Global ETD Search

1	Role de STAM dans la régulation endosomale de la signalisation JAK/STAT induite par les IFNs / Role of STAM in the endosomal regulation of IFN-induced JAK/STAT signaling pathway Zanin, Natacha 23 October 2015 (has links) La première implication des récepteurs aux interférons de type 1 (IFNAR1) dans le contrôle de la voie Jak/STAT induite par les IFNs a été établie par mon laboratoire il y a une dizaine d'années (Marchetti et al., 2006). Une des questions fondamentales était alors de déterminer comment et pourquoi l'endocytose des IFNARs pouvait contrôler la voie Jak/STAT. Deux acteurs clés du tri endosomal ont attiré notre attention : Hrs (Hepatocyte growth factor-Regulated tyrosine kinase Substrate) et STAM (Signal Transducing Adaptor Molecule). Ces deux protéines constituent le complexe ESCRT-0 (Endosomal Sorting Complexes Required for Transport-0) les localisant, de manière idéale, à l'interface entre signalisation cellulaire et trafic membranaire.La combinaison de la biologie moléculaire et cellulaire, de la biochimie et de la microscopie à fluorescence, nous a permis d'établir que STAM s'associe au complexe IFNAR1 à la membrane plasmique afin d'y exercer son effet inhibiteur sur la signalisation Jak/STAT. Cette inhibition est levée lorsqu'IFNAR est libéré dans l'endosome et qu'il peut ainsi être recruté par Hrs sous la dépendance de l'IFN-α. En nous basant sur des expériences de déplétion par shRNA ou d'inhibition pharmacologique, nous avons identifié PTP1B (Protein Tyrosine Phosphatase 1B) en tant qu'activateur de la voie Jak/STAT induite par les IFNs. Le blocage sélectif de l'endocytose d'IFNAR par déplétion de clathrin, nous a permis de montrer que l'activation de PTP1B est inhibée à la membrane plasmique. Cela a été confirmé par des expériences d'interaction protéine-protéine (Proximity Ligation Assay) indiquant que STAM est constitutivement associé à IFNAR1, tandis que l'interaction entre IFNAR1 et Hrs a seulement lieu à l'endosome.Ainsi, nos résultats permettent d'établir un modèle dans lequel, à la membrane plasmique, STAM est un frein permanent à la signalisation Jak/STAT, qui est levé après l'endocytose d'IFNAR et sa libération dans l'endosome de tri. De plus, nous avons montré que l'interaction Hrs/STAM dans l'endosome précoce permet de différencier, de manière sélective, l'activation de la signalisation Jak/STAT médiée par l'IFN-α ou l'IFN-β. / A decade ago, my laboratory established the first role of type I IFNs receptor (IFNAR) endocytosis in the control of Jak/STAT signaling induced by type 1 IFNs (Marchetti et al., 2006). A salient question is now to elucidate why and how IFNAR endocytosis could control the Jak/STAT pathway. Two key players of endosomal sorting retained our interest: Hrs (Hepatocyte growth factor-Regulated tyrosine kinase Substrate) and STAM (Signal Transducing Adaptor Molecule). These two classical components of the ESCRT-0 (Endosomal Sorting Complexes Required for Transport-0) complex were ideally placed at the interface between signaling and membrane trafficking. By using a combination of molecular and cellular biology, biochemistry, and fluorescent microscopy, we could establish that STAM binds to the IFNAR complex at the plasma membrane to exert an inhibitory effect on Jak/STAT signaling. This inhibition is removed when IFNAR is delivered to the sorting endosome by interacting with Hrs upon IFN-α stimulation. Based on shRNA down-expression and pharmacological inhibition, we further involve the PTP1B (Protein Tyrosine Phosphatase 1B) as it activates Jak/STAT signaling upon IFN stimulation. We could also show that PTP1B activation is inhibited by STAM at the plasma membrane from experiments where IFNAR endocytosis was blocked by siRNA-mediated clathrin down-expression. This was further confirmed by protein-protein interaction experiments (Proximity Ligation Assay) showing that STAM was constitutively associated with IFNAR1, whereas the interaction between IFNAR1 and Hrs occured only at the sorting endosome. Our results therefore allow to draw a model where STAM is a constitutive handbrake on Jak/STAT signaling at the plasma membrane that is released after IFNAR endocytosis and delivery to the sorting endosome. We further show that Hrs/STAM interaction at the early endosome allows to selectively distinguish the activation of Jak/STAT signaling mediated by IFN-α or IFN-β. Stam Hrs Endosome Signalisation Stam Hrs Endosome Signalisation
2	Identitet - det är allt vi är : En studie om kenyanska flickors identitetsskapande Holmberg, Caroline January 2013 (has links) No description available. Identitet Kultur Kenya Stam och Lärare
