Studies of the role of nf-κb in controlling osteoclast differentiation and bone loss

Increased osteoclast (OC) bone resorption and/or decreased osteoblast (OB) bone formation contribute to bone loss in osteoporosis and rheumatoid arthritis (RA). Findings of the basic and translational research presented in this thesis demonstrate a number of mechanisms by which cytokine-induced NF-κB activation controls bone resorption and formation: 1) Tumour necrosis factor-α (TNF) expands pool of OC precursors (OCPs) by promoting their proliferation through stimulation of the expression of macrophage colony stimulating factor (M-CSF) receptor, c-Fms, and switching M-CSF-induced resident (M2) to inflammatory (M1) macrophages with enhanced OC forming potential and increased production of inflammatory factors through induction of NF-κB RelB; 2) Similar to RANKL, TNF sequentially activates transcriptional factors NF-κB p50 and p52 followed by c-Fos and then NFATc1 to induce OC differentiation. However, TNF alone induces very limited OC differentiation. In contrast, it pre-activates OCPs to express cFos which cooperates with interleukin-1 (IL-1) produced by these OCPs in an autocrine mechanism by interacting with bone matrix to mediate the OC terminal differentiation and bone resorption from these pre-activated OCPs. 3) TNF-induced OC formation is independent of RANKL but it also induces NF-κB2 p100 to limit OC formation and bone resorption, and thus p100 deletion accelerates joint destruction and systemic bone loss in TNF-induced RA; 4) TNF receptor associated factor-3 (TRAF3) limits OC differentiation by negatively regulating non-canonical NF-κB activation and RANKL induces TRAF3 ubiquitination and lysosomal degradation to promote OC differentiation. Importantly, a lysosomal inhibitor that inhibits TRAF3 degradation prevents ovariectomy-induced bone loss; 5) RelB and Notch NICD bind RUNX2 to inhibit OB differentiation and RelB:p52 dimer association with NICD inhibit OB differentiation by enhancing the binding of RBPjκ to Hes1. These findings suggest that non-canonical NF- κB signaling could be targets to develop new therapies for RA or osteoporosis. For example 1) Agents that degrade TNF-induced RelB could block M1 macrophage differentiation to inhibit inflammation and joint destruction for the therapy of RA; 2)Agents that prevent p100 processing or TRAF3 degradation could inhibit bone resorption and also stimulate bone formation simultaneously for the therapy of osteoporosis.

Production of Polyhydroxyalkanoates by Pseudomonas mendocina using vegetable oils and their characterisation

