Plasticity is a central concept within the life-span approach of development and is defined as the ability of an individual to change and reorganize in response to environmental challenges (e.g., Baltes & Singer, 20019. Such intraindividual changes can be induced by systematic cognitive training. Recent studies suggest that substantial amounts of plasticity can be induced in executive control functions with a process-based training approach. These newer studies show that repeated practice on executive control tasks not only improved performance on these trained tasks, but also led to improvements in nontrained tasks (i.e., transfer; e.g., Jaeggi, Buschkuehl, Jonides, & Perrig, 2008; Karbach & Kray, 2009). Executive control processes are especially relevant from a developmental perspective because executive control is involved in a wide range of complex cognitive activities (e.g., van der Sluis, de Jong, & van der Leij, 2007) and is one of the most central areas of cognitive development (e.g., Craik & Bialystok, 2006). The current thesis aimed at elucidating several important questions concerning the plasticity of executive control functions induced by systematic cognitive training. Firstly, the amount, range, and stability of plasticity in adolescents and older adults were investigated. Secondly, studies explored if training design, age, and interindividual differences moderate the amount and range of plasticity. Furthermore, the current thesis aimed at exploring how process-based training specifically leads to transfer effects. To explore these questions, all studies employed a pretest-posttest-design comparing a group of participants that was trained with a process-based training approach to a group of control partici-pants that did not receive the training. Pretraining and posttraining sessions incorporated systematic assessment of transfer measures in different cognitive domains. The first study set out to investigate if executive control can be trained in adolescents with a task switching training. Additionally, the study explored what particular domains of executive control may underlie training and transfer effects, and if acute bouts of exercise directly prior to cognitive training enhance training effects. Analyses indicated substantial training effects for both training groups (with or without acute exercise) and near transfer to a similar switching task. Other findings of transfer were limited to a speed task and a tendency for faster reaction times in an updating task. Thus, findings indicate, for the first time, that executive control can be enhanced in adolescents through a short training. Furthermore, analyses suggest that updating may be of particular relevance for the effects of the task switching training. Analyses revealed no additional effects of the exercise intervention. The second study set out to explore, for the first time, the effects of a process-based training ap-proach in old-old age (above 80 years). After ten sessions of practice on working memory tasks, the training group improved in four of the five trained tasks, emphasizing the potential for plasticity even in old-old age. The gains in the training group were largely driven by individuals who started out with a low capacity in the training tasks. Thus, findings suggest that working memory can be improved with a short executive control training even in old-old age, particularly for low-capacity individuals. The absence of transfer effects in this study may point to the limits of plasticity in this age group. The third study aimed at further elucidating the mixed findings regarding the amounts of training and transfer effects induced by executive control training in older adults. For that purpose, a sample of older adults covering a wide range from young-old to old-old age (65 to 95 years) was either trained for nine sessions on a visuospatial and a verbal working memory as well as an executive control task; or served as controls. Analyses revealed significant training effects in all three trained tasks, as well as near transfer to verbal working memory and far transfer to a nonverbal reasoning task. Remarkably, all training effects and the transfer effect to verbal working memory were even stable at a nine-month follow-up. These findings suggest that cognitive plasticity is preserved over a large range of old age and that even a rather short training regimen can lead to (partly specific) training and transfer effects. However, analyses also revealed that there are a range of factors that may moderate the amount of plasticity, e.g., age and baseline performance in the training domain. To summarize, the current thesis explored effects of short executive control trainings on cognitive functions in adolescents and older adults. The findings suggest a high potential for intraindividual variability across the whole life-span. Plasticity was shown on the level of training and transfer tasks, as well as on the level of stability of effects. Furthermore, results support the notion that process-based training improves executive control processes that in turn lead to improvements in tasks that rely on these processes. The current thesis makes important contributions to the conceptual debate about the potentials and limits of training-induced plasticity across the life-span. It benefits the debate in that it specifically delineates factors that moderate the obtained effects.:Abstract ..............................................................................................1 1 General Introduction .....................................................................3 1.1 Plasticity of cognitive functions ...................................................5 1.2 Executive control functions .........................................................6 1.3 Cognitive training of executive control functions .......................9 2 Outline and Central Questions ......................................................19 2.1 What amount of plasticity does executive control training induce in different age groups? .........................................................................19 2.2 Do training and transfer effects of executive control training remain stable over time? ....................................................................20 2.3 Do training design, age, and baseline performance moderate the amount of