3	Från digitalt utanförskap till digital gemenskap : En hypotetisk väg till digital gemenskap Eberhardson Karlsson, André January 2010 (has links) <p><em>We are in an emerging digital society where we are increasingly dependent on the mastery of IT and digital technologies to better carry out our everyday tasks. They cover everything from keeping in touch with family and friends to pay bills and declare. At the same time there are those who have not learned how to use the new technology and live their lives outside of the digital society. What happens to these people, in a society that is becoming increasingly digitized? Do they take harm by being in digital exclusion? It looks like this are issues that will not become less important as digital technology constantly changes. Technology of the future will be equally undesirable for tomorrow's elderly as today's technology is undesirable for today’s elderly.</em></p><p><em>This research report looks at how to find a way to get those who involuntary find themselves in digital isolation to get an entry to digital use and become part of the digital society. The report makes use of the Technology Acceptance Model (TAM) and Senior Technology Acceptance & Adoption Model (STAM), models developed to predict whether users will accept or reject a system, to find out how you may be able to get users to want to use and learn a system.</em></p><p><em>In a study reminiscent of an experiment in which four participants with low experience in IT use has been testing a simple Content Management System (CMS), and started to use IT in their work, this report concludes that there are tendencies showing that workplace could be an interesting entrance when you are trying to create an interest in IT and digital technology in those who are in the digital exclusion.</em></p> Digitalt utanförskap STAM TAM Teknologi Acceptans Informatics Informatik
4	Secondary mathematics teachers' classroom practices: a case study of three township schools in Gauteng Province, South Africa Ngoepe, Mapula Gertrude January 2003 (has links) While there have been enormous changes in the South African system of education since 1994, the legacy of apartheid and the different education of Black teachers is still evident in township schools. This study examined the practices of mathematics teaching in three township secondary schools by conducting a detailed investigation of eight teachers in three schools. Classroom observations and video recordings of teachers of Grades 10 to 12 served as the main data collection method. A sample of 12 lessons was analysed using the Secondary Teaching Analysis Matrix-Mathematics (STAM-Mathematics) (Gallagher & Parker, 1995) instrument. The researcher used STAM to categorise teachers' classroom practices along a three pronged continuum, namely didactic, transitional and conceptual teaching for the purpose of answering research questions about the content, the teaching, the assessment practices, the interactions between the teacher and the student, and the resource availability. Analysis of the data collected using the 22 STAM descriptors showed that the practices of teaching mathematics in township secondary schools was primarily didactic, with only minimal characteristics of transitional teaching and fewer attributes of conceptual teaching. Identifying the gaps between the teachers' practice and the descriptors for transitional and conceptual teaching with respect to the content, the teaching, the approaches to assessment, interactions between teacher and students, and resources availability has provided insight and a baseline for teacher inservice. Consequently, this study has provided research-based evidence for appropriate intervention to improve mathematics teaching and learning as prioritised by the Department of Education since the creation of the democratic government in 1994. / It is recommended that mathematics teachers in township schools use the STAM instrument in pairs or groups to observe and analyse each other's lessons with particular focus on the 22 descriptors and to use this framework as a guideline for daily lesson preparations and to help guide the teachers from teacher-centred instruction to conceptual instruction. Further, the STAM could be incorporated into teacher education and professional development programs and thereby lead to more conceptual forms of teaching that could contribute towards a greater understanding of mathematics and ultimately raise the pass rate of learners in external examinations at Grade 12.