Synthesis of Polyhydroxyalkanoates (PHAs) by Pseudomonas mendocina, using different vegetable oils such as, coconut oil, groundnut oil, corn oil and olive oil, as the sole carbon source was investigated for the first time. The PHA yield obtained was compared with that obtained during the production of PHAs using sodium octanoate as the sole carbon source. The fermentation profiles at shaken flask and bioreactor levels revealed that vegetable oils supported the growth of Pseudomonas mendocina and PHA accumulation in this organism. Moreover, when vegetable oil (coconut oil) was used as the sole carbon source, fermentation profiles showed better growth and polymer production as compared to conditions when sodium octanoate was used as the carbon source. In addition, comparison of PHA accumulation at shaken flask and fermenter level confirmed the higher PHA yield at shaken flask level production. The highest cell mass found using sodium octanoate was 1.8 g/L, whereas cell mass as high as 5.1 g/L was observed when coconut oil was used as the feedstock at flask level production. Moreover, the maximum PHA yield of 60.5% dry cell weight (dcw) was achieved at shaken flask level using coconut oil as compared to the PHA yield of 35.1% dcw obtained using sodium octanoate as the sole carbon source. Characterisations of the chemical, physical, mechanical, surface and biocompatibility properties of the polymers produced have been carried out by performing different analyses as described in the second chapter of this study. Chemical analysis using GC and FTIR investigations showed medium chain length (MCL) PHA production in all conditions. GC-MS analysis revealed a unique terpolymer production, containing 3-hydroxyoctanoic acid, 3-hydroxydecanoic acid and 3-hydroxydodecanoic acid when coconut oil, groundnut oil, olive oil, and corn oil were used as the carbon source. Whereas production of the homopolymer containing 3-hydroxyoctanoic acid was observed when sodium octanoate was used as the carbon source. MCL-PHAs produced in this study using sodium octanoate, coconut oil, and olive oil exhibited melting transitions, indicating that each of the PHA was crystalline or semi-crystalline polymer. In contrast, the thermal properties of PHAs produced from groundnut and corn oils showed no melting transition, indicating that they were completely amorphous or semi-crystalline, which was also confirmed by the X-Ray Diffraction (XRD) results obtained in this study. Mechanical analysis of the polymers produced showed higher stiffness of the polymer produced from coconut oil than the polymer from sodium octanoate. Surface characterisation of the polymers using Scanning Electron Microscopy (SEM) revealed a rough surface topography and surface contact angle measurement revealed their hydrophobic nature. Moreover, to investigate the potential applicability of the produced polymers as the scaffold materials for dental pulp regeneration, multipotent human Mesenchymal stem cells (hMSCs) were cultured onto the polymer films. Results indicated that these polymers are not cytotoxic towards the hMSCs and could support their attachment and proliferation. Highest cell growth was observed on the polymer samples produced from corn oil, followed by the polymer produced using coconut oil. In conclusion, this work established, for the first time, that vegetable oils are a good economical source of carbon for production of MCL-PHA copolymers effectively by Pseudomonas mendocina. Moreover, biocompatibility studies suggest that the produced polymers may have potential for dental tissue engineering application.

Floristic And Ethnobotanical Studies Of Medicinal Plants Of The City Of El -Jadida (MOROCCO)

Abstract: BRIGUICHE. H, ZIDANE. L. Floristic And Ethnobotanical Studies Of Medicinal Plants Of The City Of El -Jadida (MOROCCO). In the framework of the ethnobotanical studies on medicinal plants undertaken by the Laboratory of Biodiversity and Natural Resources of the Faculty of Sciences of Kenitra (Morocco), we are interested in the area of El Jadida which presents a rather important floristic richness thanks to changes in its ecological conditions By using 204 questionnaire, the ethnobotanical surveys were conducted in the field during the years 2012-2013. The location of the different sampling sites was determined by the stratified sampling method. The analysis of the results obtained from the questionnaires and forms using statistical processing allowed us to identify 70 plant species distributed in 69 genera and 37 families. These results also show that most of these species are mainly used in the care of the digestive system and respiratory system. The seed is the most used part in local traditional medicines and the decoction is the most frequent mode with a rate of 31%. The species Origanum compactum is the most used by the population of the city of El Jadida 47 quotes.  

Measuring the Diversity and the Integration of Film Production in Mercosur: A Social Network Analysis

Based on an original and comprehensive database of all feature fiction films produced in Mercosur between 2004 and 2012, the paper analyses whether the Mercosur film industry has evolved towards an integrated and culturally more diverse market. It provides a summary of policy opportunities in terms of integration and diversity, emphasizing the limiter role played by regional policies. It then shows that although the Mercosur film industry remains rather disintegrated, it tends to become more integrated and culturally more diverse. From a methodological point of view, the combination of Social Network Analysis and the Stirling Model opens up interesting research tracks to analyse creative industries in terms of their market integration and their cultural diversity.