plasticity? ...........................................................................20 2.4 Are changes in trained tasks specifically related to changes in transfer tasks? .................................................................................21 3 Study 1 - Effects of a Task Switching Training in Adolescents .......22 3.1 Introduction ..............................................................................22 3.2 Methods ....................................................................................27 3.3 Results ......................................................................................33 3.4 Discussion .................................................................................43 4 Study 2 - Effects of a Working Memory Training in Old-Old adults .48 4.1 Introduction ...............................................................................48 4.2 Methods .....................................................................................51 4.3 Results .......................................................................................54 4.4 Discussion ..................................................................................59 5 Study 3 - Factors Moderating Effects of Working Memory Training in Older Adults .......................................................................63 5.1 Introduction ................................................................................63 5.2 Methods ......................................................................................67 5.3 Results .........................................................................................71 5.4 Discussion ...................................................................................78 6 General Discussion .........................................................................83 6.1 Summary of empirical findings .....................................................83 6.2 Integration of the main empirical findings ...................................85 6.3 Conclusion and Outlook ...............................................................95 6.4 Summary ......................................................................................98 References ..........................................................................................99 Appendix ............................................................................................112

To expand the understanding of aging in the model organism Caenorhabditis elegans, global quantification of metabolite and protein levels in young and aged nematodes was performed using mass spectrometry. With age, there was a decreased abundance of proteins functioning in transcription termination, mRNA degradation, mRNA stability, protein synthesis, and proteasomal function. Furthermore, there was altered S-adenosyl methionine metabolism as well as a decreased abundance of the S-adenosyl methionine synthetase (SAMS-1) protein. Other aging-related changes included alterations in free fatty acid levels and composition, decreased levels of ribosomal proteins, decreased levels of NADP-dependent isocitrate dehydrogenase (IDH1), a shift in the cellular redox state, an increase in sorbitol content, alterations in free amino acid levels, and indications of altered muscle function and sarcoplasmic reticulum Ca2+ homeostasis. There were also decreases in pyrimidine and purine metabolite levels, most markedly nitrogenous bases. Supplementing the culture medium with cytidine (a pyrimidine nucleoside) or hypoxanthine (a purine base) increased lifespan slightly, suggesting that aging-induced alterations in ribonucleotide metabolism affect lifespan. An age-related increase in body size, lipotoxicity from ectopic yolk lipoprotein accumulation, a decline in NAD+ levels, and mitochondrial electron transport chain dysfunction may explain many of these changes. In addition, dietary restriction in aged worms resulting from sarcopenia of the pharyngeal pump likely decreases the abundance of SAMS-1, possibly leading to decreased phosphatidylcholine levels, larger lipid droplets, and ER and mitochondrial stress. The complementary use of proteomics and metabolomics yielded unique insights into the molecular processes altered with age in C. elegans.

No description available.

No description available.

[pt] Assim como qualquer item, uma construção possui uma vida útil que considera o seu nascimento como momento que ela é concebida em projeto, e sua morte como sendo sua demolição final. Durante sua vida uma construção deve passar por manutenções (preventivas, adaptativas e corretivas) que permitem o prolongamento do seu uso, mantendo o seu nível de desempenho dentro do aceitável. Muitas vezes as ações corretivas se dão em períodos curtos de tempo, intervalos abaixo do esperado por seus usuários ou administradores. Obviamente toda intervenção trás consigo um custo financeiro, que cresce dependendo do momento em que ela ocorra dentro da vida da construção. Muito além do custo financeiro, toda atividade causa impacto no meio ambiente, gerando assim um custo ambiental. Determinar o preço ambiental do refazimento de uma obra, em um curto espaço de tempo (menor que o esperado) ilustra o peso deste custo, muitas vezes invisível ou negligenciado, é necessário. A Análise do refazimento de uma obra devido a falhas construtivas que trouxeram uma drástica queda no desempenho no uso do empreendimento demonstrou que o custo ambiental é proporcionalmente muito maior que o custo financeiro esperado. Sabendo que o custo financeiro de correções construtivas ao longo da vida do imóvel cresce em uma progressão geométrica de base 5, permite comparar o quanto o custo ambiental pode desequilibrar a sustentabilidade. Analisando que a intervenção de uma área de 4.200 m quadrados utilizou uma área ambiental de 1.360.000 m quadrados, faz com que os sinais de alerta se acendam demonstrando que a correção de um erro construtivo é muito maior para o meio ambiente que o custo financeiro envolvido. / [en] The world population has been growing at a dizzying rate in recent centuries. And this accelerated population gain brings with it numerous consequences, among them, the need to produce more food, housing and infrastructure. This all leads us to consume more and more natural resources and also increases the generation of waste and waste. The so-called carrying capacity of the planet (condition of sustaining a population), has not evolved in the last centuries in the same index of population growth, that is, humanity is consuming natural resources and generating waste at a speed higher than that which the planet is capable of. produce and absorb. To continue supporting the growing population of the planet, it is necessary to experiment with new technologies, methodologies and processes so that this growth is supported by the tripod of sustainability. The term sustainable development has the most common, and accepted, meaning that points to a tripod of economic growth, environmental preservation and social development. Civil construction is an essential economic sector in the development of any country and society, being responsible for a large fraction of the quality of life of human beings, since they alter the natural environment for better use of space. Understanding the environmental cost of correcting a construction failure is the objective of this work. There are countless studies that point to the financial cost of the so-called rework, but few look at this phenomenon under the environmental lens. The entire life cycle of an enterprise, from its design to its ruin, through its construction and use, causes environmental marks. To correct flaws in works already completed, or in use, there is a need to consume new materials, involving an entire production chain and generating new waste. To produce a certain input that will be used in the correction of a pathology, the following are required: consumption of raw materials to conceive it, energy consumption to manufacture it, waste to produce it, expenses with transportation to take it from the factory to the point of use. All of these steps in the process consume environmental resources. At the other end of the error correction, for the pathology to be eliminated, it must be removed from the site (demolition of a crooked wall, for example) using energy and producing residues from this removal. This waste will be transported to a suitable disposal site, that is, using more energy in this process. In addition, it is still necessary to transform a harmful waste into something less aggressive to the environment. Given the above, the purpose of this research is to understand the size of the impact that a constructive failure can cause to the environment depending on its severity and the moment it is detected. In order to carry out this work, a project was followed up with a short time of use, but which needed major interventions due to the flaws found. With the analysis of the presented pathologies it was possible to measure how much they weighed, and will weigh, to the environment. In addition, analyzing the origin and the correction method implemented will allow to index each of the flaws found environmentally, measuring how much the planet s carrying capacity could have been preserved had these defects not occurred. The useful life of a building can be understood as the time interval from its birth, marked by its design concept, until its death with its demolition and / or disuse. Project useful life (VUP) must be defined by the developer and the project designer. VUP, despite being a temporal measure, has an economic character, being defined as the best relation between global cost versus time to enjoy the good. Preventive maintenance takes place constantly and aims to increase the life of the project, whereas corrective maintenance must occur in a timely manner and correcting failures in points that are already performing below the desired level. Adaptive maintenance has the objective of adjusting the enterprise to receive new technologies, new equipment and to comply with the new legislation The economic character of the useful life of a good is characterized by its global cost, which must be defined as the sum of the cost of acquisition, or construction, of the good and the cost of maintenance throughout its life. The total cost of a construction during its life includes the costs of planning, design, construction, operation, maintenance and demolition. These construction costs represent between 15 percent and 20 percent of the total cost; 80 percent of the amount is spent on operation and maintenance and only 2 percent to 5 percent of the amount is spent on planning and design (conceptual and detailed). The total cost of a construction during its life includes the costs of planning, design, construction, operation, maintenance and demolition. These construction costs represent between 15 percent and 20 percent of the total cost; 80 percent of the amount is spent on operation and maintenance and only 2 percent to 5 percent of the amount is spent on planning and design (conceptual and detailed). The useful life of a building, for example, goes through the useful life of its components such as its foundations, superstructures, hydro-sanitary installations, electrical installations, facades, internal cladding, paintings and waterproofing. Studies show that corrective maintenance costs up to five times more than preventive maintenance. Corrective maintenance is often required in shorter time cycles than initially imagined (and desired) by those responsible for the enterprise. Currently, numerous failures in new construction (or with little use) are verified, such as buildings, bridges, roads, streets and public supply networks, which range from faults of all kinds, from simple to catastrophic. The service life can be extended with preventive, corrective and adaptive maintenance interventions. The extension of useful life is directly impacted on the overall cost of construction. The lowest global cost system is usually not the lowest initial cost nor the longest lasting. Seeking to optimize the cost-benefit ratio is the best option for society. The useful life of a building must be supported by the tripod of socio-environmental importance, cost of implementation and cost of maintenance over the years. When investors seek to save money by building buildings with low quality standards, and with low maintenance ease, they increase the cost of future maintenance. At the other end of the real estate market, users do not carry out preventive maintenance because they consider its cost to be high, often allowing certain components of the project to come close to the level of unacceptable performance and only then carry out the maintenance that