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See detailA Receding Horizon Approach to Incorporate Frequency Support into the AC/DC Converters of a Multi-Terminal DC Grid
Papangelis, Lampros ULg; Panciatici, Patrick; Debry, Marie-Sophie et al

in Electric Power Systems Research (2017)

This paper proposes a novel control scheme for provision of frequency support among asynchronous AC areas through HVDC grids. It is based on local controllers, each acting on a voltage source converter ... [more ▼]

This paper proposes a novel control scheme for provision of frequency support among asynchronous AC areas through HVDC grids. It is based on local controllers, each acting on a voltage source converter, using local measurements only, and supporting frequency of the adjacent AC area after a significant disturbance. The new discrete control is combined with the existing DC voltage droop technique. The formulation, inspired of Receding Horizon Control, enables providing to the AC area the desired frequency support, while at the same time taking into account various constraints, such as maintaining the DC voltage between secure operating limits. Examples obtained from a test system with a five-terminal DC network connecting two asynchronous areas demonstrate the effectiveness and robustness of the proposed control scheme in various scenarios, with emphasis on component failures. [less ▲]

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See detailReinforcement Learning for Electric Power System Decision and Control: Past Considerations and Perspectives
Glavic, Mevludin ULg; Fonteneau, Raphaël ULg; Ernst, Damien ULg

in The 20th World Congress of the International Federation of Automatic Control, Toulouse 9-14 July 2017 (2017, July)

In this paper, we review past (including very recent) research considerations in using reinforcement learning (RL) to solve electric power system decision and control problems. The RL considerations are ... [more ▼]

In this paper, we review past (including very recent) research considerations in using reinforcement learning (RL) to solve electric power system decision and control problems. The RL considerations are reviewed in terms of speci c electric power system problems, type of control and RL method used. We also provide observations about past considerations based on a comprehensive review of available publications. The review reveals the RL is considered as viable solutions to many decision and control problems across di erent time scales and electric power system states. Furthermore, we analyse the perspectives of RL approaches in light of the emergence of new-generation, communications, and instrumentation technologies currently in use, or available for future use, in power systems. The perspectives are also analysed in terms of recent breakthroughs in RL algorithms (Safe RL, Deep RL and path integral control for RL) and other, not previously considered, problems for RL considerations (most notably restorative, emergency controls together with so-called system integrity protection schemes, fusion with existing robust controls, and combining preventive and emergency control). [less ▲]

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See detailStable isotopes reveal effects of environmental changes on ecological niches of Iphimediidae amphipods
Michel, Loïc ULg; d'Udekem d'Acoz, Cédric; Frederich, Bruno ULg et al

Poster (2017, July)

When faced with environmental changes, organisms are expected to have some intrinsic ability to adapt through ecological plasticity. However, this process is still poorly understood in many Antarctic ... [more ▼]

When faced with environmental changes, organisms are expected to have some intrinsic ability to adapt through ecological plasticity. However, this process is still poorly understood in many Antarctic invertebrates. Here, we focused on Iphimediidae amphipods, as this widely distributed family shows important ecological diversity. In total, 248 amphipods (19 species) from two widely different zones (the West Antarctic Peninsula, or WAP, and Adélie Land, AL) were studied to elucidate how environment can influence ecological niche parameters. Ecological niches were explored using stable isotope ratios of carbon and nitrogen and the SIBER approach (Jackson et al., 2011). The isotopic niche of the whole amphipod assemblage was wider in WAP than in AL. This was true for both total (proxy of the whole range of resources exploited by animals) and the core (proxy of the most commonly used resources) isotopic niches. The ratio between total and core isotopic niches was smaller in WAP than in AL (4.13 vs. 5.74), suggesting that in WAP, animals commonly use a greater relative percentage of the resources to which they have access. Niche modelling at the specific level revealed that this trend was not found in all taxa. For example, niches of Gnathiphimedia sexdentata and Iphimediella microdentata were bigger in WAP than in AL, following the general pattern. On the other hand, niches of Echiniphimedia echinata and E. hodgsoni had the same width in both areas. Moreover, relative niche overlap between these two species was much higher in WAP (42%) than in AL (20%). Our results indicate that the widely different environmental conditions encountered by the animals in these two zones clearly influence their ecology. Overall, Iphimediidae amphipods tend to exploit more resources in WAP, i.e. in the zone where impacts of global change (temperature increase, sea ice cover decrease) are the strongest. Niche overlap between some closely related (i.e. congeneric) species was also more important in WAP. Ultimately, environmental changes in this region might reinforce these trends, which might lead to competition and perturb amphipod community structure. This research was funded by the Belgian Federal Science Policy Office (BELSPO) in the framework of the vERSO and RECTO projects. [less ▲]