Evidence for methane production by the marine algae Emiliania huxleyi

Methane (CH4), an important greenhouse gas that affects radiation balance and consequently the earth's climate, still has uncertainties in its sinks and sources. The world's oceans are considered to be a source of CH4 to the atmosphere, although the biogeochemical processes involved in its formation are not fully understood. Several recent studies provided strong evidence of CH4 production in oxic marine and freshwaters, but its source is still a topic of debate. Studies of CH4 dynamics in surface waters of oceans and large lakes have concluded that pelagic CH4 supersaturation cannot be sustained either by lateral inputs from littoral or benthic inputs alone. However, regional and temporal oversaturation of surface waters occurs frequently. This comprises the observation of a CH4 oversaturating state within the surface mixed layer, sometimes also termed the "oceanic methane paradox". In this study we considered marine algae as a possible direct source of CH4. Therefore, the coccolithophore Emiliania huxleyi was grown under controlled laboratory conditions and supplemented with two 13C-labeled carbon substrates, namely bicarbonate and a position-specific 13C-labeled methionine (R-S-13CH3). The CH4 production was 0.7 µg particular organic carbon (POC) g−1 d−1, or 30 ng g−1 POC h−1. After supplementation of the cultures with the 13C-labeled substrate, the isotope label was observed in headspace CH4. Moreover, the absence of methanogenic archaea within the algal culture and the oxic conditions during CH4 formation suggest that the widespread marine algae Emiliania huxleyi might contribute to the observed spatially and temporally restricted CH4 oversaturation in ocean surface waters.

Evidence for methane production by the marine algae Emiliania huxleyi

Methane (CH4), an important greenhouse gas that affects radiation balance and consequently the earth's climate, still has uncertainties in its sinks and sources. The world's oceans are considered to be a source of CH4 to the atmosphere, although the biogeochemical processes involved in its formation are not fully understood. Several recent studies provided strong evidence of CH4 production in oxic marine and freshwaters, but its source is still a topic of debate. Studies of CH4 dynamics in surface waters of oceans and large lakes have concluded that pelagic CH4 supersaturation cannot be sustained either by lateral inputs from littoral or benthic inputs alone. However, regional and temporal oversaturation of surface waters occurs frequently. This comprises the observation of a CH4 oversaturating state within the surface mixed layer, sometimes also termed the "oceanic methane paradox". In this study we considered marine algae as a possible direct source of CH4. Therefore, the coccolithophore Emiliania huxleyi was grown under controlled laboratory conditions and supplemented with two 13C-labeled carbon substrates, namely bicarbonate and a position-specific 13C-labeled methionine (R-S-13CH3). The CH4 production was 0.7 µg particular organic carbon (POC) g−1 d−1, or 30 ng g−1 POC h−1. After supplementation of the cultures with the 13C-labeled substrate, the isotope label was observed in headspace CH4. Moreover, the absence of methanogenic archaea within the algal culture and the oxic conditions during CH4 formation suggest that the widespread marine algae Emiliania huxleyi might contribute to the observed spatially and temporally restricted CH4 oversaturation in ocean surface waters.

La ética hacker frente al capitalismo netárquíco: software libre y peer production en las iniciativas de Economía Colaborativa en Andalucía

En los últimos años el término Economía Colaborativa se ha popularizado sin que, hasta el momento, haya sido definido de manera inequívoca. Bajo esta denominación se engloban experiencias tan diversas como bancos de tiempo, huertos urbanos, startups o grandes plataformas digitales. La proliferación de este tipo de iniciativas puede relacionarse con una multiplicidad de factores tales como el desarrollo tecnológico, la recesión económica y otras crisis superpuestas (medioambiental, de cuidados, de valores, de lo político) y un cierto cambio en los valores sociales. Entre 2014-2015 se han realizado dos investigaciones en Andalucía de manera casi paralela y con una metodología similar. La primera de ellas pretendía identificar prácticas de Economía Colaborativa en el entorno universitario. La segunda investigación identificaba experiencias de emprendimiento a nivel autonómico. A luz de los resultados obtenidos se plantea la siguiente cuestión sobre la naturaleza misma de la Economía Colaborativa: ¿nos encontramos ante prácticas postcapitalistas que abren el camino a una sociedad más justa e igualitaria o, más bien, estamos ante una respuesta del capital para, una vez más, seguir extrayendo de manera privada el valor que se genera socialmente? Este artículo, partiendo del análisis del conjunto de iniciativas detentadas en Andalucía, se centra en aquellas basadas en el software libre y la producción digital concluyendo cómo, gracias a la incorporación de ciertos aspectos de la ética hacker y las lógicas del conocimiento abierto, éstas pueden situarse dentro de un escenario de fomento de los comunes globales frente a las lógicas imperantes del capitalismo netárquico. 