has now become corrective, costing financially more than the preventive maintenance previously denied. The Sitter rule, or Law of 5, determines that the relative cost of an intervention grows in a geometric progression of ratio 5 over time in the project and its maintenance. The sooner a problem is perceived, the lower its cost. Sustainability, despite not having a unanimous definition, is a concept that must integrate aspects of social-ecological dimensions, economic factors, and the short, medium and long term advantages. Putting together all the concepts expressed by several authors, sustainability can be defined as the attempt to achieve economic and social growth while preserving the finite resources of the environment. For more than 40 years, humanity s demand for nature has exceeded the planet s replacement capacity. Currently 1.5 Earth planets would be needed to provide the ecological services that were used in the 1980s. Trees are cut faster than they can ripen, more fish are caught than the oceans can replenish and more carbon is emitted than forests and oceans can absorb. The carrying capacity of the planet has been compromised in a way never before experienced by humanity, to meet the current lifestyle of the population. Consumerism is seen as a behavior that leads to an increase in production and, consequently, to economic progress, but this equation is limited by resources that cannot sustain unlimited growth. Finite spaces cannot absorb waste that grows indefinitely. The carrying capacity of a system is obviously influenced by factors such as average income, material expectations and level of technology, that is, energy and material efficiency. There are few systems of indicators that analyze sustainable development in a generic way. The most commonly used indicators globally are as follows: (1) Sustainability Panel, (2) Sustainability Barometer and (3) Ecological Footprint. The indicator called Ecological Footprint has the advantage of being easily visualized, since the Ecological Footprint represents the ecological space necessary to sustain a given system, or community. It is a simple tool that counts the flows of matter and energy that enter and leave an economic system, converting them into areas of land, or water, necessary to sustain such a system. The Ecological Footprint is a method that transforms the consumption of raw materials and the assimilation of waste from an economic system, or from a human population, into an area corresponding to productive land or water. Using this method, it is possible to calculate the area of the ecosystem needed to ensure the eternal survival of a given population or system. Once this equivalent area of the ecosystem has been determined, it is possible to visualize how much it appropriates the carrying capacity of the planet as a whole. In fact, the size of the Footprint can change depending on the new technologies developed, which can be more or less resource-consuming and wastegenerating. The calculation method for measuring the Ecological Footprint, although easily intuitive, is difficult to carry out with regard to data collection.

Purpose: Working from lifespan development theory and the theory of Selective Optimization with Compensation (SOC), I provide theoretical analyses to inform and direct research on Taijiquan where research questions involve issues of adaptive development (optimization of gains, maintenance of function, and prevention of lost resources). I also used these frameworks to construct a biopsychosocial mind-body practices model that seeks to explain and predict the role of key aspects (curriculum, practice, context) in Taiji-related development. The above frameworks are further substantiated through a comparative analysis of health status between Taijiquan practitioners (N =120; age range = 24-83, M = 54.77) and a nationally representative sample (N = 414,629; age range = 18-99, M = 54.86) collected by the Centers for Disease Control and Prevention (CDC). The model's predictive potential is explored through an analysis of health status within a subset of experienced Taiji practitioners (N = 94; age range = 24-83, M = 55.82). Design: Theoretical and cross-sectional; between- and within-group comparisons. Methods: Responses from a convenience sample of Taiji practitioners were collected using an online survey. The instrument was designed to collect data on health-related quality of life (HRQoL), lifestyle variables, and Taiji practice regimens. Data from Taiji practitioners were merged with the CDC's 2008 Behavioral Risk Factor Surveillance System (BRFSS) dataset, forming three groups: no exercise, some exercise, and Taiji exercise. Health status was regressed on exercise group while controlling for age, income, and education, as well as the interaction between age and exercise group. Further analyses were also conducted on a subset of the Taiji data (N=94). These analyses examined the relationships among self-reported health, practice regimens, and diet while controlling for age and experience. Results: In the first set of analyses (see paper one), I controlled for the effects of age, income, education, and the differential effects of age on exercise group, while determining associations between health and group membership. A significant interaction effect (p < 0.001) occurred between age and exercise group membership. This interaction showed little difference between exercise groups in the young adult age range, but among older adults, Taijiquan practitioners displayed the best HRQoL. In the second set of analyses (see paper 2), I found significant interaction effects between (a) curricular complexity and out-of-class practice (p < 0.05) and (b) curricular complexity and diet (p < 0.05). Conclusions: The extraordinary health status trajectory among Taiji practitioners may be attributable to several conditions including: (a) the implied presence of SOC-related strategies, (b) the general benefits of psychophysical expertise, and (c) concomitant structure between Taiji-related goals and health behaviors that contributes to optimal aging. Specifically, intervention designers, Taiji teachers, and practitioners should consider the potential benefits of well rounded Taiji curricula, regular out-of-class practice, and healthy diet for optimizing health-related gains and minimizing losses typically associated with aging. / Ph. D.