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See detailCyanobacterial Contribution to Travertine Deposition in the Hoyoux River System, Belgium
Kleinteich, Julia; Golubic, Stjepko; Pessi, Igor S. et al

in Microbial Ecology (2017), 74

Travertine deposition is a landscape-forming process, usually building a series of calcareous barriers differentiating the river flow into a series of cascades and ponds. The process of carbonate ... [more ▼]

Travertine deposition is a landscape-forming process, usually building a series of calcareous barriers differentiating the river flow into a series of cascades and ponds. The process of carbonate precipitation is a complex relationship between biogenic and abiotic causative agents, involving adapted microbial assemblages but also requiring high levels of carbonate saturation, spontaneous degassing of carbon dioxide and slightly alkaline pH. We have analysed calcareous crusts and water chemistry from four sampling sites along the Hoyoux River and its Triffoy tributary (Belgium) in winter, spring, summer and autumn 2014. Different surface textures of travertine deposits correlated with particular microenvironments and were influenced by the local water flow. In all microenvironments, we have identified the cyanobacterium Phormidium incrustatum (Nägeli) Gomont as the organism primarily responsible for carbonate precipitation and travertine fabric by combining morphological analysis with molecular sequencing (16S rRNA gene and ITS, the Internal Transcribed Spacer fragments), targeting both field populations and cultures to exclude opportunistic microorganisms responding favourably to culture conditions. Several closely related cyanobacterial strains were cultured; however, only one proved identical with the sequences obtained from the field population by direct PCR. This strain was the dominant primary producer in the calcareous deposits under study and in similar streams in Europe. The dominance of one organism that had a demonstrated association with carbonate precipitation presented a valuable opportunity to study its function in construction, preservation and fossilisation potential of ambient temperature travertine deposits. These relationships were examined using scanning electron microscopy and Raman microspectroscopy. [less ▲]

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See detailRECONSTRUCTION DE L'ÉVOLUTION DU RAYONNEMENT SOLAIRE REÇU EN SURFACE EN EUROPE OCCIDENTALE SUR LA PÉRIODE 1900-2014 À L'AIDE DU MODÈLE ATMOSPHÉRIQUE RÉGIONAL MAR
Wyard, Coraline ULg; Fettweis, Xavier ULg; Belleflamme, Alexandre ULg et al

in Dahech, Salem; Charfi, Sami (Eds.) Actes du XXXe colloque de l'Association Internationale de Climatologie : Climat, ville et environnement (2017, July)

Many studies show that the surface solar radiation has underwent large variations over the second half of the 20th century as a result of variations in cloud cover and aerosol loading in the atmosphere ... [more ▼]

Many studies show that the surface solar radiation has underwent large variations over the second half of the 20th century as a result of variations in cloud cover and aerosol loading in the atmosphere. However, it is difficult to build strong conclusions before the 1950' because of the observations scarcity. The evolution of the surface solar radiation has been reconstructed over 1900-2014 using the regional model MAR (« Modèle Atmosphérique Régional ») in Belgium. Boundary conditions were provided by four reanalysis products : the ERA-interim (1979-2014) completed by the ERA40 (1958-1978), the NCEP/NCAR-v1 (1948-2014), the ERA-20C (1900-2010) and the 20CRV2C (1900-2010). Results show that the reanalyses can generate divergent trends while they assimilate observations and are supposed to represent the same climate. [less ▲]

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See detailMacroevolutionary analysis of the tempo of diversification in snappers and fusiliers (Percomorpha: Lutjanidae)
Frederich, Bruno ULg; Santini, Francesco

in Belgian Journal of Zoology (2017), 147(1), 17-35

The percomorph fish family Lutjanidae (snappers and fusiliers) includes about 135 reef-dwelling species, mainly confined to tropical and subtropical marine waters. The great majority of snappers are ... [more ▼]