Skapa förutsättningar för att implementera Lean production i en tillverkningsprocess som kännetecknas av HVLV : - En fallstudie på Tibrokök Sverige AB

Idag är det vanligt att företagen konkurrerar med produkter som innefattar en fysisk vara som har utvidgats med olika tjänster för att kunna tillfredsställa kundens behov. I takt med detta ökar produkternas komplexitet och högre krav ställs på leverantörerna. Denna utveckling har lett till att många företag som tillverkar produkter med hög variation måste arbeta helt kundorderstyrt för att kunna tillgodose kundernas ökande krav. Företagen som tillverkar dessa komplexa produkter har en tillverkning som karaktäriseras av hög variation och låg volym vilket benämns med förkortningen HVLV. Utmaningen för dessa HVLV-företag ligger i att ha en hög produktmixflexibilitet med så låg resursanvändning som möjligt. För att effektivisera verksamheten har många företag därför intresserat sig för Lean production som har visat sig vara ett framgångsrikt koncept för tillverkande företag runt om i världen som effektiviserat sin produktion. Ett flertal artiklar har uppmärksammat begränsningar vid implementeringen av Lean production i HVLV-miljöer. Artiklar pekar vidare på behovet av ytterligare forskning kring Lean productions applicerbarhet i HVLV-miljöer och detta var uppkomsten till examensarbetets bakgrund och syfte. En fallstudie har genomförts på Tibrokök som är ett företag med en helt kundorderstyrd produktion som kännetecknas av HVLV. Med hjälp av fallstudien syftar examensarbetet till att undersöka om verktygen processkartläggning inkl. tidsstudier och layoutflödesdiagram kan bidra till att skapa förutsättningar för implementering av Lean production i en enskild tillverkningsprocess i en HVLV-miljö. Trots att verktygen har behövt anpassas något så anses de ha varit användbara och bidragande till skapandet av förutsättningar för implementering av Lean production i denna HVLV-miljö. Detta eftersom vi kunde identifiera många orsaker till slöseri samt ta fram ett förslag som skapar effektiviseringar av Tibroköks ytbehandlingsprocess i det framtida läget.

Improving photofermentative hydrogen production through metabolic engineering and DOE (Design of Experiments)

