l’insuffisance de modèles multi-espèces représentant la dimension spatiale explicitement, et le manque d’attention portée aux interactions positives, tel le mutualisme, en dépit de la reconnaissance de leur ubiquité dans les systèmes écologiques. Cette thèse explore cette problématique propre à l’écologie des communautés, en utilisant une approche théorique s’inspirant de la théorie des systèmes complexes et de la mécanique statistique. Selon cette approche, les communautés d’espèces sont considérées comme des systèmes complexes dont les propriétés globales émergent des interactions locales entre les organismes qui les composent, et des interactions locales entre ces organismes et leur environnement. Le premier objectif de cette thèse est de développer un modèle de métacommunauté multi-espèces, explicitement spatial, orienté à l’échelle des individus et basé sur un réseau d’interactions interspécifiques générales comprenant à la fois des interactions d’exploitation, de compétition et de mutualisme. Dans ce modèle, les communautés locales sont formées par un processus d’assemblage des espèces à partir d’un réservoir régional. La croissance des populations est restreinte par une capacité limite et leur dynamique évolue suivant des mécanismes simples de reproduction et de dispersion des individus. Ces mécanismes sont dépendants des conditions biotiques et abiotiques des communautés locales et leur effet varie en fonction des espèces, du temps et de l’espace. Dans un deuxième temps, cette thèse a pour objectif de déterminer l’impact d’une connectivité spatiale croissante sur la dynamique spatiotemporelle et sur les propriétés structurelles et fonctionnelles de cette métacommunauté. Plus précisément, nous évaluons différentes propriétés des communautés en fonction du niveau de dispersion des espèces : i) la similarité dans la composition des communautés locales et ses patrons de corrélations spatiales; ii) la biodiversité locale et régionale, et la distribution locale de l’abondance des espèces; iii) la biomasse, la productivité et la stabilité dynamique aux échelles locale et régionale; et iv) la structure locale des interactions entre les espèces. Ces propriétés sont examinées selon deux schémas spatiaux. D’abord nous employons un environnement homogène et ensuite nous employons un environnement hétérogène où la capacité limite des communautés locales évoluent suivant un gradient. De façon générale, nos résultats révèlent que les communautés écologiques spatialement distribuées sont extrêmement sensibles aux modes et aux niveaux de dispersion des organismes. Leur dynamique spatiotemporelle et leurs propriétés structurelles et fonctionnelles peuvent subir des changements profonds sous forme de transitions significatives suivant une faible variation du niveau de dispersion. Ces changements apparaissent aussi par l’émergence de patrons spatiotemporels dans la distribution spatiale des populations qui sont typiques des transitions de phases observées généralement dans les systèmes physiques. La dynamique de la métacommunauté présente deux régimes. Dans le premier régime, correspondant aux niveaux faibles de dispersion des espèces, la dynamique d’assemblage favorise l’émergence de communautés stables, peu diverses et formées d’espèces abondantes et fortement mutualistes. La métacommunauté possède une forte diversité régionale puisque les communautés locales sont faiblement connectées et que leur composition demeure ainsi distincte. Par ailleurs dans le second régime, correspondant aux niveaux élevés de dispersion, la diversité régionale diminue au profit d’une augmentation de la diversité locale. Les communautés locales sont plus productives mais leur stabilité dynamique est réduite suite à la migration importante d’individus. Ce régime est aussi caractérisé par des assemblages incluant une plus grande diversité d’interactions interspécifiques. Ces résultats suggèrent qu’une augmentation du niveau de dispersion des organismes permet de coupler les communautés locales entre elles ce qui accroît la coexistence locale et favorise la formation de communautés écologiques plus riches et plus complexes. Finalement, notre étude suggère que le mutualisme est fondamentale à l’organisation et au maintient des communautés écologiques. Les espèces mutualistes dominent dans les habitats caractérisés par une capacité limite restreinte et servent d’ingénieurs écologiques en facilitant l’établissement de compétiteurs, prédateurs et opportunistes qui bénéficient de leur présence.

Moyens informatiques de restitution en archéologie monumentale : cas du temple de Karnak

L’objectif de notre recherche est l’exploration et l’étude de la question de l’instrumentation informatique des projets de reconstitution archéologiques en architecture monumentale dans le but de proposer de nouveaux moyens. La recherche a pour point de départ une question, à savoir : « Comment, et avec quels moyens informatiques, les projets de reconstitution architecturale pourraient-ils être menés en archéologie? ». Cette question a nécessité, en premier lieu, une étude des différentes approches de restitution qui ont été mises à contribution pour des projets de reconstitution archéologiques, et ceci, à ses différentes phases. Il s’agit de comprendre l’évolution des différentes méthodologies d’approche (épistémologiquement) que les acteurs de ce domaine ont adoptées afin de mettre à contribution les technologies d’information et de communication (TIC) dans le domaine du patrimoine bâti. Cette étude nous a permis de dégager deux principales avenues: une première qui vise exclusivement la « représentation » des résultats des projets et une seconde qui vise la modélisation de ce processus dans le but d’assister l’archéologue dans les différentes phases du projet. Nous démontrons que c’est la deuxième approche qui permet la combinaison et met à la disposition des archéologues une meilleure exploitation des possibilités que l’outil informatique peut et pourra présenter. Cette partie permet de démontrer la nature systémique et complexe de la mise à contribution des TICs dans le domaine de la restitution archéologique. La multitude des acteurs, des conditions techniques, culturelles et autres, des moyens utilisés ainsi que la variété des objectifs envisagés dans les projets de reconstitution archéologiques poussent à explorer une nouvelle approche qui tient compte de cette complexité. Pour atteindre notre objectif de recherche, la poursuite de l’étude de la nature de la démarche archéologique s’impose. Il s’agit de comprendre les liens et les interrelations qui s’établissent entre les différentes unités techniques et intellectuelles en jeu ainsi que les différents modes de réflexions présents dans les projets de reconstitution archéologique du patrimoine bâti. Cette étude met en évidence le rapport direct entre le caractère subjectif de la démarche avec la grande variabilité des approches et des raisonnements mis en œuvre. La recherche est alors exploratoire et propositionnelle pour confronter notamment le caractère systémique et complexe de l’expérience concrète et à travers les publications savantes, les éléments de la réalité connaissable. L’étude des raisonnements archéologiques à travers les publications savantes nous permet de proposer une première typologie de raisonnements étudiés. Chacune de ces typologies reflète une méthodologie d’approche basée sur une organisation d’actions qui peut être consignée dans un ensemble de modules de raisonnements. Cette recherche fait ressortir, des phénomènes et des processus observés, un modèle qui représente les interrelations et les interactions ainsi que les produits spécifiques de ces liaisons complexes. Ce modèle témoigne d’un processus récursif, par essais et erreurs, au cours duquel l’acteur « expérimente » successivement, en fonction des objectifs de l’entreprise et à travers des modules de raisonnements choisis, plusieurs réponses aux questions qui se posent à lui, au titre de la définition du corpus, de la description, de la structuration, de l’interprétation et de la validation des résultats, jusqu’à ce que cette dernière lui paraisse satisfaire aux objectifs de départ. Le modèle établi est validé à travers l’étude de cas du VIIème pylône du temple de Karnak en Égypte. Les résultats obtenus montrent que les modules de raisonnements représentent une solution intéressante pour assister les archéologues dans les projets de reconstitution archéologiques. Ces modules offrent une multiplicité de combinaisons des actions et avantagent ainsi une diversité d’approches et de raisonnements pouvant être mis à contribution pour ces projets tout en maintenant la nature évolutive du système global.