The percomorph fish family Lutjanidae (snappers and fusiliers) includes about 135 reef-dwelling species, mainly confined to tropical and subtropical marine waters. The great majority of snappers are active predators feeding on fishes or crustaceans, even though some species, including the fusiliers (Caesioninae), have evolved zooplanktivory. Lutjanids show a great diversity of habitat preferences, based on depth segregation and distribution across reef and associated habitats (e.g. mangroves, seagrass beds, estuaries). In spite of their great ecological and economic importance little is known about the tempo of evolution in this group. The present study provides the most comprehensive molecular phylogeny to date for lutjanids, including 70% of extant species and 19 of the 21 currently described genera. We time-calibrated our molecular tree using the oldest described lutjanid fossils, and show how this group likely originated during the Late Cretaceous to Early Paleocene. Lutjanids experienced significant radiation during the Late Eocene and Early Oligocene, in contrast to a pattern of Late Oligocene/Miocene radiation observed in many other reef-associated groups. The time-tree allows us to investigate the tempo of diversification, and our results suggest a variation in the rate of speciation during the evolution of the major clade formed by “lutjanins and caesionins”. Variation in diet and life history strategies could explain this clade-specific dynamic, even though future phylogenetic comparative studies combining additional ecological and morphological data are needed to test this hypothesis. [less ▲]

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See detailDevelopment of an Ericsson Heat Engine for biomass Combined Heat and Power
Oudkerk, Jean-François ULg; Lemort, Vincent ULg

in Proceedings of the 30th International conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS) (2017, July)

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See detailInfusion of mesenchymal stromal cells after deceased liver transplantation: A phase I-II, open-label, clinical study.
DETRY, Olivier ULg; VANDERMEULEN, Morgan ULg; DELBOUILLE, Marie-Hélène ULg et al

in Journal of Hepatology (2017), 67(1), 47-55

BACKGROUND & AIM: Mesenchymal stromal cell (MSC) infusion could be a mean to establish tolerance in solid organ recipients. The aim of this prospective, controlled, phase-1 study was to evaluate the ... [more ▼]

BACKGROUND & AIM: Mesenchymal stromal cell (MSC) infusion could be a mean to establish tolerance in solid organ recipients. The aim of this prospective, controlled, phase-1 study was to evaluate the feasibility, safety and tolerability of a single infusion of MSCs in liver transplant recipients. METHODS: Ten liver transplant recipients under standard immunosuppression received 1.5-3x106/kg third-party unrelated MSCs on post-operative day 3+/-2, and were prospectively compared to a control group of 10 liver transplant recipients. As primary end-points, MSC infusional toxicity was evaluated, and infectious and cancerous complications were prospectively recorded until month 12 in both groups. As secondary end-points, rejection rate, month-6 graft biopsies, and peripheral blood lymphocyte phenotyping were compared. Progressive immunosuppression weaning was attempted from month 6 to 12 in MSC recipients. RESULTS: No variation in vital parameters or cytokine release syndrome could be detected during and after MSC infusion. No patient developed impairment of organ functions (including liver graft function) following MSC infusion. No increased rate of opportunistic infection or de novo cancer was detected. As secondary end-points, there was no difference in overall rates of rejection or graft survival. Month-6 biopsies did not demonstrate a difference between groups in the evaluation of rejection according to the Banff criteria, in the fibrosis score or in immunohistochemistry (including Tregs). No difference in peripheral blood lymphocyte typing could be detected. The immunosuppression weaning in MSC recipients was not successful. CONCLUSIONS: No side effect of MSC infusion at day 3 after liver transplant could be detected, but this infusion did not promote tolerance. This study opens the way for further MSC or Treg-based trials in liver transplant recipients. LAY SUMMARY: Therapy with mesenchymal stromal cells (MSCs) has been proposed as a mean to improve results of solid organ transplantation. One of the potential MSC role could be to induce tolerance after liver transplantation, i.e. allowing the cessation of several medications with severe side effects. This study is the first-in-man use of MSC therapy in 10 liver transplant recipients. This study did not show toxicity after a single MSC infusion but it was not sufficient to allow withdrawal of immunosuppression. [less ▲]

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See detailEver invested. Ever failed. No matter. Invest again. Invest better.
Choffray, Jean-Marie ULg; Pahud de Mortanges, Charles ULg

Book published by Amazon, Kindle Edition (2017)

Welcome to the “desert of the markets”, where businesses are playthings for bigger forces! The goal of this book is to share with you what we observed on the markets over the last twenty years, and what ... [more ▼]