A l’heure actuelle, les biocarburants renouvelables et qui ne nuit pas à l'environnement sont à l'étude intensive en raison de l'augmentation des problèmes de santé et de la diminution des combustibles fossiles. H2 est l'un des candidats les plus prometteurs en raison de ses caractéristiques uniques, telles que la densité d'énergie élevée et la génération faible ou inexistante de polluants. Une façon attrayante pour produire la H2 est par les bactéries photosynthétiques qui peuvent capter l'énergie lumineuse pour actionner la production H2 avec leur système de nitrogénase. L'objectif principal de cette étude était d'améliorer le rendement de H2 des bactéries photosynthétiques pourpres non sulfureuses utilisant une combinaison de génie métabolique et le plan des expériences. Une hypothèse est que le rendement en H2 pourrait être améliorée par la redirection de flux de cycle du Calvin-Benson-Bassham envers du système de nitrogénase qui catalyse la réduction des protons en H2. Ainsi, un PRK, phosphoribulose kinase, mutant « knock-out » de Rhodobacter capsulatus JP91 a été créé. L’analyse de la croissance sur des différentes sources de carbone a montré que ce mutant ne peut croître qu’avec l’acétate, sans toutefois produire d' H2. Un mutant spontané, YL1, a été récupéré qui a retenu l'cbbP (codant pour PRK) mutation d'origine, mais qui avait acquis la capacité de se développer sur le glucose et produire H2. Une étude de la production H2 sous différents niveaux d'éclairage a montré que le rendement d’YL1 était de 20-40% supérieure à la souche type sauvage JP91. Cependant, il n'y avait pas d'amélioration notable du taux de production de H2. Une étude cinétique a montré que la croissance et la production d'hydrogène sont fortement liées avec des électrons à partir du glucose principalement dirigés vers la production de H2 et la formation de la biomasse. Sous des intensités lumineuses faibles à intermédiaires, la production d'acides organiques est importante, ce qui suggère une nouvelle amélioration additionnel du rendement H2 pourrait être possible grâce à l'optimisation des processus. Dans une série d'expériences associées, un autre mutant spontané, YL2, qui a un phénotype similaire à YL1, a été testé pour la croissance dans un milieu contenant de l'ammonium. Les résultats ont montré que YL2 ne peut croître que avec de l'acétate comme source de carbone, encore une fois, sans produire de H2. Une incubation prolongée dans les milieux qui ne supportent pas la croissance de YL2 a permis l'isolement de deux mutants spontanés secondaires intéressants, YL3 et YL4. L'analyse par empreint du pied Western a montré que les deux souches ont, dans une gamme de concentrations d'ammonium, l'expression constitutive de la nitrogénase. Les génomes d’YL2, YL3 et YL4 ont été séquencés afin de trouver les mutations responsables de ce phénomène. Fait intéressant, les mutations de nifA1 et nifA2 ont été trouvés dans les deux YL3 et YL4. Il est probable qu'un changement conformationnel de NifA modifie l'interaction protéine-protéine entre NifA et PII protéines (telles que GlnB ou GlnK), lui permettant d'échapper à la régulation par l'ammonium, et donc d'être capable d'activer la transcription de la nitrogénase en présence d'ammonium. On ignore comment le nitrogénase synthétisé est capable de maintenir son activité parce qu’en théorie, il devrait également être soumis à une régulation post-traductionnelle par ammonium. Une autre preuve pourrait être obtenue par l'étude du transcriptome d’YL3 et YL4. Une première étude sur la production d’ H2 par YL3 et YL4 ont montré qu'ils sont capables d’une beaucoup plus grande production d'hydrogène que JP91 en milieu d'ammonium, qui ouvre la porte pour les études futures avec ces souches en utilisant des déchets contenant de l'ammonium en tant que substrats. Enfin, le reformage biologique de l'éthanol à H2 avec la bactérie photosynthétique, Rhodopseudomonas palustris CGA009 a été examiné. La production d'éthanol avec fermentation utilisant des ressources renouvelables microbiennes a été traitée comme une technique mature. Cependant, la plupart des études du reformage de l'éthanol à H2 se sont concentrés sur le reformage chimique à la vapeur, ce qui nécessite généralement une haute charge énergetique et résultats dans les émissions de gaz toxiques. Ainsi le reformage biologique de l'éthanol à H2 avec des bactéries photosynthétiques, qui peuvent capturer la lumière pour répondre aux besoins énergétiques de cette réaction, semble d’être plus prometteuse. Une étude précédente a démontré la production d'hydrogène à partir d'éthanol, toutefois, le rendement ou la durée de cette réaction n'a pas été examiné. Une analyse RSM (méthode de surface de réponse) a été réalisée dans laquelle les concentrations de trois facteurs principaux, l'intensité lumineuse, de l'éthanol et du glutamate ont été variés. Nos résultats ont montré que près de 2 moles de H2 peuvent être obtenus à partir d'une mole d'éthanol, 33% de ce qui est théoriquement possible.