A chronic hyperglycemic state often results in neuropathological complications such as peripheral diabetic neuropathy (PDN). PDN is a debilitating medical condition that impacts over half of the US population with diabetes. In this study, we used the model organism Caenorhabditis elegans to determine that glucose-supplemented diet leads to an increased rate of intrauterine egg hatching (IUEH) and the reduction of dopamine and serotonin is sufficient to suppress the glucose-induced IUEH. Moreover, in this research demonstrates that a glucose-supplemented diet impacts serotonin and dopamine-associated behaviors. Additionally, we demonstrate that a diet rich in glucose impacts the structure of the serotonergic neurons HSN and NSM. These findings highlight the utility of the model organism C. elegans in elucidating the impact of a glucose-supplemented diet on the nervous system. Finally, these studies show that a glucose-supplemented diet impacts transgenerational and intergenerational phenotypes as well as changes in the transcriptional profile of subsequent generations.

L’objectif de cette étude était d'étudier les différences de mortalité régionales en Ukraine, les structures par causes de décès et les tendances à différentes échelles spatiales. Tout d'abord, des contrastes géographiques nets ont été mis en évidence : pour les hommes, entre l'ouest et l'est de l'Ukraine, et pour les femmes - entre l'ouest et le sud-est. L’étude des disparités régionales en fonction de l’âge révèle que les régions les plus avancées sont caractérisées par une diminution de la mortalité chez les personnes les plus âgées. Dans les grandes villes, pour la plupart des causes de décès (à l'exception du cancer et des maladies infectieuses) vivre dans une grande métropole est un avantage pour survivre. Le cas de la ville de Slavoutytch qui avait particulièrement souffert de l'accident de Tchernobyl a fait l’objet d’une analyse spécifique. Deuxièmement, une attention particulière a été portée aux schémas régionaux de mortalité par causes médicales de décès et a montré que les régions ukrainiennes se trouvent à différents stades de la lutte contre les maladies dégénératives. Enfin, les particularités de la dynamique de deux dernières décennies ont été étudiées. Pendant cette période l'espérance de vie a connu une forte baisse, suivie d’une stagnation, puis d’un début de reprise. Ces évolutions se sont accompagnées d’une transformation des schémas régionaux de mortalité par cause. Ces changements, qu’ils soient majeurs ou plus modestes n’ont pas été réellement identifiés par les pouvoirs publics et aucune avancée sanitaire décisive ne s’est produite dans aucune des régions de l'Ukraine. Il n'y a eu ni stratégies, ni mesures ou réformes efficaces mises en œuvre pour permettre une amélioration substantielle de la santé de la population. / The aim of this study was to investigate regional mortality differences in Ukraine, cause-of-death patterns and trends at different spatial scales. First of all, general contrasts were established: for males between the west and east of Ukraine, while for females between the west and south-east. Study of regional disparities in respect of different age groups revealed that regions that succeeded the most are those characterized by decreased mortality at older ages. As for big cities, for the most of cases of death (except cancer and infectious diseases) living in a big metropolis is an advantage to surviving. The special case of the city of Slavutych that suffered the most from Chernobyl accident was studied. Second, special attention was given to regional patterns of mortality for different medical cause of death, and which showed that Ukrainian regions are at different stages in the fight against man-made and degenerative diseases. Lastly, peculiarities of dynamics over last two decades were investigated. During this period life expectancy has experienced a sharp decrease, followed by stagnation, and recovery. This evolution was accompanied by transformation of regional cause-specific mortality patterns. These changes, larger and smaller, were not actually accounted for by public authorities and no important breakthroughs happened in any Ukraine region. There were no efficient strategies, measures or reforms implemented that would allow substantial improvements in the health of the population.