5	Från digitalt utanförskap till digital gemenskap : En hypotetisk väg till digital gemenskap Eberhardson Karlsson, André January 2010 (has links) We are in an emerging digital society where we are increasingly dependent on the mastery of IT and digital technologies to better carry out our everyday tasks. They cover everything from keeping in touch with family and friends to pay bills and declare. At the same time there are those who have not learned how to use the new technology and live their lives outside of the digital society. What happens to these people, in a society that is becoming increasingly digitized? Do they take harm by being in digital exclusion? It looks like this are issues that will not become less important as digital technology constantly changes. Technology of the future will be equally undesirable for tomorrow's elderly as today's technology is undesirable for today’s elderly. This research report looks at how to find a way to get those who involuntary find themselves in digital isolation to get an entry to digital use and become part of the digital society. The report makes use of the Technology Acceptance Model (TAM) and Senior Technology Acceptance & Adoption Model (STAM), models developed to predict whether users will accept or reject a system, to find out how you may be able to get users to want to use and learn a system. In a study reminiscent of an experiment in which four participants with low experience in IT use has been testing a simple Content Management System (CMS), and started to use IT in their work, this report concludes that there are tendencies showing that workplace could be an interesting entrance when you are trying to create an interest in IT and digital technology in those who are in the digital exclusion. Digitalt utanförskap STAM TAM Teknologi Acceptans Information Systems
6	"Jaha, det gick ju bra den här gången också" : En kvalitativ undersökning av seniorers förhållande till e-handel / "Oh well, it worked out this time as well" : A qualitative study of the relationship between seniors and e-business Ekman, Agnes, Hägglund, Emma January 2012 (has links) In this paper we have examined why seniors do not use e-business to the same extent as other age groups. Seniors belong to the age group that, according to statistics from Statistics Sweden (SCB) in 2011, utilizes e-business the least in relation to the number who use the internet. To understand how seniors reason and perceive the possibility to shop on the internet, we have conducted four interviews with people from 65 years and older. We have let the respondents answer questions regarding utility aspects, e-business interfaces, general shopping habits, risks, and whether or not they usually shop online. We also found out how seniors reason when they sell products and services. The results of our study show that seniors must see a benefit in using an e-business, that lack of knowledge can make them opposed to it and that they are characterized by a certain reluctance and aversion towards learning how e-business works. In this study we have used Technology Acceptance and Adoption Model (STAM) by Renaud and van Biljon (2008), to see what constitutes the seniors accepting or rejecting a technology. The model is focused on seniors and technology but not on e-business so we developed our own model, Senior E-Business Adoption & Acceptance Model (SEAM), focusing on seniors and e-business. / I den här uppsatsen har vi valt att ta reda på varör seniorer inte nyttjar möjligheten att handla via e-handel i samma utsträckning som övriga åldersgrupper. Seniorer tillhör den ålderskategori som, enligt statistik från Statistiska Centralbyrån (SCB) år 2011, handlar via e-handel minst i förhållande till antalet som använder internet. För att förstå hur seniorerna resonerar och upplever möjligheten att handla via internet har vi genomfört fyra kvalitativa intervjuer med personer från 65 år och uppåt. Vi har låtit intervjupersonerna besvara ett antal frågor gällande nyttoaspekt, e-handelsgränssnitt, generella shoppingvanor, risker och huruvida de själva brukar handla via internet. Vi har också tagit reda på hur seniorerna resonerar gällande att sälja produkter och tjänster. Resultatet av vår undersökning visar att seniorer måste se en nytta i att använda en e-handel, att okunskap kan göra dem negativt inställda och att de präglas av en viss ovilja och olust att lära sig hur e-handel fungerar. I studien har vi utgått från Technology Acceptance and Adoption Model (STAM) av Renaud och van Biljon (2008), för att se vad som leder fram till att seniorerna accepterar eller förkastar teknik. Modellen fokuserar på seniorer och teknik men inte på e-handel så vi valde att vidareutveckla den och skapade Senior E-business Adoption & Acceptance Model (SEAM) med inriktning på både seniorer och e-handel. E-business e-commerce seniors old people technology acceptance technology adoption internet shopping STAM SEAM E-handel elektronisk handel seniorer äldre människor teknikacceptans teknikadoption STAM SEAM Human Computer Interaction