Capital 2.0 capital formation and legal risk in a new global economic order from fiat to exit: including case studies of the proposed transatlantic trade and investment partnership between the United States and the European Union and the financing relation between the United States and the People’s Republic of China

Following the intrinsically linked balance sheets in his Capital Formation Life Cycle, Lukas M. Stahl explains with his Triple A Model of Accounting, Allocation and Accountability the stages of the Capital Formation process from FIAT to EXIT. Based on the theoretical foundations of legal risk laid by the International Bar Association with the help of Roger McCormick and legal scholars such as Joanna Benjamin, Matthew Whalley and Tobias Mahler, and founded on the basis of Wesley Hohfeld’s category theory of jural relations, Stahl develops his mutually exclusive Four Determinants of Legal Risk of Law, Lack of Right, Liability and Limitation. Those Four Determinants of Legal Risk allow us to apply, assess, and precisely describe the respective legal risk at all stages of the Capital Formation Life Cycle as demonstrated in case studies of nine industry verticals of the proposed and currently negotiated Transatlantic Trade and Investment Partnership between the United States of America and the European Union, TTIP, as well as in the case of the often cited financing relation between the United States and the People’s Republic of China. Having established the Four Determinants of Legal Risk and its application to the Capital Formation Life Cycle, Stahl then explores the theoretical foundations of capital formation, their historical basis in classical and neo-classical economics and its forefathers such as The Austrians around Eugen von Boehm-Bawerk, Ludwig von Mises and Friedrich von Hayek and most notably and controversial, Karl Marx, and their impact on today’s exponential expansion of capital formation. Starting off with the first pillar of his Triple A Model, Accounting, Stahl then moves on to explain the Three Factors of Capital Formation, Man, Machines and Money and shows how “value-added” is created with respect to the non-monetary capital factors of human resources and industrial production. Followed by a detailed analysis discussing the roles of the Three Actors of Monetary Capital Formation, Central Banks, Commercial Banks and Citizens Stahl readily dismisses a number of myths regarding the creation of money providing in-depth insight into the workings of monetary policy makers, their institutions and ultimate beneficiaries, the corporate and consumer citizens. In his second pillar, Allocation, Stahl continues his analysis of the balance sheets of the Capital Formation Life Cycle by discussing the role of The Five Key Accounts of Monetary Capital Formation, the Sovereign, Financial, Corporate, Private and International account of Monetary Capital Formation and the associated legal risks in the allocation of capital pursuant to his Four Determinants of Legal Risk. In his third pillar, Accountability, Stahl discusses the ever recurring Crisis-Reaction-Acceleration-Sequence-History, in short: CRASH, since the beginning of the millennium starting with the dot-com crash at the turn of the millennium, followed seven years later by the financial crisis of 2008 and the dislocations in the global economy we are facing another seven years later today in 2015 with several sordid debt restructurings under way and hundred thousands of refugees on the way caused by war and increasing inequality. Together with the regulatory reactions they have caused in the form of so-called landmark legislation such as the Sarbanes-Oxley Act of 2002, the Dodd-Frank Act of 2010, the JOBS Act of 2012 or the introduction of the Basel Accords, Basel II in 2004 and III in 2010, the European Financial Stability Facility of 2010, the European Stability Mechanism of 2012 and the European Banking Union of 2013, Stahl analyses the acceleration in size and scope of crises that appears to find often seemingly helpless bureaucratic responses, the inherent legal risks and the complete lack of accountability on part of those responsible. Stahl argues that the order of the day requires to address the root cause of the problems in the form of two fundamental design defects of our Global Economic Order, namely our monetary and judicial order. Inspired by a 1933 plan of nine University of Chicago economists abolishing the fractional reserve system, he proposes the introduction of Sovereign Money as a prerequisite to void misallocations by way of judicial order in the course of domestic and transnational insolvency proceedings including the restructuring of sovereign debt throughout the entire monetary system back to its origin without causing domino effects of banking collapses and failed financial institutions. In recognizing Austrian-American economist Schumpeter’s Concept of Creative Destruction, as a process of industrial mutation that incessantly revolutionizes the economic structure from within, incessantly destroying the old one, incessantly creating a new one, Stahl responds to Schumpeter’s economic chemotherapy with his Concept of Equitable Default mimicking an immunotherapy that strengthens the corpus economicus own immune system by providing for the judicial authority to terminate precisely those misallocations that have proven malignant causing default perusing the century old common law concept of equity that allows for the equitable reformation, rescission or restitution of contract by way of judicial order. Following a review of the proposed mechanisms of transnational dispute resolution and current court systems with transnational jurisdiction, Stahl advocates as a first step in order to complete the Capital Formation Life Cycle from FIAT, the creation of money by way of credit, to EXIT, the termination of money by way of judicial order, the institution of a Transatlantic Trade and Investment Court constituted by a panel of judges from the U.S. Court of International Trade and the European Court of Justice by following the model of the EFTA Court of the European Free Trade Association. Since the first time his proposal has been made public in June of 2014 after being discussed in academic circles since 2011, his or similar proposals have found numerous public supporters. Most notably, the former Vice President of the European Parliament, David Martin, has tabled an amendment in June 2015 in the course of the negotiations on TTIP calling for an independent judicial body and the Member of the European Commission, Cecilia Malmström, has presented her proposal of an International Investment Court on September 16, 2015. Stahl concludes, that for the first time in the history of our generation it appears that there is a real opportunity for reform of our Global Economic Order by curing the two fundamental design defects of our monetary order and judicial order with the abolition of the fractional reserve system and the introduction of Sovereign Money and the institution of a democratically elected Transatlantic Trade and Investment Court that commensurate with its jurisdiction extending to cases concerning the Transatlantic Trade and Investment Partnership may complete the Capital Formation Life Cycle resolving cases of default with the transnational judicial authority for terminal resolution of misallocations in a New Global Economic Order without the ensuing dangers of systemic collapse from FIAT to EXIT.