Les réseaux de capteurs sans fil (RCSFs), sont composés d'un ensemble de nœuds avec des capteurs, transmetteur/récepteur, d'un système de traitement et d'une réserve d'énergie. Au regard d'applications, de travaux de recherche sont développés sur l'utilisation de ce réseau leur performance, fiabilité ou durée de vie. La durée de vie RCSFs correspond à la période à travers laquelle le RCSF fonctionne parfaitement. Cette durée de vie est très affectée par de nombreux facteurs comme la quantité d'énergie disponible, la probabilité de défaillance et les dégradations des composants. L'énergie disponible devient le facteur prépondérant dans les cas d'applications avec des composants difficilement rechargeables ou non renouvelables. Différents algorithmes, stratégies et techniques d'optimisation ont été élaborées et mises en œuvre à cet effet sur la possibilité d'activer un sous-ensemble de capteurs qui satisfont à la contrainte de surveillance et de garder les autres capteurs en mode veille pour pouvoir être mis en œuvre ultérieurement. Ainsi, c'est un problème de type NP complet de maximisation qui peut être résolu en considérant des Ensembles Disjoints de capteurs de Couverture (EDC). Mais la solution obtenue à l'aide des EDCs ne conduit pas toujours à une extension significative de la durée de vie des RCSFs. Le présent travail vise à rechercher une meilleure solution basée sur des capteurs regroupés dans des ensembles nondisjoints de couverture (ECND). Cette approche permet à un capteur de participer à une ou plusieurs ensembles de capteurs de couvertures. Nous avons alors étudié un modèle de représentation binaire des ECNDs pour déterminer un ordonnancement optimum permettant de maximiser la vie d'un RCSF. De plus, nous avons développé une heuristique basée sur un algorithme génétique, pour trouver une solution proche de l'optimal dans un délai raisonnable. Ainsi, pour un ensemble de m capteurs utilisés pour surveiller un ensemble de n cibles, cette heuristique permet construire un nombre maximum q d'ensembles ECNDs. Des efforts supplémentaires sont donc nécessaires pour trouver le meilleur ordonnancement pour la mise en œuvre des ECNDs, qui maximise la durée de vie globale du RCSF, compte tenu de l'énergie initialement disponible dans chaque capteur. Ce problème est formulé à l'aide d'un modèle mathématique de programmation linéaire en nombres entiers (PLE). La fonction objective de ce problème est la somme de toutes les périodes de surveillance pour les q ECNDs programmés, et la contrainte est la consommation d'énergie de tous les capteurs constituant les ECNDs. La possibilité de trouver la solution à ce problème par PLE dans une période de temps donnée dépend de la complexité du modèle et des instances utilisées. Pour trouver la solution dans un délai raisonnable, nous avons développé un algorithme génétique (AG) basé sur les ECNDs. Les solutions potentielles sont représentées dans des chromosomes composés d'un certain nombre de gènes correspondant aux ECNDs, et chaque gène est caractérisé par la période de surveillance d'un ECND. Nous avons ensuite développé un AG qui combine quatre opérateurs de croisement et quatre opérateurs de mutation. La méthode basée cet AG a été codée dans le langage de programmation C pour obtenir une solution satisfaisante et le logiciel Cplex a été utilisé de déterminer la solution exacte correspondant. Une comparaison des solutions obtenues sur de petites instances en utilisant la PLE par rapport aux solutions obtenues par notre AG montre que la méthode basée sur les AG peut trouver une solution proche de l'optimale dans un délai raisonnable. Ensuite, en comparant les solutions en utilisant l'AG ECNDs à l'AG EDCs de la littérature, nous montrons que l'AG avec ECND peut prolonger la durée de vie des RCSFs plus que les AG avec EDCs pour les mêmes instances. Notre approche combine ainsi les principes d'ordonnancement et les techniques d'optimisation pour maximiser la durée de vie des RCSFs / Wireless sensor networks (WSNs), as a collection of sensing nodes with limited processing, limited energy reserve and radio communication capabilities, are widely implemented in many areas of applications such as industry, environment, healthcare, etc. Regarding this large range of applications, many research issues are introduced including the applications, performance, reliability, lifetime, etc. The WSNs lifetime considered in this work is the period of time through which theWSN is perfectly completing its function. This lifetime is affected by many factors including the amount of energy available, failure probability and components degradation. The amount of energy available become the most important factor in case of non renewable components applications. Different algorithms, strategies