Welcome to the “desert of the markets”, where businesses are playthings for bigger forces! The goal of this book is to share with you what we observed on the markets over the last twenty years, and what we believe to have learned as to their behavior. The end-product is a set of several hundred “experience-filtered” thoughts, facts and rules whose any subset could provide a reasonable basis on which to build your own theory of investing. Painful and solitary work. But, your survival on the markets is at that price. In its current 2017 edition, “Ever invested. Ever Failed. No matter. Invest again. Invest better.” is organized into seven chapters: The Great Recession of 2008; Businesses, assets and liabilities; Assessing market response; Financial engineering tricks and traps; Investors, swindlers and thieves; Rules for asset protection; Investing under non-parametric uncertainty. It concludes with a discussion of A few common myths and some Final thoughts on the art and science of investing. Each chapter comprises a short introduction, followed by an extensive, and unordered, list of thoughts, facts and rules that should help you articulate your information, decision and reward systems. [less ▲]

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See detailStandardized Settling Cell Design
Leleu, David ULg; Pfennig, Andreas ULg

Scientific conference (2017, July)

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See detailcopycat: Testing Differential Treatment of New Transport Protocols in the Wild
Edeline, Korian ULg; Kühlewind, Mirja; Trammell, Brian et al

in Applied Networking Research Workshop (2017, July)

Recent years have seen the development of multiple transport solutions to address the ossification of TCP in the Internet, and to ease transport-layer extensibility and deployability. Recent approaches ... [more ▼]

Recent years have seen the development of multiple transport solutions to address the ossification of TCP in the Internet, and to ease transport-layer extensibility and deployability. Recent approaches, such as PLUS and Google's QUIC, introduce an upper transport layer atop UDP; their deployment therefore relies on UDP not being disadvantaged with respect to TCP by the Internet. This paper introduces copycat, a generic transport protocol testing tool that highlights differential treatment by the path in terms of connectivity and QoS between TCP and a non-TCP transport protocol. copycat generates TCP-shaped traffic with custom headers, and compares its performance in terms of loss and delay with TCP. We present a proof-of-concept case study (UDP vs. TCP) in order to answer questions about the deployability of current transport evolution approaches, and demonstrate the extent of copycat's capabilities and possible applications. While the vast majority of UDP impairments are found to be access-network linked, and subtle impairment is rare, middleboxes might adapt to new protocols that would then perform differently in the wild compared to early deployments or controlled environment testing. [less ▲]

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See detailÉvolution de l'enneigement moyen dans les Alpes au cours du 20e siècle à l'aide du modèle atmosphérique régional MAR
Belleflamme, Alexandre ULg; Wyard, Coraline ULg; Doutreloup, Sébastien ULg et al

in Dahech, Salem; Charfi, Sami (Eds.) Actes du XXXème colloque de l'Association Internationale de Climatologie - Climat, ville et environnement (2017, July)

The evolution of the snow height over the Alps can strongly impact tourism, but also the water availability of the region. In this study, we have reproduced the evolution of the climate in the Alps over ... [more ▼]

The evolution of the snow height over the Alps can strongly impact tourism, but also the water availability of the region. In this study, we have reproduced the evolution of the climate in the Alps over the 20th century with the help of the regional atmospheric model MAR forced by three reanalyses (ERA-20C, NCEP/NCAR, and ERA-Interim). MAR shows that the snow height has increased since the beginning of the 20th century, first only at higher altitudes, then also at lower levels, before knowing a strong and abrupt decrease between 1985 and 1990. This evolution, which is consistent with observations given in the literature, is directly linked with the trends of NAO and AO. In fact, the atmospheric circulation changes highlighted by NAO and AO induce temperature and precipitation changes that directly determine the snow height in the Alps. [less ▲]

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See detailNew Alternatives to Chemical Pesticides: Deciphering the Action Mechanisms of Lipid based Plant Elicitors via Complementary Biophysical and Biological Approaches
Fauconnier, Marie-Laure ULg

Scientific conference (2017, July)

An elicitor may be defined as any molecule produced by pathogenic or non-pathogenic microorganisms or by host plants (synthesizing or accumulating the molecule) capable of inducing or promoting the ... [more ▼]

An elicitor may be defined as any molecule produced by pathogenic or non-pathogenic microorganisms or by host plants (synthesizing or accumulating the molecule) capable of inducing or promoting the natural resistance of plants to one or more pathogens, which resistance may be local or systemic. [less ▲]

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See detailAggregation of flexible domestic heat pumps for the provision of reserve in power systems
Georges, Emeline ULg; Quoilin, Sylvain ULg; Mathieu, Sébastien ULg et al

in Proceedings of the 30th International Conference on Efficiency, Cost, Optimisation, Simulation and Environmental Impact of Energy Systems. (2017, July)

The integration of renewable energy sources in the electricity production mix has an important impact on the management of the electricity grid, due to their intermittency. In particular, there is a ... [more ▼]