Étude du partage attentionnel : Analogie entre la production temporelle avec interruption et la double tâche

L’estimation temporelle de l’ordre des secondes à quelques minutes requiert des ressources attentionnelles pour l’accumulation d’information temporelle pendant l’intervalle à estimer (Brown, 2006; Buhusi & Meck, 2009; Zakay & Block, 2004). Ceci est démontré dans le paradigme de double tâche, où l’exécution d’une tâche concurrente pendant l’estimation d’un intervalle mène à un effet d’interférence, soit une distorsion de la durée perçue se traduisant par des productions temporelles plus longues et plus variables que si l’estimation de l’intervalle était effectuée seule (voir Brown, 1997; 2010). Un effet d’interférence est également observé lorsqu’une interruption est attendue pendant l’intervalle à estimer, l’allongement étant proportionnel à la durée d’attente de l’interruption (Fortin & Massé, 2000). Cet effet a mené à l’hypothèse que la production avec interruption serait sous-tendue par un mécanisme de partage attentionnel similaire à la double tâche (Fortin, 2003). Afin d’étudier cette hypothèse, deux études empiriques ont été effectuées dans des contextes expérimentaux associés respectivement à une augmentation et à une diminution de l’effet d’interférence, soit le vieillissement (Chapitre II) et l’entraînement cognitif (Chapitre III). Dans le Chapitre II, la tâche de production avec interruption est étudiée chez des participants jeunes et âgés à l’aide de la spectroscopie proche infrarouge fonctionnelle (SPIRf). Les résultats montrent que l’attente de l’interruption est associée à des coûts comportementaux et fonctionnels similaires à la double tâche. Au niveau comportemental, un allongement des productions proportionnel à la durée d’attente de l’interruption est observé chez l’ensemble des participants, mais cet effet est plus prononcé chez les participants âgés que chez les jeunes. Ce résultat est compatible avec les observations réalisées dans le paradigme de double tâche (voir Verhaegen, 2011 pour une revue). Au niveau fonctionnel, la production avec et sans interruption est associée à l’activation du cortex préfrontal droit et des régions préfrontales dorsolatérales connues pour leur rôle au niveau de l’estimation temporelle explicite (production d’intervalle) et implicite (processus préparatoires). En outre, l’attente de l’interruption est associée à l’augmentation de l’activation corticale préfrontale dans les deux hémisphères chez l’ensemble des participants, incluant le cortex ventrolatéral préfrontal associé au contrôle attentionnel dans la double tâche. Finalement, les résultats montrent que les participants âgés se caractérisent par une activation corticale bilatérale lors de la production sans et avec interruption. Dans le cadre des théories du vieillissement cognitif (Park & Reuter-Lorenz, 2009), cela suggère que l’âge est associé à un recrutement inefficace des ressources attentionnelles pour la production d’intervalle, ceci nuisant au recrutement de ressources additionnelles pour faire face aux demandes liées à l’attente de l’interruption. Dans le Chapitre III, la tâche de production avec interruption est étudiée en comparant la performance de participants assignés à l’une ou l’autre de deux conditions d’exécution extensive (cinq sessions successives) de double tâche ou de production avec interruption. Des sessions pré et post-test sont aussi effectuées afin de tester le transfert entre les conditions. Les résultats montrent un effet d’interférence et de durée d’interférence tant en production avec double tâche qu’en production avec interruption. Ces effets sont toutefois plus prononcés lors de la production avec interruption et tendent à augmenter au fil des sessions, ce qui n’est pas observé en double tâche. Cela peut être expliqué par l’influence des processus préparatoires pendant la période pré-interruption et pendant l’interruption. Finalement, les résultats ne mettent pas en évidence d’effets de transfert substantiels entre les conditions puisque les effets de la pratique concernent principalement la préparation temporelle, un processus spécifique à la production avec interruption. Par la convergence que permet l’utilisation d’un même paradigme avec des méthodologies distinctes, ces travaux approfondissent la connaissance des mécanismes attentionnels associés à l’estimation temporelle et plus spécifiquement à la production avec interruption. Les résultats supportent l’hypothèse d’un partage attentionnel induit par l’attente de l’interruption. Les ressources seraient partagées entre les processus d’estimation temporelle explicite et implicite, une distinction importante récemment mise de l’avant dans la recherche sur l’estimation du temps (Coull, Davranche, Nazarian & Vidal, 2013). L’implication de processus dépendant des ressources attentionnelles communes pour le traitement de l’information temporelle peut rendre compte de l’effet d’interférence robuste et systématique observé dans la tâche de production avec interruption.