and optimization techniques were developed and implemented for this purpose based on the possibility of activating a subset of sensors that satisfied the monitoring constraint, while keeping the others in sleep mode to be implemented later. This is an NP complete maximization problem that can be solved using disjoint set covers (DSCs). But the solution obtained using DSCs does not extend always significantly the WSNs lifetime. So, the present work aims to search for a better solution using non-disjoint set covers (NDSCs). This approach gives the opportunity for a sensor to be implemented in one or more subset covers. For that purpose, we studied a binary representation based model to maximize the number of NDSCs. Also, we developed a genetic algorithm based heuristic based on this model to find out the maximum number of NDSCs in a reasonable time. Thus, for a set of m sensors used to monitor a set of n targets or a field, this heuristic allows to construct a maximum number q of NDSCs. Additional effort is required to find the best scheduling for implementing the NDSCs so as to maximize the lifetime of the sensors involved in the WSNs, considering their limited available energy. This problem is formulated using integer linear programming (ILP) mathematical model. The objective function of this problem is the sum of all monitoring seasons on which all q NDSCs scheduled, and the constraint is the energy consumption in all sensors included in all NDSCs. Solving this problem using ILP in a period of time depends on the complexity of the model and the instances used. To find the solution in reasonable time, we have developed a NDSCs based genetic algorithm (NDSC-GA). The candidate solutions are represented in chromosomes composed of a number of genes equal to the number q of NDSCs, and each gene is the number of monitoring seasons on which a NDSC is scheduled. We have then developed a GA that combines the four crossover operators and four mutation operators. The GA based methods are coded in C programming language to obtain a satisfying solution and the Cplex software was used to obtain the corresponding exact solution. Comparing the optimal solution obtained using the ILP on small instances, to the solutions obtained using our GA based method explained that our methods can find a solution near the optimal in reasonable time. Then, comparing the solution obtained using our NDSCs GA based methods, to the DSCs GA based method in the literature, we showed that the NDSCs GA can prolong the WSNs lifetime better than DSCs GA for the same instances. Our approach combines together the scheduling principles and the optimization techniques to maximizing the WSNs lifetime

Knowledge of offspring production (recruitment) is fundamental to understanding and forecasting the dynamics of a population. In this thesis, I focus on two demographic characteristics of fish stocks that are important to recruitment: population density and age structure. First, populations produce more recruits at low density, but quantifying this response has proven difficult. Using data from hundreds of populations of walleye (Sander vitreus), an economically important freshwater fish, I demonstrate that the growing-degree-day metric (a temperature index) is better than age at explaining variation in density-dependent growth and maturity both within and among populations. I then incorporate multi-lake measures of density-dependent life history change into a temperature-based biphasic model of growth and reproduction to predict sustainable rates of mortality for walleye throughout most of their range. Second, the age (or size) structure of a population may also affect recruitment because of positive effects of maternal age on offspring production and survival; however, evidence for these ‘maternal influences’ on recruitment is limited. Using both an analytical model and a meta-analysis of stock-recruitment data from 25 species of exploited marine fish, I show that (i) maximum reproductive rate increased with the mean age of adults in a population, and (ii) the importance of age structure increased with a species’ longevity. I then demonstrate a similar effect of maternal influences on reproductive rate in a detailed study of Lake Erie walleye. By highlighting the importance of fisheries-induced demographic change to recruitment, this thesis provides insight into past and present failures. However, it also demonstrates clearly the benefits of proactive management strategies that (i) identify and respect the limits of exploitation, (ii) protect from exploitation reproductively valuable individuals—principles that apply generally to any freshwater, marine, or terrestrial species that is of recreational, commercial, or conservation value.