The integration of renewable energy sources in the electricity production mix has an important impact on the management of the electricity grid, due to their intermittency. In particular, there is a rising need for flexibility, both on the supply and demand sides. This paper assesses the amount of flexibility that could be reserved from a set of flexible residential heat pumps in a given geographical area. It addresses the problem of a load aggregator controlling a set of heat pumps used to provide both space-heating and domestic hot water. The flexibility of the heat pumps is unlocked in order to reduce electricity procurement costs in the day-ahead electricity market, while ensuring the provision of a predefined amount of reserve for real-time grid management. The objective of the paper is two-fold. On the one hand, an aggregation method of large sets of heat pumps based on physics-based models and random sampling techniques is proposed. On the other hand, a combined optimization problem is formulated to determine both the optimal electricity demand profile to be bought on the day-ahead market and the cost associated to the reservation of a defined amount of power. The method is applied to a set of 40000 residential heat pumps in Belgian houses. Results show that these houses can provide up to 100MW of upward reserve for 50% of the current costs. The provision of downward reserve at competitive cost is hampered by significant overconsumption. [less ▲]

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See detailOptimising workforce and energy costs by exploiting production flexibility
Cuvelier, Thibaut ULg; Louveaux, Quentin ULg

Conference (2017, July)

In a world where the electricity prices become more and more volatile, notably due to renewable energies, the industry is suffering from cost variations never seen before, especially when electro ... [more ▼]

In a world where the electricity prices become more and more volatile, notably due to renewable energies, the industry is suffering from cost variations never seen before, especially when electro-intensive. Nevertheless, the plants can significantly reduce this impact: some electro-intensive factories could shift their production to time periods where the electricity is cheaper, resulting in large savings. At the same time, the grid operator can remunerate this consumption adaptation as a flexibility service. Our research goal is to optimise the operations of a factory around this flexibility. We compute a production plan that adapts to price forecasts, but also flexibility levers that adjust this plan to react to unexpected price changes. We propose the unifying concept of reservoir to provide sufficiently good models for the plant's processes. Nevertheless, this methodology implies to have frequent production plan changes, which directly impacts the workers, as they may be asked to follow barely predictable schedules. This has a significant detrimental effect on their quality of life. As a consequence, the human aspect of flexibility must also be considered: we seek for production plans that consider both workforce and energy costs, and we then assign workers to work shifts while ensuring their well-being. This HR orientation is the most innovative contribution of this research project. [less ▲]

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See detailThe question of the methane increase through the retrieval of its isotopologues from FTIR ground-based observations
Bader, Whitney ULg; Strong, Kimberley; Walker, Kaley

Poster (2017, July)

Methane (CH4) is the second most important greenhouse gas emitted by human activities in the Earth’s atmosphere. Although it is roughly 200 times less abundant than carbon dioxide, it is a 28 times more ... [more ▼]

Methane (CH4) is the second most important greenhouse gas emitted by human activities in the Earth’s atmosphere. Although it is roughly 200 times less abundant than carbon dioxide, it is a 28 times more potent greenhouse gas. Approximately one fifth of the changes in the Earth’s balance energy caused by human-linked greenhouse gases since the beginning of industrialization (~1750) is due to methane. Methane is emitted by both natural sources and human activities. Indeed, methane can be emitted to the atmosphere through coal mining, oil and gas exploitation, rice cultures, domestic ruminant animals, biomass burning, waste management, wetlands, termites, methane hydrates and ocean. Since the beginning of the industrialization, atmospheric methane concentrations have increased by 260% to reach 1824 pbb in 2013. From the 1980s until the beginning of the 1990s, atmospheric methane was significantly on the rise, then stabilized during 1999-2006 to rise again afterwards. To this day, the source or sink responsible of this latter increase remains unexplained. Through each emission process, heavy molecules of methane (with one additional neutron either on a carbon or on one hydrogen atom) are emitted along methane (12CH4). The main heavy molecules of methane, called isotopologues (13CH4 and CH3D), are respectively ~110 and ~60 000 times less abundant than methane. Despite their small abundances, they give crucial information on the concentration of methane in the atmosphere and its evolution. Indeed, both isotopologues are emitted with specific emission ratio depending on the emission sources. Determining isotopic ratio of atmospheric methane is therefore a unique tracer of its budget. While the non-monotonous trend of methane is subject of an extensive number of studies, to our knowledge, no study of the isotopic ratio of methane derived from ground-based solar observations has been published to date. Measurements of heavy methane from Fourier Transform InfraRed spectra recorded with state of the art spectrometers installed at Eureka [Arctic, Canada] and Toronto [Ontario, Canada] will help fill this gap. Indeed, the produced time series will ease data interpretation and contribute to a global view of the question of isotopologues. [less ▲]