Creating Educational Immersive Environments Using a Computer Game Engine: Case Studies and Design Theory

This paper aims to crystallize recent research performed at the University of Worcester to investigate the feasibility of using the commercial game engine ‘Unreal Tournament 2004’ (UT2004) to produce ‘Educational Immersive Environments’ (EIEs) suitable for education and training. Our research has been supported by the UK Higher Education Academy. We discuss both practical and theoretical aspects of EIEs. The practical aspects include the production of EIEs to support high school physics education, the education of architects, and the learning of literacy by primary school children. This research is based on the development of our novel instructional medium, ‘UnrealPowerPoint’. Our fundamental guiding principles are that, first, pedagogy must inform technology, and second, that both teachers and pupils should be empowered to produce educational materials. Our work is informed by current educational theories such as constructivism, experiential learning and socio-cultural approaches as well as elements of instructional design and game principles.

Production planning, pricing and market coordination for news vendor problem with price dependent demand

Thesis (Ph.D.)--University of Washington, 2016-08

Global Trade Governance and ASEAN: Studies of Trade-Related Aspects of Labor, Environment and Culture in Southeast Asia

Thesis (Ph.D.)--University of Washington, 2016-08

Money, (Co)Production and Power in Digital

This article discusses the contribution of critical political economy approaches to digital journalism studies and argues that these offer important correctives to celebratory perspectives. The first part offers a review and critique of influential claims arising from self-styled new studies of convergence culture, media and creative industries. The second part discusses the contribution of critical political economy in examining digital journalism and responding to celebrant claims. The final part reflects on problems of restrictive normativity and other limitations within media political economy perspectives and considers ways in which challenges might be addressed by more synthesising approaches. The paper proposes developing radical pluralist, media systems and comparative analysis, and advocates drawing on strengths in both political economy and culturalist traditions to map and evaluate practices across all sectors of digital journalism.