7	Control of water and toxic gas adsorption in metal-organic frameworks McPherson, Matthew Joseph January 2016 (has links) The research presented in this thesis aims to determine the effectiveness of the uptake of toxic gases by several MOFs for future use in gas-mask cartridges, and to attempt to compensate for any deficiencies they show in “real-world” conditions. The main findings of this thesis confirm that MOFs are suitable candidates for the use in respirator cartridge materials and provide high capacity for adsorption of toxic gases like ammonia and STAM-1 in particular showed an impressive improvement in humid conditions, which normally decrease the performance of MOFs made from the same materials, such as HKUST-1. STAM-1's improved performance in humid conditions is attributed to the structural shift it displays upon dehydration and rehydration and this was shown to be the case in a structural analogue, CuEtOip, which was synthesised in the author's research group. This analogue was analysed using a combination of single crystal XRD and solid state MAS-NMR, both of which showed the structural change occurring and displays similar gas sorption behaviours, suggesting that this mechanism is the source of STAM-1's improved performance in humid conditions. This thesis also examines the “Armoured MOF” process and investigates the transferability of the process of deposition of mesoporous silica onto MOFs with vastly different properties and synthetic methods compared to those published in the original publication. Alongside this, attempts to protect MOFs using mesoporous silicates were investigated for their viability.
8	Stabil och antibiotikafri läkemedelsproduktion i rekombinant Escherichia coli Benevides, Kristina, Broström, Oscar, Elison Kalman, Grim, Swenson, Hugo, Vlassov, Andrei, Ågren, Josefin January 2017 (has links) Den här rapporten presenterar ett antibiotikafritt, stabilt och kromosombaserat expressionssystem för läkemedelsproduktion i Escherichia coli på beställning av företaget Affibody AB. E. coli-stammen BL21(DE3) valdes som värdorganism för expressionssystemet. Systemet består av en genkassett som innehåller en T7-promotor, en 5′-UTR från genen ompA och en terminatorsekvens från RNA-operonet rrnB. Fyra kopior av genkassetten ska integreras i pseudogenerna caiB, yjjM, hsdS och yjiV. En datormodell som modellerar det egentliga kopietalet i cellerna har skapats i mjukvaran MATLAB, vilket visar att det uppskattas vara maximalt 32 kopior av genkassetten per cell på grund av replikation av kromosomen. Ett högt pH i fermentorn; att använda fed-batch och blandade kolhydratkällor; och att använda stammen BL21(DE3) minskar acetatproduktionen i cellen. En lägre acetatproduktion kan leda till en högre produkthalt. En proteinutbytesmodell för mjukvaran MATLAB har konstruerats för att uppskatta koncentrationen av Affibody®-molekylen i en E. coli cell. copynumber copy-number copy number origin of replication rekombinant proteinexpression läkemedel E. coli antibiotikafri antibiotika expressionssystem expression system escherichia coli kromosom kromosombaserad kromosomal plasmidfri plasmid T7-promotor T7 promotor ompA rrnB autoinduktion auto induktion matlab kopietalmodell utbytemodell stabil pH pseudogen pseudo gen caiB yjjM hsdS yjiV fermentor batch fed-batch kontinuerlig fed batch fermentation Affibody affibody-molekyl affibody-molekyler affibodymolekyl affibodymolekyler bioreaktor acetat acetatbildning acetatproduktion acetatreduktion acetatreducering peptidläkemedel peptider peptid T7-system operator lac-operator operon 5'-UTR 3'-UTR sekundärstruktur mRNA T1 T2 terminator termineringssekvens optimering lac-operon repressor inducering BL21(DE3) BL21 B-stam B stam modell kopietal kopie tal OriC Pharmaceutical Biotechnology Läkemedelsbioteknik

Search results