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See detailWEATHERING ON THE DEVONIAN SLATES AND CHARACTERIZATION OF A BENTONITE LAYER IN THE WESTERWALD (GERMANY)
Fontaine, François ULg; Hamaekers, Helen; Hoffmann, Andreas et al

Conference (2017, July)

The Westerwald region is one of the largest and oldest clay mining areas of Germany. Those deposits were formed during the Eocene and Oligocene as a result of the weathering, erosion and redeposition of ... [more ▼]

The Westerwald region is one of the largest and oldest clay mining areas of Germany. Those deposits were formed during the Eocene and Oligocene as a result of the weathering, erosion and redeposition of Devonian rocks. During the Miocene, intense volcanic activities led to a large basalt cover, protecting the clays from the erosion. The two main goals of this study are first to improve the knowledge on the weathering processes of the Devonian slates that led to the current setting of those clay deposits by studying the mineralogical and chemical composition of the clays with depth. The second goal is to characterize a bentonite layer underneath the Miocene basalt cover using quantitative X-ray diffraction, chemical analysis, BET, cation exchange capacity and scanning electron microscope. A 20 meter deep quarry mining the Devonian bedrock in southern Westerwald has been sampled on its entire depth. The XRD results show no significant variations of the mineralogy with depth, except for the phyllosilicates. The minerals of the < 2 μm fraction are illite, kaolinite, smectite and mixed-layers minerals (vermiculite-chlorite and illite-chlorite). The proportions of the minerals in the mixed-layers chlorite-vermiculite vary with depth. At the bottom of the quarry, the proportion of vermiculite is very low while in the top, the proportion of vermiculite is higher. This is explained by the degree of the weathering, logically more intense at the top of the quarry. Trace elements compositions are currently being investigated. A 3 meter thick greenish to brownish bentonite layer has been found in the eastern part of the Westerwald region. The XRD performed on different samples of this bentonite shows a relatively heterogeneous composition: montmorillonite (60-80%), kaolinite (5-12%), illite (0-7%), goethite (2-15%), talc (0-10%), K-feldspars (0-7%), plagioclase (0-4%) and traces of amphibole and pyroxene. This bentonite is probably the result of the weathering of volcanic ashes. Since there are not many outcrops of this bentonite layer, its spatial distribution is studied by drilling. [less ▲]

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See detailAgency and delinquency among adolescence during their transition to adulthood: what role in the desistance process?
Puglia, Rosa ULg; Glowacz, Fabienne ULg

Poster (2017, June 31)

Recent studies have shown that agency plays an important role in the desistance process. This variable allows the transition from delinquent identity to non-delinquent identity. However, despite ... [more ▼]

Recent studies have shown that agency plays an important role in the desistance process. This variable allows the transition from delinquent identity to non-delinquent identity. However, despite increasing literature about this topic, there is a lack of consensus regarding the role of this variable in the desistance process. Also, the way to measure this phenomenon remains unclear. In our study, agency is thought within a border framework, namely the understanding of all kind of behavior. According to the social cognitive theory, emotional and cognitive processes influence human behavior: emotions and thoughts that will define ways of acting and will motivate behavioral changes. Outcomes expectancies can be help or hinder for the concretization of behavioral change. We conducted a qualitative research among adolescents (aged 17-18) who are engaged in a delinquent trajectory. Our objective are to understand how these young in transition to adulthood leave delinquent lifestyle by evaluating to their life course and delinquent course. Each participant was interviewed with a semi-structured interview. To ensure that the interviews provided rich insights into participants’ reality, the interview was designed to elicit detailed information on relevant themes including identity, turning point, future and delinquency trajectory. Desistance was not explicitly questioned. All interviews were taperecorded and analyzed using IPA method (Smith, 2003). Mastery Scale (Pearlin, 1978), Causal Attribution Scale (Rossier, 2002), Hope Scale (Snyder, 1991) and University Rhode Island Change Assessment Scale (McConnaughy, 1983) were also administered. We see that the younths interviewed are at different stage in their desistance process. All of them, persistent or desistant, consider taking a hold on their lives. These results encourage thinking agency in the understanding of all kind of behavior. We should then take into account the beliefs and expectations of results as a variable mediating the relationship between agency and desistance. [less ▲]

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